Stolc V, Katz A, Altman S
Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA.
Proc Natl Acad Sci U S A. 1998 Jun 9;95(12):6716-21. doi: 10.1073/pnas.95.12.6716.
RPP2, an essential gene that encodes a 15.8-kDa protein subunit of nuclear RNase P, has been identified in the genome of Saccharomyces cerevisiae. Rpp2 was detected by sequence similarity with a human protein, Rpp20, which copurifies with human RNase P. Epitope-tagged Rpp2 can be found in association with both RNase P and RNase mitochondrial RNA processing in immunoprecipitates from crude extracts of cells. Depletion of Rpp2 protein in vivo causes accumulation of precursor tRNAs with unprocessed introns and 5' and 3' termini, and leads to defects in the processing of the 35S precursor rRNA. Rpp2-depleted cells are defective in processing of the 5.8S rRNA. Rpp2 immunoprecipitates cleave both yeast precursor tRNAs and precursor rRNAs accurately at the expected sites and contain the Rpp1 protein orthologue of the human scleroderma autoimmune antigen, Rpp30. These results demonstrate that Rpp2 is a protein subunit of nuclear RNase P that is functionally conserved in eukaryotes from yeast to humans.
RPP2是一种必需基因，它编码核核糖核酸酶P的一个15.8 kDa的蛋白质亚基，已在酿酒酵母基因组中被鉴定出来。通过与一种人类蛋白质Rpp20的序列相似性检测到了Rpp2，Rpp20与人类核糖核酸酶P共纯化。在细胞粗提物的免疫沉淀中，可发现表位标记的Rpp2与核糖核酸酶P和核糖核酸酶线粒体RNA加工相关联。体内Rpp2蛋白的缺失会导致具有未加工内含子以及5'和3'末端的前体tRNA积累，并导致35S前体rRNA加工缺陷。Rpp2缺失的细胞在5.8S rRNA加工方面存在缺陷。Rpp2免疫沉淀在预期位点准确切割酵母前体tRNA和前体rRNA，并且含有人类硬皮病自身免疫抗原Rpp30的Rpp1蛋白直系同源物。这些结果表明，Rpp2是核核糖核酸酶P的一个蛋白质亚基，在从酵母到人类的真核生物中功能保守。
