MAQ1 and 7SK RNA interact with CDK9/cyclin T complexes in a transcription-dependent manner.

Détails

ID Serval
serval:BIB_5F83D8C4ABBF
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
MAQ1 and 7SK RNA interact with CDK9/cyclin T complexes in a transcription-dependent manner.
Périodique
Molecular and Cellular Biology
Auteur(s)
Michels A.A., Nguyen V.T., Fraldi A., Labas V., Edwards M., Bonnet F., Lania L., Bensaude O.
ISSN
0270-7306
Statut éditorial
Publié
Date de publication
2003
Peer-reviewed
Oui
Volume
23
Numéro
14
Pages
4859-4869
Langue
anglais
Résumé
Positive transcription elongation factor b (P-TEFb) comprises a cyclin (T1 or T2) and a kinase, cyclin-dependent kinase 9 (CDK9), which phosphorylates the carboxyl-terminal domain of RNA polymerase II. P-TEFb is essential for transcriptional elongation in human cells. A highly specific interaction among cyclin T1, the viral protein Tat, and the transactivation response (TAR) element RNA determines the productive transcription of the human immunodeficiency virus genome. In growing HeLa cells, half of P-TEFb is kinase inactive and binds to the 7SK small nuclear RNA. We now report on a novel protein termed MAQ1 (for ménage à quatre) that is also present in this complex. Since 7SK RNA is required for MAQ1 to associate with P-TEFb, a structural role for 7SK RNA is proposed. Inhibition of transcription results in the release of both MAQ1 and 7SK RNA from P-TEFb. Thus, MAQ1 cooperates with 7SK RNA to form a novel type of CDK inhibitor. According to yeast two-hybrid analysis and immunoprecipitations from extracts of transfected cells, MAQ1 binds directly to the N-terminal cyclin homology region of cyclins T1 and T2. Since Tat also binds to this cyclin T1 N-terminal domain and since the association between 7SK RNA/MAQ1 and P-TEFb competes with the binding of Tat to cyclin T1, we speculate that the TAR RNA/Tat lentivirus system has evolved to subvert the cellular 7SK RNA/MAQ1 system.
Mots-clé
Amino Acid Sequence, Base Sequence, Cell Nucleus/genetics, Cell Nucleus/metabolism, Cyclin-Dependent Kinase 9, Cyclin-Dependent Kinases/genetics, Cyclin-Dependent Kinases/metabolism, Cyclins/genetics, Cyclins/metabolism, Gene Products, tat/genetics, Gene Products, tat/metabolism, HIV Long Terminal Repeat/physiology, Hela Cells, Humans, Macromolecular Substances, Molecular Sequence Data, Positive Transcriptional Elongation Factor B, Protein Subunits/metabolism, Protein-Serine-Threonine Kinases/genetics, Protein-Serine-Threonine Kinases/metabolism, RNA, Small Nuclear/metabolism, RNA-Binding Proteins/genetics, RNA-Binding Proteins/metabolism, Sequence Homology, Amino Acid, Transcription, Genetic, Transfection, Two-Hybrid System Techniques
Pubmed
Web of science
Open Access
Oui
Création de la notice
28/07/2008 16:03
Dernière modification de la notice
20/08/2019 14:17
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