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A multifunctional serine protease primes the malaria parasite for red blood cell invasion
Author(s) -
Koussis Konstantinos,
WithersMartinez Chrislaine,
Yeoh Sharon,
Child Matthew,
Hackett Fiona,
Knuepfer Ellen,
Juliano Luiz,
Woehlbier Ute,
Bujard Hermann,
Blackman Michael J
Publication year - 2009
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2009.22
Subject(s) - biology , malaria , serine protease , parasite hosting , red blood cell , plasmodium falciparum , virology , blood cell , protozoa , protease , immunology , microbiology and biotechnology , biochemistry , enzyme , world wide web , computer science
The malaria parasite Plasmodium falciparum replicates within an intraerythrocytic parasitophorous vacuole (PV). Rupture of the host cell allows release (egress) of daughter merozoites, which invade fresh erythrocytes. We previously showed that a subtilisin‐like protease called PfSUB1 regulates egress by being discharged into the PV in the final stages of merozoite development to proteolytically modify the SERA family of papain‐like proteins. Here, we report that PfSUB1 has a further role in ‘priming’ the merozoite prior to invasion. The major protein complex on the merozoite surface comprises three proteins called merozoite surface protein 1 (MSP1), MSP6 and MSP7. We show that just before egress, all undergo proteolytic maturation by PfSUB1. Inhibition of PfSUB1 activity results in the accumulation of unprocessed MSPs on the merozoite surface, and erythrocyte invasion is significantly reduced. We propose that PfSUB1 is a multifunctional processing protease with an essential role in both egress of the malaria merozoite and remodelling of its surface in preparation for erythrocyte invasion.