Malaria protease takes an indirect route

The bug that causes malaria feeds by gobbling up chunks of hemoglobin from the red blood cells it resides in. On page 47, Klemba et al. show how the parasite brings together this food source with its own enzymes that will degrade it. The results offer insight into how to treat this deadly disease.

The parasite breaks down hemoglobin for nutrients in its specialized organelle called the food vacuole, using proteases such as plasmepsin II (PM II). Hemoglobin gets to the food vacuole in vesicles that pinch off from cytostomes—openings through the parasite plasma membrane that lead to the blood cell cytoplasm. But how the endogenous protease reaches the food vacuole to meet its substrate had not been defined, leading some researchers to wonder whether a direct targeting pathway exists...