Binding of an N-ethylmaleimide-sensitive fusion protein to Golgi membranes requires both a soluble protein(s) and an integral membrane receptor.
Binding of an N-ethylmaleimide-sensitive fusion protein to Golgi membranes requires both a soluble protein(s) and an integral membrane receptor.
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DOI：
10.1083/jcb.108.5.1589
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发表时间：
1989-05
期刊：
影响因子：
--
通讯作者：
Rothman JE
中科院分区：
文献类型：
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作者：
Weidman PJ;Melançon P;Block MR;Rothman JE
一种n -乙基马来酰亚胺（NEM）敏感融合蛋白（NSF）最近被纯化，其基础是它能够在无细胞运输系统中恢复向NEM失活的高尔基膜的运输。NSF是转运囊泡融合所需的外周膜蛋白。我们现在报告了两种新成分的存在，它们以一种饱和的方式将NSF结合到高尔基膜上。这些成分是通过检测纯化的NSF与高尔基膜在体外重新结合的要求来检测的。一个组分是一个整体的膜受体，它是热敏的，但耐Na2CO3提取和所有蛋白酶测试。第二种成分是对蛋白酶和热都敏感的细胞质因子。这种可溶性NSF附着蛋白（SNAP）对NEM有很大的抗性，并通过色谱进一步与NSF区分开来。SNAP似乎在促进NSF和膜受体之间的高亲和力相互作用中起化学计量作用。由于NSF促进囊泡融合，这两个允许NSF与膜结合的新因子似乎也可能是融合机制的一部分。
An N-ethylmaleimide (NEM)-sensitive fusion protein (NSF) has recently been purified on the basis of its ability to restore transport to NEM- inactivated Golgi membranes in a cell-free transport system. NSF is a peripheral membrane protein required for the fusion of transport vesicles. We now report the existence of two novel components that together bind NSF to Golgi membranes in a saturable manner. These components were detected by examining the requirements for reassociation of purified NSF with Golgi membranes in vitro. One component is an integral membrane receptor that is heat sensitive, but resistant to Na2CO3 extraction and to all proteases tested. The second component is a cytosolic factor that is sensitive to both proteases and heat. This soluble NSF attachment protein (SNAP) is largely resistant to NEM and is further distinguished from NSF by chromatography. SNAP appears to act stoichiometrically in promoting a high-affinity interaction between NSF and the membrane receptor. Because NSF promotes vesicle fusion, it seems likely that these two new factors that allow NSF to bind to the membrane are also part of the fusion machinery.