Functional Characterization Of The CaCNE1 In Candida Albicans

Candida albicans was the most common opportunistic fungal pathogen of humans.In most humans with a healthy immune system,C.albicans was a harmless symbiosis,but in humans with low immunity,the transformation of yeast-hyphae causes C.albicans to rapidly multiply and cause infections.There are limited clinically available antifungal drugs for the treatment of C.albicans infections.The long-term repeated use of these antifungal drugs has led to the increasingly serious drug resistance of C.albicans,and there is an urgent need to develop new antifungal drugs.In this study,through the amino acid sequence similarity comparison,in C.albicans,a gene CaCNE1 homologous to ScCNE1 encoding Saccharomyces cerevisiae was found.The calcineurin encoded by ScCNE1 in S.cerevisiae cells is a molecular chaperone,helping glycoproteins fold and assemble,and play a role in quality control.The function of CaCNE1 is currently unclear.In this study,we constructed a null mutant for CaCNE1 by homologous recombination method.The effects of CaCNE1 on the antifungal drug sensitivity,cell wall integrity,hyphae development,endoplasmic reticulum function and virulence of C.albicans were studied by drug pressure phenotype test and cell wall composition test,hyphal development test and virulence assay in mice test,etc.C.albicans delete CaCNE1,we find cells becoming sensitive to the antifungal drugs azoles,congo red,Tunicamycin,fluorescent brightener,hygromycin B,Sodium dodecyl sulfate and high concentration of calcium ions and caspofungin,but showed resistance to terbinafine.We also show that the contents of chitin were increased significantly,but the phosphomannan content was markedly reduced in the cell wall of Cacne1/Cacne1 mutant,CaCNE1 may be related to C.albicans cell wall structure and integrity.Moreover,deletion of CaCNE1 leads to severe defects in hyphal development of C.albicans cells.In addition,C.albicans CaCNE1 is associated with maintaining normal endoplasmic reticulum function.Furthermore,after the loss of C.albicansCaCNE1,the ability to infect mice is lost.CaCNE1 is necessary to maintain the virulence of C.albicans.CaPMR1 encodes the calcium pump CaPmr1 on the endoplasmic reticulum/Golgi membrane of C.albicans.In order to explore the function of CaCNE1 in the regulation of intracellular calcium homeostasis system,we construct CaCNE1 and CaPMR1 double gene deletion strains by CRISPR/Cas9 gene editing method,then study the interaction between CaCNE1 and CaPMR1 genes.In summary,CaCNE1 plays an important role in C.albicans response to drug stress,cell wall components,hyphae development,endoplasmic reticulum function and virulence.However,the specific mechanism is unclear.We will further study the physiological metabolism mechanism of CaCNE1 to provide a theoretical basis for the development of new antifungal drugs.