Identification of a Ras palmitoyltransferase in Saccharomyces cerevisiae
Identification of a Ras palmitoyltransferase in Saccharomyces cerevisiae
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DOI：
10.1074/jbc.m206573200
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发表时间：
2002-10-25
影响因子：
4.8
通讯作者：
Deschenes, RJ
中科院分区：
文献类型：
--
作者：
Lobo, S;Greentree, WK;Deschenes, RJ
大多数Ras蛋白通过硫酯键被棕榈酰脂质部分后修饰。然而，这种情况发生的机制尚不清楚。在这里，有证据表明，Ras2蛋白的酿酒酵母是棕榈酰化的Ras蛋白酰基转移酶（Ras PAT）编码的ERF2和ERF4基因。Erf2p是一种位于内质网膜上的41-kDa蛋白，含有一个保守的DHHC富含半胱氨酸结构域（DHHC-CRD）。Erf2p在酵母或大肠杆菌中表达时与Erf4p（26 kDa）共纯化。Erf2p/Erf4p复合物是Ras PAT活性所需的，并且Erf2p DHHC-CRD结构域的保守残基（Cys（189）、His（201）和Cys（203））内的突变消除Ras PAT活性。此外，棕榈酰-Erf2p中间体被检测到，这表明Erf2p直接参与棕榈酸酯转移。ERF2和ERF4是第一个被鉴定的编码Ras GT3棕榈酰转移酶的基因。
Most Ras proteins are posttranslationally modified by a palmitoyl lipid moiety through a thioester linkage. However, the mechanism by which this occurs is not known. Here, evidence is presented that the Ras2 protein of Saccharomyces cerevisiae is palmitoylated by a Ras protein acyltransferase (Ras PAT) encoded by the ERF2 and ERF4 genes. Erf2p is a 41-kDa protein localized to the membrane of the endoplasmic reticulum and contains a conserved DHHC cysteine-rich domain (DHHC-CRD). Erf2p co-purifies with Erf4p (26 kDa) when it is expressed in yeast or in Escherichia coli. The Erf2p/Erf4p complex is required for Ras PAT activity, and mutations within conserved residues (Cys(189), His(201) and Cys(203)) of the Erf2p DHHC-CRD domain abolish Ras PAT activity. Furthermore, a palmitoyl-Erf2p intermediate is detected suggesting that Erf2p is directly involved in palmitate transfer. ERF2 and ERF4 are the first genes identified that encode a palmitoyltransferase for a Ras GTPase.