- VAMP-2 and cellubrevin are expressed in pancreatic beta-cells and are essential for Ca(2+)-but not for GTP gamma S-induced insulin secretion. Regazzi, R., Wollheim, C.B., Lang, J., Theler, J.M., Rossetto, O., Montecucco, C., Sadoul, K., Weller, U., Palmer, M., Thorens, B. EMBO J. (1995)