In vivo characterization of the GPI assembly defect in yeast mcd4-174 mutants and bypass of the Mcd4p-dependent step in mcd4Delta cells.
In vivo characterization of the GPI assembly defect in yeast mcd4-174 mutants and bypass of the Mcd4p-dependent step in mcd4Delta cells.
复制标题
酵母 mcd4-174 突变体中 GPI 组装缺陷的体内表征以及 mcd4Delta 细胞中 Mcd4p 依赖性步骤的绕过。
DOI：
10.1111/j.1567-1364.2006.00139.x
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发表时间：
2007
影响因子：
3.2
通讯作者：
Orlean,Peter
中科院分区：
文献类型：
--
作者：
Wiedman,JillM;Fabre,Anne-Lise;Taron,BarbaraW;Taron,ChristopherH;Orlean,Peter
酵母mcd 4 - 174突变体在蛋白质的糖基磷脂酰肌醇（GPI）锚定中被阻断，但在体内GPI生物合成被阻断的阶段尚未确定，并且Mcd 4p还涉及磷脂酰丝氨酸和ATP转运。我们报告说，主要的GPI积累inmcd 4 -174在体内是Man 2-GlcN-（酰基-Ins）PI，一致的建议，Mcd 4p添加磷酸乙醇胺的第一个甘露糖酵母GPI前体。在cd 4 -174/gpi 11双突变体和mcd 4 Δ i突变体中，通过高水平表达PIG-BandGPI 10可以部分绕过GPI的Mcd 4 β依赖性修饰，PIG-BandGPI 10分别编码添加GPI前体的第三个甘露糖的人和酵母甘露糖基转移酶。mcd 4 Δ的抢救byGPI 10表明Mcd 4p依赖性地将EthN-P添加到GPI的第一个甘露糖上对于通过GPI 10 p转移第三个甘露糖不是必须的。
Yeastmcd4-174mutants are blocked in glycosylphosphatidylinositol (GPI) anchoring of protein, but the stage at which GPI biosynthesis is interruptedin vivohas not been identified, and Mcd4p has also been implicated in phosphatidylserine and ATP transport. We report that the major GPI that accumulates inmcd4-174 in vivois Man2-GlcN-(acyl-Ins)PI, consistent with proposals that Mcd4p adds phosphoethanolamine to the first mannose of yeast GPI precursors. Mcd4p-dependent modification of GPIs can partially be bypassed in themcd4-174/gpi11double mutant and inmcd4Δ; mutants by high-level expression ofPIG-BandGPI10, which respectively encode the human and yeast mannosyltransferases that add the third mannose of the GPI precursor. Rescue ofmcd4Δ; byGPI10indicates that Mcd4p-dependent addition of EthN-P to the first mannose of GPIs is not obligatory for transfer of the third mannose by Gpi10p.