Rapid proteasomal degradation of transcription factor IIB in accordance with F9 cell differentiation.
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.
Shiraishi
Seiji
S
Department of Biology, Graduate School of Science, Chiba University, Chiba, Japan.
Tamamura
Naomi
N
Jogo
Misako
M
Tanaka
Yuji
Y
Tamura
Taka-aki
TA
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
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