HUMAN CDNA CLONES ENCODING 2 DIFFERENT ISOFORMS OF THE NERVE-TERMINALPROTEIN SNAP-25

Two distinct cDNA sequences, corresponding to alternative isoforms of the human nerve terminal protein SNAP-25 (synaptosomal associated prot ein of 25 kDa), were cloned and characterized. Sequence analysis demon strated that the two isoforms are generated by alternative splicing be tween two distinct but homologous exons 5, a and b, each encoding 39 a mino acids (aa). Although the two isoforms, SNAP-25a and SNAP-25b, dif fer by only 9 aa, this domain encodes the portion of the protein that is a substrate for post-translational fatty acylation, and therefore m ight be important for regulating subcellular localization and membrane targeting.