Lysine 2-hydroxyisobutyrylation orchestrates cell development and aflatoxin biosynthesis in Aspergillus flavus

Environ Microbiol. 2022 May 27. doi: 10.1111/1462-2920.16077. Online ahead of print.


Lysine 2-hydroxyisobutyrylation (Khib ) is a recently identified post-translational modifications (PTM) that regulates numerous cellular metabolic processes. In pathogenic microorganism, although glycolysis and fungal virulence are regulated by Khib , its potential roles in fungi remains to be elusive. Our preliminary results showed that levels of Khib fluctuate over time in Aspergillus flavus, which frequently contaminates crops and produces carcinogenic aflatoxins. However, the perception of Khib function in A. flavus is limited, especially in mycotoxin-producing strains. Here, we performed a comprehensive analysis of Khib in A. flavus, and 7156 Khib sites were identified in 1473 proteins. Notably, we demonstrated that Khib of AflM, a key enzyme in aflatoxin biosynthesis, affected conidia production and sclerotia formation. Furthermore, aflM deletion impaired aflatoxin biosynthesis, and more importantly, strains in which Khib was mimicked by K to T mutation at K49, K179 and K180 sites showed reduced aflatoxin production compared with wild type and ΔaflM complementation strains. These results indicate that Khib at these sites of AflM negatively regulates aflatoxin biosynthesis in A. flavus. In summary, our study revealed the potential roles of Khib in A. flavus, and particularly shed light on a new way to regulate aflatoxin production via Khib . This article is protected by copyright. All rights reserved.

PMID:35621059 | DOI:10.1111/1462-2920.16077

Source: Industry