Disruption of the C-terminal region of EBA-175 in the Dd2/Nm clone of Plasmodium falciparum does not affect erythrocyte invasion.
EBA-175 is a Plasmodium falciparum micronemal protein that binds to sialic acid in the context of the peptide backbone of glycophorin A and has been implicated in sialic acid-dependent invasion of erythrocytes. The existence of an alternative invasion pathway has been suggested by the finding that the P. falciparum clone Dd2/Nm can invade sialic acid-depleted erythrocytes. To study the role of EBA-175 in this alternative pathway, we have generated Dd2/Nm clones expressing a truncated form of EBA-175 that lacks region 6 and the cytoplasmic domain. The protein still appears to be localized to the apical end in the vicinity of the micronemes, suggesting that region 6 and the cytoplasmic domain are not involved in EBA-175 trafficking to the micronemes. In these genetically modified clones, the level of truncated EBA-175 protein expression was greatly reduced. EBA-175-disrupted clones displayed normal rates of invasion of untreated and enzyme-treated human and animal erythrocytes, suggesting a lack of involvement of EBA-175 in this alternative invasion pathway.
Kaneko
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Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Room 126, National Institutes of Health, 4 Center Drive, Bethesda, MD 20892-0425, USA.
Fidock
D A
DA
Schwartz
O M
OM
Miller
L H
LH
D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan; D015139:Blotting, Southern; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004912:Erythrocytes / Q000378:metabolism / Q000469:parasitology*; D006801:Humans; D016778:Malaria, Falciparum / Q000469:parasitology; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D010963:Plasmodium falciparum / Q000472:pathogenicity*; D011233:Precipitin Tests; D015800:Protozoan Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017384:Sequence Deletion; D014170:Transformation, Genetic
D000953:Antigens, Protozoan; D002352:Carrier Proteins; D015800:Protozoan Proteins; C065668:erythrocyte-binding antigen 175, Plasmodium; D019158:N-Acetylneuraminic Acid