In response to DNA damage, p53 activates G(1)/S blocking and apoptotic genes through sequence-specific binding. p53 also represses genes with no target site, such as those for Cdc2 and cyclin B, key regulators of the G(2)/M transition. Like most G2/M promoters, they rely on multiple CCAAT boxes activated by NF-Y, whose binding to DNA is temporally regulated during the cell cycle. NF-Y associates with p53 in vitro and in vivo through the alpha C helix of NF-YC (a subunit of NF-Y) and a region close to the tetramerization domain of p53. Chromatin immunoprecipitation experiments indicated that p53 is associated with cyclin B2, CDC25C, and Cdc2 promoters in vivo before and after DNA damage, requiring DNA-bound NF-Y. Following DNA damage, p53 is rapidly acetylated at K320 and K373 to K382, histories are deacetylated, and the release of PCAF and p300 correlates with the recruitment of histone deacetylases (HDACs)-HDAC1 before HDAC4 and HDAC5 and promoter repression. HDAC recruitment requires intact NF-Y binding sites. In transfection assays, PCAF represses cyclin B2, and a nonacetylated p53 mutant shows a complete loss of repression potential, despite its abilities to bind NF-Y and to be recruited on G(2)/M promoters. These data (i) detail a strategy of direct p53 repression through associations with multiple NF-Y trimers that is independent of sequence-specific binding of p53 and that requires C-terminal acetylation, (ii) suggest that p53 is a DNA damage sentinel of the G(2)/M transition, anti (iii) delineate a new role for PCAF in cell cycle control.
|Titolo:||Direct p53 transcriptional repression : in vivo analysis of CCAAT-containing G2/M promoters|
MANTOVANI, ROBERTO (Ultimo)
|Parole Chiave:||DNA binding ; DNA damage ; acetylation ; amino acid sequence ; article ; binding site ; carboxy terminal sequence ; cell cycle G2 phase ; chromatin ; controlled study ; correlation analysis ; deacetylation ; gene function ; gene repression ; gene sequence ; genetic transfection ; human cell ; human ; immunoprecipitation ; in vitro study ; in vivo study ; priority journal ; promoter region ; protein binding ; protein domain; protein function; protein protein interaction ; protein secretion ; transcription regulation ; CCAAT enhancer binding protein ; cell DNA ; cell cycle protein Cdc25C ; cell cycle protein cdc2 ; cell cycle protein ; cyclin B2 ; histone acetyltransferase PCAF ; histone deacetylase 1 ; histone deacetylase 4 ; histone deacetylase 5 ; histone deacetylase ; histone ; maturation promoting factor ; mutant protein ; protein p300 ; protein p53 ; unclassified drug|
|Settore Scientifico Disciplinare:||Settore BIO/18 - Genetica|
|Data di pubblicazione:||mag-2005|
|Digital Object Identifier (DOI):||10.1128/MCB.25.9.3737-3751.2005|
|Appare nelle tipologie:||01 - Articolo su periodico|