Casein kinase II regulation of yeast TFIIIB is mediated by the TATA-binding protein.
The highly conserved protein kinase casein kinase II (CKII) is required for efficient Pol III transcription of the tRNA and 5S rRNA genes in Saccharomyces cerevisiae. Using purified factors from wild-type cells to complement transcription extracts from a conditional lethal mutant of CKII we show that TFIIIB is the CKII-responsive component of the Pol III transcription machinery. Dephosphorylation of TFIIIB eliminated its ability to complement CKII-depleted extract, and a single TFIIIB subunit, the TATA-binding protein (TBP), is a preferred substrate of CKII in vitro. Recombinant TBP purified from Escherichia coli is phosphorylated efficiently by CKII and, in the presence of a limiting amount of CKII, is able to substantially rescue transcription in CKII-deficient extract. Our results establish that TBP is a key component of the pathway linking CKII activity and Pol III transcription and suggest that TBP is the target of a CKII-mediated regulatory mechanism that can modulate Pol III transcription.
Ghavidel
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Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7.
Schultz
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MC
D047390:Casein Kinase II; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D004258:DNA Polymerase III / Q000302:isolation & purification / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli; D007700:Kinetics; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012331:RNA, Fungal / Q000096:biosynthesis; D012341:RNA, Ribosomal, 5S / Q000096:biosynthesis; D012343:RNA, Transfer / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D016385:TATA Box; D035181:TATA-Box Binding Protein; D035581:Transcription Factor TFIIB; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism*; D019474:Transcription Factors, TFIII; D014158:Transcription, Genetic; D014638:Vanadates / Q000494:pharmacology; D000098832:Transcription Factor TFIIIC
D004268:DNA-Binding Proteins; D012331:RNA, Fungal; D012341:RNA, Ribosomal, 5S; D011994:Recombinant Proteins; D035181:TATA-Box Binding Protein; D035581:Transcription Factor TFIIB; D014157:Transcription Factors; D019474:Transcription Factors, TFIII; D000098832:Transcription Factor TFIIIC; D014638:Vanadates; D012343:RNA, Transfer; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D004258:DNA Polymerase III