Identification of rhoptry trafficking determinants and evidence for a novel sorting mechanism in the malaria parasite Plasmodium falciparum.
The rhoptry of the malaria parasite Plasmodium falciparum is an unusual secretory organelle that is thought to be related to secretory lysosomes in higher eukaryotes. Rhoptries contain an extensive collection of proteins that participate in host cell invasion and in the formation of the parasitophorous vacuole, but little is known about sorting signals required for rhoptry protein targeting. Using green fluorescent protein chimeras and in vitro pull-down assays, we performed an analysis of the signals required for trafficking of the rhoptry protein RAP1. We provide evidence that RAP1 is escorted to the rhoptry via an interaction with the glycosylphosphatidyl inositol-anchored rhoptry protein RAMA. Once within the rhoptry, RAP1 contains distinct signals for localisation within a sub-compartment of the organelle and subsequent transfer to the parasitophorous vacuole after invasion. This is the first detailed description of rhoptry trafficking signals in Plasmodium.
Richard
Dave
D
The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
Kats
Lev M
LM
Langer
Christine
C
Black
Casilda G
CG
Mitri
Khosse
K
Boddey
Justin A
JA
Cowman
Alan F
AF
Coppel
Ross L
RL
D000818:Animals; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D008954:Models, Biological; D009154:Mutation; D015388:Organelles / Q000378:metabolism; D010963:Plasmodium falciparum / Q000235:genetics / Q000502:physiology*; D021381:Protein Transport / Q000502:physiology*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
D017261:Glycosylphosphatidylinositols; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; C065352:rhoptry associated protein, Plasmodium; D049452:Green Fluorescent Proteins