Molecular Identification of Two Novel Munc-18 Isoforms Expressed in Non-neuronal Tissues (*)
Molecular Identification of Two Novel Munc-18 Isoforms Expressed in Non-neuronal Tissues (*)
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非神经元组织中表达的两种新型 Munc-18 亚型的分子鉴定 (*)
DOI：
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发表时间：
1995
影响因子：
4.8
通讯作者：
D. James
中科院分区：
文献类型：
--
作者：
J. Tellam;S. McIntosh;D. James
Munc-18，也称为n-Sec 1或rbSec 1，是一种突触融合蛋白结合蛋白，被认为在调节突触囊泡胞吐中起作用。虽然已经鉴定了一个突触融合蛋白基因家族，但只有有限的子集与Munc-18结合。这意味着存在其他哺乳动物的Munc-18同系物，可能参与了一系列的囊泡运输反应。本研究的目的是通过cDNA克隆鉴定Munc-18家族的其他成员。从3 T3-L1脂肪细胞cDNA文库中分离出3种不同的Munc-18亚型，Munc-18 a，和2种新的亚型，Munc-18 b和Munc-18 c。Munc-18 a与Munc-18相同，并且通过北方分析，主要在大脑中表达，在睾丸和3 T3-L1细胞中表达程度较小。Munc-18 b在氨基酸水平上与Munc-18有62%的相同性，并且在睾丸、肠、肾、大鼠脂肪组织和3 T3-L1细胞中表达。Munc-18 c与Munc-18有51%的相同性，并且普遍表达。很可能，基于这些发现，独特的Munc-18/syntaxin相互作用可能发挥重要作用，在哺乳动物细胞中产生一个组合的机制，调节囊泡运输。
Munc-18, also known as n-Sec1 or rbSec1, is a syntaxin-binding protein thought to play a role in regulating synaptic vesicle exocytosis. Although a gene family of syntaxins has been identified, only a limited subset bind to Munc-18. This implicates the existence of other mammalian Munc-18 homologues that may be involved in a range of vesicle transport reactions. The purpose of the present study was to identify other members of the Munc-18 family by cDNA cloning. Three distinct Munc-18 isoforms, Munc-18a, previously identified in neuronal tissue, and two novel isoforms, Munc-18b and Munc-18c, were isolated from a 3T3-L1 adipocyte cDNA library by screening with a rat brain Munc-18 DNA probe. Munc-18a is identical to Munc-18 and by Northern analysis is expressed predominantly in brain and to a lesser extent in testis and 3T3-L1 cells. Munc-18b is 62% identical to Munc-18 at the amino acid level and is expressed in testis, intestine, kidney, rat adipose tissue, and 3T3-L1 cells. Munc-18c is 51% identical to Munc-18 and is ubiquitously expressed. It is likely, based on these findings, that unique Munc-18/syntaxin interactions may play an important role in generating a combinatorial mechanism for the regulation of vesicle transport in mammalian cells.
DOI：
10.1073/pnas.91.6.2003
发表时间：
1994-03-15
影响因子：
11.1
作者：
GARCIA, EP;GATTI, E;DECAMILLI, P
通讯作者：
DECAMILLI, P