Cellular Protein Interactions in Malaria

Researchers have found that protein interactions in the malaria parasite Plasmodium falciparum differ markedly from those found in a group of model organisms.

Falciparum malaria causes more than a million deaths every year worldwide and has long been the target of efforts to eradicate it. Investigators at the University of California, San Diego (USA), have shown that one reason why conventional techniques work so poorly with this organism is that its cellular protein interactions differ markedly from those of other organisms.

They examined the degree of conservation between the Plasmodium protein network and those of model organisms. Results published in the November 3, 2005, issue of Nature identified 29 highly connected protein complexes specific to the network of the pathogen. However, there was very little conservation with complexes observed in other organisms (three in yeast, none in the others).

"We have known since the Plasmodium genome was sequenced three years ago that 40% of its 5,300 proteins are significantly similar, or homologous, to proteins in other eukaryotes, but until now we didn't know that the malaria parasite assembles those proteins so uniquely,” said senior author Dr. Trey Ideker, professor of bioengineering at the University of California, San Diego. "What really jumps out of our paper is the large number of membrane protein interactions in Plasmodium that are absent in other organisms. While this is potentially good news for fighting malaria, we need to know much more before we start talking about which membrane-protein interactions to target with a new drug.”