An Omics View on the Response to Singlet Oxygen

Berghoff, Bork A.; Klug, Gabriele

doi:10.1002/9781119004813.ch59

Cited by 4 publications

(5 citation statements)

References 90 publications

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“…The simultaneous presence of bacteriochlorophyll, oxygen and light, however, leads to the generation of the harmful singlet oxygen causing photooxidative stress. To minimize damage from singlet oxygen, R. sphaeroides uses cellular surveillance and regulatory mechanisms with respect to light and oxygen availability to strictly control the formation of photosynthetic complexes (Gregor and Klug, 2002; Zeilstra‐Ryalls and Kaplan, 2004), and to rapidly respond to singlet oxygen to prevent the damage to cellular components (Anthony et al ., 2005; Ziegelhoffer and Donohue, 2009; Berghoff et al ., 2011; Nam et al ., 2013; Berghoff and Klug, 2016; Licht et al ., 2020).…”

Section: Introductionmentioning

confidence: 99%

A major checkpoint for protein expression in Rhodobacter sphaeroides during heat stress response occurs at the level of translation

McIntosh

Köchling

Latz

et al. 2021

Environmental Microbiology

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Temperature above the physiological optimum is a stress condition frequently faced by bacteria in their natural environments. Here, we were interested in the correlation between levels of RNA and protein under heat stress. Changes in RNA and protein levels were documented in cultures of Rhodobacter sphaeroides using RNA sequencing, quantitative mass spectrometry, western blot analysis, in vivo [ 35 S] methioninelabelling and plasmid-borne reporter fusions. Changes in the transcriptome were extensive. Strikingly, the proteome remained unchanged except for very few proteins. Examples include a heat shock protein, a DUF1127 protein of unknown function and sigma factor proteins from leaderless transcripts. Insight from this study indicates that R. sphaeroides responds to heat stress by producing a broad range of transcripts while simultaneously preventing translation from nearly all of them, and that this selective production of protein depends on the untranslated region of the transcript. We conclude that measurements of transcript abundance are insufficient to understand gene regulation. Rather, translation can be an important checkpoint for protein expression under certain environmental conditions. Furthermore, during heat shock, regulation at the level of transcription might represent preparation for survival in an unpredictable environment while regulation at translation ensures production of only a few proteins.

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Section: Introductionmentioning

confidence: 99%

A major checkpoint for protein expression in Rhodobacter sphaeroides during heat stress response occurs at the level of translation

McIntosh

Köchling

Latz

et al. 2021

Environmental Microbiology

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“…Bacteriochlorophyll can act as a photosensitizer that in presence of oxygen and light converts the ground‐state triplet oxygen to the harmful singlet oxygen. As a consequence, R. sphaeroides has developed efficient defense mechanisms against singlet oxygen that are controlled by a network of regulatory proteins (reviewed in Glaeser et al ., ; Berghoff and Klug ) and regulatory sRNAs (Adnan et al ., ; Billenkamp et al ., ; Peng et al ., ; Müller et al ., ). To reduce the risk of singlet oxygen generation R. sphaeroides has also developed sophisticated regulatory networks to control the formation of photosynthetic complexes in response to oxygen and light signals (reviewed in: Gregor and Klug ; Zeilstra‐Ryalls and Kaplan ).…”

Section: Introductionmentioning

confidence: 99%

PcrX, an sRNA derived from the 3′‐ UTR of the Rhodobacter sphaeroides puf operon modulates expression of puf genes encoding proteins of the bacterial photosynthetic apparatus

Eisenhardt

Reuscher

Klug

2018

Molecular Microbiology

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Facultative phototrophic bacteria like Rhodobacter sphaeroides can produce ATP by anoxygenic photosynthesis, which is of advantage under conditions with limiting oxygen. However, the simultaneous presence of pigments, light and oxygen leads to the generation of harmful singlet oxygen. In order to avoid this stress situation, the formation of photosynthetic complexes is tightly regulated by light and oxygen signals. In a complex regulatory network several regulatory proteins and the small non-coding RNA PcrZ contribute to the balanced expression of photosynthesis genes. With PcrX this study identifies a second sRNA that is part of this network. The puf operon encodes pigment binding proteins of the light-harvesting I complex (PufBA) and of the reaction center (PufLM), a protein regulating porphyrin flux (PufQ), and a scaffolding protein (PufX). The PcrX sRNA is derived from the 3' UTR of the puf operon mRNA by RNase E-mediated cleavage. It targets the pufX mRNA segment, reduces the half-life of the pufBALMX mRNA and as a consequence affects the level of photosynthetic complexes. By its action PcrX counteracts the increased expression of photosynthesis genes that is mediated by protein regulators and is thus involved in balancing the formation of photosynthetic complexes in response to external stimuli.

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“…As part of incoherent feed-forward loops, they balance the induction of photosynthesis genes upon reduction of oxygen tension. Several sRNAs are induced in response to various stress conditions and were identified as important regulators in the photooxidative stress response of R. sphaeroides [ 43 ]. The four homologous sRNAs, CcsR1-4, target the mRNA for the FlhR regulator and affect the glutathione pool and the pyruvate dehydrogenase complex [ 35 ].…”

Section: Resultsmentioning

confidence: 99%

A Complex Network of Sigma Factors and sRNA StsR Regulates Stress Responses in R. sphaeroides

Eisenhardt

Remes

Grützner

et al. 2021

IJMS

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Adaptation of bacteria to a changing environment is often accompanied by remodeling of the transcriptome. In the facultative phototroph Rhodobacter sphaeroides the alternative sigma factors RpoE, RpoHI and RpoHII play an important role in a variety of stress responses, including heat, oxidative stress and nutrient limitation. Photooxidative stress caused by the simultaneous presence of chlorophylls, light and oxygen is a special challenge for phototrophic organisms. Like alternative sigma factors, several non-coding sRNAs have important roles in the defense against photooxidative stress. RNAseq-based transcriptome data pointed to an influence of the stationary phase-induced StsR sRNA on levels of mRNAs and sRNAs with a role in the photooxidative stress response. Furthermore, StsR also affects expression of photosynthesis genes and of genes for regulators of photosynthesis genes. In vivo and in vitro interaction studies revealed that StsR, that is under control of the RpoHI and RpoHII sigma factors, targets rpoE mRNA and affects its abundance by altering its stability. RpoE regulates expression of the rpoHII gene and, consequently, expression of stsR. These data provide new insights into a complex regulatory network of protein regulators and sRNAs involved in defense against photooxidative stress and the regulation of photosynthesis genes.

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An Omics View on the Response to Singlet Oxygen

Cited by 4 publications

References 90 publications

A major checkpoint for protein expression in Rhodobacter sphaeroides during heat stress response occurs at the level of translation

A major checkpoint for protein expression in Rhodobacter sphaeroides during heat stress response occurs at the level of translation

PcrX, an sRNA derived from the 3′‐ UTR of the Rhodobacter sphaeroides puf operon modulates expression of puf genes encoding proteins of the bacterial photosynthetic apparatus

A Complex Network of Sigma Factors and sRNA StsR Regulates Stress Responses in R. sphaeroides

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