Histone acetyltransferases MystA and MystB contribute to morphogenesis and aflatoxin biosynthesis by regulating acetylation in fungus Aspergillus flavus

Environ Microbiol. 2021 Dec 4. doi: 10.1111/1462-2920.15856. Online ahead of print.


Myst family are highly conserved histone acetyltransferases in eukaryotic cells and are known to play crucial roles in various cellular processes, however, acetylation catalyzed by acetyltransferases is unclear in filamentous fungi. Here, we identified two classical nonessential Myst enzymes and analyzed their functions in Aspergillus flavus, which generates aflatoxin B1, one of the most carcinogenic secondary metabolites. MystA and MystB located in nuclei and cytoplasm, and mystA could acetylates H4K16ac, while mystB acetylates H3K14ac, H3K18ac and H3K23ac. Deletion mystA resulted in decreased conidiation, increased sclerotia formation and aflatoxin production. Deletion mystB lead to significant defects in conidiation, sclerotia formation and aflatoxin production. Additionally, double-knockout mutant (ΔmystA/mystB) display a stronger and similar defect to ΔmystB mutant, indicating that mystB plays major role in regulating development and aflatoxin production. Both mystA and mystB play important role in crop colonization. Moreover, catalytic domain MOZ and the catalytic site E199/E243 were important for the acetyltransferase function of Myst. Notably, chromatin immunoprecipitation results indicated that mystB participated in oxidative detoxification by regulating the acetylation level of H3K14, and further regulated nsdD to affect sclerotia formation and aflatoxin production. This study provides new evidences to discover the biological functions of histone acetyltransferase in A. flavus. This article is protected by copyright. All rights reserved.

PMID:34863014 | DOI:10.1111/1462-2920.15856

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