Binding to medium and long chain fatty acyls is a common property of HEAT and ARM repeat modules

Tie-Mei Li,Or Gozani,Lichao Zhang,John P Coan,Joshua E Elias,Katrin F Chua,Krzysztof Krajewski,Brian D Strahl

doi:10.1038/s41598-019-50817-6

Abstract

Covalent post-translational modification (PTM) of proteins with acyl groups of various carbon chain-lengths regulates diverse biological processes ranging from chromatin dynamics to subcellular localization. While the YEATS domain has been found to be a prominent reader of acetylation and other short acyl modifications, whether additional acyl-lysine reader domains exist, particularly for longer carbon chains, is unclear. Here, we employed a quantitative proteomic approach using various modified peptide baits to identify reader proteins of various acyl modifications. We discovered that proteins harboring HEAT and ARM repeats bind to lysine myristoylated peptides. Recombinant HEAT and ARM repeats bind to myristoylated peptides independent of the peptide sequence or the position of the myristoyl group. Indeed, HEAT and ARM repeats bind directly to medium- and long-chain free fatty acids (MCFA and LCFA). Lipidomic experiments suggest that MCFAs and LCFAs interact with HEAT and ARM repeat proteins in mammalian cells. Finally, treatment of cells with exogenous MCFAs and inhibitors of MCFA-CoA synthases increase the transactivation activity of the ARM repeat protein β-catenin. Taken together, our results suggest an unappreciated role for fatty acids in the regulation of proteins harboring HEAT or ARM repeats.

Highlights

Acyl groups ranging from acetyl to long-chain fatty acyls covalently modify proteins for various biological purposes[1,2]
These results demonstrate that HEAT and ARM repeat proteins bind to mediumand long-chain free fatty acyl moieties
We have identified HEAT and ARM repeats as general in vitro reader domains of medium- and long-chain fatty acyl groups, with the potential that different HEAT and ARM proteins may have distinctive binding profiles

Summary

Introduction

Acyl groups ranging from acetyl to long-chain fatty acyls covalently modify proteins for various biological purposes[1,2]. In addition to lysine acetylation, many structurally diverse acyl modifications have been identified on histones and other proteins[2,5]. Reader domains for short chain acylation such as crotonylation and succinylation have been identified[8,9,10,11]. These studies suggest that analogous to the paradigm of lysine acetylation signaling, reader domain proteins exist for the broader family of acyl modifications. We report the identification of HEAT and ARM repeats as reader domains of medium- and long-chain acylation. Characterization of the interaction suggests that fatty acyl-binding is a common property of diverse HEAT and ARM repeat proteins. We provide functional evidence that β-catenin function, via its ARM-repeats, is impacted by the interaction with fatty acids in cells

Methods

Results

Conclusion