ApiLoc - A database of published protein sub-cellular localisation in Apicomplexa
|version 3 (curated until May 28, 2011)|
Dual targeting of antioxidant and metabolic enzymes to the mitochondrion and the apicoplast of Toxoplasma gondii.
Pino, P., Foth, B. J., Kwok, L. Y., Sheiner, L., Schepers, R., Soldati, T., Soldati-Favre, D. (2007 Aug 31, PLoS Pathog)
Toxoplasma gondii is an aerobic protozoan parasite that possesses mitochondrial antioxidant enzymes to safely dispose of oxygen radicals generated by cellular respiration and metabolism. As with most Apicomplexans, it also harbors a chloroplast-like organelle, the apicoplast, which hosts various biosynthetic pathways and requires antioxidant protection. Most apicoplast-resident proteins are encoded in the nuclear genome and are targeted to the organelle via a bipartite N-terminal targeting sequence. We show here that two antioxidant enzymes-a superoxide dismutase (TgSOD2) and a thioredoxin-dependent peroxidase (TgTPX1/2)-and an aconitase are dually targeted to both the apicoplast and the mitochondrion of T. gondii. In the case of TgSOD2, our results indicate that a single gene product is bimodally targeted due to an inconspicuous variation within the putative signal peptide of the organellar protein, which significantly alters its subcellular localization. Dual organellar targeting of proteins might occur frequently in Apicomplexans to serve important biological functions such as antioxidant protection and carbon metabolism.
PFF1130c (SOD2) superoxide dismutaseExperimental localisation: apicoplast during ring, apicoplast during trophozoite, apicoplast during schizont, not mitochondrion during ring, not mitochondrion during trophozoite, not mitochondrion during schizont
TGME49_116330 (SOD2, SODB2) iron-containing superoxide dismutaseExperimental localisation: apicoplast during tachyzoite, mitochondrion during tachyzoite
TGME49_116190 (SOD3, SODB3) superoxide dismutase, putativeExperimental localisation: mitochondrion during intracellular tachyzoite
TGME49_030410 (PRX3, Prx3) peroxiredoxin 3Experimental localisation: mitochondrion during intracellular tachyzoite
TGME49_066120 (TPX1/1, TPX1/2) glutathione/thioredoxin peroxidase, putativeExperimental localisation: apicoplast during intracellular tachyzoite, mitochondrion during intracellular tachyzoite
TGME49_026730 (ACN/IRP, Aconitase (ACN)) aconitate hydratase, putativeExperimental localisation: mitochondrion during intracellular tachyzoite, apicoplast during intracellular tachyzoite
TGME49_057680 (MLC1) myosin light chain TgMLC1Experimental localisation: periphery of parasite during intracellular tachyzoite