Slobbe R L, Pluk W, van Venrooij W J, Pruijn G J
Department of Biochemistry, University of Nijmegen, The Netherlands.
J Mol Biol. 1992 Sep 20;227(2):361-6. doi: 10.1016/0022-2836(92)90890-v.
The human Y RNAs, small RNAs with an unknown function, are complexed with at least three proteins: the 60,000 M(r) Ro protein (Ro60), the 52,000 M(r) Ro protein (Ro52) and the La protein (La). In this study we examined the intermolecular interactions between the components of these so-called Ro ribonucleoprotein (Ro RNP) complexes. Incubation of 32P-labelled hY1 RNA in HeLa S100 extract allows the reconstitution of Ro RNP complexes, which were analysed by immunoprecipitation with monospecific antisera. By immunodepletion of HeLa S100 extracts for either Ro60, Ro52 or La, followed by supplementation with recombinant Ro60 or La, it was demonstrated that both Ro60 and La bind to hY1 RNA directly without being influenced by one of the other proteins. However, binding of Ro52 to hY1 RNA required the presence of Ro60, which strongly suggests that the association of Ro52 with Ro RNPs is mediated by protein-protein interactions between Ro60 and Ro52.
人类Y RNA是一类功能未知的小RNA，它与至少三种蛋白质形成复合物：60,000 M(r)的Ro蛋白（Ro60）、52,000 M(r)的Ro蛋白（Ro52）和La蛋白（La）。在本研究中，我们检测了这些所谓的Ro核糖核蛋白（Ro RNP）复合物各组分之间的分子间相互作用。在HeLa S100提取物中孵育32P标记的hY1 RNA可实现Ro RNP复合物的重组，通过用单特异性抗血清进行免疫沉淀来分析这些复合物。通过对HeLa S100提取物进行Ro60、Ro52或La的免疫去除，然后补充重组Ro60或La，结果表明Ro60和La均直接结合hY1 RNA，且不受其他蛋白质的影响。然而，Ro52与hY1 RNA的结合需要Ro60的存在，这强烈表明Ro52与Ro RNP的结合是由Ro60和Ro52之间的蛋白质-蛋白质相互作用介导的。
