title: Inhibition of lysine acetyltransferase KAT3B/p300 activity by a naturally occurring hydroxynaphthoquinone, plumbagin.
abstract: Lysine acetyltransferases (KATs), p300 (KAT3B), and its close homologue CREB-binding protein (KAT3A) are probably the most widely studied KATs with well documented roles in various cellular processes. Hence, the dysfunction of p300 may result in the dysregulation of gene expression leading to the manifestation of many disorders. The acetyltransferase activity of p300/CREB-binding protein is therefore considered as a target for new generation therapeutics. We describe here a natural compound, plumbagin (RTK1), isolated from Plumbago rosea root extract, that inhibits histone acetyltransferase activity potently in vivo. Interestingly, RTK1 specifically inhibits the p300-mediated acetylation of p53 but not the acetylation by another acetyltransferase, p300/CREB-binding protein -associated factor, PCAF, in vivo. RTK1 inhibits p300 histone acetyltransferase activity in a noncompetitive manner. Docking studies and site-directed mutagenesis of the p300 histone acetyltransferase domain suggest that a single hydroxyl group of RTK1 makes a hydrogen bond with the lysine 1358 residue of this domain. In agreement with this, we found that indeed the hydroxyl group-substituted plumbagin derivatives lost the acetyltransferase inhibitory activity. This study describes for the first time the chemical entity (hydroxyl group) required for the inhibition of acetyltransferase activity.
authors: Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
authors: Kodihalli C
authors: KC
authors: Ravindra
authors: B Ruthrotha
authors: BR
authors: Selvi
authors: Mohammed
authors: M
authors: Arif
authors: B A Ashok
authors: BA
authors: Reddy
authors: Gali R
authors: GR
authors: Thanuja
authors: Shipra
authors: S
authors: Agrawal
authors: Suman Kalyan
authors: SK
authors: Pradhan
authors: Natesh
authors: N
authors: Nagashayana
authors: Dipak
authors: D
authors: Dasgupta
authors: Tapas K
authors: TK
authors: Kundu
mesh_terms: D000107:Acetylation; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology; D045744:Cell Line, Tumor; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D006801:Humans; D008297:Male; D051379:Mice; D016297:Mutagenesis, Site-Directed; D009285:Naphthoquinones / Q000737:chemistry* / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry*; D029606:Plumbaginaceae / Q000737:chemistry*; D017434:Protein Structure, Tertiary / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D050880:p300-CBP Transcription Factors / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000099224:p300-CBP-Associated Factor
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004791:Enzyme Inhibitors; D009285:Naphthoquinones; D016159:Tumor Suppressor Protein p53; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor; C495901:TP53 protein, human; C014758:plumbagin