The yeast TFB1 and SSL1 genes, which encode subunits of transcription factor IIH, are required for nucleotide excision repair and RNA polymerase II transcription.
The essential TFB1 and SSL1 genes of the yeast Saccharomyces cerevisiae encode two subunits of the RNA polymerase II transcription factor TFIIH (factor b). Here we show that extracts of temperature-sensitive mutants carrying mutations in both genes (tfb1-101 and ssl1-1) are defective in nucleotide excision repair (NER) and RNA polymerase II transcription but are proficient for base excision repair. RNA polymerase II-dependent transcription at the CYC1 promoter was normal at permissive temperatures but defective in extracts preincubated at a restrictive temperature. In contrast, defective NER was observed at temperatures that are permissive for growth. Additionally, both mutants manifested increased sensitivity to UV radiation at permissive temperatures. The extent of this sensitivity was not increased in a tfb1-101 strain and was only slightly increased in a ssl1-1 strain at temperatures that are semipermissive for growth. Purified factor TFIIH complemented defective NER in both tfb1-101 and ssl1-1 mutant extracts. These results define TFB1 and SSL1 as bona fide NER genes and indicate that, as is the case with the yeast Rad3 and Ss12 (Rad25) proteins, Tfb1 and Ssl1 are required for both RNA polymerase II basal transcription and NER. Our results also suggest that the repair and transcription functions of Tfb1 and Ssl1 are separable.
Wang
Z
Z
Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75235.
Buratowski
S
S
Svejstrup
J Q
JQ
Feaver
W J
WJ
Wu
X
X
Kornberg
R D
RD
Donahue
T F
TF
Friedberg
E C
EC
D001483:Base Sequence; D004260:DNA Repair / Q000235:genetics*; D004307:Dose-Response Relationship, Radiation; D005656:Fungal Proteins / Q000235:genetics; D005800:Genes, Fungal / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D012319:RNA Polymerase II / Q000378:metabolism*; D011836:Radiation Tolerance / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D029701:Saccharomyces cerevisiae Proteins; D013347:Subcellular Fractions / Q000378:metabolism; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D051758:Transcription Factor TFIIH; D014157:Transcription Factors / Q000235:genetics*; D019473:Transcription Factors, TFII; D014158:Transcription, Genetic; D014466:Ultraviolet Rays
D005656:Fungal Proteins; C083908:SSL1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C490039:TAF6 protein, S cerevisiae; D035381:TATA-Binding Protein Associated Factors; C086993:TFB1 protein, S cerevisiae; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D051758:Transcription Factor TFIIH; D012319:RNA Polymerase II