Characterization of the small exported Plasmodium falciparum membrane protein SEMP1

PLoS One. 2014 Jul 25;9(7):e103272. doi: 10.1371/journal.pone.0103272. eCollection 2014.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cytosol / parasitology
  • Erythrocytes / metabolism
  • Erythrocytes / parasitology
  • Gametogenesis
  • Host-Parasite Interactions*
  • Humans
  • Malaria / genetics*
  • Malaria / parasitology
  • Membrane Proteins / genetics*
  • Plasmodium falciparum / genetics*
  • Plasmodium falciparum / metabolism
  • Plasmodium falciparum / pathogenicity
  • Protozoan Proteins / genetics*
  • Protozoan Proteins / metabolism
  • Virulence


  • Membrane Proteins
  • Protozoan Proteins
  • SEMP1 protein, Plasmodium falciparum

Grants and funding

This project was supported by the Swiss National Science Foundation ( under grant number 31003A_132709 and 31003A_143916. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.