A PROTEIN COMPLEX REQUIRED FOR SIGNAL-SEQUENCE-SPECIFIC SORTING AND TRANSLOCATION
A PROTEIN COMPLEX REQUIRED FOR SIGNAL-SEQUENCE-SPECIFIC SORTING AND TRANSLOCATION
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DOI：
10.1038/370434a0
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发表时间：
1994-08-11
期刊：
影响因子：
64.8
通讯作者：
WIEDMANN, M
中科院分区：
文献类型：
--
作者：
WIEDMANN, B;SAKAI, H;WIEDMANN, M
我们已经提纯了一种新生多肽相关复合体(NAC)，它可以防止核糖体相关的新生短肽与细胞质中的蛋白质发生不适当的相互作用。NAC结合核糖体中新生的多肽结构域，除非信号肽完全暴露。携带新生多肽的核糖体中胞浆蛋白(包括NAC)的耗尽允许信号识别颗粒(SRP)与多肽交联，而无论它们是否含有信号肽。在没有胞浆的情况下，缺乏信号肽的蛋白质在体外可以被错误地移位到内质网中，尽管效率很低。NAC的再诊断恢复了SRP的特异性和易位的保真性。
We have purified a nascent-polypeptide-associated complex (NAC) which prevents short ribosome-associated nascent polypeptides from inappropriate interactions with proteins in the cytosol. NAC binds nascent-polypeptide domains emerging from ribosomes unless a signal peptide is fully exposed. Depletion of cytosolic proteins (including NAC) from ribosomes carrying nascent polypeptides allows the signal recognition particle (SRP) to crosslink to polypeptides irrespective of whether or not they contain signal peptides. In the absence of cytosol, proteins lacking signal peptides can be mistranslocated into the endoplasmic reticulum in vitro, albeit with low efficiency. Readdition of NAC restores the specificity of SRP and fidelity of translocation.