RRP20, a component of the 90S preribosome, is required for pre-18S rRNA processing in Saccharomyces cerevisiae.
A strain of Saccharomyces cerevisiae, defective in small subunit ribosomal RNA processing, has a mutation in YOR145c ORF that converts Gly235 to Asp. Yor145c is a nucleolar protein required for cell viability and has been reported recently to be present in 90S pre-ribosomal particles. The Gly235Asp mutation in YOR145c is found in a KH-type RNA-binding domain and causes a marked deficiency in 18S rRNA production. Detailed studies by northern blotting and primer extension analyses show that the mutant strain impairs the early pre-rRNA processing cleavage essentially at sites A1 and A2, leading to accumulation of a 22S dead-end processing product that is found in only a few rRNA processing mutants. Furthermore, U3, U14, snR10 and snR30 snoRNAs, involved in early pre-rRNA cleavages, are not destabilized by the YOR145c mutation. As the protein encoded by YOR145c is found in pre-ribosomal particles and the mutant strain is defective in ribosomal RNA processing, we have renamed it as RRP20.
Molecular Genetics and Evolution Group, Research School of Biological Sciences, The Australian National University, GPO Box 475, Canberra ACT 2601, Australia.
Saengchan
S
Senapin
G Desmond
GD
Clark-Walker
Xin Jie
XJ
Chen
Bertrand
B
Séraphin
Marie-Claire
MC
Daugeron
D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence / Q000235:genetics; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005816:Genetic Complementation Test; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism*; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D012337:RNA, Ribosomal, 18S / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D004271:DNA, Fungal; D009687:Nuclear Proteins; C474861:PNO1 protein, S cerevisiae; D012322:RNA Precursors; D012335:RNA, Ribosomal; D012337:RNA, Ribosomal, 18S; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins