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Bilger R, Migur A, Wulf A, Steglich C, Urlaub H, Hess WR. A type III-Dv CRISPR-Cas system is controlled by the transcription factor RpaB and interacts with the DEAD-box RNA helicase CrhR. Cell Rep 2024; 43:114485. [PMID: 38996066 DOI: 10.1016/j.celrep.2024.114485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 05/26/2024] [Accepted: 06/25/2024] [Indexed: 07/14/2024] Open
Abstract
How CRISPR-Cas systems defend bacteria and archaea against invading genetic elements is well understood, but less is known about their regulation. In the cyanobacterium Synechocystis sp. PCC 6803, the expression of one of the three different CRISPR-Cas systems responds to changes in environmental conditions. The cas operon promoter of this system is controlled by the light- and redox-responsive transcription factor RpaB binding to an HLR1 motif, resulting in transcriptional activation at low light intensities. However, the strong promoter that drives transcription of the cognate repeat-spacer array is not controlled by RpaB. Instead, the leader transcript is bound by the redox-sensitive RNA helicase CrhR. Crosslinking coupled with mass spectrometry analysis and site-directed mutagenesis revealed six residues involved in the CrhR-RNA interaction, with C371 being critically important. Thus, the expression of a type III-Dv CRISPR-Cas system is linked to the redox status of the photosynthetic cell at the transcriptional and post-transcriptional levels.
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Affiliation(s)
- Raphael Bilger
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Angela Migur
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Alexander Wulf
- Bioanalytics Research Group, Department of Clinical Chemistry, University Medical Centre, 37075 Göttingen, Germany; Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Claudia Steglich
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Henning Urlaub
- Bioanalytics Research Group, Department of Clinical Chemistry, University Medical Centre, 37075 Göttingen, Germany; Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Wolfgang R Hess
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany.
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2
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Leusenko AV, Mironov KS, Los DA. Transmembrane and PAS domains of the histidine kinase Hik33 as regulators of cold and light responses in the cyanobacterium Synechocystis sp. PCC 6803. Biochimie 2024; 218:76-84. [PMID: 37567357 DOI: 10.1016/j.biochi.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 07/05/2023] [Accepted: 08/07/2023] [Indexed: 08/13/2023]
Abstract
The PAS (Per-ARNT-Sim) domain is a sensory protein regulatory module found in archaea, prokaryotes, and eukaryotes. Histidine and serine/threonine protein kinases, chemo- and photoreceptors, circadian rhythm regulators, ion channels, phosphodiesterases, and other cellular response regulators are among these proteins. Hik33 is a multifunctional sensory histidine kinase that is implicated in cyanobacterial responses to cold, salt, hyperosmotic, and oxidative stressors. The functional roles of individual Hik33 domains in signal transduction were investigated in this study. Synechocystis Hik33 deletion variants were developed, in which either both or a portion of the transmembrane domains and/or the PAS domain were deleted. Cold stress was applied to the mutant strains either under illumination or in the dark. The findings show that the transmembrane domains govern temperature responses, whereas PAS domain may be involved in regulation of downstream gene expression in light-dependent manner.
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Affiliation(s)
- Anna V Leusenko
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow, 127276, Russia
| | - Kirill S Mironov
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow, 127276, Russia
| | - Dmitry A Los
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow, 127276, Russia.
