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Characterization of Light-Enhanced Respiration in Cyanobacteria

In eukaryotic algae, respiratory O(2) uptake is enhanced after illumination, which is called light-enhanced respiration (LER). It is likely stimulated by an increase in respiratory substrates produced during photosynthetic CO(2) assimilation and function in keeping the metabolic and redox homeostasi...

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Autores principales: Shimakawa, Ginga, Kohara, Ayaka, Miyake, Chikahiro
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7796093/
https://www.ncbi.nlm.nih.gov/pubmed/33396191
http://dx.doi.org/10.3390/ijms22010342
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author Shimakawa, Ginga
Kohara, Ayaka
Miyake, Chikahiro
author_facet Shimakawa, Ginga
Kohara, Ayaka
Miyake, Chikahiro
author_sort Shimakawa, Ginga
collection PubMed
description In eukaryotic algae, respiratory O(2) uptake is enhanced after illumination, which is called light-enhanced respiration (LER). It is likely stimulated by an increase in respiratory substrates produced during photosynthetic CO(2) assimilation and function in keeping the metabolic and redox homeostasis in the light in eukaryotic cells, based on the interactions among the cytosol, chloroplasts, and mitochondria. Here, we first characterize LER in photosynthetic prokaryote cyanobacteria, in which respiration and photosynthesis share their metabolisms and electron transport chains in one cell. From the physiological analysis, the cyanobacterium Synechocystis sp. PCC 6803 performs LER, similar to eukaryotic algae, which shows a capacity comparable to the net photosynthetic O(2) evolution rate. Although the respiratory and photosynthetic electron transports share the interchain, LER was uncoupled from photosynthetic electron transport. Mutant analyses demonstrated that LER is motivated by the substrates directly provided by photosynthetic CO(2) assimilation, but not by glycogen. Further, the light-dependent activation of LER was observed even with exogenously added glucose, implying a regulatory mechanism for LER in addition to the substrate amounts. Finally, we discuss the physiological significance of the large capacity of LER in cyanobacteria and eukaryotic algae compared to those in plants that normally show less LER.
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spelling pubmed-77960932021-01-10 Characterization of Light-Enhanced Respiration in Cyanobacteria Shimakawa, Ginga Kohara, Ayaka Miyake, Chikahiro Int J Mol Sci Article In eukaryotic algae, respiratory O(2) uptake is enhanced after illumination, which is called light-enhanced respiration (LER). It is likely stimulated by an increase in respiratory substrates produced during photosynthetic CO(2) assimilation and function in keeping the metabolic and redox homeostasis in the light in eukaryotic cells, based on the interactions among the cytosol, chloroplasts, and mitochondria. Here, we first characterize LER in photosynthetic prokaryote cyanobacteria, in which respiration and photosynthesis share their metabolisms and electron transport chains in one cell. From the physiological analysis, the cyanobacterium Synechocystis sp. PCC 6803 performs LER, similar to eukaryotic algae, which shows a capacity comparable to the net photosynthetic O(2) evolution rate. Although the respiratory and photosynthetic electron transports share the interchain, LER was uncoupled from photosynthetic electron transport. Mutant analyses demonstrated that LER is motivated by the substrates directly provided by photosynthetic CO(2) assimilation, but not by glycogen. Further, the light-dependent activation of LER was observed even with exogenously added glucose, implying a regulatory mechanism for LER in addition to the substrate amounts. Finally, we discuss the physiological significance of the large capacity of LER in cyanobacteria and eukaryotic algae compared to those in plants that normally show less LER. MDPI 2020-12-31 /pmc/articles/PMC7796093/ /pubmed/33396191 http://dx.doi.org/10.3390/ijms22010342 Text en © 2020 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 (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Shimakawa, Ginga
Kohara, Ayaka
Miyake, Chikahiro
Characterization of Light-Enhanced Respiration in Cyanobacteria
title Characterization of Light-Enhanced Respiration in Cyanobacteria
title_full Characterization of Light-Enhanced Respiration in Cyanobacteria
title_fullStr Characterization of Light-Enhanced Respiration in Cyanobacteria
title_full_unstemmed Characterization of Light-Enhanced Respiration in Cyanobacteria
title_short Characterization of Light-Enhanced Respiration in Cyanobacteria
title_sort characterization of light-enhanced respiration in cyanobacteria
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7796093/
https://www.ncbi.nlm.nih.gov/pubmed/33396191
http://dx.doi.org/10.3390/ijms22010342
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