The Ccr4-not complex and yTAF1 (yTaf(II)130p/yTaf(II)145p) show physical and functional interactions.
The Saccharomyces cerevisiae Ccr4-Not complex is a global regulator of transcription that is thought to regulate TATA binding protein (TBP) function at certain promoters specifically. In this paper, we show interactions between the essential domain of Not1p, which interacts with Not4p and Not5p, and the N-terminal domain of yTAF1. We isolated a temperature-sensitive nonsense allele of TAF1, taf1-4, which is synthetically lethal at the permissive temperature when combined with not4 and not5 mutants and which produces high levels of a C-terminally truncated yTAF1 derivative. Overexpression of C-terminally truncated yTAF1 is toxic in not4 or not5 mutants, whereas overexpression of full-length yTAF1 suppresses not4. Furthermore, mutations in the autoinhibitory N-terminal TAND domain of yTAF1 suppress not5, and the overexpression of similar mutants does not suppress not4. We find that, like Not5p, yTAF1 acts as a repressor of stress response element-dependent transcription. Finally, we have evidence for stress-regulated occupancy of promoter DNA by Not5p and for Not5p-dependent regulation of yTAF1 association with promoter DNA. Taken together with our finding that Not1p copurifies with glutathione S-transferase-yTaf1 in large complexes, these results provide the first molecular evidence that the Ccr4-Not complex might interact with yTAF1 to regulate its association at promoters, a function that might in turn regulate the autoinhibitory N-terminal domain of yTAF1.
Deluen
Cécile
C
Département de Biochimie Médicale, CMU, 1211 Geneva 4, Switzerland.
James
Nicole
N
Maillet
Laurent
L
Molinete
Miguel
M
Theiler
Grégory
G
Lemaire
Marc
M
Paquet
Nicole
N
Collart
Martine A
MA
D018797:Cell Cycle Proteins / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal / Q000502:physiology; D046911:Macromolecular Substances; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D035381:TATA-Binding Protein Associated Factors; D013696:Temperature; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019473:Transcription Factors, TFII / Q000737:chemistry / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases
C079592:CDC39 protein, S cerevisiae; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D046911:Macromolecular Substances; C111175:NOT5 protein, S cerevisiae; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; C106785:TAF1 protein, S cerevisiae; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D019473:Transcription Factors, TFII; C086923:MOT2 protein, S cerevisiae; D044767:Ubiquitin-Protein Ligases; C078657:CCR4 protein, S cerevisiae; D012260:Ribonucleases