ELSEVIER
journal homepage: www.elsevier.com/locate/jbior
A
Advances in BIOLOGICAL REGULATION
Check for updates
Steroidogenic Factor-1 form and function: From phospholipids to physiology
Alexis N. Campbell a,b,1, Woong Jae Choi ª,1, Ethan S. Chia,1, Abigail R. Orun ª,1, James C. Poland ª,1, Elizabeth A. Stivison ª,1, Jakub N. Kubina ª, Kimora L. Hudson ª, Mong Na Claire Loi ª, Jay N. Bhatiaª, Joseph W. Gilligan ª, Adrian A. Quintana ª, Raymond D. Blind a, b, c,
a Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
b Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
” Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
ARTICLE INFO
Handling Editor: Dr. L. Cocco
Keywords: Ad4BP integrative structural biology of steroidogenesis and gene expression R255L polymorphism Nuclear phosphoinositide function
ABSTRACT
Steroidogenic Factor-1 (SF-1, NR5A1) is a member of the nuclear receptor superfamily of ligand- regulated transcription factors, consisting of a DNA-binding domain (DBD) connected to a tran- scriptional regulatory ligand binding domain (LBD) via an unstructured hinge domain. SF-1 is a master regulator of development and adult function along the hypothalamic pituitary adrenal and gonadal axes, with strong pathophysiological association with endometriosis and adrenocortical carcinoma. SF-1 was shown to bind and be regulated by phospholipids, one of the most inter- esting aspects of SF-1 regulation is the manner in which SF-1 interacts with phospholipids: SF-1 buries the phospholipid acyl chains deep in the hydrophobic core of the SF-1 protein, while the lipid headgroups remain solvent-exposed on the exterior of the SF-1 protein surface. Here, we have reviewed several aspects of SF-1 structure, function and physiology, touching on other transcription factors that help regulate SF-1 target genes, non-canonical functions of SF-1, the DNA-binding properties of SF-1, the use of mass spectrometry to identify lipids that associate with SF-1, how protein phosphorylation regulates SF-1 and the structural biology of the phospholipid- ligand binding domain. Together this review summarizes the form and function of Steroidogenic Factor-1 in physiology and in human disease, with particular emphasis on adrenal cancer.
1. A brief history of SF-1 physiology
Steroidogenic factor 1 (SF-1) was first described in the early 1990s when researchers became aware that expression of many cy- tochrome P450s, which catalyze the addition of hydroxyl groups during the synthesis of steroids, were regulated by a single factor thought to be a master regulator of steroidogenesis (Morohashisqll et al., 1992; Rice et al., 1991; Lala et al., 1992a). This factor also was identified in cow, mouse, rat, fly, and human, and was shown to regulate expression of the cytochrome p450 genes (Lala et al., 1992b,
* Corresponding author. Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
E-mail address: ray.blind@vanderbilt.edu (R.D. Blind).
1 Equal Contributions.
https://doi.org/10.1016/j.jbior.2023.100991
1992c; Morohashi et al., 1993; Honda et al., 1990; Oba et al., 1996; Wong et al., 1996) and act as a regulator of the hypothalamic-pituitary-gonadal axis (Ingraham et al., 1994; Zhao et al., 2001; Kim et al., 2011a). SF-1 has since been shown to be expressed exclusively along the HPA and HPG axes and in the spleen, as reviewed previously (Meinsohn et al., 2019a). In mice, complete developmental genetic knockout of Sf-1 causes lethality by postnatal day 8 due to a lack of corticosteroids (Luo et al., 1994a). These animals lack adrenal glands and gonads in both male and female animals. Sf-1 knockout mice can be kept alive with perinatal corticosteroid injections and adrenal transplants, although Sf-1 knockout mice eventually develop an obese phenotype (Majdic et al., 2002a). In male mice, loss of Sf-1 leads to persistent Mullerian structures and female external genitalia (Luo et al., 1994b; Sadovsky et al., 1995), reviewed by (Lin and Achermann, 2008). Conditional knockout models in mice have shown Sf-1 is required for ovulation and developing ovarian reserves (Hughes et al., 2023; Smith et al., 2022). So although SF-1 knockout leads to perinatal lethality, even complete loss of all alleles during development can be managed to permit a relatively low-impact phenotype in mice, suggesting inhibitors of SF-1 would be well tolerated in human patients.
Several human polymorphisms in SF-1 associate with infertility and a wide range of differences of sex development in humans (Bertrand-Delepine et al., 2020; Buonocore et al., 2019; Nagy et al., 2019; Teoli et al., 2023; Achermann et al., 1999). The causative nature of some of these polymorphisms is unclear due to the presence of other polymorphisms in the affected patients (Lapiscina et al., 2023). In addition to classic loss-of-function polymorphisms which decrease SF-1 function, improper expression of SF-1 that affects dosage also leads to physiological defects in mouse models and human patients. Indeed, SF-1 gene dosage is a critical aspect of SF-1 pathophysiology and normal function, with SF-1 appropriately coined a “Goldilocks” transcription factor in a recent review from Enzo Lalli’s lab (Relav et al., 2023). Along those lines, mouse models in which SF-1 functions have been altered by mutation of post-translational modification sites cause an adrenal-like gene expression pattern in the gonads, and a gonad-like gene expression pattern in the adrenals of these knock-in mice (Lee et al., 2011). The data suggest SF-1 control of gene expression patterns under physiological conditions is fluid, and represents more of an equilibrium between states, rather than discreet on/off regulation in both human patients and mouse models.
Silencing of SF-1 in the endometrium is required for maintenance of pregnancy, and aberrant expression of SF-1 has been associated with endometriosis although the mechanism is less than clear (Smith et al., 2022; Vasquez et al., 2016; Utsunomiya et al., 2008a, 2008b; Xue et al., 2007; Noël et al., 2011; Attar et al., 2009). Beyond reproduction, improper levels of SF-1 have been found in cancers, including SF-1 upregulation in adrenal cancer, specifically in adrenocortical carcinoma, where inhibition of SF-1 slowed the prolif- eration of these cancer cells (Doghman et al., 2007a, 2009a). In ovarian cancers there is some evidence that overexpressing SF-1 in ovarian cancer cell lines inhibits proliferation of the cells (Ramayya et al., 2010). Together, the data suggest links between SF-1 and adrenocortical cancer (Muzzi et al., 2022) and endometriosis in adults (Zhu et al., 2023), however full SF-1 function appears to be somewhat dispensable in development, as suggested by mouse knockout studies and the identification of human polymorphisms with loss of SF-1 function.
2. The brain and SF-1
SF-1 is expressed in the ventromedial hypothalamus (VMH) in human: a brain region integral for neuroendocrine homeostasis, notably modulating glucose sensitivity, metabolic regulation, appetite, and thermogenesis (Khodai and Luckman, 2021; Choi et al., 2013). While the role of SF-1 across VMH pathologies is not yet fully understood, mouse Sf-1 expression is essential for differentiation of the VMH (Majdic et al., 2002b). Knockout of Sf-1 (Nr5a1) in mice promoted development of metabolic disorders such as diabetes and obesity under high fat diet compared to wild type animals (Kim et al., 2011b; Fosch et al., 2021). Many pathologies associated with Sf-1 deletion had been thought to derive from the loss of Sf-1 associated leptin receptors (Tong et al., 2007a) and decreased gluta- minergic excitation of POMC and AgRP neurons, which have been implicated in the regulation of satiety (Tong et al., 2007b; Marino et al., 2011). However, recent data suggests overeating may not be the only factor in metabolic imbalance associated with Sf-1 dysfunction. Instead, Sf-1 knockout mice display increased insulin resistance, decreased blood glucose sensitivity, impairment in free fatty acid mobilization and decreased energy utilization leading to increased adiposity (Majdic et al., 2002b; Fujikawa et al., 2016). Further, Sf-1 expressing neurons in the VMH have recently been shown to control inflammation in fat depots associated with high fat diet-induced obesity (Rashid et al., 2023).
Sf-1 knockout mice also show impairment in weight, muscle development, protein turnover and metabolite recovery post-exercise as compared to wild type animals (Fujikawa et al., 2016). Moreover, studies have shown that there is a correlation between Sf-1 neuronal activity and the leptin-PI3K-FoxO1 pathway in regulation of hypoglycemia in peripheral tissues (Klöckener et al., 2011; Kim et al., 2012). Finally, optogenetic activation of Sf-1 neurons reduced food intake and increased energy usage, glucose regulation and insulin sensitivity (Coutinho et al., 2017; Ruud et al., 2017). Overall, SF-1 expression in the brain permits development of the VMH and allows the VMH to regulate metabolic processes. Further research is necessary to determine the molecular mechanisms of VMH and brain SF-1 activation by regulatory ligands and other brain-specific factors.
