Interaction between cyclin T1 and SCF(SKP2) targets CDK9 for ubiquitination and degradation by the proteasome.
Mol Cell Biol
; 21(23): 7956-70, 2001 Dec.
Article
em En
| MEDLINE
| ID: mdl-11689688
ABSTRACT
CDK9 paired with cyclin T1 forms the human P-TEFb complex and stimulates productive transcription through phosphorylation of the RNA polymerase II C-terminal domain. Here we report that CDK9 is ubiquitinated and degraded by the proteasome whereas cyclin T1 is stable. SCF(SKP2) was recruited to CDK9/cyclin T1 via cyclin T1 in an interaction requiring its PEST domain. CDK9 ubiquitination was modulated by cyclin T1 and p45(SKP2). CDK9 accumulated in p45(SKP2-/-) cells, and its expression during the cell cycle was periodic. The transcriptional activity of CDK9/cyclin T1 on the class II major histocompatibility complex promoter could be regulated by CDK9 degradation in vivo. We propose a novel mechanism whereby recruitment of SCF(SKP2) is mediated by cyclin T1 while ubiquitination occurs exclusively on CDK9.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cisteína Endopeptidases
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Ubiquitinas
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Ciclinas
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Quinases Ciclina-Dependentes
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Complexos Ubiquitina-Proteína Ligase
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Ligases
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Complexos Multienzimáticos
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2001
Tipo de documento:
Article