Ca2+ transport into an intracellular acidic compartment of Candida parapsilosis

FEBS Letters

Schereiber, Angelica Z¹  Milani, Graziela¹  Vercesi, Anibal E¹ 

[1] Departamento de Patologia Clı́nica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas 13083 970, SP, Brazil

关键词: Candida parapsilosis;    Ca2+ transport;    Ketoconazole;    Lyticase;    Intracellular Ca2+;    FCCP;    carbonyl cyanide p-trifluoromethoxyphenylhydrazone;    AO;    acridine orange;    BHT;    3;    5-dibutyl-4-hydroxytoluene;   

DOI  :  10.1016/S0014-5793(01)02585-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In this report, we study Ca²⁺ transport in permeabilized Candida parapsilosis spheroplasts prepared by a new technique using lyticase. An intracellular non-mitochondrial Ca²⁺ uptake pathway, insensitive to orthovanadate and sensitive to the V-H⁺-ATPase inhibitor bafilomycin A₁, nigericin and carbonyl cyanide p-trifluoromethoxyphenylhydrazone was characterized. Acidification of the compartment in which Ca²⁺ accumulated was followed using the fluorescent dye acridine orange. Acidification was stimulated by the Ca²⁺ chelator EGTA and inhibited by Ca²⁺. These results, when added to the observation that Ca²⁺ induces alkalization of a cellular compartment, provide evidence for the presence of a Ca²⁺/nH⁺ antiporter in the acid compartment membrane. Interestingly, like in acidocalcisomes of trypanosomatids, the antioxidant 3,5-dibutyl-4-hydroxytoluene inhibits the V-H⁺-ATPase. In addition, the antifungal agent ketoconazole promoted a fast alkalization of the acidic compartment. Ketoconazole effects were dose-dependent and occurred in a concentration range close to that attained in the plasma of patients treated with this drug.

【 授权许可】

Unknown