title: p53 requires an intact C-terminal domain for DNA binding and transactivation.
abstract: The tumor suppressor p53 plays a critical role in mediating cellular response to a wide range of environmental stresses. p53 regulates these processes mainly by acting as a short-lived DNA binding protein that stimulates transcription from numerous genes involved in cell cycle arrest, programmed cell death, and other processes. To investigate the importance of the C-terminal domain of p53, we generated a series of deletion and point mutations in this region and analyzed their effects on p53 transcription activity. Our results show that C-terminal deletion and point mutations at K320 and K382 abolish p53-mediated transcription in the context of DNA or chromatin. This defect is specific for DNA molecules because inactive mutants fail to bind a consensus p53 response element in both free DNA and nucleosomes. Chromatin immunoprecipitation assays further substantiate the importance of the p53 C-terminal domain for the targeted localization of p53 and the concomitant recruitment of p300 onto p53-responsive genes. Moreover, a synthetic peptide comprising the last 30 amino acids of p53 interacts with the N-terminal and C-terminal domains of p53 and antagonizes p53-dependent transcription. Taken together, our data reveal a functional requirement for the p53 C-terminal domain in p53 transactivation and support a working model in which the C-terminus serves as a positive regulator for N-terminal activation and central DNA binding domains.
authors.affiliation: Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90033, USA.
authors.forename: Hyunjung
authors.initials: H
authors.lastname: Kim
authors.forename: Kyunghwan
authors.initials: K
authors.lastname: Kim
authors.forename: Jongkyu
authors.initials: J
authors.lastname: Choi
authors.forename: Kyu
authors.initials: K
authors.lastname: Heo
authors.forename: Hwa Jin
authors.initials: HJ
authors.lastname: Baek
authors.forename: Robert G
authors.initials: RG
authors.lastname: Roeder
authors.forename: Woojin
authors.initials: W
authors.lastname: An
mesh_terms: D000595:Amino Acid Sequence; D002843:Chromatin / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D017353:Gene Deletion; D006801:Humans; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000235:genetics; D017354:Point Mutation; D017434:Protein Structure, Tertiary; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D002843:Chromatin; D009842:Oligopeptides; D016159:Tumor Suppressor Protein p53; D004247:DNA