| Primary Identifier | IPR043387 | Type | Family |
| Short Name | INSL3/INSL4/GSS |
| description | This entry includes insulin-like 3 from mammals, insulin-like peptide 4 (Ilp4 or dILP4) from fruit flies []and Gonad-stimulating substance (GSS) from Starfish.Insulin-like 3 (INSL3) is a secreted protein produced by testicular Leydig cells and in lower amounts by ovarian follicular theca interna cells and the corpus luteum []. It acts as a theca cell-derived growth factor for preantral follicle and its action is mediated by growth differentiation factor 9 []. Signaling through INSL3 and its cognate G protein-coupled receptor RXFP2 is important for testicular descent. It seems to be dispensable for spermatogenesis and fertility in adult males [].The function of Ilp4 is not clear.Gonad-stimulating substance (GSS) induces oocyte maturation and ovulation in vitro in ovarian fragments and triggers spawning behaviour and gamete release in vivo []. GSS probably mediates these effects through binding to a G protein-coupled receptor located in follicle cell membranes [, , ]. Upon receptor binding, GSS stimulates GTP-dependent adenylyl cyclase activity in follicle cell membranes of fully grown stage V ovaries, but not in younger stage IV ovaries, resulting in cAMP production [, ]. This in turn stimulates production of the maturation-inducing hormone 1-methyladenine specifically in stage V ovaries [, , ]. The absence of activity in stage IV ovaries is likely attributable to very low expression levels of the G protein alpha s subunit, which is not highly expressed in follicle cells until stage V []. |