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Balaga RR, Itoh F, Chauhan S, Mandal M, Krishna PS, Suzuki I, Prakash JSS. Sll1252 Coordinates Electron Transport between Plastoquinone and Cytochrome b6/f Complex in Synechocystis PCC 6803. Genes (Basel) 2023; 14:2151. [PMID: 38136973 PMCID: PMC10743179 DOI: 10.3390/genes14122151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/13/2023] [Accepted: 11/24/2023] [Indexed: 12/24/2023] Open
Abstract
A mutant, Δsll1252ins, was generated to functionally characterize Sll1252. Δsll1252ins exhibited a slow-growth phenotype at 70 µmol photons m-2 s-1 and glucose sensitivity. In Δsll1252ins, the rate of PSII activity was not affected, whereas the whole chain electron transport activity was reduced by 45%. The inactivation of sll1252 led to the upregulation of genes, which were earlier reported to be induced in DBMIB-treated wild-type, suggesting that Sll1252 may be involved in electron transfer from the reduced-PQ pool to Cyt b6/f. The inhibitory effect of DCMU on PSII activity was similar in both wild-type and Δsll1252ins. However, the concentration of DBMIB for 50% inhibition of whole chain electron transport activity was 140 nM for Δsll1252ins and 300 nM for wild-type, confirming the site of action of Sll1252. Moreover, the elevated level of the reduced-PQ pool in Δsll1252ins supports that Sll1252 functions between the PQ pool and Cyt b6/f. Interestingly, we noticed that Δsll1252ins reverted to wild-type phenotype by insertion of natural transposon, ISY523, at the disruption site. Δsll1252-Ntrn, expressing only the C-terminal region of Sll1252, exhibited a slow-growth phenotype and disorganized thylakoid structure compared to wild-type and Δsll1252-Ctrn (expressing only the N-terminal region). Collectively, our data suggest that Sll1252 regulates electron transfer between the PQ pool and the Cyt b6/f complex in the linear photosynthetic electron transport chain via coordinated function of both the N- and C-terminal regions of Sll1252.
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Affiliation(s)
- Radha Rani Balaga
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India;
| | - Fumihiro Itoh
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba 305-8572, Japan;
| | - Suraj Chauhan
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India; (S.C.); (M.M.); (P.S.K.)
| | - Mukulika Mandal
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India; (S.C.); (M.M.); (P.S.K.)
| | - Pilla Sankara Krishna
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India; (S.C.); (M.M.); (P.S.K.)
| | - Iwane Suzuki
- Institute of Life and Environmental Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba 305-8572, Japan;
| | - Jogadhenu S. S. Prakash
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India; (S.C.); (M.M.); (P.S.K.)
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Whitman BT, Wang Y, Murray CRA, Glover MJN, Owttrim GW. Liquid-Liquid Phase Separation of the DEAD-Box Cyanobacterial RNA Helicase Redox (CrhR) into Dynamic Membraneless Organelles in Synechocystis sp. Strain PCC 6803. Appl Environ Microbiol 2023; 89:e0001523. [PMID: 36920190 PMCID: PMC10132119 DOI: 10.1128/aem.00015-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/17/2023] [Indexed: 03/16/2023] Open
Abstract
Compartmentalization of macromolecules into discrete non-lipid-bound bodies by liquid-liquid phase separation (LLPS) is a well-characterized regulatory mechanism frequently associated with the cellular stress response in eukaryotes. In contrast, the formation and importance of similar complexes is just becoming evident in bacteria. Here, we identify LLPS as the mechanism by which the DEAD-box RNA helicase, cyanobacterial RNA helicase redox (CrhR), compartmentalizes into dynamic membraneless organelles in a temporal and spatial manner in response to abiotic stress in the cyanobacterium Synechocystis sp. strain PCC 6803. Stress conditions induced CrhR to form a single crescent localized exterior to the thylakoid membrane, indicating that this region is a crucial domain in the cyanobacterial stress response. These crescents rapidly dissipate upon alleviation of the stress conditions. Furthermore, CrhR aggregation was mediated by LLPS in an RNA-dependent reaction. We propose that dynamic CrhR condensation performs crucial roles in RNA metabolism, enabling rapid adaptation of the photosynthetic apparatus to environmental stresses. These results expand our understanding of the role that functional compartmentalization of RNA helicases and thus RNA processing in membraneless organelles by LLPS-mediated protein condensation performs in the bacterial response to environmental stress. IMPORTANCE Oxygen-evolving photosynthetic cyanobacteria evolved ~3 billion years ago, performing fundamental roles in the biogeochemical evolution of the early Earth and continue to perform fundamental roles in nutrient cycling and primary productivity today. The phylum consists of diverse species that flourish in heterogeneous environments. A prime driver for survival is the ability to alter photosynthetic performance in response to the shifting environmental conditions these organisms continuously encounter. This study demonstrated that diverse abiotic stresses elicit dramatic changes in localization and structural organization of the RNA helicase CrhR associated with the photosynthetic thylakoid membrane. These dynamic changes, mediated by a liquid-liquid phase separation (LLPS)-mediated mechanism, reveal a novel mechanism by which cyanobacteria can compartmentalize the activity of ribonucleoprotein complexes in membraneless organelles. The results have significant consequences for understanding bacterial adaptation and survival in response to changing environmental conditions.