3. Adrenal cancer and SF-1
Outside the metabolic physiopathology in the brain, adrenocortical cancer has similarly been implicated in SF-1 function. The gene dosage of SF-1 is important in all aspects of SF-1 ability to regulate transcription and physiology, and regulation of the adrenal glands is no exception. SF-1 overexpression in mice increased development and proliferation of adult and pediatric adrenocortical tumors (Doghman et al., 2013) and adrenocortical cancers have previously been linked to SF-1 overexpression (Doghman et al., 2007b, 2009b). Heterozygous SF-1 mice with a haploinsufficient decrease in SF-1 expression manifest with adrenal hypoplasia and decreased
stress response from the adrenal glands (Bland et al., 2000a, 2000b). These Sf-1 heterozygous mice have smaller adrenals, but those smaller adrenals have increased steroid production per cell, suggesting a decoupling of SF-1 gene dosage affects in adult endocrine function of the adrenals, when compared to developmental aspects of adrenal growth that are driven by SF-1 expression (Bland et al., 2004). SF-1 knockdown and overexpression in a human adrenocortical carcinoma cell line (NCI-H295R) shows SF-1 dosage-dependent chromatin-binding site occupancy nearly triples during SF-1 overexpression in these cells (Doghman et al., 2013). SF-1 upregulation has been found in adrenal cancer, specifically adrenocortical carcinoma, and chemical inhibition of SF-1 slowed the proliferation of these cancer cells (Doghman et al., 2007a, 2009a). SF-1 has also been shown to control proper centrosome amplification in an adrenal cell line, a process that when dysregulated has well-established links to cancer (Ganem et al., 2009; Fukasawa, 2007).
SF-1 also associates with several factors that are known to regulate adrenal development and/or oncogenesis. In resected human adrenocortical tumors (both adenomas and carcinomas), expression of SF-1 was linked with expression of the GATA6 transcription factor, and GATA6 expression correlated with expression of the classic SF-1 target gene CYP17A1, suggesting a functional link between GATA6 and SF-1 (Kiiveri et al., 2005). Adrenocortical H295R cells show negative crosstalk between transforming growth factor beta (TGF-beta) and SF-1, as well as between Wnt/Beta-catenin and SF-1 (Ehrlund et al., 2012), further linking SF-1 expression with activated adrenal cancer cell growth. These same human adrenocortical H295R cells when overexpressing SF-1 can also change the cadre of transcriptional coregulators that associate with SF-1, specifically with the powerful transcriptional coregulator NRSF/REST coregulator (Doghman et al., 2013), which has been previously shown to affect classic SF-1 target genes and steroidogenesis in these cells (Somekawa et al., 2009). Together, the data suggest SF-1 expression can drive the growth of adrenocortical carcinoma, with the clear implication that an SF-1 inhibitor could have therapeutic value in treating this rare form of cancer (Padua et al., 2023). Further, the manageable side effects even from developmental loss of the entire Sf-1 gene in mice (Luo et al., 1994a; Majdic et al., 2002b) suggests inhibitors of SF-1 would be well tolerated (Doghman et al., 2009b).
4. Transcription factors that collaborate with SF-1
SF-1 collaborates with other transcription factors to regulate target gene expression, full regulation of SF-1 target genes usually requires a diversity of transcription factors, each with their own cis regulatory elements in the promoters of target loci. The final transcriptional output from these loci is the sum product of all these transcription factors, such as transcriptional regulation of SF-1 target gene AMH, which encodes Anti-Müllerian hormone (AMH; Müllerian inhibiting substance or MIS). The AMH gene product is necessary for normal male sex differentiation through Müllerian duct regression (Shen et al., 1994) and fully regulated expression of this locus is dependent on SF-1 collaboration with several other transcription factors known to regulate this locus, such as SOX-9 (De Santa Barbara et al., 1998), Wilm’s Tumor protein (WT-1) (Nachtigal et al., 1998), and GATA-4 (Tremblay and Viger, 1999). Although AMH is a well-validated target gene of SF-1 (De Santa Barbara et al., 1998), robust transcriptional activity is not achieved by SF-1 alone, but rather other transcription factors are required at the AMH locus for full transcriptional regulation. Another classic SF-1 target gene is CYP11A1, which encodes cytochrome P450 side-chain cleavage enzyme, a mitochondrial enzyme responsible for catalyzing the first and rate-limiting step in steroidogenesis (Miller and Auchus, 2011). The CYP11A1 locus is regulated by several transcription factors including SF-1, c-JUN (Li et al., 1999), SP1 (Liu and Simpson, 1997) (Liu et al., 1999) and CBP/p300 (Monté et al., 1998) in gonadal and adrenocortical cells. These transcription factors all collaborate to enhance gene regulation at this locus, causing changes of up to nearly ~20-fold (Nachtigal et al., 1998). Thus, the diversity of transcription factors at SF-1 target genes reflects a basic principle in metazoan transcriptional regulation, that many transcription factors often collaborate to regulate a target promoter.
5. DNA binding properties of SF-1
SF-1 binds DNA as a monomer to regulate the expression of many genes in tissues along the hypothalamic-pituitary adrenal/ gonadal (HPA/HPG) axes in humans (Meinsohn et al., 2019b; Little et al., 2006). The SF-1 DNA-binding domain (DBD) has a bipartite structure containing a highly conserved nuclear receptor core DBD and a carboxy-terminal extension, but SF-1 also has an FTZ-F1-like box (Ueda et al., 1992) that is unique to the NR5A subclass of nuclear receptors (Little et al., 2006). The SF-1 nuclear receptor DBD core (human amino acids 10 to 76) contains the typical and highly conserved nuclear receptor DBD structure containing two zinc atoms, each chelated by four cysteines (Meinsohn et al., 2019b; Little et al., 2006; Weikum et al., 2018). The C-terminal extension is shared by the monomeric nuclear receptor proteins, where the C-terminal extension makes base-specific interactions in the DNA minor groove (Little et al., 2006; Solomon et al., 2005). This C-terminal extension structure is shared with other nuclear receptors nerve growth factor-induced-B (NR4A2/NGFI-B) (Jiang et al., 2020; Meinke and Sigler, 1999), estrogen-related receptor 2 (NR3B2/ERR2) (Gearhart et al., 2003), and the close SF-1 homolog liver receptor homolog-1 (NR5A2/LRH-1) (Solomon et al., 2005; Weikum et al., 2016). Proximal to the SF-1 C-terminal extension is the 33-residue FTZ-F1 box (human amino acids 79 to 111), which is unique to the SF-1 sub-class of nuclear receptors (Little et al., 2006). The FTZ-F1 box is highly conserved across species within the NR5A nuclear receptor sub-class, with the drosophila FTZ-F1 box having 82% sequence identity to the human, and the mouse FTZ-F1 box having 100% sequence identity with the human SF-1 FTZ-F1 box (Little et al., 2006).
As part of an NMR-based structural analysis of the SF-1 DNA-binding domain, Little and colleagues found that several single point mutations within the SF-1 FTZ-F1 box (R87A; R92A; Y99A and Y99F) and one double mutation (R101P/D102P) decreased SF-1 transcriptional on an SF-1 target promoter (Inhibin alpha) luciferase reporter, without affecting SF-1 expression levels (Little et al., 2006). However other single point mutations in the FTZ-F1 region had no effect on SF-1 transcriptional activity (L80K; R89A; M98A) in the same luciferase reporter assay (Little et al., 2006). Perhaps as expected, all tested mutations in the FTZ-F1 region (Y99F and Y99A single point mutations and the R101P/D102P double mutation) decreased DNA-binding to a canonical SF-1 DNA-binding site oligo by
EMSA, and almost completely eliminated DNA-binding to an atypical SF-1 DNA-binding site oligo by EMSA (Little et al., 2006). This decrease in DNA-interaction induced by point mutations in the FTZ-F1 region of SF-1 is slightly different compared to the close ho- molog LRH-1, as Solomon et al. found that a triple point mutant within the FTZ-F1 helix of LRH-1 (Y92A/F186A/Y178A) did not affect LRH-1 DBD binding to DNA by EMSA, yet dramatically decreased LRH-1 transcriptional activity to background levels (Solomon et al., 2005). This phenotype is consistent with the FTZ-F1 region communicating with the LRH-1 ligand binding domain, as suggested by the proposed full-length model of LRH-1 (Seacrist et al., 2020), however no full-length model of SF-1 (including the alpha-fold model) has been rigorously tested in the wet lab. Thus, the data suggest mutations in the FTZ-F1 region have non-identical effects on SF-1 vs. LRH-1, as well as different effects on SF-1 DNA-binding to higher-affinity vs. lower affinity DNA sequences. Further, the FTZ-F1 region is a common feature of the NR5A subclass of nuclear receptors (Little et al., 2006; Solomon et al., 2005; Weikum et al., 2016; Meinsohn et al., 2019c) and elicits specific DNA-binding at a 9-nt recognition element, 5’-YCAAGGYCR-3’ [Y = T/C; R = G/A] (Wilson et al., 1993), with mutation of the FTZ-F1 having different effects in different NR5A receptors.
