Mitotic phosphorylation of the TBP-containing factor SL1 represses ribosomal gene transcription.
Entry into mitosis is accompanied by a global repression of transcription. To investigate the molecular mechanisms which shut-down rRNA synthesis during mitosis, we have compared RNA polymerase I (Pol I) transcription in extracts from asynchronous and mitotic HeLa cells. We show by several experimental approaches that phosphorylation by cdc2/cyclin B inactivates the TBP-containing factor SL1 and thus abrogates Pol I transcription during mitosis. This finding links the cell's cycle with the transcriptional activity of Pol I and suggests a common mechanism for mitotic silencing of all three classes of nuclear RNA polymerases, i.e. reversible inactivation of the respective TBP-TAF complexes by (a) mitotic kinase(s).
Kuhn
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German Cancer Research Center, Heidelberg, D-69120, Germany.
Vente
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Dorée
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Grummt
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D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D018797:Cell Cycle Proteins; D002457:Cell Extracts; D019926:Cyclin B / Q000187:drug effects / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000494:pharmacology; D006367:HeLa Cells / Q000187:drug effects; D006801:Humans; D051379:Mice; D008938:Mitosis; D015739:Nocodazole / Q000494:pharmacology; D019319:Okadaic Acid / Q000494:pharmacology; D010766:Phosphorylation; D035463:Pol1 Transcription Initiation Complex Proteins; D012318:RNA Polymerase I / Q000235:genetics / Q000378:metabolism; D012335:RNA, Ribosomal / Q000187:drug effects / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins; D013936:Thymidine / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic
D018797:Cell Cycle Proteins; D002457:Cell Extracts; D019926:Cyclin B; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D035463:Pol1 Transcription Initiation Complex Proteins; D012335:RNA, Ribosomal; D012097:Repressor Proteins; D029702:Schizosaccharomyces pombe Proteins; C051655:Suc1 protein, S pombe; D014157:Transcription Factors; C063660:transcription initiation factor TIF-IB; D019319:Okadaic Acid; C001020:N(6),N(6)-dimethyladenine; D012318:RNA Polymerase I; D000225:Adenine; D015739:Nocodazole; D013936:Thymidine