Inhibition of CBF/NF-Y mediated transcription activation arrests cells at G2/M phase and suppresses expression of genes activated at G2/M phase of the cell cycle.
Previous studies showed that binding of the CBF/NF-Y (CBF) transcription factor to cellular promoters is essential for cell proliferation. This observation prompted us to investigate the function of CBF in relation to cell cycle progression and in cell-cycle-regulated transcription. In this study, we used a tetracycline-inducible adenoviral vector to express a truncated CBF-B subunit, Bdbd, lacking a transcription activation domain in various mammalian cell lines. The Bdbd polypeptide interacts with cellular CBF-A/CBF-C and binds to promoters containing CBF-binding sites. Interestingly, expression of Bdbd in various mammalian cells resulted in the inhibition of cell proliferation and specific cell cycle arrest at G2/M phase. Gene expression analysis demonstrated that the expression of Bdbd strongly suppressed cell cycle-dependent transcription activation of Cyclin B1, Aurora A and CDK1 genes, key regulators for cell cycle progression at G2/M phase. Chromatin immunoprecipitation analysis showed that Bdbd significantly inhibited binding of TATA-binding protein, TBP to both Cyclin B1 and Aurora A promoters, but did not inhibit binding of E2F3 activator to Cyclin B1 promoter. This study suggested that the activation domain of CBF-B plays an essential role in the transcription activation of Cyclin B1 and Aurora A genes at G2/M phase, thus regulating cell cycle progression at G2/M phase.
Hu
Qianghua
Q
Department of Molecular Genetics, The University of Texas M. D. Anderson Cancer center, Houston, TX 77030, USA.
Lu
Jing-Fang
JF
Luo
Rong
R
Sen
Subrata
S
Maity
Sankar N
SN
D000256:Adenoviridae / Q000235:genetics; D064127:Aurora Kinases; D023081:CCAAT-Binding Factor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000235:genetics*; D019926:Cyclin B / Q000235:genetics*; D056744:Cyclin B1; D016195:G2 Phase / Q000235:genetics*; D005822:Genetic Vectors; D006367:HeLa Cells; D006801:Humans; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D017434:Protein Structure, Tertiary; D017384:Sequence Deletion; D035181:TATA-Box Binding Protein / Q000378:metabolism; D013752:Tetracycline / Q000494:pharmacology; D015533:Transcriptional Activation
D023081:CCAAT-Binding Factor; C534699:CCNB1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; D035181:TATA-Box Binding Protein; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D013752:Tetracycline