The structure of full-length SF-1 has yet to be elucidated, so any structural relationships between the DBD and LBD have yet to be resolved. This is of particular interest as a polymorphism identified in a human patient within the LBD of SF-1 (R255L) was shown to dramatically decrease the ability of full-length SF-1 to interact with DNA oligos in electromobility shift assays (Biason-Lauber and Schoenle, 2000), suggesting the R255L mutation in the LBD somehow affects the ability of SF-1 to bind DNA. Other studies have shown the R255L mutation can also alter the ability of SF-1 to bind phosphoinositide lipids while decreasing SF-1 transcriptional activity (Sablin et al., 2009). Mechanistically, it is therefore unclear if R255 in the LBD might directly mediate an interdomain interaction between the LBD and DBD to affect DNA-binding, or if R255 might participate in phospholipid ligand discrimination by SF-1, which in turn regulates SF-1 DNA-binding properties. Regardless of how R255 is translating structural information from the LBD to the DBD, the data indeed suggest that changes in the LBD can be communicated to the DBD in the context of the full-length SF-1. A structure of full-length SF-1 will be valuable in determining how the human R255L polymorphism in the LBD regulates SF-1 DNA-binding properties, and more generally how any potential DBD-LBD interactions might affect the overall activity of SF-1.
6. Structural biology of the SF-1 ligand binding domain
Full-length SF-1 consists of the classic structural composition of a nuclear receptor: a DNA binding domain (DBD) with two zinc fingers, a flexible hinge region and a C-terminal activation function region (AF-2) that is part of the ligand-regulated transcriptional activation domain, called the ligand binding domain (LBD). There have been several crystal structures solved of the SF-1 LBD (see Table 1). The structure of the LBD is comprised of 12x helices distributed in 3 layers with an atypical 4th layer in the NR5A nuclear receptors SF-1 and LRH-1 formed by Helix 2 (Krylova et al., 2005). The LBD also encompasses the AF-2 domain which is located at the c-terminal. Helix 12 largely accounts for AF-2 function as Helix 12 facilitates the formation of a surface which interacts with co-regulatory proteins by the nuclear receptor conserved Helix 12, & helical motif within the AF-2 region (Shiau et al., 1998; Gampe et al., 2000; Darimont et al., 1998; Yu et al., 1997). The final element of the LBD is the hydrophobic cavity known as the lipid-binding pocket (LBP). The SF-1 LBP has an elliptical shape and an opening at the bottom of the pocket with an area of around 100 Å2 which is surrounded by the ends of helices H3, H6, H7, and H10.
While the ligand binding pocket cavity is largely hydrophobic, a hydrophilic patch exists near the entrance of the pocket (Li et al., 2005). Interestingly, the binding pocket of SF-1 is significantly larger than its close homolog Liver Receptor Homolog-1 (LRH-1, NR5A2), mouse SF-1 has a volume of 1640 Å3 compared to only 800 Å3 for the mouse LRH-1, and this trend was further seen in human SF-1 and human LRH-1 (Krylova et al., 2005; Li et al., 2005). The biological implications of the differing size of the ligand binding pockets in NR5A nuclear receptors have not been firmly established (Cato et al., 2023), however the simplest hypothesis is that SF-1 may bind endogenous ligands that are in some way larger than ligands for LRH-1. Crystallographic studies have shown that diverse bacterial phospholipids, aquired from the ectopic E. coli expression systems used to express SF-1, bind inside the canonical ligand binding pocket (Krylova et al., 2005; Wang et al., 2005). The data all suggest phospholipids are dynamically exchangeable regulatory ligands for SF-1, however it is unclear which of the many phospholipids that bind SF-1 is the most biologically relevant.
One class of SF-1 ligands that are of particularly high biological interest are the phosphoinositides since these lipids have been studied within the nuclear compartment for several decades (Barlow et al., 2010; Vidalle et al., 2023; Shah et al., 2013; Sztacho et al., 2019; Crowder et al., 2017; Hamann and Blind, 2018; Boronenkov et al., 1998; Bryant and Blind, 2019), have low abundance and potent signaling properties (Balla, 2013). Direct binding analyses have suggested the phosphoinositides PI(4,5)P2 and PI(3,4,5)P3
| PDB | Organism | Co-crystalized ligand | Co-crystalized LXXLL Peptide | Reference |
|---|---|---|---|---|
| 4QJR | Homo Sapiens | PIP3 (PIZ) | PGC-1 alpha | Blind et al. (2014) |
| 4QK4 | Homo Sapiens | PIP2 (PIK) | PGC-1 alpha | Blind et al. (2014) |
| 8DAF | Homo Sapiens | 6N-10CA, Bacterial Phospholipid (PEF) | NCOA2 | Cato et al. (2023) |
| 1YP0 | Mus Musculus | Phosphatidylethanolamine (PEF) | SHP | Li et al. (2005) |
| 1YOW | Homo Sapiens | Phosphatidylethanol (P0E) | TIF2 | Krylova et al. (2005) |
| 7KHT | Homo Sapiens | PIP3 (WES) | PGC-1 alpha | Bryant et al. (2021) |
| 1ZDT | Homo Sapiens | Phosphatidylethanolamine (PEF) | NCOA2 | Wang et al. (2005) |
| 1YMT | Mus Musculus | Phosphatidylglycerol (DR8) | NR0B2 | Krylova et al. (2005) |
| 3F7D | Mus Musculus | Phosphatidylcholine (P42) | PGC-1 alpha | Sablin et al. (2009) |
bind to SF-1 (Krylova et al., 2005), confirmed later by co-crystal structures of several phosphoinositides with SF-1 (Blind et al., 2014; Bryant et al., 2021). These structures suggest the phosphatidylinositol lipids take advantage of the amphipathic nature of the canonical ligand biding site, as the hydrophobic acyl chains of the ligand are sequestered from water deep within the lipid-binding pocket, and the hydrophilic headgroup is located at the water-exposed entrance to the ligand binding pocket (Blind et al., 2014). There is evidence that PI(4,5)P2 associates with full-length SF-1 ectopically expressed in human HEK cells, as a PI(4,5)P2-specific kinase is able to incorporate radiolabel into immunoprecipitates of wild-type SF-1, but not a ligand-binding mutant of SF-1 (Blind et al., 2012a). Further, displacement of all lipids from these SF-1 immunoprecipitates with a chemical competitor of PIP2 called RJW100 (Whitby et al., 2011)’ (Mays et al., 2020) also prevented radiolabel incorporation by the PIP2-kinase (Blind et al., 2012a). These data suggest PIP2 associates with SF-1 at the canonical ligand binding site of SF-1, in a human cell line. More recent studies also suggest phos- phoinositides functionally regulate the isolated ligand binding domain of SF-1, as changes to the acyl chain composition of PIP3 can alter the recruitment capabilities of SF-1 for coregulatory proteins (Cato et al., 2023; Blind et al., 2014; Bryant et al., 2021). It remains unclear if ligands might regulate the structure of full-length SF-1 in a way that could alter interactions that might occur between the ligand binding domain and other domains in SF-1, as has been suggested to occur with the close SF-1 homolog LRH-1 (Seacrist et al., 2020). More studies will be needed to evaluate how phospholipid ligands or other lipid molecules might affect regulation of SF-1 functions in transcription.