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Affiliation(s)
- Brendan T. Whitman
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Yixiong Wang
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Cameron R. A. Murray
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Mark J. N. Glover
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - George W. Owttrim
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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Li C, Zhang X, Ye T, Li X, Wang G. Protection and Damage Repair Mechanisms Contributed To the Survival of Chroococcidiopsis sp. Exposed To a Mars-Like Near Space Environment. Microbiol Spectr 2022; 10:e0344022. [PMID: 36453906 PMCID: PMC9769825 DOI: 10.1128/spectrum.03440-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 11/16/2022] [Indexed: 12/03/2022] Open
Abstract
Chroococcidiopsis spp. can withstand extremely harsh environments, including a Mars-like environment. However, studies are lacking on the molecular mechanisms of Chroococcidiopsis sp. surviving in Mars-like environments. In the HH-21-5 mission, the desert cyanobacterium Chroococcidiopsis sp. was exposed to a Mars-like environment (near space; 35 km altitude) for 4 h, and a single-factor environment of near space was simulated on the ground. We investigated the survival and endurance mechanisms of Chroococcidiopsis sp. ASB-02 after exposing it to near space by studying its physiological and transcriptional properties. After the exposure, Chroococcidiopsis sp. ASB-02 exhibited high cell viability, although photosystem II activity decreased and the levels of reactive oxygen species increased. The single-factor simulation experiments revealed that for the survival of Chroococcidiopsis sp. ASB-02 in near space, UV radiation was the most important limiting factor, and it was followed by temperature. The near space environment triggered multiple metabolic pathway responses in Chroococcidiopsis sp. ASB-02. The upregulation of extracellular polysaccharides as well as carotenoid and scytonemin biosynthesis genes in response to UV radiation attenuated the extent of radiation reaching the cells. At the same time, genes related to protein synthesis were upregulated in response to the low temperature, overcoming the decrease in metabolic activity that was caused by the low temperature. In near space and after rehydration, the genes involved in various DNA and photosystem II repair pathways were upregulated. This reflected the damage to the DNA and photosystem II protein subunits in cells during the flight and suggested that repair mechanisms play an important role in the recovery of Chroococcidiopsis sp. ASB-02. IMPORTANCE This study reported that the protective and repair mechanisms of Chroococcidiopsis sp. ASB-02 contributed to its endurance ability in a Mars-like near space environment. In Chroococcidiopsis sp. ASB-02, a Mars-like near space environment activated the expression of genes involved in extracellular polysaccharides (EPS), carotenoid, scytonemin, and protein syntheses, which provided additional protection. Additionally, the cell damage repair process enhanced the recovery rate of Chroococcidiopsis sp. ASB-02 after the flight. This study will help to enhance the understanding of the tolerance mechanism of Chroococcidiopsis sp. and to provide important guidance as to the survival requirements for microbial life in a Mars-like environment.
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Affiliation(s)
- Caiyan Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xianyuan Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Tong Ye
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoyan Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Gaohong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
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Zhang J, Hess WR, Zhang C. "Life is short, and art is long": RNA degradation in cyanobacteria and model bacteria. MLIFE 2022; 1:21-39. [PMID: 38818322 PMCID: PMC10989914 DOI: 10.1002/mlf2.12015] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/03/2022] [Accepted: 03/03/2022] [Indexed: 06/01/2024]
Abstract
RNA turnover plays critical roles in the regulation of gene expression and allows cells to respond rapidly to environmental changes. In bacteria, the mechanisms of RNA turnover have been extensively studied in the models Escherichia coli and Bacillus subtilis, but not much is known in other bacteria. Cyanobacteria are a diverse group of photosynthetic organisms that have great potential for the sustainable production of valuable products using CO2 and solar energy. A better understanding of the regulation of RNA decay is important for both basic and applied studies of cyanobacteria. Genomic analysis shows that cyanobacteria have more than 10 ribonucleases and related proteins in common with E. coli and B. subtilis, and only a limited number of them have been experimentally investigated. In this review, we summarize the current knowledge about these RNA-turnover-related proteins in cyanobacteria. Although many of them are biochemically similar to their counterparts in E. coli and B. subtilis, they appear to have distinct cellular functions, suggesting a different mechanism of RNA turnover regulation in cyanobacteria. The identification of new players involved in the regulation of RNA turnover and the elucidation of their biological functions are among the future challenges in this field.
