( gs that disrupt proteins in pathogens w...)Researchers develop new method to help find deadly malaria parasite's Achilles heel

The malaria parasite has a four-stage life cycle, and the Fields group analyzed only the proteins expressed in the phase that infects human red blood cells, an infection that leads to fever, shaking chills, headache, muscle aches, and other symptoms. Ideker said critics may fault his study because only a subset of the Plasmodium's proteins is expressed in the erythrocytic stage. However, he noted that the parasite's asexual-phase is actually enriched in proteins for which homologs have been found in other species. Ideker also noted that the known protein interactions in yeast, worm, and fly represent only 20 percent of the total interactions and some of the reported interactions may be erroneous.

"All the protein networks described so far are incomplete and statistically noisy," said Ideker. "But whether they are incomplete and noisy in the same way or not, we can say with confidence that this particular stage of Plasmodium is different from the other organisms we've examined so far. It's this lack of overlap with other species that's surprising."

Ideker said the Plasmodium's membrane-protein complexes may be of particular interest. "Plasmodium presents many of these proteins to the red blood cell during infection and prior to replication," he said. "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."