Synaptotagmin Like Protein 4 (SYTL4)

SYTL4 encodes a member of the synaptotagmin like protein family. Members of this family are characterized by an N-terminal Rab27 binding domain and C-terminal tandem C2 domains. The encoded protein binds specific small Rab GTPases and is involved in intracellular membrane trafficking. This protein binds Rab27 and may be involved in inhibiting dense core vesicle exocytosis. Alternate splicing results in multiple transcript variants that encode the same protein.The granuphilin cDNA encodes 2 isoforms: granuphilin-a and granuphilin-b. The former is a deduced 673-amino acid protein with a zinc finger motif at the N terminus, 2 C2 domains at the C terminus, and a glutamate stretch between them; the latter is a deduced 502-amino acid protein that has only the first C2 domain and a different C-terminal sequence.