Parasite Invasion Strategy

Science Signaling  17 Jan 2012:
Vol. 5, Issue 207, pp. ec24
DOI: 10.1126/scisignal.2002854

Exocytosis is essential to the lytic cycle of apicomplexan parasites and required for the pathogenesis of toxoplasmosis and malaria. DOC2 proteins recruit the membrane fusion machinery required for exocytosis in a Ca2+-dependent manner. Farrell et al. describe the phenotype of a Toxoplasma gondii conditional mutant impaired in host cell invasion and egress. The phenotype was explained by a defect in secretion of the micronemes, an apicomplexan-specific organelle that contains adhesion proteins. A T. gondii Doc2 gene was identified by whole-genome sequencing to be involved in the secretion defect, and a conditional allele of the orthologous gene engineered into the malaria parasite, Plasmodium falciparum, also caused defects in microneme secretion.

A. Farrell, S. Thirugnanam, A. Lorestani, J. D. Dvorin, K. P. Eidell, D. J. P. Ferguson, B. R. Anderson-White, M. T. Duraisingh, G. T. Marth, M.-J. Gubbels, A DOC2 protein identified by mutational profiling is essential for apicomplexan parasite exocytosis. Science 335, 218–221 (2012). [Abstract] [Full Text]