In eukaryotic cells, vesicle docking is thought to be regulated in part by the specific interactions of a vesicle-associated
membrane protein (VAMP), or synaptobrevin, with the presynaptic plasma membrane proteins syntaxin and
SNAP25. The presynaptic plasma membrane protein
plays an important role in the synaptic vesicle membrane docking and fusion pathway.
NCBI Summary:
This gene encodes a member of the syntaxin or t-SNARE (target-SNAP receptor) family. These proteins are found on cell membranes and serve as the targets for v-SNAREs (vesicle-SNAP receptors), permitting specific synaptic vesicle docking and fusion. The encoded protein regulates endoplasmic reticulum to Golgi transport and plays a critical role in autophagy. Autoantibodies targeting the encoded protein may be a diagnostic marker for endometriosis. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Sep 2011]
General function
Comment
Cellular localization
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Ovarian function
Steroid metabolism, Oogenesis
Comment
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Schulze KL et al reported that Drosophila syntaxin is required for cell viability and may function in membrane formation and stabilization. In the ovary, SYX is present in the germarium,
but it is predominantly localized to nurse cell membranes. Mitotic recombination experiments in the
germline show SYX is essential for oogenesis and may participate in membrane biogenesis in the
nurse cells.
Expression regulated by
Comment
Ovarian localization
Granulosa
Comment
SNARE-mediated cholesterol movement to mitochondria supports steroidogenesis in rodent cells. Lin Y et al. (2016) Vesicular transport involving SNARE proteins is known to be responsible for many major cellular activities. In steroidogenic tissues, chronic hormone stimulation results in increased expression of proteins involved in the steroidogenic pathway, whereas acute hormone stimulation prompts the rapid transfer of cholesterol to the inner mitochondrial membrane to be utilized as substrate for steroid hormone production. Several different pathways are involved in supplying cholesterol to mitochondria, but mobilization of stored cholesteryl esters appears to initially constitute the preferred source; however, the mechanisms mediating this cholesterol transfer are not fully understood. In order to study the potential contribution of SNARE proteins in steroidogenesis, we examined the expression levels of various SNARE proteins in response to hormone stimulation in steroidogenic tissues and cells and established an in vitro mitochondria reconstitution assay system to assess the contribution of various SNARE proteins on cholesterol delivery for steroidogenesis. Our results from reconstitution experiments along with knockdown studies in rat primary granulosa cells and in a Leydig cell line show that NSFα, SNAP25, syntaxin-5 and syntaxin-17 facilitate the transport of cholesterol to mitochondria. Thus, although StAR is required for efficient cholesterol movement into mitochondria for steroidogenesis, specific SNAREs participate and are necessary to mediate cholesterol movement to mitochondria.//////////////////