Cooperation of calcineurin and vacuolar H(+)-ATPase in intracellular Ca2+ homeostasis of yeast cells.
Saccharomyces cerevisiae VMA genes, encoding essential components for the expression of vacuolar membrane H(+)-ATPase activity, are involved in intracellular ionic homeostasis and vacuolar biogenesis. We report here that the immunosuppressants FK506 and cyclosporin A cause general growth inhibition of the vma3 mutant. Upon addition of the drugs, the mutant grew neither in the presence of more than 5 mM Ca2+ nor above pH 6.0. The action of the immunosuppressants is dependent on their binding proteins and ascribable to inhibition of calcineurin activity; a mutation of a calcineurin subunit (cnb1) shows synthetic lethal interaction with the vma mutation. The addition of FK506 decreases the cytosolic free concentration of Ca2+ in the vma3 mutant cells. Consequently, FK506 induces an 8.9-fold elevation of a nonexchangeable Ca2+ pool. These results suggest that calcineurin controls calcium homeostasis by repression of Ca2+ flux into a cellular compartment(s) and that the vacuolar H(+)-ATPase is essential for cell growth cooperating with calcineurin to regulate the cytosolic free concentration of Ca2+.
Tanida
I
I
Department of Plant Sciences, Graduate School of Science, University of Tokyo, Japan.
Hasegawa
A
A
Iida
H
H
Ohya
Y
Y
Anraku
Y
Y
D001483:Base Sequence; D019703:Calcineurin; D002118:Calcium / Q000378:metabolism*; D002148:Calmodulin-Binding Proteins / Q000378:metabolism*; D002352:Carrier Proteins / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D016572:Cyclosporine / Q000494:pharmacology; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000494:pharmacology; D006360:Heat-Shock Proteins / Q000494:pharmacology; D006706:Homeostasis; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000201:enzymology; D008969:Molecular Sequence Data; D009154:Mutation; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D016559:Tacrolimus / Q000494:pharmacology; D022021:Tacrolimus Binding Proteins; D014617:Vacuoles / Q000201:enzymology*
D002148:Calmodulin-Binding Proteins; D002352:Carrier Proteins; D017931:DNA Primers; D004268:DNA-Binding Proteins; D006360:Heat-Shock Proteins; D016572:Cyclosporine; D019703:Calcineurin; D010749:Phosphoprotein Phosphatases; D006180:Proton-Translocating ATPases; D022021:Tacrolimus Binding Proteins; D002118:Calcium; D016559:Tacrolimus