title: Rapid proteasomal degradation of transcription factor IIB in accordance with F9 cell differentiation.
abstract: We found that the levels of all general transcription factors (GTFs) for RNA polymerase II decreased in F9 cells when the cells were subjected to a differentiation procedure. Different from other GTFs, decrease of TFIIB during the differentiation was suppressed by addition of a proteasome inhibitor, MG132. The half-life of TFIIB in the differentiated cells was remarkably reduced compared with that in the undifferentiated cells. Moreover, it was demonstrated that TFIIB is a poly-ubiquitinated protein. Results of this study suggest that components of the transcription machinery decreased in accordance with cell differentiation and that TFIIB is specifically and rapidly degraded by the ubiquitin-proteasome pathway.
authors.affiliation: Department of Biology, Graduate School of Science, Chiba University, Chiba, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Shiraishi
authors.forename: Naomi
authors.initials: N
authors.lastname: Tamamura
authors.forename: Misako
authors.initials: M
authors.lastname: Jogo
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Taka-aki
authors.initials: TA
authors.lastname: Tamura
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019556:COS Cells; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D047468:Immunoprecipitation; D007976:Leupeptins / Q000494:pharmacology; D051379:Mice; D025821:Polyubiquitin / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D061988:Proteasome Inhibitors; D013997:Time Factors; D035581:Transcription Factor TFIIB / Q000235:genetics / Q000378:metabolism*; D035165:Transcription Factors, General / Q000378:metabolism; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology; D054875:Ubiquitination
chemical_list: D015853:Cysteine Proteinase Inhibitors; D007976:Leupeptins; D061988:Proteasome Inhibitors; D035581:Transcription Factor TFIIB; D035165:Transcription Factors, General; D025821:Polyubiquitin; D014212:Tretinoin; D046988:Proteasome Endopeptidase Complex; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde