The regulatory role for the ERCC3 helicase of general transcription factor TFIIH during promoter escape in transcriptional activation.
Eukaryotic transcriptional activators have been proposed to function, for the most part, by promoting the assembly of preinitiation complex through the recruitment of the RNA polymerase II transcriptional machinery to the promoter. Previous studies have shown that transcriptional activation is critically dependent on transcription factor IIH (TFIIH), which functions during promoter opening and promoter escape, the steps following preinitiation complex assembly. Here we have analyzed the role of TFIIH in transcriptional activation and show that the excision repair cross-complementing (ERCC) 3 helicase activity of TFIIH plays a regulatory role to stimulate promoter escape in activated transcription. The stimulatory effect of the ERCC3 helicase is observed until approximately 10-nt RNA is synthesized, and the helicase seems to act throughout the entire course of promoter escape. Analyses of the early phase of transcription show that a majority of the initiated complexes abort transcription and fail to escape the promoter; however, the proportion of productive complexes that escape the promoter apparently increases in response to activation. Our results establish that promoter escape is an important regulatory step stimulated by the ERCC3 helicase activity in response to activation and reveal a possible mechanism of transcriptional synergy.
Fukuda
Aya
A
Department of Molecular Biology, Saitama Medical School, 38 Morohongo, Moroyama, Iruma-gun, Saitama 350-0495, Japan.
Nogi
Yasuhisa
Y
Hisatake
Koji
K
D000409:Alanine; D019943:Amino Acid Substitution; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism*; D029721:Drosophila Proteins; D005656:Fungal Proteins / Q000378:metabolism; D005822:Genetic Vectors; D008239:Lysine; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D016385:TATA Box; D014157:Transcription Factors / Q000378:metabolism; D019474:Transcription Factors, TFIII / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D019474:Transcription Factors, TFIII; C078672:hay protein, Drosophila; D012319:RNA Polymerase II; D008239:Lysine; D000409:Alanine