7. Protein phosphorylation of SF-1
Like many cellular proteins, SF-1 likely exists as a phosphorylated protein in cells (see Table 2). Phosphorylation can be detected when SF-1 is immunoprecipitated from adrenocortical cells (Lund et al., 1997). More specifically, S203, a residue located in the hinge region of SF-1, has been shown to be phosphorylated by MAPK (Hammer et al., 1999). Mutating the serine residue to an alanine residue (S203A) leads to reduced ability to transactivate luciferase reporters. Structurally, phosphorylation of S203 has been shown to stabilize the SF-1 LBD (Desclozeaux et al., 2002), in a chymotrypsin-based protease protection assay akin to other nuclear receptor LBDs un- dergoing similar protection from proteases upon binding to ligand (Blind et al., 2012b). Mechanistically, SF-1 recruitment of GRIP-1, a coactivator of SF-1, is enhanced upon the phosphorylation of Serine 203 (Hammer et al., 1999). The functional importance of phosphorylation of Serine 203 was suggested in studies where the S203A mutation leads to reduction of SF-1 dependent transcription of StAR, but not the high-density lipoprotein receptor (HDLR) gene, suggesting that S203 phosphorylation might selectively regulate SF-1 to induce context-dependent transcriptional regulation (Lopez et al., 2001). Serine 203 is phosphorylated by MAPK can also be phosphorylated by CDK7; an activity that has been confirmed in vitro (Lewis et al., 2008). The authors also report that a mutation within the ligand binding pocket that prevents phospholipid binding leads to decreased levels of Serine 203 phosphorylation by CDK7, suggesting a complex interplay between SF-1 phosphorylation and ligand binding.
In addition to the clear role of S203 phosphorylation in SF-1 function, there is evidence that other modes of phosphorylation may regulate SF-1. PKA has been shown to be able to phosphorylate the rat SF-1 DBD, which decreased SF-1 DBD DNA binding in vitro (Zhang and Mellon, 1996) however the exact residue that is phosphorylated has not been identified. Mutating a putative PKA phosphorylation site did not lead to a change in transcriptional activity of SF-1 in a luciferase reporter assay (Lopez et al., 2001; ÆSØY et al., 2002). Together, the data suggest SF-1 is a phosphoprotein, and that phosphorylation, particularly of S203, can regulate several SF-1 functions.
8. Non-canonical function of SF-1
While nuclear receptors have traditionally been associated with regulation of transcription and gene expression, non-genomic functions have also been defined. These non-genomic actions usually can be detected within seconds to minutes, in contrast with transcriptional responses that often require dozens of minutes to hours for a detectable response (Falkenstein et al., 2000; Blind et al., 2012c). Many non-genomic functions of nuclear receptors take place outside the nucleus, in the cytoplasm, at the plasma membrane, or within intracellular organelles (Unsworth et al., 2018). SF-1 has been observed localized at the centrosome, where SF-1 was sur- prisingly shown to be required for maintaining centrosome homeostasis (Lai et al., 2011), which is a clear example of one non-canonical function of SF-1, independent of SF-1 gene regulatory activity.
During mitosis, centrosomes function as the microtubule organizing centers and form the bipolar spindles that facilitate the equal division of chromosomes (Doxsey et al., 2005). Like chromosomes, centrosome division only occurs once in each cell cycle (Doxsey, 2001). Correct division and amounts of centrosomes are required for proper cell growth and genetic stability, while centrosome
| Description of SF-1 Phosphorylation Event | Comments | References |
|---|---|---|
| PKA phosphorylation of SF-1 | PKA phosphorylates rat SF-1 DBD and decreased DNA binding (Zhang and Mellon, 1996), phosphorylation site not definitively identified. | Zhang and Mellon (1996) |
| Ser 203 by MAPK Ser 203 by CDK7 | Genetic evidence (S203A) that S203 phosphorylation is necessary for full SF-1 transcriptional activity. | (Hammer et al., 1999; Desclozeaux et al., 2002; Lopez et al., 2001) |
| In vitro phosphorylation of S203 by CDK, SF-1 ligand binding pocket mutant phosphorylated less efficiently by CDK7. | Lewis et al. (2008) |
amplification leads to aberrant mitosis (Ganem et al., 2009; Pihan et al., 1998; D’Assoro et al., 2002). SF-1 maintains correct centrosome counts in mouse adrenocortical Y1 cells by regulating the activity of DNA-dependent protein kinase (DNA-PK) in the centrosome (Wang et al., 2013). The data suggest SF-1 interacts with DNA repair proteins Ku70 and Ku80, sequestering them from the catalytic subunit of DNA-PK (DNA-PKcs) (Wang et al., 2013). Loss of SF-1 induces activation of DNA-PK, causing overactivation of Akt and CDK2/cyclin (Wang et al., 2013). CDK2 phosphorylates proteins involved in the initiation of centrosome replication (Okuda et al., 2000; Chen et al., 2002; Kasbek et al., 2007) and is associated with centrosome overduplication. Activation of DNA-PK also leads to the phosphorylation and inactivation of GSK3B, leading to accumulation of ß-catenin and centriole splitting (Wang et al., 2014), itself an important step in centrosome amplification (Saladino et al., 2009). Overexpression of SF-1, however, does not appear to inhibit the duplication of centrosomes. Instead, SF-1 appears to block centrosome overduplication under challenged or stressed conditions (Wang et al., 2013). This observation suggests SF-1 can prevent abnormal duplication of centrosomes without obviously regulating normal duplication, consistent with the function of other centrosomal proteins (Trachana et al., 2007; Tsang et al., 2009).
Depletion of SF-1 does associate with centrosome over-duplication, genomic instability, and decreased cell counts (Lai et al., 2011), and these defects were not only rescued by wild-type SF-1, but also by a transcriptionally inactive point mutant of SF-1 (G35E), was well as a truncated SF-1 lacking the DNA-binding domain (Lai et al., 2011; Wang et al., 2014). These important rescue experiments suggest the activity of SF-1 in the centrosome is independent of SF-1 transcriptional regulation, and the ability of SF-1 to bind DNA directly, a hallmark of non-genomic action. A centrosomal localization signal was also identified and shown to be dependent on SF-1 amino acids 348-367 (Lai et al., 2011). Overall, these non-transcriptional actions of SF-1 describe a mechanism of centrosome amplification through DNA-PK that is independent from previously described mechanisms involving the DNA damage checkpoint. Although adrenocortical cancers have previously been linked to SF-1 overexpression (Doghman et al., 2007b, 2009b), centrosome amplification has also been linked to cancers (Ganem et al., 2009; Fukasawa, 2007). Thus, it remains possible that the link between SF-1 and adrenocortical cancers could also involve defects in centrosome biology.
9. Mass spectrometry to identify SF-1 ligands
Mass spectrometry (MS) is an analytical tool used to detect and measure a large array of small molecules, including most species of lipids. It was thus mass spectrometry-based approaches that have been used to unequivocally chemically identify the electron density seen in crystal structures of SF-1 (Crowder et al., 2017)’ (Forman, 2005). Some studies have used lipidomic mass spectrometry to confirm the presence of particular phospholipids bound to the SF-1 ligand binding domain (Sablin et al., 2009; Krylova et al., 2005; Li et al., 2005; Wang et al., 2005) while other studies have used mass spectrometry in de novo, discovery-based ligand identification. It was reported that 25-, 26-, or 27-hydroxycholesterol regulate SF-1 activity in living cells, and that deletion mutants of the SF-1 ligand binding domain did not respond to these ligands (Lala et al., 1997), in line with a feedback-regulatory role for oxysterol-based steroid metabolism controlled by SF-1. However, oxysterols do not likely bind SF-1 within the canonical ligand binding pocket (Mellon and Bair, 1998), although the cholesterol-based detergent CHAPS is required for efficient purification of the SF-1 ligand binding domain from bacterial cell lysates (Sablin et al., 2009; Blind et al., 2014).
