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. and Soldati-Favre, D. (2007) Dual targeting of antioxidant and metabolic enzymes to the mitochondrion and the apicoplast of Toxoplasma gondii. PLoS Pathogens, 3(8), e115. (doi: 10.1371/journal.ppat.0030115)

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Publisher's URL: http://dx.doi.org/10.1371/journal.ppat.0030115

Abstract

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.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Sheiner, Professor Lilach
Authors: Pino, P., Foth, B.J., Kwok, L.-Y., Sheiner, L., Schepers, R., Soldati, T., and Soldati-Favre, D.
College/School:College of Medical Veterinary and Life Sciences > School of Infection & Immunity
Journal Name:PLoS Pathogens
Publisher:Public Library of Science
ISSN:1553-7366
ISSN (Online):1553-7374
Copyright Holders:Copyright © 2007 The Authors
First Published:First published in PLoS ONE 3(8):e115
Publisher Policy:Reproduced under a Creative Commons License
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