title: Two Plasmodium 6-Cys family-related proteins have distinct and critical roles in liver-stage development.
abstract: The 10 Plasmodium 6-Cys proteins have critical roles throughout parasite development and are targets for antimalaria vaccination strategies. We analyzed the conserved 6-cysteine domain of this family and show that only the last 4 positionally conserved cysteine residues are diagnostic for this domain and identified 4 additional "6-Cys family-related" proteins. Two of these, sequestrin and B9, are critical to Plasmodium liver-stage development. RT-PCR and immunofluorescence assays show that B9 is translationally repressed in sporozoites and is expressed after hepatocyte invasion where it localizes to the parasite plasma membrane. Mutants lacking B9 expression in the rodent malaria parasites P. berghei and P. yoelii and the human parasite P. falciparum developmentally arrest in hepatocytes. P. berghei mutants arrest in the livers of BALB/c (100%) and C57BL6 mice (>99.9%), and in cultures of Huh7 human-hepatoma cell line. Similarly, P. falciparum mutants while fully infectious to primary human hepatocytes abort development 3 d after infection. This growth arrest is associated with a compromised parasitophorous vacuole membrane a phenotype similar to, but distinct from, mutants lacking the 6-Cys sporozoite proteins P52 and P36. Our results show that 6-Cys proteins have critical but distinct roles in establishment and maintenance of a parasitophorous vacuole and subsequent liver-stage development.
authors: 3Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, the Netherlands. s.m.khan@lumc.nl.
authors: Takeshi
authors: T
authors: Annoura
authors: Ben C L
authors: BC
authors: van Schaijk
authors: Ivo H J
authors: IH
authors: Ploemen
authors: Mohammed
authors: M
authors: Sajid
authors: Jing-wen
authors: JW
authors: Lin
authors: Martijn W
authors: MW
authors: Vos
authors: Avinash G
authors: AG
authors: Dinmohamed
authors: Daniel K
authors: DK
authors: Inaoka
authors: Sanna R
authors: SR
authors: Rijpma
authors: Geert-Jan
authors: GJ
authors: van Gemert
authors: Severine
authors: S
authors: Chevalley-Maurel
authors: Szymon M
authors: SM
authors: Kiełbasa
authors: Fay
authors: F
authors: Scheltinga
authors: Blandine
authors: B
authors: Franke-Fayard
authors: Onny
authors: O
authors: Klop
authors: Cornelus C
authors: CC
authors: Hermsen
authors: Kiyoshi
authors: K
authors: Kita
authors: Audrey
authors: A
authors: Gego
authors: Jean-Francois
authors: JF
authors: Franetich
authors: Dominique
authors: D
authors: Mazier
authors: Stephen L
authors: SL
authors: Hoffman
authors: Chris J
authors: CJ
authors: Janse
authors: Robert W
authors: RW
authors: Sauerwein
authors: Shahid M
authors: SM
authors: Khan
mesh_terms: D000818:Animals; D002460:Cell Line; D019295:Computational Biology; D003545:Cysteine / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D005838:Genotype; D049452:Green Fluorescent Proteins / Q000378:metabolism; D022781:Hepatocytes / Q000469:parasitology*; D008288:Malaria / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009154:Mutation; D010641:Phenotype; D010961:Plasmodium / Q000378:metabolism*; D010962:Plasmodium berghei / Q000378:metabolism; D010963:Plasmodium falciparum / Q000378:metabolism; D010967:Plasmodium yoelii / Q000378:metabolism; D014176:Protein Biosynthesis; D015800:Protozoan Proteins / Q000378:metabolism*; D034101:Sporozoites / Q000254:growth & development
chemical_list: D015800:Protozoan Proteins; D049452:Green Fluorescent Proteins; D003545:Cysteine
keywords: B9; genetically attenuated; liver; malaria; s48/45