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.