title: Dynamic recruitment of NF-Y and histone acetyltransferases on cell-cycle promoters.
abstract: Regulation of transcription during the cell-cycle is under the control of E2 factors (E2Fs), often in cooperation with nuclear factor Y (NF-Y), a histone-like CCAAT-binding trimer. NF-Y is paradigmatic of a constitutive, ubiquitous factor that pre-sets the promoter architecture for other regulatory proteins to access it. We analyzed the recruitment of NF-Y, E2F1/4/6, histone acetyltransferases, and histone deacetylase (HDAC) 1/3/4 to several cell-cycle promoters by chromatin immunoprecipitation assays in serum-starved and restimulated NIH3T3 cells. NF-Y binding is not constitutive but timely regulated in all promoters tested, being displaced when promoters are repressed. p300 association correlates with activation, and it is never found in the absence of NF-Y, whereas PCAF/hGCN5 is often found before NF-Y association. E2F4 and E2F6, together with HDACs, are bound to repressed promoters, including the G2/M Cyclin B2. As expected, an inverse relationship between HDACs association and histones H3/H4 acetylation is observed. Blocking cells in G1 with the cyclin-dependent kinase 2 inhibitor R-roscovitine confirms that NF-Y is bound to G1/S but not to G2/M promoters in G1. These data indicate that following the release of E2Fs/HDACs, a hierarchy of PCAF-NF-Y-p300 interactions and H3-H4 acetylations are required for activation of cell-cycle promoters.
authors.affiliation: Dipartimento di Biologia Animale, Università di Modena e Reggio, Via Campi 213/d, 41100 Modena, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Caretti
authors.forename: Valentina
authors.initials: V
authors.lastname: Salsi
authors.forename: Chiara
authors.initials: C
authors.lastname: Vecchi
authors.forename: Carol
authors.initials: C
authors.lastname: Imbriano
authors.forename: Roberto
authors.initials: R
authors.lastname: Mantovani
mesh_terms: D016475:3T3 Cells; D000123:Acetyltransferases / Q000378:metabolism*; D000818:Animals; D023081:CCAAT-Binding Factor / Q000378:metabolism*; D002467:Cell Nucleus / Q000201:enzymology; D004268:DNA-Binding Proteins / Q000378:metabolism; D050704:E2F4 Transcription Factor; D050701:E2F6 Transcription Factor; D016193:G1 Phase / Q000502:physiology*; D016195:G2 Phase / Q000502:physiology; D051548:Histone Acetyltransferases; D006657:Histones / Q000378:metabolism; D051379:Mice; D008938:Mitosis / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000502:physiology*; D011485:Protein Binding / Q000502:physiology; D016196:S Phase / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D023081:CCAAT-Binding Factor; D004268:DNA-Binding Proteins; D050704:E2F4 Transcription Factor; D050701:E2F6 Transcription Factor; C111236:E2f6 protein, mouse; D006657:Histones; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000123:Acetyltransferases; D051548:Histone Acetyltransferases