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Effect of Hydrogen Peroxide on the Biosynthesis of Heme and Proteins: Potential Implications for the Partitioning of Glu-tRNA(Glu) between These Pathways

Glutamyl-tRNA (Glu-tRNA(Glu)) is the common substrate for both protein translation and heme biosynthesis via the C(5) pathway. Under normal conditions, an adequate supply of this aminoacyl-tRNA is available to both pathways. However, under certain circumstances, Glu-tRNA(Glu) can become scarce, resu...

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Autores principales: Farah, Carolina, Levicán, Gloria, Ibba, Michael, Orellana, Omar
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284751/
https://www.ncbi.nlm.nih.gov/pubmed/25514408
http://dx.doi.org/10.3390/ijms151223011
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author Farah, Carolina
Levicán, Gloria
Ibba, Michael
Orellana, Omar
author_facet Farah, Carolina
Levicán, Gloria
Ibba, Michael
Orellana, Omar
author_sort Farah, Carolina
collection PubMed
description Glutamyl-tRNA (Glu-tRNA(Glu)) is the common substrate for both protein translation and heme biosynthesis via the C(5) pathway. Under normal conditions, an adequate supply of this aminoacyl-tRNA is available to both pathways. However, under certain circumstances, Glu-tRNA(Glu) can become scarce, resulting in competition between the two pathways for this aminoacyl-tRNA. In Acidithiobacillus ferrooxidans, glutamyl-tRNA synthetase 1 (GluRS1) is the main enzyme that synthesizes Glu-tRNA(Glu). Previous studies have shown that GluRS1 is inactivated in vitro by hydrogen peroxide (H(2)O(2)). This raises the question as to whether H(2)O(2) negatively affects in vivo GluRS1 activity in A. ferrooxidans and whether Glu-tRNA(Glu) distribution between the heme and protein biosynthesis processes may be affected by these conditions. To address this issue, we measured GluRS1 activity. We determined that GluRS1 is inactivated when cells are exposed to H(2)O(2), with a concomitant reduction in intracellular heme level. The effects of H(2)O(2) on the activity of purified glutamyl-tRNA reductase (GluTR), the key enzyme for heme biosynthesis, and on the elongation factor Tu (EF-Tu) were also measured. While exposing purified GluTR, the first enzyme of heme biosynthesis, to H(2)O(2) resulted in its inactivation, the binding of glutamyl-tRNA to EF-Tu was not affected. Taken together, these data suggest that in A. ferrooxidans, the flow of glutamyl-tRNA is diverted from heme biosynthesis towards protein synthesis under oxidative stress conditions.
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spelling pubmed-42847512015-01-21 Effect of Hydrogen Peroxide on the Biosynthesis of Heme and Proteins: Potential Implications for the Partitioning of Glu-tRNA(Glu) between These Pathways Farah, Carolina Levicán, Gloria Ibba, Michael Orellana, Omar Int J Mol Sci Article Glutamyl-tRNA (Glu-tRNA(Glu)) is the common substrate for both protein translation and heme biosynthesis via the C(5) pathway. Under normal conditions, an adequate supply of this aminoacyl-tRNA is available to both pathways. However, under certain circumstances, Glu-tRNA(Glu) can become scarce, resulting in competition between the two pathways for this aminoacyl-tRNA. In Acidithiobacillus ferrooxidans, glutamyl-tRNA synthetase 1 (GluRS1) is the main enzyme that synthesizes Glu-tRNA(Glu). Previous studies have shown that GluRS1 is inactivated in vitro by hydrogen peroxide (H(2)O(2)). This raises the question as to whether H(2)O(2) negatively affects in vivo GluRS1 activity in A. ferrooxidans and whether Glu-tRNA(Glu) distribution between the heme and protein biosynthesis processes may be affected by these conditions. To address this issue, we measured GluRS1 activity. We determined that GluRS1 is inactivated when cells are exposed to H(2)O(2), with a concomitant reduction in intracellular heme level. The effects of H(2)O(2) on the activity of purified glutamyl-tRNA reductase (GluTR), the key enzyme for heme biosynthesis, and on the elongation factor Tu (EF-Tu) were also measured. While exposing purified GluTR, the first enzyme of heme biosynthesis, to H(2)O(2) resulted in its inactivation, the binding of glutamyl-tRNA to EF-Tu was not affected. Taken together, these data suggest that in A. ferrooxidans, the flow of glutamyl-tRNA is diverted from heme biosynthesis towards protein synthesis under oxidative stress conditions. MDPI 2014-12-11 /pmc/articles/PMC4284751/ /pubmed/25514408 http://dx.doi.org/10.3390/ijms151223011 Text en © 2014 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Farah, Carolina
Levicán, Gloria
Ibba, Michael
Orellana, Omar
Effect of Hydrogen Peroxide on the Biosynthesis of Heme and Proteins: Potential Implications for the Partitioning of Glu-tRNA(Glu) between These Pathways
title Effect of Hydrogen Peroxide on the Biosynthesis of Heme and Proteins: Potential Implications for the Partitioning of Glu-tRNA(Glu) between These Pathways
title_full Effect of Hydrogen Peroxide on the Biosynthesis of Heme and Proteins: Potential Implications for the Partitioning of Glu-tRNA(Glu) between These Pathways
title_fullStr Effect of Hydrogen Peroxide on the Biosynthesis of Heme and Proteins: Potential Implications for the Partitioning of Glu-tRNA(Glu) between These Pathways
title_full_unstemmed Effect of Hydrogen Peroxide on the Biosynthesis of Heme and Proteins: Potential Implications for the Partitioning of Glu-tRNA(Glu) between These Pathways
title_short Effect of Hydrogen Peroxide on the Biosynthesis of Heme and Proteins: Potential Implications for the Partitioning of Glu-tRNA(Glu) between These Pathways
title_sort effect of hydrogen peroxide on the biosynthesis of heme and proteins: potential implications for the partitioning of glu-trna(glu) between these pathways
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284751/
https://www.ncbi.nlm.nih.gov/pubmed/25514408
http://dx.doi.org/10.3390/ijms151223011
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