NCBI Summary:
This gene encodes a member of the syntaxin family. Syntaxins have been implicated in the targeting and fusion of intracellular transport vesicles. This family member may regulate protein transport among late endosomes and the trans-Golgi network. Mutations in this gene have been associated with familial hemophagocytic lymphohistiocytosis. [provided by RefSeq, Jul 2008]
General function
Comment
Cellular localization
Cytoplasmic
Comment
Ovarian function
Oocyte maturation
Comment
Expression regulated by
Comment
Ovarian localization
Oocyte
Comment
Regulation of Gap Junctional Communication Between Cumulus Cells During In Vitro Maturation in Swine, a Gap-FRAP Study. Santiquet NW et al. Intercellular gap junctional communication (GJC) plays an important role in ovarian cell physiology. Closure of GJC has been proposed to be involved in oocyte maturation, particularly in the resumption of meiosis, both in vivo and in vitro, by controlling the flow of meiosis inhibitors such as cAMP and cGMP. Understanding how GJC dynamics are regulated during in vitro maturation (IVM) could provide a powerful tool for controlling meiotic resumption and oocyte maturation in vitro. Since little is known about the GJC dynamic regulation between cumulus cells, we have developed an assay based on recovery of calcein fluorescence in photo-bleached cumulus cells, a gap-FRAP assay (Fluorecence Recovery After Photobleaching). The GJC profile has been characterized during the first hours of porcine IVM. We showed that equine chorionic gonadotropin (eCG) and epidermal growth factor (EGF) down-regulated GJC effectiveness between cumulus cells. However, human chorionic gonadotropin was not down-regulating GJC effectiveness. We also showed that the GJC network expanded during this period and that this effect was not regulated by gonadotropins. Porcine follicular fluid present in the maturation medium also had an impact on GJC regulation, increasing GJC network establishment and the effectiveness of calcein transfer rate between cumulus cells. These results show that both eCG and EGF are regulating the decrease in GJC effectiveness after 4.5 h of IVM while the network extension is gonadotropin-independent. Regulation of GJC between cumulus cells would then be specifically regulated during in vitro maturation.