Effect of lysine side chain length on histone lysine acetyltransferase catalysis

Giordano Proietti,Jasmin Mecinović,Yali Wang,Giorgio Rainone

doi:10.1038/s41598-020-69510-0

Abstract

Histone lysine acetyltransferase (KAT)-catalyzed acetylation of lysine residues in histone tails plays a key role in regulating gene expression in eukaryotes. Here, we examined the role of lysine side chain length in the catalytic activity of human KATs by incorporating shorter and longer lysine analogs into synthetic histone H3 and H4 peptides. The enzymatic activity of MOF, PCAF and GCN5 acetyltransferases towards histone peptides bearing lysine analogs was evaluated using MALDI-TOF MS assays. Our results demonstrate that human KAT enzymes have an ability to catalyze an efficient acetylation of longer lysine analogs, whereas shorter lysine analogs are not substrates for KATs. Kinetics analyses showed that lysine is a superior KAT substrate to its analogs with altered chain length, implying that lysine has an optimal chain length for KAT-catalyzed acetylation reaction.

Highlights

Which is highly conserved among the GNAT and MYST families, or aspartic acid in the case of p300, to date different catalytic mechanisms have been proposed among KATs20,21
To investigate the role of the length of lysine’s side chain on human KAT catalysis, a panel of histone peptides bearing lysine analogs that differ in the chain length was developed via Fmoc-based Solid-Phase Peptide Synthesis (SPPS) (Fig. 2)
Fmoc-protected lysine analogs containing a modified chain length were incorporated into the key positions of H3 and H4 peptides by SPPS (Fig. 3b,c)

Summary

Introduction

Which is highly conserved among the GNAT and MYST families, or aspartic acid in the case of p300, to date different catalytic mechanisms have been proposed among KATs20,21. Several KAT crystal structures have been determined, only a few examples include ternary complexes with both histone substrates and AcCoA cosubstrate (or CoASH product), contributing to a limited understanding of KATs’ catalytic properties (PDB ID: 2P0W and 1QSN, Fig. 1b,c). Due to their indisputable importance in tuning gene expression, not surprisingly many KATs have been found overexpressed and/or dysregulated in several human pathologies, such as cancer, inflammation, and neurodegenerative disorders[25,26,27,28]. To provide a better insight into the role of lysine side chain on histone acetylation, this study is aimed at understanding of the relevance of lysine side chain length on human KAT catalysis

Objectives

Methods

Results

Conclusion