FYVE-related domain found in Slp homolog lacking C2 domains c (SlaC2-c) and similar proteins
SlaC2-c, also termed Rab effector MyRIP, or exophilin-8, or myosin-VIIa- and Rab-interacting protein, or synaptotagmin-like protein lacking C2 domains c, is a GTP-bound form of Rab27A-, myosin Va/VIIa-, and actin-binding protein mainly present on retinal melanosomes and secretory granules. It may play a role in insulin granule exocytosis. It is also involved in the control of isoproterenol (IPR)-induced amylase release from parotid acinar cells. SlaC2-c belongs to the Slp homolog lacking C2 domains (Slac2) family. It contains an N-terminal Slp homology domain (SHD), but lacks tandem C2 domains. The SHD consists of two conserved regions, designated SHD1 (Slp homology domain 1) and SHD2, which may function as protein interaction sites. The SHD1 and SHD2 of SlaC2-c are separated by a putative FYVE zinc finger, which resembles a FYVE-related domain that is structurally similar to the canonical FYVE domains but lacks the three signature sequences: an N-terminal WxxD motif (x for any residue), the central basic R(R/K)HHCRxCG patch, and a C-terminal RVC motif. Moreover, Slac2-c has a middle myosin-binding domain and a C-terminal actin-binding domain.