p53 Negatively Regulates cdc2 Transcription via the CCAAT-binding NF-Y Transcription Factor

• Published in: The Journal of biological chemistry 1999-10, Vol.274 (42), p.29677-29682
• Main Authors: Yun, Jeanho, Chae, Hee-Don, Choy, Hyon E., Chung, Jongkyeong, Yoo, Hyang-Sook, Han, Moon-Hi, Shin, Deug Y.
• Format: Article
• Language: English
• Subjects: Base Sequence; CCAAT-Enhancer-Binding Proteins; cdc2 gene; CDC2 Protein Kinase - genetics; Cell Line; DNA Primers; DNA-Binding Proteins - metabolism; Gene Expression Regulation, Enzymologic; p53 gene; Promoter Regions, Genetic; Transcription Factors - metabolism; Transcription, Genetic; Tumor Suppressor Protein p53 - physiology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.274.42.29677

The p53 tumor suppressor protein regulates the transcription of regulatory genes involved in cell cycle arrest and apoptosis. We have reported previously that inducible expression of the p53 gene leads to the cell cycle arrest both at G1and G2/M in association with induction of p21 and reduction of mitotic cyclins (cyclin A and B) and cdc2 mRNA. In this study, we investigated the mechanism by which p53 regulates transcription of the cdc2 gene. Transient transfection analysis showed that wild type p53 represses whereas various dominant negative mutants of p53 increase cdc2 transcription. Thecdc2 promoter activity is not repressed in cells transfected with a transactivation mutant, p5322/23. An adenovirus oncoprotein, E1B-55K inhibits the p53-mediated repression of the cdc2 promoter, while E1B-19K does not. Since thecdc2 promoter does not contain a TATA sequence, we performed deletion and point mutation analyses and identified the inverted CCAAT sequence located at −76 as a cis-acting element for the p53-mediated regulation. We found that a specific DNA-protein complex is formed at the CCAAT sequence and that this complex contains the NF-Y transcription factor. Consistently, a dominant negative mutant of the NF-YA subunit, NF-YAm29, decreases the cdc2 promoter, and p53 does not further decrease the promoter activity in the presence of NF-YAm29. These results suggest that p53 negatively regulatescdc2 transcription and that the NF-Y transcription factor is required for the p53-mediated regulation.