title: Multi-protein complexes in eukaryotic gene transcription.
abstract: Specific transcription initiation by RNA polymerase II at eukaryotic protein-coding genes involves the cooperative assembly at the core promoter of more than 40 distinct proteins--with a total mass of over 2 MDa--including RNA polymerase II itself and general/basal transcription initiation factors, to form a stable pre-initiation complex (PIC). In vivo, PIC assembly is a major point of regulation by sequence-specific transcription regulators (activators and repressors) and is hindered by the packaging of promoter DNA into nucleosomes and higher order chromatin structures. Genetic and biochemical studies have recently identified a variety of transcription cofactors/co-regulators (coactivators and corepressors) that interact with sequence-specific regulators and/or various components of the general/basal transcription machinery and are essential for regulated transcription. An emerging view from these studies is that regulators must target two types of transcription cofactors: chromatin-modifying/remodeling cofactors and general cofactors that associate with and/or influence the activities of components of the general/basal transcription machinery. The recent biochemical identification and characterization of many different chromatin-modifying and general transcription cofactors has revealed their often complex multi-subunit nature and a previously unsuspected level of structural and functional redundancy. Another emerging theme is the multi-functional nature of chromatin-modifying cofactor complexes that appear to couple gene-specific transcription to other cellular processes.
authors.affiliation: Department of Biochemistry, University of California, Riverside, CA 92521, USA. ernest.martinez@ucr.edu
authors.forename: Ernest
authors.initials: E
authors.lastname: Martinez
mesh_terms: D000818:Animals; D001665:Binding Sites; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D005057:Eukaryotic Cells / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D008954:Models, Biological; D010944:Plants / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035561:Transcription Factor TFIIA / Q000378:metabolism; D035581:Transcription Factor TFIIB / Q000378:metabolism; D035362:Transcription Factor TFIID / Q000378:metabolism; D051758:Transcription Factor TFIIH; D019473:Transcription Factors, TFII / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*
chemical_list: D029701:Saccharomyces cerevisiae Proteins; C490039:TAF6 protein, S cerevisiae; D035381:TATA-Binding Protein Associated Factors; D035561:Transcription Factor TFIIA; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D019473:Transcription Factors, TFII; C066644:transcription factor TFIIE; D051758:Transcription Factor TFIIH; D012321:DNA-Directed RNA Polymerases