title: The PHD finger of p300 influences its ability to acetylate histone and non-histone targets.
abstract: In enzymes that regulate chromatin structure, the combinatorial occurrence of modules that alter and recognise histone modifications is a recurrent feature. In this study, we explored the functional relationship between the acetyltransferase domain and the adjacent bromodomain/PHD finger (bromo/PHD) region of the transcriptional coactivator p300. We found that the bromo/PHD region of p300 can bind to the acetylated catalytic domain in vitro and augment the catalytic activity of the enzyme. Deletion of the PHD finger, but not the bromodomain, impaired the ability of the enzyme to acetylate histones in vivo, whilst it enhanced p300 self-acetylation. A point mutation in the p300 PHD finger that is related to the Rubinstein-Taybi syndrome resulted in increased self-acetylation but retained the ability to acetylate histones. Hence, the PHD finger appears to negatively regulate self-acetylation. Furthermore, our data suggest that the PHD finger has a role in the recruitment of p300 to chromatin.
authors.affiliation: Department of Molecular Biology, University of Bergen, Postbox 7803, 5020 Bergen, Norway; Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom.
authors.forename: Johannes G M
authors.initials: JGM
authors.lastname: Rack
authors.affiliation: Department of Molecular Biology, University of Bergen, Postbox 7803, 5020 Bergen, Norway.
authors.forename: Timo
authors.initials: T
authors.lastname: Lutter
authors.affiliation: Department of Molecular Biology, University of Bergen, Postbox 7803, 5020 Bergen, Norway; Centre for Applied Biotechnology, Uni Research, Postbox 7810, 5020 Bergen, Norway.
authors.forename: Gro Elin
authors.initials: GE
authors.lastname: Kjæreng Bjerga
authors.affiliation: Department of Molecular Biology, University of Bergen, Postbox 7803, 5020 Bergen, Norway; Faculty of Medicine and Dentistry, University of Bergen, Haukelandsveien 28, 5020 Bergen, Norway.
authors.forename: Corina
authors.initials: C
authors.lastname: Guder
authors.affiliation: Department of Molecular Biology, University of Bergen, Postbox 7803, 5020 Bergen, Norway; Institute of Molecular Biotechnology (IMBA), Dr. Bohr-Gasse 3, 1030 Vienna, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Ehrhardt
authors.affiliation: Department of Molecular Biology, University of Bergen, Postbox 7803, 5020 Bergen, Norway.
authors.forename: Signe
authors.initials: S
authors.lastname: Värv
authors.affiliation: Department of Molecular Biology, University of Bergen, Postbox 7803, 5020 Bergen, Norway.
authors.forename: Mathias
authors.initials: M
authors.lastname: Ziegler
authors.affiliation: Department of Molecular Biology, University of Bergen, Postbox 7803, 5020 Bergen, Norway. Electronic address: aasland@mbi.uib.no.
authors.forename: Rein
authors.initials: R
authors.lastname: Aasland
mesh_terms: D000107:Acetylation; D001665:Binding Sites / Q000235:genetics; D055162:Biocatalysis; D050881:E1A-Associated p300 Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D017354:Point Mutation; D011485:Protein Binding; D017434:Protein Structure, Tertiary
chemical_list: D006657:Histones; D050881:E1A-Associated p300 Protein; C494360:EP300 protein, human
keywords: CBP; RING finger; Rubinstein-Taybi syndrome; acetylation; bromodomain