Formation and nuclear export of tRNA, rRNA and mRNA is regulated by the ubiquitin ligase Rsp5p.
The yeast ubiquitin-protein ligase Rsp5p regulates processes as diverse as polII transcription and endocytosis. Here, we identify Rsp5p in a screen for tRNA export (tex) mutants. The tex23-1/rsp5-3 mutant, which is complemented by RSP5, not only shows a strong nuclear accumulation of tRNAs at the restrictive temperature, but also is severely impaired in the nuclear export of mRNAs and 60S pre-ribosomal subunits. In contrast, nuclear localization sequence (NLS)-mediated nuclear protein import is unaffected in this mutant. Strikingly, the nuclear RNA export defects seen in the rsp5-3 strain are accompanied by a dramatic inhibition of both rRNA and tRNA processing, a combination of phenotypes that has not been reported for any previously characterized mutation in yeast. These data implicate ubiquitination as a mechanism coordinating the major nuclear RNA biogenesis pathways.
Neumann
Silvia
S
Biochemie-Zentrum Heidelberg, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
Petfalski
Elisabeth
E
Brügger
Britta
B
Grosshans
Helge
H
Wieland
Felix
F
Tollervey
David
D
Hurt
Ed
E
D056827:Endosomal Sorting Complexes Required for Transport; D005089:Exocytosis; D006824:Hybridization, Genetic; D008055:Lipids / Q000032:analysis / Q000096:biosynthesis; D008854:Microscopy, Electron; D009154:Mutation; D010641:Phenotype; D010957:Plasmids; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism*; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000737:chemistry / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors; D043743:Ubiquitin-Protein Ligase Complexes / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D015003:Yeasts / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure
D056827:Endosomal Sorting Complexes Required for Transport; D008055:Lipids; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D012343:RNA, Transfer; D043743:Ubiquitin-Protein Ligase Complexes; D012319:RNA Polymerase II; C469287:RSP5 protein, S cerevisiae