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Affiliation(s)
- Ju‐Yuan Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Algal Biology, Institute of HydrobiologyChinese Academy of SciencesWuhanChina
| | - Wolfgang R. Hess
- Genetics and Experimental Bioinformatics, Faculty of BiologyUniversity of FreiburgFreiburgGermany
| | - Cheng‐Cai Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Algal Biology, Institute of HydrobiologyChinese Academy of SciencesWuhanChina
- Institut WUT‐AMUAix‐Marseille University and Wuhan University of TechnologyWuhanChina
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Migur A, Heyl F, Fuss J, Srikumar A, Huettel B, Steglich C, Prakash JSS, Reinhardt R, Backofen R, Owttrim GW, Hess WR. The temperature-regulated DEAD-box RNA helicase CrhR interactome: Autoregulation and photosynthesis-related transcripts. JOURNAL OF EXPERIMENTAL BOTANY 2021:erab416. [PMID: 34499142 DOI: 10.1093/jxb/erab416] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Indexed: 06/13/2023]
Abstract
RNA helicases play crucial functions in RNA biology. In plants, RNA helicases are encoded by large gene families, performing roles in abiotic stress responses, development, the post-transcriptional regulation of gene expression as well as house-keeping functions. Several of these RNA helicases are targeted to the organelles, mitochondria and chloroplasts. Cyanobacteria are the direct evolutionary ancestors of plant chloroplasts. The cyanobacterium Synechocystis 6803 encodes a single DEAD-box RNA helicase, CrhR, that is induced by a range of abiotic stresses, including low temperature. Though the ΔcrhR mutant exhibits a severe cold-sensitive phenotype, the physiological function(s) performed by CrhR have not been described. To identify transcripts interacting with CrhR, we performed RNA co-immunoprecipitation with extracts from a Synechocystis crhR deletion mutant expressing the FLAG-tagged native CrhR or a K57A mutated version with an anticipated enhanced RNA binding. The composition of the interactome was strikingly biased towards photosynthesis-associated and redox-controlled transcripts. A transcript highly enriched in all experiments was the crhR mRNA, suggesting an auto-regulatory molecular mechanism. The identified interactome explains the described physiological role of CrhR in response to the redox poise of the photosynthetic electron transport chain and characterizes CrhR as an enzyme with a diverse range of transcripts as molecular targets.
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Affiliation(s)
- Anzhela Migur
- Faculty of Biology, University of Freiburg, Schänzlestr., Freiburg, Germany
| | - Florian Heyl
- Department of Computer Science, University of Freiburg, Georges-Koehler-Allee, Freiburg, Germany
| | - Janina Fuss
- Max Planck-Genome-Centre Cologne, Carl-von-Linné-Weg, Köln, Germany
| | - Afshan Srikumar
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Bruno Huettel
- Max Planck-Genome-Centre Cologne, Carl-von-Linné-Weg, Köln, Germany
| | - Claudia Steglich
- Faculty of Biology, University of Freiburg, Schänzlestr., Freiburg, Germany
| | - Jogadhenu S S Prakash
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | | | - Rolf Backofen
- Department of Computer Science, University of Freiburg, Georges-Koehler-Allee, Freiburg, Germany
| | - George W Owttrim
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Wolfgang R Hess
- Faculty of Biology, University of Freiburg, Schänzlestr., Freiburg, Germany
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Whitford DS, Whitman BT, Owttrim GW. Genera specific distribution of DEAD-box RNA helicases in cyanobacteria. Microb Genom 2021; 7. [PMID: 33539277 PMCID: PMC8190605 DOI: 10.1099/mgen.0.000517] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Although RNA helicases are essentially ubiquitous and perform roles in all stages of RNA metabolism, phylogenetic analysis of the DEAD (Asp-Glu-Ala-Asp)-box RNA helicase family in a single phylum has not been performed. Here, we performed a phylogenetic analysis on DEAD-box helicases from all currently available cyanobacterial genomes, comprising