Perin M S
Division of Neuroscience, Baylor College of Medicine, Houston, Texas 77030.
J Biol Chem. 1994 Mar 18;269(11):8576-81.
The interaction of the synaptic vesicle protein, synaptotagmin, and the presynaptic alpha-latrotoxin receptor, a neurexin, has been proposed to be involved in docking of synaptic vesicles at active sites or modulation of neurotransmitter release. Here I report the investigation of the domain of synaptotagmin responsible for this interaction. Pieces of synaptotagmin containing the carboxyl terminus are capable of purifying neurexins from solubilized brain homogenates. Pieces as small as a synthesized peptide corresponding to the COOH-terminal 34 amino acids are capable of enriching neurexins 100-fold. The binding of neurexins to synaptotagmin is calcium-independent and of moderate affinity. This COOH-terminal segment of synaptotagmin is conserved in all species characterized to date. Reflective of this, a synthetic peptide corresponding to the carboxyl terminus of Drosophila synaptotagmin is capable of purification of rat neurexins, suggesting the possibility that this interaction may also exist in Drosophila. I propose that the carboxyl terminus of synaptotagmin binds to the carboxyl terminus of the neurexins and that this interaction may mediate docking of synaptic vesicles or modulation of neurotransmitter release.
突触小泡蛋白（突触结合蛋白）与突触前α- latrotoxin受体（一种神经连接蛋白）的相互作用被认为参与了突触小泡在活性位点的对接或神经递质释放的调节。在此，我报告了对负责这种相互作用的突触结合蛋白结构域的研究。含有羧基末端的突触结合蛋白片段能够从溶解的脑匀浆中纯化神经连接蛋白。小至对应于COOH末端34个氨基酸的合成肽片段能够使神经连接蛋白富集100倍。神经连接蛋白与突触结合蛋白的结合不依赖于钙且具有中等亲和力。突触结合蛋白的这个COOH末端片段在迄今所研究的所有物种中都是保守的。与此相应的是，对应于果蝇突触结合蛋白羧基末端的合成肽能够纯化大鼠神经连接蛋白，这表明这种相互作用也可能存在于果蝇中。我提出突触结合蛋白的羧基末端与神经连接蛋白的羧基末端结合，并且这种相互作用可能介导突触小泡的对接或神经递质释放的调节。
