Distinct regions of MAT1 regulate cdk7 kinase and TFIIH transcription activities.
The transcription/DNA repair factor TFIIH may be resolved into at least two subcomplexes: the core TFIIH and the cdk-activating kinase (CAK) complex. The CAK complex, which is also found free in the cell, is composed of cdk7, cyclin H, and MAT1. In the present work, we found that the C terminus of MAT1 binds to the cdk7 x cyclin H complex and activates the cdk7 kinase activity. The median portion of MAT1, which contains a coiled-coil motif, allows the binding of CAK to the TFIIH core through interactions with both XPD and XPB helicases. Furthermore, using recombinant TFIIH complexes, it is demonstrated that the N-terminal RING finger domain of MAT1 is crucial for transcription activation and participates to the phosphorylation of the C-terminal domain of the largest subunit of the RNA polymerase II.
Busso
D
D
Institut de Genetique et de Biologie Moleculaire et Cellulaire, CNRS/INSERM/Université Louis Pasteur, Boíte Postale 163, 67404 Illkirch Cedex, Communauté Urbaine de Strasbourg, France.
Keriel
A
A
Sandrock
B
B
Poterszman
A
A
Gileadi
O
O
Egly
J M
JM
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D056748:Cyclin H; D018844:Cyclin-Dependent Kinases; D016213:Cyclins / Q000378:metabolism; D004265:DNA Helicases / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018411:Spodoptera; D013379:Substrate Specificity; D051758:Transcription Factor TFIIH; D014157:Transcription Factors / Q000378:metabolism*; D019473:Transcription Factors, TFII; D014158:Transcription, Genetic / Q000502:physiology*; D000095043:Cyclin-Dependent Kinase-Activating Kinase
D056748:Cyclin H; D016213:Cyclins; D011994:Recombinant Proteins; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D051758:Transcription Factor TFIIH; D017346:Protein Serine-Threonine Kinases; D018844:Cyclin-Dependent Kinases; D004265:DNA Helicases; D000095043:Cyclin-Dependent Kinase-Activating Kinase