Synaptotagmin I-DeltaC2B. A novel synaptotagmin isoform with a single C2 domain in the bovine adrenal medulla.
Synaptotagmin I-DeltaC2B. A novel synaptotagmin isoform with a single C2 domain in the bovine adrenal medulla.
复制标题
突触结合蛋白 I-DeltaC2B。
DOI：
10.1016/s0005-2736(01)00459-x
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Dean,GaryE
中科院分区：
文献类型：
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作者：
Hewitt,EricW;Tao,Jing-Xian;Strasser,JaneE;Cutler,DanielF;Dean,GaryE
Synaptotagmin I是一种65 kDa的1型膜糖蛋白，存在于分泌细胞器中，在调节胞吐中起关键作用。我们已经确定了两种形式（长和短）的突触结合蛋白我是目前在牛肾上腺髓质。长型是一种I型整合膜蛋白，具有两个细胞质C2结构域，对应于之前表征的全长突触结合蛋白I亚型。短型突触结合蛋白I-ΔC2B在内腔和跨膜序列中具有相同的结构，但突触结合蛋白I-ΔC2B被截短，使得其仅具有单个胞质C2结构域。对突触结合蛋白I-ΔC2B表达的分析表明，突触结合蛋白I-ΔC2B优先在牛肾上腺髓质中表达。然而，它是缺乏的致密核心嗜铬颗粒。此外，当在大鼠嗜铬细胞瘤细胞系PC 12中表达时，牛突触结合蛋白I-ΔC2B在致密的核心颗粒和突触样微泡中基本上不存在。相反，间接免疫荧光显微镜显示突触结合蛋白I-ΔC2B的细胞内位置是质膜。
Synaptotagmin I is a 65 kDa type 1 membrane glycoprotein found in secretory organelles that plays a key role in regulated exocytosis. We have characterised two forms (long and short) of synaptotagmin I that are present in the bovine adrenal medulla. The long form is a type I integral membrane protein which has two cytoplasmic C2 domains and corresponds to the previously characterised full-length synaptotagmin I isoform. The short-form synaptotagmin I-ΔC2B has the same structure in the lumenal and transmembrane sequences, but synaptotagmin I-ΔC2B is truncated such that it only has a single cytoplasmic C2 domain. Analysis of synaptotagmin I-ΔC2B expression indicates that synaptotagmin I-ΔC2B is preferentially expressed in the bovine adrenal medulla. However, it is absent from the dense core chromaffin granules. Furthermore, when expressed in the rat pheochromocytoma cell line PC12 bovine synaptotagmin I-ΔC2B is largely absent from dense core granules and synaptic-like microvesicles. Instead, indirect immunofluorescence microscopy reveals the intracellular location of synaptotagmin I-ΔC2B to be the plasma membrane.