Synthesis and assembly of human small nuclear ribonucleoproteins generated by cell-free translation.
Synthesis and assembly of human small nuclear ribonucleoproteins generated by cell-free translation.
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通过无细胞翻译产生的人类小核核糖核蛋白的合成和组装。
DOI：
10.1073/pnas.80.20.6356
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发表时间：
1983
影响因子：
11.1
通讯作者：
Kunkel,HG
中科院分区：
文献类型：
--
作者：
Fisher,DE;Conner,GE;Reeves,WH;Blobel,G;Kunkel,HG
对人多聚(A)+ RNA进行了细胞外翻译，生成并分析了小核核糖核蛋白（snRNP）颗粒的蛋白质成分。用系统性红斑狼疮患者血清免疫沉淀法鉴定snRNP蛋白。翻译前mRNA的大小分拣表明，这些snBNP蛋白都是由单独的信息编码的。其中一种蛋白（A蛋白，分子量32000）在RNase处理后，无论是从细胞中提取还是在体外生成，都失去了抗原性。免疫沉淀snRNPs的RNase处理以电泳纯形式释放A蛋白。对体外翻译snRNPs的分析显示，通过蔗糖密度梯度沉降测定，存在未组装和组装的颗粒。snRNPs的翻译后组装涉及rna -蛋白结合（如蛋白质抗原性所示）和其他snRNP蛋白的关联，发生在本文采用的体外系统中。此外，未组装snRNP蛋白的存在允许测定Sm和RNP自身免疫血清识别的精确抗原肽。研究发现，Sm血清能够识别8种snRNP蛋白中的每一种，而RNP血清只能识别8种snRNP蛋白中的2种。
Cell-free translation of human poly(A)+ RNA was carried out to generate and analyze the protein constituents of small nuclear ribonucleoprotein (snRNP) particles. The snRNP proteins were identified by immunoprecipitation with sera from patients with systemic lupus erythematosus. Size fractionation of mRNA prior to translation revealed that these snBNP proteins are all encoded by separate messages. One of the proteins (the A protein, molecular weight 32,000) was seen to lose antigenicity upon RNase treatment either when extracted from cells or when generated in vitro. RNase treatment of immunoprecipitated snRNPs released the A protein in an electrophoretically pure form. Analysis of snRNPs translated in vitro revealed the presence of unassembled and assembled particles as determined by sucrose density gradient sedimentation. Post-translational assembly of snRNPs involving both RNA-protein binding (as revealed by A protein antigenicity) and associations of other snRNP proteins occurred in the in vitro system employed here. In addition, the presence of unassembled snRNP proteins permitted the determination of the precise antigen peptides recognized by Sm and RNP autoimmune sera. It was observed that Sm sera are capable of recognizing each of the eight snRNP proteins, whereas RNP sera recognize only two of the eight.