The Basic Functions Of The Acetyltransferase NuA4 Complex Platform Protein EafA Were Identified And Analyzed In Aspergillus Nidulans

Histone H4 acetyltransferase Nu A4(nucleosome acetyltransferase of H4)is a multi-subunit complex.Its scaffold protein,named Eaf A in Aspergillus nidulans.It is involved in the normal mitotic process of cells and responds to DNA destruction reagents.The acetylation of site Eaf1 K173 in Candida albicans,a conditioned pathogen,determines the morphological transformation between the yeast state and the hyphae state.The pathogenic mechanism of aspergillus is very similar to Candida albicans.Aspergillus infects human tissues and organs in spore state,and then germinates into hyphae and produces toxicity.Therefore,it is of great significance to study the effect of Eaf A Q576 and the protein on the growth and development of mycelia in opportunistic pathogenic Aspergillus nidulans for the aspergillus' pathogenesis.First,we constructed Eaf A-Flag strain to detect the hydrolysis of amide groups of Eaf A Q576 site in Aspergillus nidulans by mass spectrometry,but the Eaf A-Flag fusion protein could not be extracted by salt extraction.Next,it is planned to construct eaf A gene knockout strain and introduce the site mutated fragment of eaf A Q576R/K into this strain to observe its influence on the development and polarity growth of aspergillus.However,it was found that eaf A was an essential gene and could not construct the knockout strain.However,this experimental result further proves that Eaf A must have more important new functions in Aspergillus nidulans,and it is possible that this protein itself directly affects the growth and development of mycelia.Therefore,a conditional strain controlled by alcohol promoter was constructed next,and it was found that when Eaf A expression was low,mycelium development was inhibited and polar loss was caused.So what is the regulatory mechanism of Eaf A affecting mycelium development and polarity growth? By detecting the acetylation levels of the lysine at the 5th and 12 th sites of histone H4 and the transcription levels of the protein subunit of Nu A4 complex,and constructing the double sites mutant strains at the H4K5 R and H4K12 R,this regulatory process was demonstrated in a concise and clear way.When Eaf A is underexpressed,the expression of most subunits in Nu A4 complex decreases,resulting in the failure of Nu A4 complex to properly perform acetyltransferase function,which affects the acetylation level of histone specific sites,and finally affects the transcription and expression of genes related to hyphae development and polar growth.These results are of great significance for the future research on the pathogenic mechanism of fungal hyphae.