Acetylome analysis of acetylation providing new insight into sclerotial generation in medicinal fungus Polyporus umbellatus

Sclerotium-forming fungi are ecologically diverse and possess notable pathogenic or medicinal properties. The sclerotial generation mechanism is still elusive though Polyporus umbellatus sclerotia are typical Traditional Chinese Medicine with diuretic and antitumor effects. Protein acetylation displays a crucial role in several biological processes, but the functions of acetylation in this valuable fungus are unknown at present. In this study, acetylome of P. umbellatus was studied using nano LC-Triple TOF mass spectrometry system following immune-affinity-based enrichment. Totally, 648 acetylated sites in 342 proteins were identified and nine motifs were found to be conserved in P. umbellatus including K(ac)Y, K(ac)A, K(ac)L, K(ac)G, M(ac)S, M(ac)A, R(ac)A, R(ac)L, and R(ac)G. Acetylated proteins taken part in types of biological processes, particularly to those in biological processes associated with reactive oxygen species (ROS) metabolism. Inhibitors complement tests were carried out to verify the role of ROS in acetylation modification. It was concluded that oxidative stress regulated sclerotial generation via proteins acetylation in P. umbellatus. The present study presents new insight into the essential roles of acetylation in sclerotial formation, which may also be applicable for other sclerotium-forming fungi.