title: E2F and histone deacetylase mediate transforming growth factor beta repression of cdc25A during keratinocyte cell cycle arrest.
abstract: cdc25A is a tyrosine phosphatase that activates G1 cyclin-dependent kinases (Cdk's). In human keratinocytes, cdc25A expression is down-regulated after the initial drop in Cdk activity caused by cell exposure to the antimitogenic cytokine transforming growth factor beta (TGF-beta) or removal of serum factors. Here we show that the TGF-beta-inhibitory-response element in the cdc25A promoter maps to an E2F site at nucleotides -62 to -55 from the transcription start site. This site is not required for basal transcription in keratinocytes. We provide evidence that the cell cycle arrest program activated by TGF-beta in human keratinocytes includes the generation of E2F4-p130 complexes that in association with histone deacetylase HDAC1 inhibit the activity of the cdc25A promoter from this repressor E2F site. This mechanism is part of a program that places keratinocytes in the quiescent state following the initial drop in Cdk activity caused by cell exposure to TGF-beta.
authors.affiliation: Cell Biology Program and Howard Hughes Medical Institute, Memorial Sloan-Kettering Cancer Center, New York, New York, USA.
authors.forename: A
authors.initials: A
authors.lastname: Iavarone
authors.forename: J
authors.initials: J
authors.lastname: Massagué
mesh_terms: D001483:Base Sequence; D002352:Carrier Proteins; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D002460:Cell Line; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D015536:Down-Regulation / Q000187:drug effects; D050684:E2F Transcription Factors; D050703:E2F2 Transcription Factor; D050704:E2F4 Transcription Factor; D006655:Histone Deacetylases / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D017027:Protein Tyrosine Phosphatases / Q000235:genetics*; D011506:Proteins; D016160:Retinoblastoma Protein / Q000378:metabolism; D056465:Retinoblastoma-Binding Protein 1; D050720:Retinoblastoma-Like Protein p107; D050717:Retinoblastoma-Like Protein p130; D050680:Transcription Factor DP1; D014157:Transcription Factors / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism* / Q000494:pharmacology; D020687:cdc25 Phosphatases
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050703:E2F2 Transcription Factor; D050704:E2F4 Transcription Factor; C493762:E2F4 protein, human; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011506:Proteins; C493837:RBL2 protein, human; D016160:Retinoblastoma Protein; D056465:Retinoblastoma-Binding Protein 1; D050720:Retinoblastoma-Like Protein p107; D050717:Retinoblastoma-Like Protein p130; D050680:Transcription Factor DP1; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; C517004:CDC25A protein, human; D017027:Protein Tyrosine Phosphatases; D020687:cdc25 Phosphatases; D006655:Histone Deacetylases