PROTEIN TRANSLOCATION ACROSS THE ENDOPLASMIC-RETICULUM .2. ISOLATION AND CHARACTERIZATION OF THE SIGNAL RECOGNITION PARTICLE RECEPTOR
PROTEIN TRANSLOCATION ACROSS THE ENDOPLASMIC-RETICULUM .2. ISOLATION AND CHARACTERIZATION OF THE SIGNAL RECOGNITION PARTICLE RECEPTOR
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DOI：
10.1083/jcb.95.2.470
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发表时间：
1982-01-01
影响因子：
7.8
通讯作者：
BLOBEL, G
中科院分区：
文献类型：
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作者：
GILMORE, R;WALTER, P;BLOBEL, G
信号识别粒子(SRP)介导的新生分泌蛋白合成的延长停滞可以被盐抽提的粗微粒体膜(Walter，P.和G.Blobel)释放。用非离子洗涤剂Nikkol和250 mM KOAc[醋酸钾]从粗大的微粒体膜上溶解抑制释放活性和信号肽活性。该提取物经SRP-Sepharose柱层析分离出抑制释放活性和信号肽活性。用蔗糖梯度离心法进一步纯化停滞释放活性，从而鉴定出72,000道尔顿多肽是负责该活性的蛋白质。根据其与SRP的亲和力，72,000道尔顿蛋白被称为SRP受体。一个60,000道尔顿的蛋白片段(Meyer，D.I.和B.Dobberstein)先前已被证明重建了蛋白酶消化膜的转位活性，这里通过肽图和来自SRP受体的免疫学标准证明了这一点。与本文和前一篇论文中报道的结果部分相似，部分不同的发现是独立完成的(Meyer，D.I.，E.Krause和B.Dobberstein)，术语对接蛋白被建议用于SRP受体。SRP和SRP受体的膜含量都低于膜结合的核糖体，这表明SRP-SRP受体相互作用可能在核糖体-膜连接形成和转位过程中短暂存在。
The signal recognition particle (SRP)-mediated elongation arrest of the synthesis of nascent secretory proteins can be released by salt-extracted rough microsomal membranes (Walter, P. and G. Blobel). Both the arrest-releasing activity and the signal peptidase activity were solubilized from rough microsomal membranes using the nonionic detergent Nikkol in conjunction with 250 mM KOAc [potassium acetate]. Chromatography of this extract on SRP-Sepharose separated the arrest-releasing activity from the signal peptidase activity. Further purification of the arrest-releasing activity using sucrose gradient centrifugation allowed the identification of a 72,000-dalton polypeptide as the protein responsible for the activity. Based upon its affinity for SRP, the 72,000-dalton protein is referred to as the SRP receptor. A 60,000-dalton protein fragment (Meyer, D. I. and B. Dobberstein) that had been shown previously to reconstitute the translocation activity of protease-digested membranes, was shown here by peptide mapping and immunological criteria to be derived from the SRP receptor. Findings in part similar, and in part different from these reported here and in a preceding paper were made independently (Meyer, D. I., E. Krause and B. Dobberstein) and the term docking protein was proposed for the SRP receptor. A lower membrane content of both SRP and the SRP receptor than that of membrane-bound ribosomes suggests that the SRP-SRP receptor interaction may exist transiently during the formation of a ribosome-membrane junction and during translocation.