Study On The Biological Functions And Characteristics Of Aspergillus Fumigatus V-ATPasa Subunit C

Aspergillus fumigatus is a primary and opportunistic pathogen,which produces prodigious amounts of conidia to reproduce and grow.Despite great medical and ecological importance and a perfect genetic systerm,the function of genes have not been identified yet.Vacuolar H+-ATPases(V-ATPase)is a multisubunit complex,composed of a peripheral domain(?)that hydrolyzes A,TP and an integral domain(V0)that conducts protons.vmaC gene encodes the subunit C,which is a ? sector subunit that connects the VO sector to assembling into V-ATPase holoenzyme complexes.Inthis study,we explore the function of vmaC in A.fumigatus.First,we verified the vmaC full deletion strain by homologous gene replacement displays severe defects in hyphal growth,conidiation and vacuolar acidity.The ?vmaC mutant played a changed cell wall components by analyzed the cell wall component of ?vmaC via HPLC and real-time PCR.These results suggest the vmaC is necessary for hypha growth,sporulation,vacuolar function and cell wall integrity.The dynamics of[Ca2+]c and[Ca2+]v in living cells organelles expressing the calcium reporter aequorin in the vmaC conditional strain are defective in responses to high extracellular Ca2+ sress,suggeting V-ATPase participates in the calcium ion homeostasis.Using the Co-immunoprecipitation with proteomic mass spectrometry,we affirmed that VmaC is the component of vacuolar H+-ATPases(V-ATPase).In addition,the vegetative growth and sporulation defects in the conditional strain can be recovered using AfvmaC orthologs of A.nidulans S.cerevisiae under the A.fumigatus native promoter.But the truncated cDNAs lacking C-terminal hydrophobic domain of vmaC displayed the similar phenotype to wild-type strains,except the slower hyphal growth and conidiation,which was also different from the truncation strain in S.cerevisiae.These founds suggested that VmaC has the similar function in fungus,neverthless,the impact of conservative domain was unlike.Overall,Our findings suggest the VmaC is necessary for hypha growth and sporulation,and provide possible candidate for antifungal drugs.