Role for the Plasmodium sporozoite-specific transmembrane protein S6 in parasite motility and efficient malaria transmission

Cell Microbiol. 2009 Feb;11(2):279-88. doi: 10.1111/j.1462-5822.2008.01252.x. Epub 2008 Oct 30.


Malaria transmission occurs by intradermal deposition of Plasmodium sporozoites during the infectious bite of a female Anopheles mosquito. After formation in midgut-associated oocysts sporozoites actively enter mosquito salivary glands and subsequently invade host hepatocytes where they transform into clinically silent liver stages. To date, two sporozoite-specific transmembrane proteins have been identified that perform vital functions in natural malaria transmission. The sporozoite invasin TRAP drives sporozoite motility and target cell entry whereas the adhesin MAEBL mediates sporozoite recognition of and attachment to salivary glands. Here, we demonstrate that the sporozoite-specific transmembrane protein S6 is required for efficient malaria transmission to the vertebrate host. Targeted deletion of S6 results in severe impairment of sporozoite gliding motility and invasion of mosquito salivary glands. During sporozoite maturation S6 expression is tightly regulated by transcriptional and translational control. We propose that S6 functions together with TRAP/MIC2 family invasins to direct fast, efficient and specific cell entry and, ultimately, life cycle progression of the malaria sporozoite.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Structures / parasitology
  • Animals
  • Anopheles
  • DNA, Protozoan / chemistry
  • DNA, Protozoan / genetics
  • Gene Deletion
  • Locomotion*
  • Malaria / transmission*
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology*
  • Molecular Sequence Data
  • Plasmodium berghei / genetics
  • Plasmodium berghei / physiology*
  • Protozoan Proteins / genetics
  • Protozoan Proteins / physiology*
  • Salivary Glands / parasitology
  • Sequence Analysis, DNA


  • DNA, Protozoan
  • Membrane Proteins
  • Protozoan Proteins

Associated data

  • GENBANK/FJ160771