title: Ecm7, a regulator of HACS, functions in calcium homeostasis maintenance, oxidative stress response and hyphal development in Candida albicans.
abstract: Calcium is a universal messenger that translates diverse environmental stresses and developmental cues into specific cellular and developmental responses. In yeast, Cch1 and Mid1 function as part of a high affinity Ca²⁺ influx system (HACS) that becomes activated rapidly in response to sudden stimuli. Here, we report that Ecm7, a regulator of HACS, plays important roles in calcium homeostasis maintenance, oxidative stress response and hyphal development in Candida albicans. Disruption of ECM7 led to increased sensitivity to calcium-depleted conditions. Flow cytometry analysis revealed that Ecm7 mediated Ca²⁺ influx under high pH shock. Cycloheximide chase experiments further showed that MID1 deletion significantly decreased the stability of Ecm7. We also provided evidences that ecm7Δ/Δ cells were hypersensitive to oxidative stress. ECM7 deletion induced the degradation of Cap1 when exposed to H₂O₂ treatment. Besides, the ecm7Δ/Δ mutant showed a defect in hyphal development, which was accompanied with the decreased expression of hyphal related gene HWP1. Though subsequent experiments revealed that the ecm7Δ/Δ mutant showed similar virulence to the wild-type strain, the ability of invasion and diffusion of the mutant in mouse kidneys decreased. Taken together, Ecm7 plays important roles in the adaptation and pathogenicity of C. albicans.
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Science, Nankai University, Tianjin, PR China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Ding
authors.forename: Qilin
authors.initials: Q
authors.lastname: Yu
authors.forename: Ning
authors.initials: N
authors.lastname: Xu
authors.forename: Yuzhou
authors.initials: Y
authors.lastname: Wang
authors.forename: Xinxin
authors.initials: X
authors.lastname: Cheng
authors.forename: Kefan
authors.initials: K
authors.lastname: Qian
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhao
authors.forename: Biao
authors.initials: B
authors.lastname: Zhang
authors.forename: Laijun
authors.initials: L
authors.lastname: Xing
authors.forename: Mingchun
authors.initials: M
authors.lastname: Li
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000235:genetics*; D002176:Candida albicans / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D002177:Candidiasis; D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D006861:Hydrogen Peroxide; D006863:Hydrogen-Ion Concentration; D025301:Hyphae / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D018384:Oxidative Stress; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development
chemical_list: D005656:Fungal Proteins; D008565:Membrane Proteins; D006861:Hydrogen Peroxide; D002118:Calcium
keywords: 2′,7′-dichlorodihydrofluorescein diacetate; 5-FOA; 5-fluoroorotic acid; CHX; Calcium homeostasis; Candida albicans; DCFH-DA; EGTA; Ecm7; FBS; HACS; HBSS; Hank’s balanced salt solution; Hyphal development; Oxidative stress; SC; SD; VGCC; Virulence; cycloheximide; ethylene glycol bis(2-aminoethyl) tetraacetic acid; fetal bovine serum; high affinity Ca(2+) influx system; synthetic complete; synthetic drop-out; voltage-gated calcium channels