title: Characterization of the small exported Plasmodium falciparum membrane protein SEMP1.
abstract: Survival and virulence of the human malaria parasite Plasmodium falciparum during the blood stage of infection critically depend on extensive host cell refurbishments mediated through export of numerous parasite proteins into the host cell. The parasite-derived membranous structures called Maurer's clefts (MC) play an important role in protein trafficking from the parasite to the red blood cell membrane. However, their specific function has yet to be determined. We identified and characterized a new MC membrane protein, termed small exported membrane protein 1 (SEMP1). Upon invasion it is exported into the RBC cytosol where it inserts into the MCs before it is partly translocated to the RBC membrane. Using conventional and conditional loss-of-function approaches we showed that SEMP1 is not essential for parasite survival, gametocytogenesis, or PfEMP1 export under culture conditions. Co-IP experiments identified several potential interaction partners, including REX1 and other membrane-associated proteins that were confirmed to co-localize with SEMP1 at MCs. Transcriptome analysis further showed that expression of a number of exported parasite proteins was up-regulated in SEMP1-depleted parasites. By using Co-IP and transcriptome analysis for functional characterization of an exported parasite protein we provide a new starting point for further detailed dissection and characterisation of MC-associated protein complexes.
authors: Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors: Olivier
authors: O
authors: Dietz
authors: Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors: Sebastian
authors: S
authors: Rusch
authors: Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors: Françoise
authors: F
authors: Brand
authors: Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors: Esther
authors: E
authors: Mundwiler-Pachlatko
authors: Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors: Annette
authors: A
authors: Gaida
authors: Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors: Till
authors: T
authors: Voss
authors: Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors: Hans-Peter
authors: HP
authors: Beck
mesh_terms: D000818:Animals; D003600:Cytosol / Q000469:parasitology; D004912:Erythrocytes / Q000378:metabolism / Q000469:parasitology; D005718:Gametogenesis; D006790:Host-Parasite Interactions; D006801:Humans; D008288:Malaria / Q000235:genetics* / Q000469:parasitology; D008565:Membrane Proteins / Q000235:genetics*; D010963:Plasmodium falciparum / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D014774:Virulence
chemical_list: D008565:Membrane Proteins; D015800:Protozoan Proteins; C000596822:SEMP1 protein, Plasmodium falciparum