a total of 362 helicase protein sequences from 280 strains. DEAD-box helicases belonging to three distinct clades were observed. Two clades, the CsdA (cold shock DEAD-box A)-like and RhlE (RNA helicase E)-like helicases, cluster with the homologous proteins from Escherichia coli. The third clade, the CrhR (cyanobacterial RNA helicase Redox)-like helicases, is unique to cyanobacteria and characterized by a conserved sequence motif in the C-terminal extension. Restricted distribution is observed across cyanobacterial diversity with respect to both helicase type and strain. CrhR-like and CsdA-like helicases essentially never occur together, while RhlE always occurs with either a CrhR-like or CsdA-like helicase. CrhR-like and RhlE-like proteins occurred in filamentous cyanobacteria of the orders Nostocales, Oscillatoriales and Synechococcales. Similarly, CsdA- and RhlE-like proteins are restricted to unicellular cyanobacteria of the genera Cyanobium and Synechococcus. In addition, the unexpected occurrence of RhlE in two Synechococcus strains suggests recent acquisition and evolutionary divergence. This study, therefore, raises physiological and evolutionary questions as to why DEAD-box RNA helicases encoded in cyanobacterial lineages display restricted distributions, suggesting niches that require either CrhR or CsdA RNA helicase activity but not both. Extensive conservation of gene synteny surrounding the previously described rimO–crhR operon is also observed, indicating a role in the maintenance of photosynthesis. The analysis provides insights into the evolution, origin and dissemination of sequences within a single gene family to yield divergent functional roles.
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Affiliation(s)
- Denise S Whitford
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Brendan T Whitman
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - George W Owttrim
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
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Ritter SPA, Lewis AC, Vincent SL, Lo LL, Cunha APA, Chamot D, Ensminger I, Espie GS, Owttrim GW. Evidence for convergent sensing of multiple abiotic stresses in cyanobacteria. Biochim Biophys Acta Gen Subj 2019; 1864:129462. [PMID: 31669584 DOI: 10.1016/j.bbagen.2019.129462] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/18/2019] [Accepted: 09/20/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Bacteria routinely utilize two-component signal transduction pathways to sense and alter gene expression in response to environmental cues. While cyanobacteria express numerous two-component systems, these pathways do not regulate all of the genes within many of the identified abiotic stress-induced regulons. METHODS Electron transport inhibitors combined with western analysis and measurement of chlorophyll a fluorescent yield, using pulse amplitude modulation fluorometry, were used to detect the effect of a diverse range of abiotic stresses on the redox status of the photosynthetic electron transport chain and the accumulation and degradation of the Synechocystis sp. PCC 6803 DEAD box RNA helicase, CrhR. RESULTS Alterations in CrhR abundance were tightly correlated with the redox poise of the electron transport chain between QA and cytochrome b6f, with reduction favoring CrhR accumulation. CONCLUSIONS The results provide evidence for an alternative, convergent sensing mechanism mediated through the redox poise of QB/PQH2 that senses multiple, divergent forms of abiotic stress and regulates accumulation of CrhR. The RNA helicase activity of CrhR could then function as a post-translational effector to regulate downstream gene expression. GENERAL SIGNIFICANCE The potential for a related system in Staphylococcus aureus and higher plant chloroplasts suggest convergent sensing mechanisms may be evolutionarily conserved and occur more widely than anticipated.
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Affiliation(s)
- Sean P A Ritter
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Allison C Lewis
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, Dresden 01307, Germany.
