Inhibition of lysine acetyltransferase KAT3B/p300 activity by a naturally occurring hydroxynaphthoquinone, plumbagin.
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.
Ravindra
Kodihalli C
KC
Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
Selvi
B Ruthrotha
BR
Arif
Mohammed
M
Reddy
B A Ashok
BA
Thanuja
Gali R
GR
Agrawal
Shipra
S
Pradhan
Suman Kalyan
SK
Nagashayana
Natesh
N
Dasgupta
Dipak
D
Kundu
Tapas K
TK
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
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