synaptotagmin-like mitochondrial-lipid-binding protein (SMP) domain found in extended synaptotagmin-2 (E-Syt2) and similar proteins
Extended synaptotagmin-2 (E-Syt2), also called Chr2Syt, tethers the endoplasmic reticulum to the cell membrane and promotes the formation of appositions between the endoplasmic reticulum and the cell membrane. It binds glycerophospholipids in a barrel-like domain and may play a role in cellular lipid transport. E-Syt2 plays a role in fibroblast growth factor (FGF) signaling via its role in the rapid internalization of FGFreceptor 1 (FGFR1) that has been activated by FGF1 binding; this occurs most likely via the AP-2 complex. E-Syt2 consists of an N-terminal endoplasmic reticulum (ER)-membrane anchor, a central SMP-domain, and three C-terminal cytoplasmic C2-domains. The ER-membrane anchor and C2 domains are required for tethering, and the SMP domain may be implicated in lipid transport. This model corresponds to SMP domain.