The Plasmodium falciparum protein RESA interacts with the erythrocyte cytoskeleton and modifies erythrocyte thermal stability.
The ring-infected erythrocyte surface antigen (RESA) associates with spectrin in the erythrocyte membrane (Foley, M., Tilley, L., Sawyer, W. H. and Anders, R. F. (1991) Mol. Biochem. Parasitol., 46, 137-148). A fragment of the RESA protein, which was expressed in Escherichia coli, was found to bind to inside-out vesicles of erythrocyte membranes in an apparently saturable manner. Upon extraction of inside-out vesicles with Triton X-100, the RESA fragment remained associated with the erythrocyte cytoskeleton. Using the technique of steady-state fluorescence polarisation, we have studied the thermal denaturation of fluorescein-labelled spectrin in the presence of recombinant RESA. We found that the RESA fragment partially protected spectrin against heat-induced conformational changes. Furthermore, erythrocytes infected with a RESA (-) laboratory strain (FCR3) were shown to be more susceptible to heat-induced fragmentation than erythrocytes infected with a RESA (+) strain of the parasite. RESA does not, however, appear to play an essential role in the invasion process per se as erythrocytes resealed to contain anti-RESA antibodies were efficiently invaded.
Da Silva
E
E
Department of Biochemistry, La Trobe University, Bundoora, Victoria, Australia.
Foley
M
M
Dluzewski
A R
AR
Murray
L J
LJ
Anders
R F
RF
Tilley
L
L
D000818:Animals; D000953:Antigens, Protozoan / Q000378:metabolism*; D000954:Antigens, Surface / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism*; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000469:parasitology / Q000502:physiology*; D004926:Escherichia coli / Q000235:genetics; D005454:Fluorescence Polarization; D015870:Gene Expression; D006358:Hot Temperature; D010446:Peptide Fragments / Q000378:metabolism; D010963:Plasmodium falciparum / Q000737:chemistry* / Q000235:genetics; D011489:Protein Denaturation; D015800:Protozoan Proteins / Q000378:metabolism*; D013049:Spectrin / Q000378:metabolism
D000953:Antigens, Protozoan; D000954:Antigens, Surface; D010446:Peptide Fragments; D015800:Protozoan Proteins; C050256:ring-infected erythrocyte surface antigen (RESA), Plasmodium falciparum; D013049:Spectrin