A tetracycline-repressible transactivator system to study essential genes in malaria parasites

Cell Host Microbe. 2012 Dec 13;12(6):824-34. doi: 10.1016/j.chom.2012.10.016.


A major obstacle in analyzing gene function in apicomplexan parasites is the absence of a practical regulatable expression system. Here, we identified functional transcriptional activation domains within Apicomplexan AP2 (ApiAP2) family transcription factors. These ApiAP2 transactivation domains were validated in blood-, liver-, and mosquito-stage parasites and used to create a robust conditional expression system for stage-specific, tetracycline-dependent gene regulation in Toxoplasma gondii, Plasmodium berghei, and Plasmodium falciparum. To demonstrate the utility of this system, we created conditional knockdowns of two essential P. berghei genes: profilin (PRF), a protein implicated in parasite invasion, and N-myristoyltransferase (NMT), which catalyzes protein acylation. Tetracycline-induced repression of PRF and NMT expression resulted in a dramatic reduction in parasite viability. This efficient regulatable system will allow for the functional characterization of essential proteins that are found in these important parasites.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gene Expression Regulation*
  • Genes, Essential*
  • Genes, Protozoan
  • Genetics, Microbial / methods*
  • Molecular Biology / methods*
  • Plasmodium berghei / genetics*
  • Plasmodium falciparum / genetics*
  • Tetracycline / metabolism
  • Toxoplasma / genetics*
  • Trans-Activators / biosynthesis


  • Trans-Activators
  • Tetracycline