Fungal Induced Protein Hyperacetylation Identified by Acetylome Profiling

Lysine acetylation is a key post-translational modification that regulates diverse proteins involved in a range of biological processes. The role of histone acetylation in plant defense is well established and it is known that pathogen effector proteins encoding acetyltransferses can directly acetylate host proteins to alter immunity. However, it is unclear whether endogenous plant enzymes can modulate protein acetylation during an immune response. Here we investigate how the effector molecule HC-toxin, a histone deacetylase inhibitor, produced by Cochliobolus carbonum race 1 promotes pathogen virulence in maize through altering protein acetylation. Using mass spectrometry we globally quantified the abundance of 3,636 proteins and the levels of acetylation at 2,791 sites in maize plants treated with HC-toxin as well as HC-toxin deficient or producing strains of C. carbonum. Analyses of these data demonstrate that acetylation is a widespread post-translational modification impacting proteins encoded by many intensively studied maize genes. Furthermore, the application of exogenous HC-toxin enabled us to show that the activity of plant-encoded enzymes can be modulated to alter acetylation of non-histone proteins during an immune response. Collectively, these results provide a resource for further mechanistic studies examining the regulation of protein function and offer insight into the complex immune response triggered by virulent C. carbonum. . CC-BY-NC-ND 4.0 International license peer-reviewed) is the author/funder. It is made available under a The copyright holder for this preprint (which was not . http://dx.doi.org/10.1101/057174 doi: bioRxiv preprint first posted online Jun. 5, 2016;