title: A novel mutation lacking the bromodomain of the transcriptional coactivator p300 in the SiHa cervical carcinoma cell line.
abstract: The transcriptional coactivator p300, a histone acetyltransferase (HAT), plays key roles in the regulation of cell proliferation and differentiation. p300 is targeted by viral oncoproteins, and mutations of p300, accompanied by inactivation of the second allele, have been reported in certain types of cancers originating in the epithelium. Here, we identified a homozygous p300 deletion of exons 15--18 in the SiHa cervical carcinoma cell line, which results in an in-frame deletion that causes specific loss of the bromodomain, a conserved domain implicated in the regulation of HAT activity. Furthermore, we show that the mutation severely impaired its ability to activate the p21(WAF1/CIP1) promoter in transient reporter assay. These results suggest a critical role for the bromodomain in p300 functions as a tumor-suppressor gene.
authors.affiliation: Department of Oral Microbiology, Tsurumi University, School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ohshima
authors.forename: T
authors.initials: T
authors.lastname: Suganuma
authors.forename: M
authors.initials: M
authors.lastname: Ikeda
mesh_terms: D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D002460:Cell Line; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006367:HeLa Cells; D006801:Humans; D020014:K562 Cells; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017384:Sequence Deletion; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014407:Tumor Cells, Cultured; D020298:U937 Cells; D002583:Uterine Cervical Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D018076:DNA, Complementary; D009687:Nuclear Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D008156:Luciferases