May play a role in regulated exocytosis. 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. May also play a role in GLUT4 storage and transport to the plasma membrane. (Microbial infection) May play a role in the assembly of cytoplasmic inclusion bodies required for SFTS phlebovirus replication. (Microbial infection) Interacts with SFTS phlebovirus protein NSs; may be involved in virus replication. Localizes to cytoplasmic vesicles associated with the recycling endosomes. (Microbial infection) Upon SFTS phlebovirus infection, the protein localizes in lipid droplets and inclusion bodies. Ubiquitous; low expression in brain. (Microbial infection) Up-regulated upon SFTS phlebovirus infection (at protein level). May be tyrosine phosphorylated by Src. Belongs to the synaptogyrin family.