NCBI Summary:
This gene encodes a protein which is capable of interacting with the major nonstructural protein of parvovirus H-1 and 70-kDa heat shock cognate protein; however, its function is not known. Since this transcript is expressed ubiquitously in various tissues, this protein may serve a housekeeping function. [provided by RefSeq, Jul 2008]
General function
Comment
Cellular localization
Cytoplasmic
Comment
candidate123
Ovarian function
Comment
Expression regulated by
Comment
Ovarian localization
Granulosa, Theca
Comment
Small glutamine-rich tetratricopeptide repeat-containing protein alpha is present in human ovaries but may not be differentially expressed in relation to polycystic ovary syndrome. Butler MS et al. OBJECTIVE: To evaluate the expression and function of small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA), an androgen receptor (AR) molecular chaperone, in human ovarian tissues. DESIGN: Examine the effect of SGTA on AR subcellular localization in granulosa tumor cells (KGN) and SGTA expression in ovarian tissues. SETTING: University-based research laboratory. PATIENT(S): Archived tissues from premenopausal women and granulosa cells from infertile women receiving assisted reproduction. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): AR subcellular localization and SGTA protein or mRNA levels. RESULT(S): SGTA and AR proteins were expressed in the cytoplasm of KGN cells and exposure to androgen stimulated AR nuclear localization. SGTA protein knockdown increased AR nuclear localization at low (0-0.1 nmol/L) but not high (1-10 nmol/L) concentrations of androgen hormone. In ovarian tissues, SGTA was localized to the cytoplasm of granulosa cells at all stages of folliculogenesis and in thecal cells of antral follicles. SGTA protein levels were similar when comparing primordial and primary follicles within core biopsies (n = 40) from women with and without polycystic ovary syndrome (PCOS). Likewise, SGTA mRNA levels were not significantly different in granulosa cells from preovulatory follicles after hyperstimulation of women with and without PCOS. CONCLUSION(S): SGTA is present in human ovaries and has the potential to modulate AR signalling, but it may not be differentially expressed in PCOS.
Follicle stages
Secondary
Comment
Phenotypes
PCO (polycystic ovarian syndrome)
Mutations
1 mutations
Species: human
Mutation name: None
type: naturally occurring fertility: subfertile Comment: Small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA), a candidate gene for polycystic ovary syndrome. Goodarzi MO et al. BACKGROUND Polycystic ovary syndrome (PCOS) is a heterogenic, complex common genetic disease. Multiple pathways are involved in its pathogenesis, including the androgen signaling pathway and insulin signaling pathway. Small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA) is a putative member of the androgen receptor-chaperone-co-chaperone complex, and may play a role in androgen signaling as a co-chaperone. Polymorphisms in the SGTA gene have not been evaluated for a role in PCOS. METHODS Women with and without PCOS (287 cases, 187 controls) were genotyped for three single nucleotide polymorphisms (SNPs) in SGTA. SNPs and haplotypes were determined and tested for association with PCOS and component traits of PCOS. RESULTS For SNP rs1640262, homozygotes for the minor allele were protected against PCOS (P = 0.009). Haplotype 1 (G-A-T) was associated with increased risk of PCOS (P = 0.015). In women with PCOS, haplotype 2 (A-G-C) was associated with increased insulin resistance (P = 0.013), consequently resulting in increased insulin secretion (P = 0.014). CONCLUSIONS This study presents genetic evidence suggesting a potential role of SGTA in the pathogenesis of PCOS. SGTA may provide a connection between multiple pathways in PCOS.