Calcium signaling components in the human pathogen: Cryptococcus neoformans.

Calcium signaling through calmodulin and the phosphatase calcineurin are required for key events of the biology of the human pathogen Cryptococcus neoformans, including mating, morphogenesis, growth at 37°C and virulence. In a recent work we described the functional characterization of a new component of this calcium signaling network: the vacuolar calcium exchanger Vcx1. This transporter is involved in calcium tolerance and virulence in C. neoformans. Two other uncharacterized calcium transporters which are putative orthologs of Saccharomyces cerevisiae PMC1 (a vacuolar calcium ATPase) and PMR1 (a Golgi calcium ATPase) are also functional in C. neoformans. No ortholog of CRZ1, the target of calcineurin in other fungi, has been identified in C. neoformans, indicating a high complexity in cryptococcal calcium-related pathways. Future studies are necessary for the complete understanding of calcium signaling regulation in C. neoformans.