| | - Shelby L Vincent
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Li Ling Lo
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | | | - Danuta Chamot
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Ingo Ensminger
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - George S Espie
- Department of Cell and Systems Biology, University of Toronto, Mississauga, ON L5L 1C6, Canada
| | - George W Owttrim
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
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Universal Molecular Triggers of Stress Responses in Cyanobacterium Synechocystis. Life (Basel) 2019; 9:life9030067. [PMID: 31434306 PMCID: PMC6789579 DOI: 10.3390/life9030067] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/15/2019] [Accepted: 08/17/2019] [Indexed: 02/07/2023] Open
Abstract
Systemic analysis of stress-induced transcription in the cyanobacterium Synechocystis sp. strain PCC 6803 identifies a number of genes as being induced in response to most abiotic stressors (heat, osmotic, saline, acid stress, strong light, and ultraviolet radiation). Genes for heat-shock proteins (HSPs) are activated by all these stresses and form a group that universally responds to all environmental changes. The functions of universal triggers of stress responses in cyanobacteria can be performed by reactive oxygen species (ROS), in particular H2O2, as well as changes in the redox potential of the components of the photosynthetic electron transport chain. The double mutant of Synechocystis sp. PCC 6803 (katG/tpx, or sll1987/sll0755), which is defective in antioxidant enzymes catalase (KatG) and thioredoxin peroxidase (Tpx), cannot grow in the presence of exogenous hydrogen peroxide (H2O2); and it is extremely sensitive to low concentrations of H2O2, especially under conditions of cold stress. Experiments on this mutant demonstrate that H2O2 is involved in regulation of gene expression that responds to a decrease in ambient temperature, and affects both the perception and the signal transduction of cold stress. In addition, they suggest that formation of ROS largely depends on the physical state of the membranes such as fluidity or viscosity. In cyanobacteria, an increase in membrane turnover leads to a decrease in the formation of ROS and an increase in resistance to cold stress. Therefore: (1) H2O2 is the universal trigger of stress responses in cyanobacterial cells; (2) ROS formation (in particular, H2O2) depends on the physical properties of both cytoplasmic and thylakoid membranes; (3) The destructive effect of H2O2 is reduced by increasing of fluidity of biological membranes.
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Singh DK, Lingaswamy B, Koduru TN, Nagu PP, Jogadhenu PSS. A putative merR family transcription factor Slr0701 regulates mercury inducible expression of MerA in the cyanobacterium Synechocystis sp. PCC6803. Microbiologyopen 2019; 8:e00838. [PMID: 31094100 PMCID: PMC6741143 DOI: 10.1002/mbo3.838] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/24/2019] [Accepted: 02/26/2019] [Indexed: 11/23/2022] Open
Abstract
In cyanobacteria, genes conferring mercury resistance are not organized as mer‐operon, unlike in other bacterial phyla. Synechocystis contains only a putative MerR regulator, Slr0701, and a mercury reductase, MerA, located aside from each other in the genome. The slr0701‐mutant showed reduction in photosynthetic activity and reduced tolerance to mercury compared to the wild‐type. The incubation of wild‐type cells with HgCl2 resulted in the upregulation of slr0701 and slr1849 genes whereas mercury‐induced expression was not observed in the slr0701‐mutant. Slr0701 binds to a conserved cis‐regulatory element located in the upstream of slr1849 and slr0701 ORFs. The same element was also identified in the upstream of other cyanobacterial homologs. Slr0701 binds to cis‐regulatory element with faster association and slower dissociation rates in the presence of HgCl2. Although these genes were constitutively expressed, the addition of HgCl2 enhanced their promoter activity suggesting that mercury‐bound Slr0701 triggers induced expression of these genes. The enhanced promoter activity could be attributed to the observed secondary structural changes in Slr0701 in the presence of HgCl2. For the first time, we demonstrated the mechanism of merA regulation in a cyanobacterium, Synechocystis. Although merA and merR genes are distantly located on the cyanobacterial genome and distinct from other bacterial mer‐operons, the transcriptional regulatory mechanism is conserved.
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Affiliation(s)
- Deepak Kumar Singh
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Bantu Lingaswamy
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Tejaswi Naidu Koduru
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Prakash Prabhu Nagu
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
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12
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Systematic identification of light-regulated cold-responsive proteome in a model cyanobacterium. J Proteomics 2018; 179:100-109. [DOI: 10.1016/j.jprot.2018.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/02/2018] [Accepted: 03/06/2018] [Indexed: 11/19/2022]
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13
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Cyanobacterial RNA Helicase CrhR Localizes to the Thylakoid Membrane Region and Cosediments with Degradosome and Polysome Complexes in Synechocystis sp. Strain PCC 6803. J Bacteriol 2016; 198:2089-99. [PMID: 27215789 DOI: 10.1128/jb.00267-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 05/20/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The cyanobacterium Synechocystis sp. strain PCC 6803 encodes a single DEAD box RNA helicase, CrhR, whose expression is tightly autoregulated in response to cold stress. Subcellular localization and proteomic analysis results indicate that CrhR localizes to both the cytoplasmic and thylakoid membrane regions and cosediments with polysome and RNA degradosome components. Evidence is presented that either functional RNA helicase activity or a C-terminal localization signal was required for polysome but not thylakoid membrane localization. Polysome fractionation and runoff translation analysis results indicate that CrhR associates with actively translating polysomes. The data implicate a role for CrhR in translation or RNA degradation in the thylakoid region related to thylakoid biogenesis or stability, a role that is enhanced at low temperature. Furthermore, CrhR cosedimentation with polysome and RNA degradosome complexes links alteration of RNA secondary structure with a potential translation-RNA degradation complex in Synechocystis IMPORTANCE The interaction between mRNA translation and degradation is a major determinant controlling gene expression. Regulation of RNA function by alteration of secondary structure by RNA helicases performs crucial roles, not only in both of these processes but also in all aspects of RNA metabolism. Here, we provide evidence that the cyanobacterial RNA helicase CrhR localizes to both the cytoplasmic and thylakoid membrane regions and cosediments with actively translating polysomes and RNA degradosome components. These findings link RNA helicase alteration of RNA secondary structure with translation and RNA degradation in prokaryotic systems and contribute to the data supporting the idea of the existence of a macromolecular machine catalyzing these reactions in prokaryotic systems, an association hitherto recognized only in archaea and eukarya.
