title: Loss-of-function analyses defines vital and redundant functions of the Plasmodium rhomboid protease family.
abstract: Rhomboid-like proteases cleave membrane-anchored proteins within their transmembrane domains. In apicomplexan parasites substrates include molecules that function in parasite motility and host cell invasion. While two Plasmodium rhomboids, ROM1 and ROM4, have been examined, the roles of the remaining six rhomboids during the malaria parasite's life cycle are unknown. We present systematic gene deletion analyses of all eight Plasmodium rhomboid-like proteins as a means to discover stage-specific phenotypes and potential functions in the rodent malaria model, P. berghei. Four rhomboids (ROM4, 6, 7 and 8) are refractory to gene deletion, suggesting an essential role during asexual blood stage development. In contrast ROM1, 3, 9 and 10 were dispensable for blood stage development and exhibited no, subtle or severe defects in mosquito or liver development. Parasites lacking ROM9 and ROM10 showed no major phenotypic defects. Parasites lacking ROM1 presented a delay in blood stage patency following liver infection, but in contrast to a previous study blood stage parasites had similar growth and virulence characteristics as wild type parasites. Parasites lacking ROM3 in mosquitoes readily established oocysts but failed to produce sporozoites. ROM3 is the first apicomplexan rhomboid identified to play a vital role in sporogony.
authors.affiliation: Leiden Malaria Research Group (Parasitology), Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Jing-Wen
authors.initials: JW
authors.lastname: Lin
authors.forename: Patrícia
authors.initials: P
authors.lastname: Meireles
authors.forename: Miguel
authors.initials: M
authors.lastname: Prudêncio
authors.forename: Sabine
authors.initials: S
authors.lastname: Engelmann
authors.forename: Takeshi
authors.initials: T
authors.lastname: Annoura
authors.forename: Mohammed
authors.initials: M
authors.lastname: Sajid
authors.forename: Séverine
authors.initials: S
authors.lastname: Chevalley-Maurel
authors.forename: Jai
authors.initials: J
authors.lastname: Ramesar
authors.forename: Carolin
authors.initials: C
authors.lastname: Nahar
authors.forename: Cristina M C
authors.initials: CM
authors.lastname: Avramut
authors.forename: Abraham J
authors.initials: AJ
authors.lastname: Koster
authors.forename: Kai
authors.initials: K
authors.lastname: Matuschewski
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Waters
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Janse
authors.forename: Gunnar R
authors.initials: GR
authors.lastname: Mair
authors.forename: Shahid M
authors.initials: SM
authors.lastname: Khan
mesh_terms: D000818:Animals; D001769:Blood / Q000469:parasitology; D009033:Culicidae / Q000469:parasitology; D005260:Female; D017353:Gene Deletion; D008018:Life Cycle Stages; D008099:Liver / Q000469:parasitology; D008288:Malaria / Q000469:parasitology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism*; D010962:Plasmodium berghei / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D034101:Sporozoites / Q000502:physiology; D014774:Virulence
chemical_list: D015800:Protozoan Proteins; D010447:Peptide Hydrolases