May play a role in regulated exocytosis (PubMed:10383386). In neuronal cells, modulates the localization of synaptophysin/SYP into synaptic-like microvesicles and may therefore play a role in the formation and/or the maturation of this vesicles (PubMed:12928441, PubMed:15590695). May also play a role in GLUT4 storage and transport to the plasma membrane (PubMed:26071524). Localizes to cytoplasmic vesicles associated with the recycling endosomes. Ubiquitously expressed with lower expression in brain (at protein level). May be tyrosine phosphorylated by Src. Belongs to the synaptogyrin family. Extended N-terminus.