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14
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Sinetova MA, Los DA. New insights in cyanobacterial cold stress responses: Genes, sensors, and molecular triggers. Biochim Biophys Acta Gen Subj 2016; 1860:2391-2403. [PMID: 27422804 DOI: 10.1016/j.bbagen.2016.07.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/16/2016] [Accepted: 07/09/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Cold stress strongly induces the expression of ~100 genes in cyanobacteria. Some of these genes are necessary to protect cellular functions by adjustment of membranes, as well as transcriptional and translational machineries. About a half of cold-induced genes are not functionally characterized. A part of cold-induced genes is under control of a two-component regulatory system, consisting of histidine kinase Hik33 and response regulator Rre26. The mechanism(s) that control another part of cold-inducible genes are still unknown. SCOPE OF REVIEW The aim of this review is to summarise the latest findings in cyanobacterial cold-stress responses including transcriptomics, cold sensing, and molecular triggers. MAJOR CONCLUSIONS A feedback loop between the membrane fluidity and transcription of genes for fatty acid desaturases operates via the transmembrane red-light-activated cold sensor Hik33, which perceives cold-induced membrane rigidification as a change in its thickness. The cold-induced kinase activity of Hik33 is facilitated by interaction with a small protein, Ssl3451 - the third contributor to a canonical two-component regulatory system, which may explain the ability of some cyanobacterial histidine kinases to interact with different response regulators under different stress conditions. Other regulatory systems that control cold-stress responses operate via Ser/Thr protein kinase, SpkE, and via temperature-dependent changes in DNA supercoiling. Transcriptomic analysis shows that universal triggers of stress responses are reactive oxygen species and changes in redox status of plastoquinone pool. GENERAL SIGNIFICANCE Deeper understanding of molecular mechanisms of temperature sensing and regulation of cold-stress responses in photosynthetic cells provide a background for generation of cold-resistant crops.
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Affiliation(s)
- Maria A Sinetova
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, 127276 Moscow, Russian Federation
| | - Dmitry A Los
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, 127276 Moscow, Russian Federation.
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15
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Sinetova MA, Los DA. Systemic analysis of stress transcriptomics of Synechocystis reveals common stress genes and their universal triggers. MOLECULAR BIOSYSTEMS 2016; 12:3254-3258. [DOI: 10.1039/c6mb00551a] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Systemic analysis of stress transcriptomics reveals that ROS and redox changes may universally trigger stress responses in Synechocystis (cyanobacteria).