The first evidence that phospholipids serve as regulatory ligands for SF-1 came when bacterial phospholipids from the recombinant protein expression system used to express SF-1, fortuitously co-crystalized with SF-1, with 1:1 stoichiometry and clearly bound within the canonical nuclear receptor ligand binding pocket (Krylova et al., 2005; Li et al., 2005; Wang et al., 2005). Again, mass spectrometry-based lipidomic analyses unequivocally confirmed the chemical nature of the electron density observed in the crystal structures as bacterial phospholipids from the E. coli system used to express and purify SF-1 (Sablin et al., 2009; Krylova et al., 2005; Li et al., 2005; Wang et al., 2005). In one of these studies, the mass spectrometry data suggested phosphatidylethanolamine (PE) with shorter C12:0 acyl chains associates with SF-1, however the phospholipid ligand in the co-crystal structure in that same study was identified as a palmitic ester of PE diC16:1 (Wang et al., 2005), suggesting PEs with longer acyl chain lengths (14-18 carbons) and with various degrees of saturation would also fit into the SF-1 ligand binding pocket (Wang et al., 2005). Krylova et al., demonstrated phosphatidic acid (PA) and phosphatidylinositol (3,4,5) triphosphate (PIP3) also bind SF-1, suggesting phosphatidylinositols as po- tential SF-1 ligands (Krylova et al., 2005), later confirmed by studies in human cells (Blind et al., 2012a) and in several x-ray co-crystal structures (Blind et al., 2014; Bryant et al., 2021). In another study, Yong et al., used electrospray ionization (ESI) and tandem MS/MS
to identify PE C34:2 or C32:1 lipids associated with SF-1 (Li et al., 2005). Later work from Marion Sewer and Al Merrill on full-length SF-1 purified from human adrenocortical cells suggested SF-1 binds to sphingosines and sphingomyelin using a combination of LC-ESI-MS/MS techniques and multiple reaction monitoring (MRM) (Urs et al., 2006, 2007), and further interaction with some of these sphingolipids was altered by cAMP signaling. Another study used lipid mass spectrometry to suggest PE species with 16:0/16:1, 16:1/16:1, and 18:1/16:1 were associated with the isolated SF-1 ligand binding domain expressed and purified from bacteria (Bryant et al., 2021), with both structural and functional changes induced by PIP3 with 18:1/18:1 dioleoyl acyl chains (Bryant et al., 2021), observations also in line with the C34:2 chain length reported by other groups for phospholipids bound to SF-1 (Li et al., 2005). Although these studies show the extensive mass spectrometry used to identify lipid ligands that associate with SF-1, there have been no mass spectrometry studies identifying phosphoinositides in particular associated with SF-1, which require highly specialized protocols (Kielkowska et al., 2014; Barneda et al., 2019).
10. Conclusions and future perspectives
SF-1 has high potential therapeutic value in adrenocortical carcinoma, however without understanding the molecular details of how SF-1 is regulated by endogenous phospholipids, the development of compounds that inhibit SF-1 becomes a more difficult task.
Thus, more high-resolution structural studies of SF-1 are needed to unlock the full therapeutic potential of SF-1, and to develop new therapies for adrenal cancer, a disease currently with no FDA approved targeted therapies. As reviewed here, the role of SF-1 in adrenal physiology is well established in both humans and mice, and mouse knockout models suggest that even developmental loss of SF-1 function does not lead to physiological consequences that cannot be successfully managed. The genetic studies therefore suggest that chemical inhibitors of SF-1 can be well tolerated, although that remains to be tested. Together, the connections between SF-1 and adrenal cancer are too important to ignore, and deserve further investigation.
Declaration of competing interest
The authors have no conflicts of interest to declare.
Data availability
Data will be made available on request.
Acknowledgements
The authors would like to thank Lucia E. Rameh for her mentorship, Funding was from R01 GM138873 to R.D.B .; and NIH training grant slots awarded T32GM008320 to A.N.C .; T32DK007061 to A.R.O .; T32DK007563 to E.A.S .; T32DK101003 to J.C.P .; R21 CA243036 to R.D.B.
References
Achermann, J.C., Ito, M., Ito, M., Hindmarsh, P.C., Jameson, J.L., 1999. A mutation in the gene encoding steroidogenic factor-1 causes XY sex reversal and adrenal failure in humans. Nat. Genet. 22, 125-126.
ÆSØY, R., Mellgren, G., Morohashi, K.I., Lund, J., 2002. Activation of cAMP-dependent protein kinase increases the protein level of steroidogenic factor-1. Endocrinology 143, 295-303.
Attar, E., et al., 2009. Prostaglandin E2 via steroidogenic factor-1 coordinately regulates transcription of steroidogenic genes necessary for estrogen synthesis in endometriosis. J. Clin. Endocrinol. Metab. 94, 623-631.
Balla, T., 2013. Phosphoinositides: tiny lipids with giant impact on cell regulation. Physiol. Rev. 93, 1019-1137.
Barlow, C.A., Laishram, R.S., Anderson, R.A., 2010. Nuclear phosphoinositides: a signaling enigma wrapped in a compartmental conundrum. Trends Cell Biol. 20, 25-35.
Barneda, D., Cosulich, S., Stephens, L., Hawkins, P., 2019. How is the acyl chain composition of phosphoinositides created and does it matter? Biochem. Soc. Trans. 47, 1291-1305.
Bertrand-Delepine, J., et al., 2020. In cases of familial primary ovarian insufficiency and disorders of gonadal development, consider NR5A1/SF-1 sequence variants. Reprod. Biomed. Online 40, 151-159.
Biason-Lauber, A., Schoenle, E.J., 2000. Apparently normal ovarian differentiation in a prepubertal girl with transcriptionally inactive steroidogenic factor 1 (NR5A1/SF-1) and adrenocortical insufficiency. Am. J. Hum. Genet. 67, 1563-1568.
Bland, M.L., et al., 2000a. Haploinsufficiency of steroidogenic factor-1 in mice disrupts adrenal development leading to an impaired stress response. Proc. Natl. Acad. Sci. U. S. A. 97, 14488-14493.
Bland, M.L., Jamieson, C., Akana, S., Dallman, M., Ingraham, H.A., 2000b. Gene dosage effects of steroidogenic factor 1 (SF-1) in adrenal development and the stress. Endocr. Res. 26, 515-516.
Bland, M.L., Fowkes, R.C., Ingraham, H.A., 2004. Differential requirement for steroidogenic factor-1 gene dosage in adrenal development versus endocrine function. Mol. Endocrinol. 18, 941-952.
Blind, R.D., Suzawa, M., Ingraham, H.A., 2012a. Direct modification and activation of a nuclear receptor-PIP2 complex by the inositol lipid kinase IPMK. Sci. Signal. 5, ra44.
Blind, R.D., Pineda-Torra, I., Xu, Y., Xu, H.E., Garabedian, M.J., 2012b. Ligand structural motifs can decouple glucocorticoid receptor transcriptional activation from target promoter occupancy. Biochem. Biophys. Res. Commun. 420, 839-844.
Blind, R.D.D., Pineda-Torra, I., Xu, Y., Xu, H.E.E., Garabedian, M.J.J., 2012c. Ligand structural motifs can decouple glucocorticoid receptor transcriptional activation from target promoter occupancy. Biochem. Biophys. Res. Commun. 420, 839-844.
Blind, R.D., et al., 2014. The signaling phospholipid PIP3 creates a new interaction surface on the nuclear receptor NR5A1 (SF-1). Proc. Natl. Acad. Sci. U. S. A. 111, 15054-15059.
Boronenkov, I.V., Loijens, J.C., Umeda, M., Anderson, R.A., 1998. Phosphoinositide signaling pathways in nuclei are associated with nuclear speckles. Mol. Biol. Cell 9, 3547-3560.
Bryant, J.M., Blind, R.D., 2019. Signaling through non-membrane nuclear phosphoinositide binding proteins in human health and disease. J. Lipid Res. 60, 299-311. Bryant, J.M., et al., 2021. The acyl chains of phosphoinositide PIP3 alter the structure and function of nuclear receptor Steroidogenic Factor-1 (NR5A1). J. Lipid Res. 100081 https://doi.org/10.1016/j.jlr.2021.100081.
Buonocore, F., et al., 2019. Next-generation sequencing reveals novel genetic variants (SRY, DMRT1, NR5A1, DHH, DHX37) in adults with 46,XY DSD. J Endocr Soc 3, 2341-2360.
Cato, M.L., et al., 2023. Comparison of activity, structure, and dynamics of SF-1 and LRH-1 complexed with small molecule modulators. J. Biol. Chem. 299, 104921. Chen, Z., Indjeian, V.B., McManus, M., Wang, L., Dynlacht, B.D., 2002. CP110, a cell cycle-dependent CDK substrate, regulates centrosome duplication in human cells. Dev. Cell 3, 339-350.
