Experimental Genetics of Plasmodium berghei NFU in the Apicoplast Iron-Sulfur Cluster Biogenesis Pathway

PLoS One. 2013 Jun 21;8(6):e67269. doi: 10.1371/journal.pone.0067269. Print 2013.

Abstract

Eukaryotic pathogens of the phylum Apicomplexa contain a non-photosynthetic plastid, termed apicoplast. Within this organelle distinct iron-sulfur [Fe-S] cluster proteins are likely central to biosynthesis pathways, including generation of isoprenoids and lipoic acid. Here, we targeted a nuclear-encoded component of the apicoplast [Fe-S] cluster biosynthesis pathway by experimental genetics in the murine malaria parasite Plasmodium berghei. We show that ablation of the gene encoding a nitrogen fixation factor U (NifU)-like domain containing protein (NFUapi) resulted in parasites that were able to complete the entire life cycle indicating redundant or non-essential functions. nfu (-) parasites displayed reduced merosome formation in vitro, suggesting that apicoplast NFUapi plays an auxiliary role in establishing a blood stage infection. NFUapi fused to a combined fluorescent protein-epitope tag delineates the Plasmodium apicoplast and was tested to revisit inhibition of liver stage development by azithromycin and fosmidomycin. We show that the branched apicoplast signal is entirely abolished by azithromycin treatment, while fosmidomycin had no effect on apicoplast morphology. In conclusion, our experimental genetics analysis supports specialized and/or redundant role(s) for NFUapi in the [Fe-S] cluster biosynthesis pathway in the apicoplast of a malarial parasite.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apicoplasts* / genetics
  • Apicoplasts* / metabolism
  • Azithromycin / pharmacology
  • Female
  • Fosfomycin / analogs & derivatives
  • Fosfomycin / pharmacology
  • Iron-Sulfur Proteins* / biosynthesis
  • Iron-Sulfur Proteins* / genetics
  • Mice
  • Plasmodium berghei* / genetics
  • Plasmodium berghei* / metabolism
  • Protozoan Proteins* / biosynthesis
  • Protozoan Proteins* / genetics

Substances

  • Iron-Sulfur Proteins
  • Protozoan Proteins
  • Fosfomycin
  • fosmidomycin
  • Azithromycin

Grants and funding

This work was supported by the Max Planck Society and partly by the European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n°242095: EVIMalaR - Towards the establishment of a permanent European Virtual Institute dedicated to Malaria Research (EVIMalaR). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.