Synaptosomal Associated Protein 91kDa (SNAP91)

The predominant mRNA encodes an 896-amino acid protein with a calculated molecular mass of about 91 kD. The protein does not contain a signal sequence or any extensive hydrophobic regions, but it does have a number of putative phosphorylation sites. The C terminus of Snap91 shares weak similarity with rabbit calpastatin . In mouse brain, Snap91 is a synapse-associated protein. Expression of Snap91 is developmentally regulated in a pattern coincident with active synaptogenesis and synaptic maturation. Biochemical analysis revealed that Snap91 is phosphorylated in vivo and that it is a substrate for Ca(2+)-dependent proteolysis.The deduced full-length protein contains 907 amino acids and shares about 83% identity with the short form of rat clathrin assembly protein Ap180.