An EGF-like Protein Forms a Complex with PfRh5 and Is Required for Invasion of Human Erythrocytes by Plasmodium falciparum
Figure 5
Protein expression patterns of PfRh5 and PfRipr are consistent with the complex formation.
(A) Both anti-PfRh5 and anti-PfRipr antibodies recognize the same complex resolved by blue native gel electrophoresis. (B) Both PfRh5 and PfRipr are expressed late in the blood stage life cycle of parasite development. Synchronized PfRiprHA parasites were distributed into six 5 ml cultures. One was harvested immediately after synchronization (8 – 12 hr ring stage). The second was harvested 16 hr post synchronization, and the third 8 hr later. The rest of the time points were harvested every 6 hr until the end of growth cycle. Proteins were extracted from saponin pellets, separated by SDS-PAGE and transferred to nitrocellulose membrane. The membrane was probed with monoclonal anti-HA antibody (top panel) to detect PfRiprHA and then stripped and re-probed to detect PfRh5 (middle panel) and PfHsp70 (bottom panel). Both PfRh5 and PfRipr proteins are expressed primarily in late schizonts.