Vacuoles Play a Decisive Role in Calcium Homeostasis in Neurospora crassa

Abstract

SUMMARY: Mutants of the filamentous fungus Neurospora crassa which grow well only in a medium in which the concentration of calcium is lower than in the medium used for culture of the wild-type strain were isolated by use of the ionophore A23187 and medium which contained a high concentration of calcium. These mutants showed a significantly lower uptake of calcium into their vacuoles than the wild-type, while other activities associated with the transport of calcium across several other types of membrane were not affected. The results indicated an essential role for the vacuoles in the regulation of the cytosolic concentration of calcium.