Differences in Specificity and Selectivity Between CBP and p300 Acetylation of Histone H3 and H3/H4

Citations Over TimeTop 10% of 2013 papers

Abstract

Although p300 and CBP lysine acetyltransferases are often treated interchangeably, the inability of one enzyme to compensate for the loss of the other suggests unique roles for each. As these deficiencies coincide with aberrant levels of histone acetylation, we hypothesized that the key difference between p300 and CBP activity is differences in their specificity/selectivity for lysines within the histones. Utilizing a label-free, quantitative mass spectrometry based technique, we determined the kinetic parameters of both CBP and p300 at each lysine of H3 and H4, under conditions we would expect to encounter in the cell (either limiting acetyl-CoA or histone). Our results show that while p300 and CBP acetylate many common residues on H3 and H4, they do in fact possess very different specificities, and these specificities are dependent on whether histone or acetyl-CoA is limiting. Steady-state experiments with limiting H3 demonstrate that both CBP and p300 acetylate H3K14, H3K18, H3K23, with p300 having specificities up to 10¹⁰-fold higher than CBP. Utilizing tetramer as a substrate, both enzymes also acetylate H4K5, H4K8, H4K12, and H4K16. With limiting tetramer, CBP displays higher specificities, especially at H3K18, where CBP specificity is 10³²-fold higher than p300. With limiting acetyl-CoA, p300 has the highest specificity at H4K16, where specificity is 10¹⁸-fold higher than CBP. This discovery of unique specificity for targets of CBP- vs p300-mediated acetylation of histone lysine residues presents a new model for understanding their respective biological roles and possibly an opportunity for selective therapeutic intervention.

Related Papers

• → Expression analysis of histone acetyltransferases in rice under drought stress(2013)126 cited
• → Quantitating the Specificity and Selectivity of Gcn5-Mediated Acetylation of Histone H3(2013)111 cited
• → Relationship between lunasin's sequence and its inhibitory activity of histones H3 and H4 acetylation(2011)65 cited
• → Identification of lysine K18 acetylation on histone H3 peptide using gold nanoparticles’ aggregation behaviour(2015)2 cited
• → Inhibition of different histone acetyltransferases (HATs) uncovers transcription-dependent and -independent acetylation-mediated mechanisms in memory formation(2016)25 cited