A malaria membrane skeletal protein is essential for normal morphogenesis, motility, and infectivity of sporozoites.
Membrane skeletons are structural elements that provide mechanical support to the plasma membrane and define cell shape. Here, we identify and characterize a putative protein component of the membrane skeleton of the malaria parasite. The protein, named PbIMC1a, is the structural orthologue of the Toxoplasma gondii inner membrane complex protein 1 (TgIMC1), a component of the membrane skeleton in tachyzoites. Using targeted gene disruption in the rodent malaria species Plasmodium berghei, we show that PbIMC1a is involved in sporozoite development, is necessary for providing normal sporozoite cell shape and mechanical stability, and is essential for sporozoite infectivity in insect and vertebrate hosts. Knockout of PbIMC1a protein expression reduces, but does not abolish, sporozoite gliding locomotion. We identify a family of proteins related to PbIMC1a in Plasmodium and other apicomplexan parasites. These results provide new functional insight in the role of membrane skeletons in apicomplexan parasite biology.
Khater
Emad I
EI
Department of Biological Sciences, Imperail College London, London SW7 2AZ, England, UK.
Sinden
Robert E
RE
Dessens
Johannes T
JT
D000595:Amino Acid Sequence; D000818:Animals; D009033:Culicidae / Q000469:parasitology; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D040461:Gene Components; D008124:Locomotion; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D009024:Morphogenesis; D010962:Plasmodium berghei / Q000737:chemistry* / Q000166:cytology / Q000254:growth & development / Q000502:physiology; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D034101:Sporozoites / Q000737:chemistry* / Q000166:cytology / Q000254:growth & development / Q000502:physiology; D014158:Transcription, Genetic; D014774:Virulence
D003598:Cytoskeletal Proteins; C435912:IMC1 protein, Toxoplasma gondii; D008565:Membrane Proteins; D015800:Protozoan Proteins