Chemical inhibition of the TFIIH-associated kinase Cdk7/Kin28 does not impair global mRNA synthesis.
The process of gene transcription requires the recruitment of a hypophosphorylated form of RNA polymerase II (Pol II) to a gene promoter. The TFIIH-associated kinase Cdk7/Kin28 hyperphosphorylates the promoter-bound polymerase; this event is thought to play a crucial role in transcription initiation and promoter clearance. Studies using temperature-sensitive mutants of Kin28 have provided the most compelling evidence for an essential role of its kinase activity in global mRNA synthesis. In contrast, using a small molecule inhibitor that specifically inhibits Kin28 in vivo, we find that the kinase activity is not essential for global transcription. Unlike the temperature-sensitive alleles, the small-molecule inhibitor does not perturb protein-protein interactions nor does it provoke the disassociation of TFIIH from gene promoters. These results lead us to conclude that other functions of TFIIH, rather than the kinase activity, are critical for global gene transcription.
Kanin
Elenita I
EI
Department of Biochemistry and Genome Center of Wisconsin, University of Wisconsin, Madison, WI 53706, USA.
Kipp
Ryan T
RT
Kung
Charles
C
Slattery
Matthew
M
Viale
Agnes
A
Hahn
Steven
S
Shokat
Kevan M
KM
Ansari
Aseem Z
AZ
D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000483:Alleles; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects; D005656:Fungal Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D006358:Hot Temperature; D007700:Kinetics; D009154:Mutation; D010749:Phosphoprotein Phosphatases / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D012331:RNA, Fungal / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D051758:Transcription Factor TFIIH / Q000378:metabolism*; D014158:Transcription, Genetic
D018528:ATP-Binding Cassette Transporters; C465210:Act1 protein, S cerevisiae; D000199:Actins; D005656:Fungal Proteins; C092438:PDR5 protein, S cerevisiae; D012331:RNA, Fungal; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D051758:Transcription Factor TFIIH; D018844:Cyclin-Dependent Kinases; C084210:Kin28 protein kinase, S cerevisiae; D010749:Phosphoprotein Phosphatases