PEXEL-independent trafficking of Plasmodium falciparum SURFIN4.2 to the parasite-infected red blood cell and Maurer's clefts

Parasitol Int. 2011 Sep;60(3):313-20. doi: 10.1016/j.parint.2011.05.003. Epub 2011 May 17.


SURFIN(4.2) is a parasite-infected red blood cell (iRBC) surface associated protein of Plasmodium falciparum. To analyze the region responsible for the intracellular trafficking of SURFIN(4.2) to the iRBC and Maurer's clefts, a panel of transgenic parasite lines expressing recombinant SURFIN(4.2) fused with green fluorescent protein was generated and evaluated for their localization. We found that the cytoplasmic region containing a tryptophan rich (WR) domain is not necessary for trafficking, whereas the transmembrane (TM) region was. Two PEXEL-like sequences were shown not to be responsible for the trafficking of SURFIN(4.2), demonstrating that the protein is trafficked in a PEXEL-independent manner. N-terminal replacement, deletion of the cysteine-rich domain or the variable region also did not prevent the protein from localizing at the iRBC or Maurer's clefts. A recombinant SURFIN(4.2) protein possessing 50 amino acids upstream of the TM region, TM region itself and a part of the cytoplasmic region was shown to be trafficked into the iRBC and Maurer's clefts, suggesting that there are no essential trafficking motifs in the SURFIN(4.2) extracellular region. A mini-SURFIN(4.2) protein containing WR domain was shown by Western blotting to be more abundantly detected in a Triton X-100-insoluble fraction, compared to the one without WR domain. We suggest that the cytoplasmic region containing the WR may be responsible for their difference in solubility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Protozoan / metabolism
  • Erythrocyte Membrane / metabolism
  • Erythrocyte Membrane / parasitology
  • Erythrocytes / parasitology*
  • Erythrocytes / ultrastructure
  • Fluorescent Antibody Technique, Indirect
  • Green Fluorescent Proteins
  • Host-Parasite Interactions
  • Humans
  • Intracellular Membranes / metabolism
  • Intracellular Membranes / ultrastructure
  • Malaria, Falciparum / parasitology*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Organisms, Genetically Modified
  • Plasmodium falciparum / metabolism*
  • Protein Transport
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism
  • Recombinant Fusion Proteins


  • Antigens, Protozoan
  • Membrane Proteins
  • Protozoan Proteins
  • Recombinant Fusion Proteins
  • SURFIN 4.2 protein, Plasmodium falciparum
  • Green Fluorescent Proteins