ApiLoc - A database of published protein sub-cellular localisation in Apicomplexa

version 3 (curated until May 28, 2011)

The malaria parasite Plasmodium falciparum has only one pyruvate dehydrogenase complex, which is located in the apicoplast.

Foth, B. J., Stimmler, L. M., Handman, E., Crabb, B. S., Hodder, A. N., McFadden, G. I. (2005 Jan, Mol Microbiol)

The relict plastid (apicoplast) of apicomplexan parasites synthesizes fatty acids and is a promising drug target. In plant plastids, a pyruvate dehydrogenase complex (PDH) converts pyruvate into acetyl-CoA, the major fatty acid precursor, whereas a second, distinct PDH fuels the tricarboxylic acid cycle in the mitochondria. In contrast, the presence of genes encoding PDH and related enzyme complexes in the genomes of five Plasmodium species and of Toxoplasma gondii indicate that these parasites contain only one single PDH. PDH complexes are comprised of four subunits (E1alpha, E1beta, E2, E3), and we confirmed four genes encoding a complete PDH in Plasmodium falciparum through sequencing of cDNA clones. In apicomplexan parasites, many nuclear-encoded proteins are targeted to the apicoplast courtesy of two-part N-terminal leader sequences, and the presence of such N-terminal sequences on all four PDH subunits as well as phylogenetic analyses strongly suggest that the P. falciparum PDH is located in the apicoplast. Fusion of the two-part leader sequences from the E1alpha and E2 genes to green fluorescent protein experimentally confirmed apicoplast targeting. Western blot analysis provided evidence for the expression of the E1alpha and E1beta PDH subunits in blood-stage malaria parasites. The recombinantly expressed catalytic domain of the PDH subunit E2 showed high enzymatic activity in vitro indicating that pyruvate is converted to acetyl-CoA in the apicoplast, possibly for use in fatty acid biosynthesis.

PubMed: 15612915, full text

Localisation information

PF11_0256 (PDH E1a) pyruvate dehydrogenase E1 alpha subunit

Experimental localisation: nowhere except apicoplast during intraerythrocytic
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "Colocalization with the apicoplast-resident protein ACP using -ACP antibodies unambiguously shows that the presequences of PDH subunits E1 and E2 are sufficient to target proteins exclusively to the apicoplast (A and C)."
  • Microscopy type: Light
  • Microscopy method: GFP tag after 191 amino acids
  • Strain: D10
  • Gene model mapping comments: Blast from AY484441, annotation matches
  • Localisation record: Apicoplast only during asexual

PF10_0407 (PDH E2) dihydrolipoamide acyltransferase component E2

Experimental localisation: nowhere except apicoplast during intraerythrocytic
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "Colocalization with the apicoplast-resident protein ACP using -ACP antibodies unambiguously shows that the presequences of PDH subunits E1 and E2 are sufficient to target proteins exclusively to the apicoplast (A and C)."
  • Microscopy type: Light
  • Microscopy method: GFP tag after 61 amino acids
  • Strain: D10
  • Gene model mapping comments: Blast from AY484443
  • Localisation record: Apicoplast only during asexual

PFB0385w (ACP) acyl carrier protein

Experimental localisation: nowhere except apicoplast during intraerythrocytic
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "Colocalization with the apicoplast-resident protein ACP using -ACP antibodies unambiguously shows that the presequences of PDH subunits E1 and E2 are sufficient to target proteins exclusively to the apicoplast (A and C)."
  • Microscopy type: Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain: D10
  • Gene model mapping comments: inferred from another publication
  • Localisation record: apicoplast only during asexual