Choi, Y.H., Fujikawa, T., Lee, J., Reuter, A., Kim, K.W., 2013. Revisiting the ventral medial nucleus of the hypothalamus: the roles of SF-1 neurons in energy homeostasis. Front. Neurosci. 7.
Coutinho, E.A., et al., 2017. Activation of SF1 neurons in the ventromedial hypothalamus by DREADD technology increases insulin sensitivity in peripheral tissues. Diabetes 66, 2372-2386.
Crowder, M.K.M.K., Seacrist, C.D.C.D., Blind, R.D.R.D., 2017. Phospholipid regulation of the nuclear receptor superfamily. Advances in Biological Regulation 63 6-6314.
Darimont, B.D., et al., 1998. Structure and specificity of nuclear receptor-coactivator interactions. Genes Dev. 12, 3343-3356.
De Santa Barbara, P., et al., 1998. Direct interaction of SRY-related protein SOX9 and steroidogenic factor 1 regulates transcription of the human anti-müllerian hormone gene. Mol. Cell Biol. 18, 6653-6665.
Desclozeaux, M., Krylova, I.N., Horn, F., Fletterick, R.J., Ingraham, H.A., 2002. Phosphorylation and intramolecular stabilization of the ligand binding domain in the nuclear receptor steroidogenic factor 1. Mol. Cell Biol. 22, 7193-7203.
Doghman, M., et al., 2007a. Increased steroidogenic factor-1 dosage triggers adrenocortical cell proliferation and cancer. Mol. Endocrinol. 21, 2968-2987.
Doghman, M., et al., 2007b. Increased steroidogenic factor-1 dosage triggers adrenocortical cell proliferation and cancer. Mol. Endocrinol. 21, 2968-2987.
Doghman, M., et al., 2009a. Inhibition of adrenocortical carcinoma cell proliferation by steroidogenic factor-1 inverse agonists. J. Clin. Endocrinol. Metab. 94, 2178-2183.
Doghman, M., et al., 2009b. Inhibition of adrenocortical carcinoma cell proliferation by steroidogenic factor-1 NR5A1 (SF-1) inverse agonists. J. Clin. Endocrinol. Metab. 94, 2178-2183.
Doghman, M., Figueiredo, B.C., Volante, M., Papotti, M., Lalli, E., 2013. Integrative analysis of SF-1 transcription factor dosage impact on genome-wide binding and gene expression regulation. Nucleic Acids Res. 41, 8896-8907.
Doxsey, S., 2001. Re-evaluating centrosome function. Nat. Rev. Mol. Cell Biol. 2, 688-698.
Doxsey, S., Zimmerman, W., Mikule, K., 2005. Centrosome control of the cell cycle. Trends Cell Biol. 15, 303-311.
D’Assoro, A.B., Lingle, W.L., Salisbury, J.L., 2002. Centrosome amplification and the development of cancer. Oncogene 21, 6146-6153.
Ehrlund, A., et al., 2012. Knockdown of SF-1 and RNF31 affects components of steroidogenesis, TGFß, and Wnt/ß-catenin signaling in adrenocortical carcinoma cells. PLoS One 7.
Falkenstein, E., Norman, A.W., Wehling, M., 2000. Mannheim classification of nongenomically initiated (rapid) steroid action(s). J. Clin. Endocrinol. Metab. 85, 2072-2075.
Forman, B.M., 2005. Are those phospholipids in your pocket? Cell Metabol. 1, 153-155.
Fosch, A., Zagmutt, S., Casals, N., Rodríguez-Rodríguez, R., 2021. New insights of SF1 neurons in hypothalamic regulation of obesity and diabetes. Int. J. Mol. Sci. 22.
Fujikawa, T., et al., 2016. SF-1 expression in the hypothalamus is required for beneficial metabolic effects of exercise. Elife 5.
Fukasawa, K., 2007. Oncogenes and tumour suppressors take on centrosomes. Nat. Rev. Cancer 7, 911-924.
Gampe, R.T.J., et al., 2000. Asymmetry in the PPARgamma/RXRalpha crystal structure reveals the molecular basis of heterodimerization among nuclear receptors. Mol. Cell. 5, 545-555.
Ganem, N.J., Godinho, S.A., Pellman, D., 2009. A mechanism linking extra centrosomes to chromosomal instability. Nature 460, 278-282.
Gearhart, M.D., Holmbeck, S.M.A., Evans, R.M., Dyson, H.J., Wright, P.E., 2003. Monomeric complex of human orphan estrogen related receptor-2 with DNA: a pseudo-dimer interface mediates extended half-site recognition. J. Mol. Biol. 327, 819-832.
Hamann, B.L., Blind, R.D., 2018. Nuclear phosphoinositide regulation of chromatin. J. Cell. Physiol. 233, 107-123.
Hammer, G.D., et al., 1999. Phosphorylation of the nuclear receptor SF-1 modulates cofactor recruitment: integration of hormone signaling in reproduction and stress. Mol. Cell. 3, 521-526.
Honda, S.I., Morohashi, K.I., Omura, T., 1990. Novel cAMP regulatory elements in the promoter region of bovine P-450(11 beta) gene. J. Biochem. 108, 1042-1049.
Hughes, C.H.K., et al., 2023. Steroidogenic factor 1 (SF-1; Nr5a1) regulates the formation of the ovarian reserve. Proc. Natl. Acad. Sci. U. S. A. 120.
Ingraham, H.A., et al., 1994. The nuclear receptor steroidogenic factor 1 acts at multiple levels of the reproductive axis. Genes Dev. 8, 2302-2312.
Jiang, L., et al., 2020. Structural basis of NR4A1 bound to the human pituitary proopiomelanocortin gene promoter. Biochem. Biophys. Res. Commun. 523, 1-5.
Kasbek, C., et al., 2007. Preventing the degradation of mps1 at centrosomes is sufficient to cause centrosome reduplication in human cells. Mol. Biol. Cell 18, 4457-4469.
Khodai, T., Luckman, S.M., 2021. Ventromedial nucleus of the hypothalamus neurons under the magnifying glass. Endocrinology 162.
Kielkowska, A., et al., 2014. A new approach to measuring phosphoinositides in cells by mass spectrometry. Advances in Biological Regulation 54, 131-141. https:// doi.org/10.1016/j.jbior.2013.09.001. Preprint at.
Kiiveri, S., et al., 2005. Transcription factors GATA-6, SF-1, and cell proliferation in human adrenocortical tumors. Mol. Cell. Endocrinol. 233, 47-56.
Kim, K.W., et al., 2011a. Steroidogenic factor 1 directs programs regulating diet-induced thermogenesis and leptin action in the ventral medial hypothalamic nucleus. Proc. Natl. Acad. Sci. U. S. A. 108, 10673-10678.
Kim, K.W., et al., 2011b. Steroidogenic factor 1 directs programs regulating diet-induced thermogenesis and leptin action in the ventral medial hypothalamic nucleus. Proc. Natl. Acad. Sci. U. S. A. 108, 10673-10678.
Kim, K.W., et al., 2012. FOXO1 in the ventromedial hypothalamus regulates energy balance. J. Clin. Invest. 122, 2578-2589.
Klockener, T., et al., 2011. High-fat feeding promotes obesity via insulin receptor/PI3K-dependent inhibition of SF-1 VMH neurons. Nat. Neurosci. 14, 911-918. Krylova, I.N., et al., 2005. Structural analyses reveal phosphatidyl inositols as ligands for the NR5A orphan receptors SF-1 and LRH-1. Cell 120, 343-355.
Lai, P.Y., et al., 2011. Steroidogenic Factor 1 (NR5A1) resides in centrosomes and maintains genomic stability by controlling centrosome homeostasis. Cell Death Differ. 18, 1836-1844.
Lala, D.S., Rice, D.A., Parker, K.L., 1992a. Steroidogenic factor i, a key regulator of steroidogenic enzyme expression, is the mouse homolog of fushi tarazu-factor i. Mol. Endocrinol. 6, 1249-1258.
Lala, D.S., Rice, D.A., Parker, K.L., 1992b. Steroidogenic factor I, a key regulator of steroidogenic enzyme expression, is the mouse homolog of fushi tarazu-factor I. Mol. Endocrinol. 6, 1249-1258.
Lala, D.S., Rice, D.A., Parker, K.L., 1992c. Steroidogenic factor I, a key regulator of steroidogenic enzyme expression, is the mouse homolog of fushi tarazu-factor I. Mol. Endocrinol. 6, 1249-1258.
