title: Elevated cytosolic free Ca2+ concentrations and massive Ca2+ accumulation within vacuoles, in yeast mutant lacking PMR1, a homolog of Ca2+ -ATPase.
abstract: The Ca2+ -ATPase homolog of Saccharomyces cerevisiae, PMR1, cloned by Rudolph et al. (Cell 58 (1989) 133-145) is required for normal Golgi functions. We have investigated the role of Pmr1-protein in maintaining homeostasis of cytosolic free Ca2+ concentration ([Ca2+]i). It was found that exposure to moderately high Ca2+ concentrations led to elevated levels of [Ca2+]i in cells of pmr1 null mutant, in comparison with cells of pmr2 isogenic mutant (defective in cell-membrane Na+ - ATPase) and of an isogenic wild type. In addition, we showed that PMR1 deletion causes massive accumulation of Ca2+ in the vacuoles and affects the rates of Ca2+ influx and efflux.
authors.affiliation: Department of Bacteriology, Hebrew University, Hadassah Medical School, Jerusalem, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Halachmi
authors.forename: Y
authors.initials: Y
authors.lastname: Eilam
mesh_terms: D002118:Calcium / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism*; D017136:Ion Transport; D008274:Magnesium / Q000378:metabolism; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism*
chemical_list: D000252:Calcium-Transporting ATPases; D008274:Magnesium; D002118:Calcium