The Plasmodium falciparum MESA erythrocyte cytoskeleton-binding (MEC) motif binds to erythrocyte ankyrin

Journal Article · Mon Jul 01 04:00:00 EDT 2019 · Molecular and Biochemical Parasitology

DOI:https://doi.org/10.1016/j.molbiopara.2019.111189· OSTI ID:1776814

Kilili, Geoffrey K. ^[1]; Shakya, Bikash ^[1]; Dolan, Patrick T. ^[1]; Wang, Ling ^[1]; Nakayasu, Ernesto S. ^[2]; Lacount, Douglas J. ^[1]

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

The MESA erythrocyte cytoskeleton binding (MEC) motif is a 13-amino acid sequence found in 14 exported Plasmodium falciparum proteins. First identified in the P. falciparum Mature-parasite-infected Erythrocyte Surface Antigen (MESA), the MEC motif is sufficient to target proteins to the infected red blood cell cytoskeleton. To identify host cell targets, purified MESA MEC motif was incubated with a soluble extract from uninfected erythrocytes, precipitated and subjected to mass spectrometry. The most abundant co-purifying protein was erythrocyte ankyrin (ANK1). A direct interaction between the MEC motif and ANK1 was independently verified using co-purification experiments, the split-luciferase assay, and the yeast two-hybrid assay. A systematic mutational analysis of the MEC motif demonstrated the critical role of the conserved aspartic acid residue at the C-terminus of the MEC motif for binding to both erythrocyte inside-out vesicles and to ANK1. Using a panel of ANK1 constructs, the MEC motif binding site was localized to the ZU5C domain, which has no known function. The MEC motif had no impact on erythrocyte deformability when introduced into uninfected erythrocyte ghosts, suggesting the MEC motif’s primary function is to target exported proteins to the cytoskeleton. Finally, we show that PF3D7_0402100 (PFD0095c) binds to ANK1 and band 4.1, likely through its MEC and PHIST motifs, respectively. In conclusion, we have provided multiple lines of evidence that the MEC motif binds to erythrocyte ANK1.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1776814
• Report Number(s): PNNL-SA-139742
• Journal Information: Molecular and Biochemical Parasitology, Journal Name: Molecular and Biochemical Parasitology Vol. 231
• Country of Publication: United States
• Language: English