To invade host cells, one group of parasites relies on a protein that promotes the release of sticky molecules from a specialized organelle called a microneme.

Parasites of the phylum Apicomplexa, which includes those responsible for malaria (Plasmodium falciparum) and toxoplasmosis (Toxoplasma gondii), secrete a mixture of adhesion proteins at their surfaces, allowing them to stick to host cells. Marc-Jan Gubbels at Boston College in Massachusetts and his colleagues sequenced the genome of a mutant strain of Toxoplasma with an impaired ability to release its microneme contents or invade cells. They found a mutation in a protein called DOC2.1. Shutting off the gene encoding an equivalent protein in Plasmodium also impaired this parasite's ability to invade.

Science 335, 218–221 (2012)