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Licensed Unlicensed Requires Authentication Published by De Gruyter June 1, 2005

A Putative Glutathione Peroxidase of Drosophila Encodes a Thioredoxin Peroxidase That Provides Resistance against Oxidative Stress But Fails to Complement a Lack of Catalase Activity

  • F. Missirlis , S. Rahlfs , N. Dimopoulos , H. Bauer , K. Becker , A. Hilliker , J.P. Phillips and H. Jäckle
From the journal

Abstract

Cellular defense systems against reactive oxygen species (ROS) include thioredoxin reductase (TrxR) and glutathione reductase (GR). They generate sulfhydryl-reducing systems which are coupled to antioxidant enzymes, the thioredoxin and glutathione peroxidases (TPx and GPx). The fruit fly Drosophila lacks a functional GR, suggesting that the thioredoxin system is the major source for recycling glutathione. Whole genome in silico analysis identified two non-selenium containing putative GPx genes. We examined the biochemical characteristics of one of these gene products and found that it lacks GPx activity and functions as a TPx. Transgene-dependent overexpression of the newly identified Glutathione peroxidase homolog with thioredoxin peroxidase activity (Gtpx-1) gene increases resistance to experimentally induced oxidative stress, but does not compensate for the loss of catalase, an enzyme which, like GTPx-1, functions to eliminate hydrogen peroxide. The results suggest that GTPx-1 is part of the Drosophila Trx antioxidant defense system but acts in a genetically distinct pathway or in a different cellular compartment than catalase.

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Published Online: 2005-06-01
Published in Print: 2003-03-14

Copyright © 2003 by Walter de Gruyter GmbH & Co. KG

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