title: Transcription factor TFIIF is not required for initiation by RNA polymerase II, but it is essential to stabilize transcription factor TFIIB in early elongation complexes.
abstract: Transcription factors TFIIB and TFIIF are both required for RNA polymerase II preinitiation complex (PIC) assembly, but their roles at and downstream of initiation are not clear. We now show that TFIIF phosphorylated by casein kinase 2 remains competent to support PIC assembly but is not stably retained in the PIC. PICs completely lacking TFIIF are not defective in initiation or subsequent promoter clearance, demonstrating that TFIIF is not required for initiation or clearance. Lack of TFIIF in the PIC reduces transcription levels at some promoters, coincident with reduced retention of TFIIB. TFIIB is normally associated with the early elongation complex and is only destabilized at +12 to +13. However, if TFIIF is not retained in the PIC, TFIIB can be lost immediately after initiation. TFIIF therefore has an important role in stabilizing TFIIB within the PIC and after transcription initiates.
authors: Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, NE20, Cleveland, OH 44195, USA.
authors: Pavel
authors: P
authors: Čabart
authors: Andrea
authors: A
authors: Újvári
authors: Mahadeb
authors: M
authors: Pal
authors: Donal S
authors: DS
authors: Luse
mesh_terms: D001483:Base Sequence; D047390:Casein Kinase II / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000235:genetics; D012319:RNA Polymerase II / Q000378:metabolism*; D013698:Templates, Genetic; D035581:Transcription Factor TFIIB / Q000235:genetics / Q000378:metabolism*; D019473:Transcription Factors, TFII / Q000235:genetics / Q000378:metabolism*; D024363:Transcription Initiation Site; D014158:Transcription, Genetic
chemical_list: D035581:Transcription Factor TFIIB; D019473:Transcription Factors, TFII; D047390:Casein Kinase II; D012319:RNA Polymerase II; C056604:transcription factor TFIIF