Identification And Characterization Of Candida Albicans RCH1 Gene

CaRCH1 gene has an ORF of 1236 bp, encoding a protein of 411 amino acids. In this study, we have found that Candida albicans rch1Δ/rch1Δmutants have Ca²⁺ hypersensitive phenotype and is resistant to azoles and lithium, which resembles the deletion of CaPMC1. We know that cyclosporin A (CsA) is a Firstly, we added CsA into calcium media to observe phenotypes and found that The hypersensitivity to calcium of rch1Δ/rch1Δmutant was abolished by CsA,the specific inhibitor of the Ca²⁺/calcineurin signaling in C. albicans. Secondly, the Ca²⁺ hypersensitivity due to deletion of CaRCH1 could be abolished by Mg²⁺. Thirdly, we deleted the RCH1 gene in the pmc1Δ/pmc1Δbackground and found that rch1/rch1 pmc1/pmc1 mutant is more sensitive to Ca²⁺ than the pmc1/pmc1 mutant. In addition, deletion of CaPMC1 and CaRCH1 reduced the in vitro filamentation of C. albicans cells in 20 % FBS media. However, we found that in a mouse model of systemic candidasis only deletion of CaPMC1 can attenuate the virulence of C. albicans. In conclusion, CaRch1p is involved in the regulation of cytosolic calcium homeostasis, so we renamed this gene as CaRCH1 (C. albicans regulator of calcium homeostasis).