Characterization of an alternatively spliced isoform of rat vesicle associated membrane protein-2 (VAMP-2)

VAMPs are vesicle associated membrane proteins that are essential for secretion. A spliced isoform of rat VAMP-2, called VAMP-2B, is characterized in this study, The VAMP-2B transcript is the result of alternative RNA splicing in which an intron is retained. The predicted amino acid sequence of VAMP-2B differs from VAMP-2 at its carboxy-terminal end. Because recent studies have shown that VAMP's carboxy-terminal end influences the protein's sorting, the location of myc-epitope tagged VAMP-2B in PC12 cells was determined. Subcellular fractionation showed colocalization of myc-VAMP-2B and endogenous VAMP-2, Thus alternative RNA splicing does not affect VAMP-2 sorting in PC12 cells. (C) 1999 Federation of European Biochemical Societies.