Pyruvate kinase type-II isozyme in Plasmodium falciparum localizes to the apicoplast

Parasitol Int. 2009 Mar;58(1):101-5. doi: 10.1016/j.parint.2008.10.005. Epub 2008 Oct 31.

Abstract

Bioinformatics research on Plasmodium falciparum revealed two isoforms of pyruvate kinase: type-I and type-II enzymes. The type-I enzyme shows typical glycolytic properties, while type-II enzyme is involved in fatty acid type-II biosynthesis and has been predicted to localize to the apicoplast with the targeting signal in its N-terminus. The type-I and type-II isoforms have the same evolutionary origin as Toxoplasma gondii isozymes, TgPyKI and TgPyKII, respectively; however, TgPyKII localizes to both the mitochondrion and the apicoplast. Accordingly, we made a recombinant full length of P. falciparum pyruvate kinase type-II protein using a wheat germ cell-free expression system and obtained a specific antibody against the type-II protein. Fluorescent microscopic analysis revealed that P. falciparum type-II enzyme was localized only to the apicoplast, not to the mitochondrion. The data suggest differences in localization and metabolic pathways between P. falciparum and T. gondii pyruvate kinase isoforms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Isoenzymes / chemistry
  • Isoenzymes / genetics
  • Isoenzymes / metabolism*
  • Microscopy, Fluorescence
  • Mitochondria / enzymology
  • Molecular Sequence Data
  • Plasmodium falciparum / enzymology*
  • Plasmodium falciparum / genetics
  • Plastids / enzymology*
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism
  • Pyruvate Kinase / chemistry
  • Pyruvate Kinase / genetics
  • Pyruvate Kinase / metabolism*
  • Recombinant Proteins
  • Sequence Analysis, DNA

Substances

  • Isoenzymes
  • Protozoan Proteins
  • Recombinant Proteins
  • Pyruvate Kinase