Bark I C, Hahn K M, Ryabinin A E, Wilson M C
Department of Neuropharmacology, Scripps Research Institute, La Jolla, CA 92037.
Proc Natl Acad Sci U S A. 1995 Feb 28;92(5):1510-4. doi: 10.1073/pnas.92.5.1510.
The presynaptic plasma membrane protein SNAP-25 (synaptosome-associated protein of 25 kDa) has been implicated as one of several neural-specific components that direct constitutive fusion mechanisms to the regulated vesicle trafficking and exocytosis of neurotransmitter release. There exist two alternatively spliced isoforms of SNAP-25, a and b, which differ in a putative membrane-interacting domain. We show that these two isoforms have distinct quantitative and anatomical patterns of expression during brain development, in neurons, and in neuroendocrine cells and that the proteins localize differently in neurites of transfected PC12 pheochromocytoma cells. These findings indicate that alternative isoforms of SNAP-25 may play distinct roles in vesicular fusion events required for membrane addition during axonal outgrowth and for release of neuromodulatory peptides and neurotransmitters.
突触前质膜蛋白SNAP - 25（25 kDa的突触体相关蛋白）被认为是将组成型融合机制导向神经递质释放的调节性囊泡运输和胞吐作用的几种神经特异性成分之一。SNAP - 25存在两种可变剪接异构体，a和b，它们在一个假定的膜相互作用结构域有所不同。我们发现这两种异构体在脑发育过程中、神经元以及神经内分泌细胞中具有不同的表达定量和解剖学模式，并且在转染的PC12嗜铬细胞瘤细胞的神经突中蛋白质定位也不同。这些发现表明，SNAP - 25的可变异构体可能在轴突生长过程中膜添加以及神经调节肽和神经递质释放所需的囊泡融合事件中发挥不同作用。