Lala, D.S., et al., 1997. Activation of the orphan nuclear receptor steroidogenic factor 1 by oxysterols. Proc. Natl. Acad. Sci. U. S. A. 94, 4895-4900.
Lapiscina, I. M. de, et al., 2023. Genetic reanalysis of patients with a difference of sex development carrying the NR5A1/SF-1 variant p.Gly146Ala has discovered other likely disease-causing variations. PLoS One 18, e0287515.
Lee, F.Y., et al., 2011. Eliminating SF-1 (NR5A1) sumoylation in vivo results in ectopic hedgehog signaling and disruption of endocrine development. Dev. Cell 21, 315-327.
Lewis, A.E., et al., 2008. Phosphorylation of steroidogenic factor 1 is mediated by cyclin-dependent kinase 7. Mol. Endocrinol. 22, 91-104.
Li, L.A., et al., 1999. Function of steroidogenic factor 1 domains in nuclear localization, transactivation, and interaction with transcription factor TFIIB and c-Jun. Mol. Endocrinol. 13, 1588-1598.
Li, Y., et al., 2005. Crystallographic identification and functional characterization of phospholipids as ligands for the orphan nuclear receptor steroidogenic factor-1. Mol. Cell. 17, 491-502.
Lin, L., Achermann, J.C., 2008. Steroidogenic factor-1 (SF-1, Ad4BP, NR5A1) and disorders of testis development. Sex. Dev. 2, 200-209.
Little, T.H., et al., 2006. Sequence-specific deoxyribonucleic acid (DNA) recognition by steroidogenic factor 1: a helix at the carboxy terminus of the DNA binding domain is necessary for complex stability. Mol. Endocrinol. 20, 831-843.
Liu, Z., Simpson, E.R., 1997. Steroidogenic factor 1 (SF-1) and SP1 are required for regulation of bovine CYP11A gene expression in bovine luteal cells and adrenal Y1 cells. Mol. Endocrinol. 11, 127-137.
Liu, Z., Simpson E, R., 1999. Molecular mechanism for cooperation between Sp1 and steroidogenic factor-1 (SF-1) to regulate bovine CYP11A gene expression. Mol. Cell. Endocrinol. 153, 183-196.
Lopez, D., et al., 2001. Effects of mutating different steroidogenic factor-1 protein regions on gene regulation. Endocrine 14, 353-362.
Lund, J., Bakke, M., Mellgren, G., Morohashi, K.I., Døskeland, S.O., 1997. Transcriptional regulation of the bovine CYP17 gene by cAMP. Steroids 62, 43-45.
Luo, X., Ikeda, Y., Parker, K.L., 1994a. A cell-specific nuclear receptor is essential for adrenal and gonadal development and sexual differentiation. Cell 77, 481-490.
Luo, X., Ikeda, Y., Parker, K.L., 1994b. A cell-specific nuclear receptor is essential for adrenal and gonadal development and sexual differentiation. Cell 77, 481-490. Majdic, G., et al., 2002a. Knockout mice lacking steroidogenic factor 1 are a novel genetic model of hypothalamic obesity. Endocrinology 143, 607-614. Majdic, G., et al., 2002b. Knockout mice lacking steroidogenic factor 1 are a novel genetic model of hypothalamic obesity. Endocrinology 143, 607-614. Marino, J.S., Xu, Y., Hill, J.W., 2011. Central insulin and leptin-mediated autonomic control of glucose homeostasis. Trends Endocrinol. Metabol. 22, 275-285. Mays, S.G., et al., 2020. Enantiomer-specific activities of an LRH-1 and SF-1 dual agonist. Sci. Rep. 10.
Meinke, G., Sigler, P.B., 1999. DNA-binding mechanism of the monomeric orphan nuclear receptor NGFI-B. Nat. Struct. Biol. 6, 471-477.
Meinsohn, M.C., Smith, O.E., Bertolin, K., Murphy, B.D., 2019a. The orphan nuclear receptors steroidogenic factor-1 and liver receptor homolog-1: structure, regulation, and essential roles in mammalian reproduction. Physiol. Rev. 99, 1249-1279.
Meinsohn, M .- C., Smith, O.E., Bertolin, K., Murphy, B.D., 2019b. The orphan nuclear receptors steroidogenic factor-1 and liver receptor homolog-1: structure, regulation, and essential roles in mammalian reproduction. Physiol. Rev. 99, 1249-1279.
Meinsohn, M.C., Smith, O.E., Bertolin, K., Murphy, B.D., 2019c. The orphan nuclear receptors steroidogenic factor-1 and liver receptor homolog-1: structure, regulation, and essential roles in mammalian reproduction. Physiol. Rev. 99, 1249-1279.
Mellon, S.H., Bair, S.R., 1998. 25-Hydroxycholesterol is not a ligand for the orphan nuclear receptor steroidogenic factor-1 (SF-1). Endocrinology 139, 3026-3029.
Miller, W.L., Auchus, R.J., 2011. The molecular biology, biochemistry, and physiology of human steroidogenesis and its disorders. Endocr. Rev. 32, 81-151.
Monté, D., DeWitte, F., Hum, D.W., 1998. Regulation of the human P450scc gene by steroidogenic factor 1 is mediated by CBP/p300. J. Biol. Chem. 273, 4585-4591.
Morohashi, K.I., et al., 1993. Activation of CYP11A and CYP11B gene promoters by the steroidogenic cell-specific transcription factor, Ad4BP. Mol. Endocrinol. 7, 1196-1204.
Morohashisqll, K .- I., Hondas, S .- I., Inomatall, Y., Handall, H., Omuras, T., 1992. THE JOURNAL of BIOLOGICAL CHEMISTRY A Common Trans-acting Factor, Ad4- Binding Protein, to the Promoters of Steroidogenic P-450s, vol. 267, pp. 17913-17919.
Muzzi, J.C.D., et al., 2022. Comprehensive characterization of the regulatory landscape of adrenocortical carcinoma: novel transcription factors and targets associated with prognosis. Cancers 14.
Nachtigal, M.W., et al., 1998. Wilms’ tumor 1 and Dax-1 modulate the orphan nuclear receptor SF-1 in sex-specific gene expression. Cell 93, 445-454.
Nagy, O., et al., 2019. The importance of the multiplex ligation-dependent probe amplification in the identification of a novel two-exon deletion of the NR5A1 gene in a patient with 46,XY differences of sex development. Mol. Biol. Rep. 46, 5595-5601.
Noël, J.C., et al., 2011. The steroidogenic factor-1 protein is not expressed in various forms of endometriosis but is strongly present in ovarian cortical or medullary mesenchymatous cells adjacent to endometriotic foci. Fertil. Steril. 95, 2655-2657.
Oba, K., et al., 1996. Structural characterization of human Ad4bp (SF-1) gene. Biochem. Biophys. Res. Commun. 226, 261-267.
Okuda, M., et al., 2000. Nucleophosmin/B23 is a target of CDK2/cyclin E in centrosome duplication. Cell 103, 127-140.
Padua, T. C. de, et al., 2023. A systematic review of published clinical trials in the systemic treatment of adrenocortical carcinoma: an initiative led on behalf of the global society of rare genitourinary tumors. Clin. Genitourin. Cancer 21, 1-7.
Pihan, G.A., et al., 1998. Centrosome defects and genetic instability in malignant tumors. Cancer Res. 58, 3974-3985.
Ramayya, M.S., Sheng, M., Moroz, K., Hill, S.M., Rowan, B.G., 2010. Human steroidogenic factor-1 (hSF-1) regulates progesterone biosynthesis and growth of ovarian surface epithelial cancer cells. J. Steroid Biochem. Mol. Biol. 119, 14-25.
Rashid, M., Kondoh, K., Palfalvi, G., Nakajima, K. ichiro, Minokoshi, Y., 2023. Inhibition of high-fat diet-induced inflammatory responses in adipose tissue by SF1- expressing neurons of the ventromedial hypothalamus. Cell Rep. 42.
Relav, L., et al., 2023. Steroidogenic factor 1, a goldilocks transcription factor from adrenocortical organogenesis to malignancy. Int. J. Mol. Sci. 24.
Rice, D.A., Mouw, A.R., Bogerd, A.M., Parker, K.L., 1991. A shared promoter element regulates the expression of three steroidogenic enzymes. Mol. Endocrinol. 5, 1552-1561.
