Lysine acetylation contributes to development, aflatoxin biosynthesis and pathogenicity in Aspergillus flavus

Abstract

Summary Aspergillus flavus is a pathogenic fungus that produces carcinogenic aflatoxins, posing a great threat to crops, animals and humans. Lysine acetylation is one of the most important reversible post‐translational modifications and plays a vital regulatory role in various cellular processes. However, current information on the extent and function of lysine acetylation and aflatoxin biosynthesis in A. flavus is limited. Here, a global acetylome analysis of A. flavus was performed by peptide pre‐fractionation, pan‐acetylation antibody enrichment and liquid chromatography–mass spectrometry. A total of 1313 high‐confidence acetylation sites in 727 acetylated proteins were identified in A. flavus. These acetylation proteins are widely involved in glycolysis/gluconeogenesis, pentose phosphate pathway, citric acid cycle and aflatoxin biosynthesis. AflO (O‐methyltransferase), a key enzyme in aflatoxin biosynthesis, was found to be acetylated at K241 and K384. Deletion of aflO not only impaired conidial and sclerotial developments, but also dramatically suppressed aflatoxin production and pathogenicity of A. flavus. Further site‐specific mutations showed that lysine acetylation of AflO could also result in defects in development, aflatoxin production and pathogenicity, suggesting that acetylation plays a vital role in the regulation of the enzymatic activity of AflO in A. flavus. Our findings provide evidence for the involvement of lysine acetylation in various biological processes in A. flavus and facilitating in the elucidation of metabolic networks.

MAPK pathway‐related tyrosine phosphatases regulate development, secondary metabolism and pathogenicity in fungus Aspergillus flavus

“…To generate site-directed mutants, an approach of sitedirected mutagenesis was carried out according to a previously described method with minor modifications (Yang et al, 2019a). Briefly, the point-mutation fragment of the ORF, pyrG selectable marker and downstream fragment were amplified by specific primers, fused together by an overlap PCR and then transformed into protoplasts of A. flavus CA14 PTS strain.…”

Proteogenomic Characterization of the Pathogenic Fungus Aspergillus flavus Reveals Novel Genes Involved in Aflatoxin Production

“…To the best of our knowledge, many important PTMs (such as acetylation, succinylation, propionylation and malonylation) could provide a mechanism to respond to changes in the energy status of the cell and regulate metabolic pathways (86)(87)(88)(89)(90)(91)(92). In addition, we have previously provided the first evidence that phosphorylation, methylation, acetylation, succinylation, ubiquitination and sumoylation may be a mechanism involved in aflatoxin biosynthesis by regulating the activities of enzymes in A. flavus (72,73,85,(93)(94)(95). Therefore, the identified PTM datasets from our work may provide a foundation for studying the biological functions of these PTM events in metabolic pathways and aflatoxin biosynthesis.…”

“…Despite widespread recognition of the importance of PTMs in various biological processes (81-84), there still lack of a holistic view of PTMs events on Aspergillus proteins and the functional roles of many types of PTMs have not yet been uncovered.In this study, we identified 8,724 annotated protein-coding genes with high confidence and a significant number of these proteins were found to be modified with different types of PTMs. Although the phosphorylation, acetylation and succinylation have been reported from large-scale MS/MS studies(72,73,85), the current understanding of PTMs in Aspergillus is still limited and many important PTM events have not yet been discovered in this pathogenic fungus. Comprehensive analysis of these by guest on December 1, 2020…”

Protein Acetylation/Deacetylation: A Potential Strategy for Fungal Infection Control

“…AflO, a key enzyme in aflatoxin biosynthesis, was acetylated at lysine 241 and 384 and played a vital role in the pathogenicity of A. flavus ( Yang et al, 2019 ). Six proteins involved in the virulence of B. cinerea were found to be acetylated (BcSak1, Hpt1, Bcchs2, CHSV, PKS, and BOS1) ( Lv et al, 2016 ).…”

“…In plant pathogenic fungi, Yang et al identified 1,313 high-confidence acetylation sites in 727 acetylated proteins in Aspergillus flavus , while 577 acetylated sites were reported in 364 different proteins in Fusarium graminearum ( Zhou S. et al, 2016 ; Yang et al, 2019 ). Several published studies have described the acetylome of different fungal species, including plant pathogenic fungi Phytophthora sojae , Botrytis cinerea , and Magnaporthe oryzae ; fungal insect pathogens, such as Beauveria bassiana and Metarhizium anisopliae ; and nonpathogenic fungi species, such as Saccharomyces cerevisiae and Yarrowia lipolytica ; which are considered as important resources to explore the physiological role of this modification in eukaryotes ( Henriksen et al, 2012 ; Mukherjee et al, 2012 ; Li et al, 2016 ; Lv et al, 2016 ; Wang et al, 2017 ; Cai et al, 2018c ; Liang et al, 2018 ).…”