Mapping of Lysine Methylation and Acetylation in Core Histones of Neurospora crassa

摘要

Core histones are susceptible to a variety of post-translational modifications (PTMs), amongnwhich methylation and acetylation play critical roles in various chromatin-dependent processes. The naturenand biological functions of these PTMs have been extensively studied in plants, animals, and yeasts. Inncontrast, the histone modifications in Neurospora crassa, a convenient model organism for multicellularneukaryotes, remained largely undefined. In this study, we used severalmass spectrometric techniques, couplednwith HPLC separation and multiple-protease digestion, to identify the methylation and acetylation sites inncore histones isolated from Neurospora. Electron transfer dissociation (ETD) was employed to fragment thenheavilymodified longN-terminal peptides. In addition, accuratemassmeasurement of fragment ions allowednfor unambiguous differentiation of acetylation from trimethylation. Many modification sites conserved innother organisms were identified in Neurospora. In addition, some unique modification sites in histone H2B,nincluding N-terminal R methylation, methylation at K3, and acetylation at K19, K28, and K29, werenobserved. Our analysis provides a potentially comprehensive picture of methylation and acetylation of corenhistones in Neurospora, which should serve as a foundation for future studies of the function of histone PTMsnin this model organism.