The Ca(2+)-calcineurin signaling pathway in the human fungal pathogen Cryptococcus neoformans is essential for adaptation to the host environment during infection. Calcium transporters regulate cytosolic calcium concentrations, providing Ca(2+) loading into storage organelles. The three calcium transporters that have been characterized in C. neoformans, Cch1, Eca1 and Vcx1, are required for fungal virulence, supporting a role for calcium-mediated signaling in cryptococcal pathogenesis. In the present study, we report the functional characterization of the putative vacuolar calcium ATPase Pmc1 in C. neoformans. Our results demonstrate that Pmc1 provides tolerance to high Ca(2+) concentrations. The double knockout of C. neoformans PMC1 and VCX1 genes impaired the intracellular calcium transport, resulting in a significant increase in cytosolic calcium levels. Furthermore, Pmc1 was essential for both the progression of pulmonary infection and brain colonization in mice, emphasizing the crucial role of calcium signaling and transport for cryptococcal pathogenesis.
Keywords: Cryptococcus neoformans; calcium transport; cryptococcosis; vacuolar calcium storage; virulence.
© 2013 FEBS.