The Plasmodium falciparum exported protein PF3D7_0402000 binds to erythrocyte ankyrin and band 4.1

Journal Article · Fri Sep 01 04:00:00 EDT 2017 · Molecular and Biochemical Parasitology

DOI:https://doi.org/10.1016/j.molbiopara.2017.06.002· OSTI ID:1776812

Shakya, Bikash ^[1]; Penn, Wesley D. ^[1]; Nakayasu, Ernesto S. ^[2]; Kilili, Geoffrey K. ^[1]; Lacount, Douglas J. ^[1]

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1. Purdue University
2. BATTELLE (PACIFIC NW LAB)

Plasmodium proteins are exported to the erythrocyte cytoplasm to create an environment that supports parasite replication. Although hundreds of proteins are predicted to be exported through PEXEL-dependent and -independent mechanisms, the functions of exported proteins are largely uncharacterized. In this study, we used a biochemical screening approach to identify exported P. falciparum proteins that bound to inside-out vesicles prepared from erythrocytes. Out of 70 exported P. falciparum proteins tested, 18 bound to IOVs in 2 or more independent assays. Using co-affinity purifications followed by mass spectrometry, pairwise co-purification experiments and the split-luciferase assay, we identified 31 putative protein-protein interactions between erythrocyte cytoskeletal proteins and exported P. falciparum proteins. We further showed that PF3D7_1401600 binds to the spectrin-binding domain of erythrocyte ankyrin via its MESA erythrocyte cytoskeleton binding (MEC) motif and to the N-terminal domains of ankyrin and 4.1R through a fragment that required an intact PHIST domain. Introduction of PF3D7_1401600 into erythrocyte ghosts increased retention in the microsphiltration assay, consistent with previous data that reported a reduction of rigidity in red blood cells infected with PF3D7_1401600-deficient parasites. Finally, we found that PfEPF3 proteins bound to erythrocyte GAPDH, providing a potential link between Maurer’s clefts and the erythrocyte cytoskeleton early during infection.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1776812
• Report Number(s): PNNL-SA-139741
• Journal Information: Molecular and Biochemical Parasitology, Journal Name: Molecular and Biochemical Parasitology Vol. 216
• Country of Publication: United States
• Language: English