Ruud, J., Steculorum, S.M., Bruning, J.C., 2017. Neuronal control of peripheral insulin sensitivity and glucose metabolism. Nat. Commun. 8.
Sablin, E.P., et al., 2009. Structure of SF-1 bound by different phospholipids: evidence for regulatory ligands. Mol. Endocrinol. 23.
Sadovsky, Y., et al., 1995. Mice deficient in the orphan receptor steroidogenic factor 1 lack adrenal glands and gonads but express P450 side-chain-cleavage enzyme in the placenta and have normal embryonic serum levels of corticosteroids. Proc. Natl. Acad. Sci. U. S. A. 92, 10939-10943.
Saladino, C., Bourke, E., Conroy, P.C., Morrison, C.G., 2009. Centriole separation in DNA damage-induced centrosome amplification. Environ. Mol. Mutagen. 50, 725-732.
Seacrist, C.D., et al., 2020. Integrated structural modeling of full-length LRH-1 reveals inter-domain interactions contribute to receptor structure and function. Structure 28.
Shah, Z.H., et al., 2013. Nuclear phosphoinositides and their impact on nuclear functions. FEBS J. 280, 6295-6310.
Shen, W.H., Moore, C.C.D., Ikeda, Y., Parker, K.L., Ingraham, H.A., 1994. Nuclear receptor steroidogenic factor 1 regulates the müllerian inhibiting substance gene: a link to the sex determination cascade. Cell 77, 651-661.
Shiau, A.K., et al., 1998. The structural basis of estrogen receptor/coactivator recognition and the antagonism of this interaction by tamoxifen. Cell 95, 927-937.
Smith, O.E., et al., 2022. Steroidogenic factor 1 regulation of the hypothalamic-pituitary-ovarian Axis of adult female mice. Endocrinology 163.
Solomon, I.H., et al., 2005. Crystal structure of the human LRH-1 DBD-DNA complex reveals Ftz-F1 domain positioning is required for receptor activity. J. Mol. Biol. 354, 1091-1102.
Somekawa, S., et al., 2009. Regulation of aldosterone and cortisol production by the transcriptional repressor neuron restrictive silencer factor. Endocrinology 150, 3110-3117.
Sztacho, M., Sobol, M., Balaban, C., Escudeiro Lopes, S.E., Hozák, P., 2019. Nuclear phosphoinositides and phase separation: important players in nuclear compartmentalization. Adv. Biol. Regul. 71, 111-117.
Teoli, J., et al., 2023. Case Report: longitudinal follow-up and testicular sperm extraction in a patient with a pathogenic NR5A1 (SF-1) frameshift variant: p.(Phe70Ser fs*5). Front. Endocrinol. 14.
Tong, Q., et al., 2007a. Synaptic glutamate release by ventromedial hypothalamic neurons is part of the neurocircuitry that prevents hypoglycemia. Cell Metabol. 5, 383-393.
Tong, Q., et al., 2007b. Synaptic glutamate release by ventromedial hypothalamic neurons is part of the neurocircuitry that prevents hypoglycemia. Cell Metabol. 5, 383-393.
Trachana, V., Van Wely, K.H.M., Guerrero, A.A., Fütterer, A., Martinez-A, C., 2007. Dido disruption leads to centrosome amplification and mitotic checkpoint defects compromising chromosome stability. Proc. Natl. Acad. Sci. U. S. A. 104, 2691-2696.
Tremblay, J.J., Viger, R.S., 1999. Transcription factor GATA-4 enhances Mullerian inhibiting substance gene transcription through a direct interaction with the nuclear receptor SF-1. Mol. Endocrinol. 13, 1388-1401.
Tsang, W.Y., et al., 2009. Cep76, a centrosomal protein that specifically restrains centriole re-duplication. Dev. Cell 16, 649.
Ueda, H., Sun, G .- C., Murata, T., Hirose, S., 1992. A novel DNA-binding motif abuts the zinc finger domain of insect nuclear hormone receptor FTZ-F1 and mouse embryonal long terminal repeat-binding protein. Mol. Cell Biol. 12, 5667-5672.
Unsworth, A.J., Flora, G.D., Gibbins, J.M., 2018. Non-genomic effects of nuclear receptors: insights from the anucleate platelet. Cardiovasc. Res. 114, 645-655.
Urs, A.N., Dammer, E., Sewer, M.B., 2006. Sphingosine regulates the transcription of CYP17 by binding to steroidogenic factor-1. Endocrinology 147, 5249-5258. Urs, A.N., et al., 2007. Steroidogenic factor-1 is a sphingolipid binding protein. Mol. Cell. Endocrinol. 265-266, 174-178.
Utsunomiya, H., et al., 2008a. Upstream stimulatory factor-2 regulates steroidogenic factor-1 expression in endometriosis. Mol. Endocrinol. 22, 904-914. Utsunomiya, H., et al., 2008b. Upstream stimulatory factor-2 regulates steroidogenic factor-1 expression in endometriosis. Mol. Endocrinol. 22, 904-914.
Vasquez, Y.M., et al., 2016. Endometrial expression of steroidogenic factor 1 promotes cystic glandular morphogenesis. Mol. Endocrinol. 30, 518-532. Vidalle, M.C., et al., 2023. Nuclear phosphoinositides as key determinants of nuclear functions. Biomolecules 13, 1049.
Wang, W., et al., 2005. The crystal structures of human steroidogenic factor-1 and liver receptor homologue-1. Proc. Natl. Acad. Sci. USA 102, 7505-7510.
Wang, C .- Y., Kao, Y .- H., Lai, P .- Y., Chen, W .- Y., Chung, B., 2013. Steroidogenic factor 1 (NR5A1) maintains centrosome homeostasis in steroidogenic cells by restricting centrosomal DNA-dependent protein kinase activation. Mol. Cell Biol. 33, 476-484.
Wang, C.Y., Lai, P.Y., Chen, T.Y., Chung, B.C., 2014. NR5A1 prevents centriole splitting by inhibiting centrosomal DNA-PK activation and ß-catenin accumulation. Cell Commun. Signal. 12.
Weikum, E.R., Tuntland, M.L., Murphy, M.N., Ortlund, E.A., 2016. A structural investigation into Oct4 regulation by orphan nuclear receptors, germ cell nuclear factor (GCNF), and liver receptor homolog-1 (LRH-1). J. Mol. Biol. 428, 4981-4992.
Weikum, E.R., Liu, X., Ortlund, E.A., 2018. The nuclear receptor superfamily: a structural perspective. Protein Sci. 27, 1876-1892.
Whitby, R.J., et al., 2011. Small molecule agonists of the orphan nuclear receptors steroidogenic factor-1 (SF-1, NR5A1) and liver receptor homologue-1 (LRH-1, NR5A2). J. Med. Chem. 54, 2266-2281.
Wilson, T.E., Mouw, A.R., Weaver, C.A., Milbrandt, J., Parker, K.L., 1993. The orphan nuclear receptor NGFI-B regulates expression of the gene encoding steroid 21- hydroxylase. Mol. Cell Biol. 13, 861-868.
Wong, M., Ramayya, M.S., Chrousos, G.P., Driggers, P.H., Parker, K.L., 1996. Cloning and sequence analysis of the human gene encoding steroidogenic factor 1. J. Mol. Endocrinol. 17, 139-147.
Xue, Q., et al., 2007. Transcriptional activation of steroidogenic factor-1 by hypomethylation of the 5’ CpG island in endometriosis. J. Clin. Endocrinol. Metab. 92, 3261-3267.
Yu, Y., et al., 1997. The nuclear hormone receptor Ftz-F1 is a cofactor for the Drosophila homeodomain protein Ftz. Nature 385, 552-555.
Zhang, P., Mellon, S.H., 1996. The orphan nuclear receptor steroidogenic factor-1 regulates the cyclic adenosine 3’,5’-monophosphate-mediated transcriptional activation of rat cytochrome P450c17 (17 alpha-hydroxylase/c17-20 lyase). Mol. Endocrinol. 10, 147-158.
Zhao, L., et al., 2001. Steroidogenic factor 1 (SF1) is essential for pituitary gonadotrope function. Development 128, 147-154.
Zhu, J., et al., 2023. MicroRNA-92a-3p inhibits cell proliferation and invasion by regulating the transcription factor 21/steroidogenic factor 1 Axis in endometriosis. Reprod. Sci. 30.