Ten years of TFIIH
Résumé
A complete molecular description of the transcriptionmachinery is now at hand. The essential transcription factors that allow RNA polymerase II (pol II) to transcribeaccurately from different promoters have been identified,and when these are added together in an in vitro system,transcription occurs. Crucial questions remain as to howregulatory signals are conveyed from adjacent specificDNA sequences and/or external stimuli to the core promoter and the basal transcription machinery. Three basaltranscription factors have been described as potentialcandidates for transcription regulation: TFIID, whichthrough its connection with cell-type- and gene-specificactivators and mediators, selects and regulates theTATA-binding protein (TBP)-associated factors (TAFs)(Hampsey and Reinberg 1997); TFIIB, which stabilizesTBP and is targeted by activators (Roberts et al. 1995),and TFIIH, which possesses several enzymatic activities,which must be regulated. Before investigating howTFIIH could function as a key regulatory point of transcription, it was of interest to analyze TFIIH in the context of the basal transcription apparatus knowing that, besides pol II, it is the only factor with a number ofenzymatic activitie...