This gene encodes an integral membrane protein of small synaptic vesicles in brain and endocrine cells. The protein also binds cholesterol and is thought to direct targeting of vesicle-associated membrane protein 2 (synaptobrevin) to intracellular compartments. Mutations in this gene are associated with X-linked mental retardation (XLMR). [provided by RefSeq, Aug 2011],
Function:
Domain:The calcium-binding activity is thought to be localized in the cytoplasmic tail of the protein.,Function:Possibly involved in structural functions as organizing other membrane components or in targeting the vesicles to the plasma membrane.,online information:Synaptophysin entry,PTM:Ubiquitinated; mediated by SIAH1 or SIAH2 and leading to its subsequent proteasomal degradation.,similarity:Belongs to the synaptophysin/synaptobrevin family.,similarity:Contains 1 MARVEL domain.,subunit:Homohexamer or homotetramer.,tissue specificity:Characteristic of a type of small (30-80 nm) neurosecretory vesicles, including presynaptic vesicles, but also vesicles of various neuroendocrine cells of both neuronal and epithelial phenotype.,