title: CtBP represses p300-mediated transcriptional activation by direct association with its bromodomain.
abstract: Histone acetyltransferase coactivators bind to acetylated histones through their bromodomains and catalyze the acetylation of histone H3 and H4 tails for transcriptional activation. C-terminal binding protein (CtBP) serves as a transcriptional corepressor by recruiting histone deacetylases. However, the precise mechanism by which CtBP represses transcription has not been determined. In this study we found that CtBP1 directly associates with p300 by binding to the PXDLS motif in the bromodomain of p300. Moreover, CtBP1 blocks the accessibility of p300 to histones in an NADH-sensitive manner and thus represses p300-mediated histone acetylation and transcriptional activation. In addition, an NADH-nonresponsive, monomeric mutant, CtBP1 (G183V), was found to strongly repress p300-mediated transcriptional activation. Thus, the dissociation of NADH from CtBP1 leads to the repression of p300-driven general transcriptional activity by CtBP1. These results suggest a novel mechanism whereby CtBP1 serves as an energy-sensing repressor of histone acetyltransferase(s) and thus affects general transcription.
authors.affiliation: Department of Biochemistry and Molecular Biology, Cancer Research Institute, Interdisciplinary Program in Genetic Engineering, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea.
authors.forename: Jae-Hwan
authors.initials: JH
authors.lastname: Kim
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Cho
authors.forename: Seong-Tae
authors.initials: ST
authors.lastname: Kim
authors.forename: Hong-Duk
authors.initials: HD
authors.lastname: Youn
mesh_terms: D000123:Acetyltransferases / Q000737:chemistry* / Q000378:metabolism*; D000429:Alcohol Oxidoreductases; D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000378:metabolism*; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051548:Histone Acetyltransferases; D006657:Histones / Q000378:metabolism; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009243:NAD / Q000378:metabolism; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism*; D015533:Transcriptional Activation / Q000235:genetics*; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor
chemical_list: D000123:Acetyltransferases; D000429:Alcohol Oxidoreductases; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D051548:Histone Acetyltransferases; D006657:Histones; D009243:NAD; D010750:Phosphoproteins; D012097:Repressor Proteins; D014157:Transcription Factors; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor; C096794:C-terminal binding protein