title: Taspase1 processing alters TFIIA cofactor properties in the regulation of TFIID.
abstract: TFIIA is an important positive regulator of TFIID, the primary promoter recognition factor of the basal RNA polymerase II transcription machinery. TFIIA antagonises negative TFIID regulators such as negative cofactor 2 (NC2), promotes specific binding of the TBP subunit of TFIID to TATA core promoter sequence elements and stimulates the interaction of TBP-associated factors (TAFs) in the TFIID complex with core promoter elements located downstream of TATA, such as the initiator element (INR). Metazoan TFIIA consists of 3 subunits, TFIIAα (35 kDa), β (19 kDa) and γ (12 kDa). TFIIAα and β subunits are encoded by a single gene and result from site-specific cleavage of a 55 kDa TFIIA(α/β) precursor protein by the protease Taspase1. Metazoan cells have been shown to contain variable amounts of TFIIA (55/12 kDa) and Taspase1-processed TFIIA (35/19/12 kDa) depending on cell type, suggesting distinct gene-specific roles of unprocessed and Taspase1-processed TFIIA. How precisely Taspase1 processing affects TFIIA functions is not understood. Here we report that Taspase1 processing alters TFIIA interactions with TFIID and the conformation of TFIID/TFIIA promoter complexes. We further show that Taspase1 processing induces increased sensitivity of TFIID/TFIIA complexes to the repressor NC2, which is counteracted by the presence of an INR core promoter element. Our results provide first evidence that Taspase1 processing affects TFIIA regulation of TFIID and suggest that Taspase1 processing of TFIIA is required to establish INR-selective core promoter activity in the presence of NC2.
authors.affiliation: a Marie Curie Research Institute; The Chart , Oxted , Surrey , United Kingdom.
authors.forename: Barbora
authors.initials: B
authors.lastname: Malecová
authors.forename: Valentina S
authors.initials: VS
authors.lastname: Caputo
authors.forename: Diane F
authors.initials: DF
authors.lastname: Lee
authors.forename: James J
authors.initials: JJ
authors.lastname: Hsieh
authors.forename: Thomas
authors.initials: T
authors.lastname: Oelgeschläger
mesh_terms: D004268:DNA-Binding Proteins / Q000235:genetics; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D010750:Phosphoproteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D021122:Protein Subunits / Q000235:genetics; D012319:RNA Polymerase II / Q000235:genetics; D016385:TATA Box / Q000235:genetics; D035381:TATA-Binding Protein Associated Factors / Q000235:genetics; D035561:Transcription Factor TFIIA / Q000096:biosynthesis* / Q000235:genetics; D035362:Transcription Factor TFIID / Q000096:biosynthesis* / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; D010750:Phosphoproteins; D021122:Protein Subunits; D035381:TATA-Binding Protein Associated Factors; D035561:Transcription Factor TFIIA; D035362:Transcription Factor TFIID; D014157:Transcription Factors; C075995:down-regulator of transcription 1; D012319:RNA Polymerase II; D010450:Endopeptidases; C480823:taspase1, human
keywords: CPE, core promoter element; INR, initiator core promoter element; NC2; NC2, negative cofactor 2; RNA polymerase II transcription; RNAP II, RNA polymerase II; TBP, TATA-binding protein; TFII (TFIIA, -D), general transcription factor for RNA polymerase II; TFIIA; TFIID; TFIID promoter binding; TFIID regulation; Taspase1; core promoter