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Affiliation(s)
- M. A. Sinetova
- Institute of Plant Physiology
- Russian Academy of Sciences
- Moscow
- Russia
| | - D. A. Los
- Institute of Plant Physiology
- Russian Academy of Sciences
- Moscow
- Russia
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16
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Kodru S, Malavath T, Devadasu E, Nellaepalli S, Stirbet A, Subramanyam R. The slow S to M rise of chlorophyll a fluorescence reflects transition from state 2 to state 1 in the green alga Chlamydomonas reinhardtii. PHOTOSYNTHESIS RESEARCH 2015; 125:219-31. [PMID: 25663564 DOI: 10.1007/s11120-015-0084-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 01/08/2015] [Indexed: 05/03/2023]
Abstract
The green alga Chlamydomonas (C.) reinhardtii is a model organism for photosynthesis research. State transitions regulate redistribution of excitation energy between photosystem I (PS I) and photosystem II (PS II) to provide balanced photosynthesis. Chlorophyll (Chl) a fluorescence induction (the so-called OJIPSMT transient) is a signature of several photosynthetic reactions. Here, we show that the slow (seconds to minutes) S to M fluorescence rise is reduced or absent in the stt7 mutant (which is locked in state 1) in C. reinhardtii. This suggests that the SM rise in wild type C. reinhardtii may be due to state 2 (low fluorescence state; larger antenna in PS I) to state 1 (high fluorescence state; larger antenna in PS II) transition, and thus, it can be used as an efficient and quick method to monitor state transitions in algae, as has already been shown in cyanobacteria (Papageorgiou et al. 1999, 2007; Kaňa et al. 2012). We also discuss our results on the effects of (1) 3-(3,4-dichlorophenyl)-1,4-dimethyl urea, an inhibitor of electron transport; (2) n-propyl gallate, an inhibitor of alternative oxidase (AOX) in mitochondria and of plastid terminal oxidase in chloroplasts; (3) salicylhydroxamic acid, an inhibitor of AOX in mitochondria; and (4) carbonyl cyanide p-trifluoromethoxyphenylhydrazone, an uncoupler of phosphorylation, which dissipates proton gradient across membranes. Based on the data presented in this paper, we conclude that the slow PSMT fluorescence transient in C. reinhardtii is due to the superimposition of, at least, two phenomena: qE dependent non-photochemical quenching of the excited state of Chl, and state transitions.
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Affiliation(s)
- Sireesha Kodru
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500 046, India
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17
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Zavřel T, Sinetova MA, Búzová D, Literáková P, Červený J. Characterization of a model cyanobacteriumSynechocystissp. PCC 6803 autotrophic growth in a flat-panel photobioreactor. Eng Life Sci 2015. [DOI: 10.1002/elsc.201300165] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Tomáš Zavřel
- Faculty of Science, Department of Experimental Biology; Masaryk University; Brno Czech Republic
| | - Maria A. Sinetova
- Laboratory of Intracellular Regulation, Institute of Plant Physiology; Russian Academy of Sciences; Moscow Russian Federation
| | - Diana Búzová
- Department of Adaptation Biotechnologies, Global Change Research Centre; Academy of Science of the Czech Republic; Drásov Czech Republic
| | - Petra Literáková
- Department of Adaptation Biotechnologies, Global Change Research Centre; Academy of Science of the Czech Republic; Drásov Czech Republic
| | - Jan Červený
- Department of Adaptation Biotechnologies, Global Change Research Centre; Academy of Science of the Czech Republic; Drásov Czech Republic
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18
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Lei H, Chen G, Wang Y, Ding Q, Wei D. Sll0528, a Site-2-Protease, Is Critically Involved in Cold, Salt and Hyperosmotic Stress Acclimation of Cyanobacterium Synechocystis sp. PCC 6803. Int J Mol Sci 2014; 15:22678-22693. [PMID: 25493476 PMCID: PMC4284730 DOI: 10.3390/ijms151222678] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 11/21/2014] [Accepted: 11/25/2014] [Indexed: 12/17/2022] Open
Abstract
Site-2-proteases (S2Ps) mediated proteolysis of transmembrane transcriptional regulators is a conserved mechanism to regulate transmembrane signaling. The universal presence of S2P homologs in different cyanobacterial genomes suggest conserved and fundamental functions, though limited data has been available. Here we provide the first evidence that Sll0528, a site-2-protease in Synechocystis sp. PCC 6803 is crucial for salt, cold and hyperosmotic stress acclimation. Remarkable induction of sll0528 gene expression was observed under salt, cold and hyperosmotic stress, much higher than induction of the other three S2Ps. Knock-out of sll0528 gene in wild type Synechocystis sp. PCC 6803 increased their sensitivity to salt, cold and hyperosmotic stress, as revealed by retarded growth, reduced pigments and disrupted photosystems. The sll0528 gene was induced to a much smaller extent by high light and mixotrophic growth with glucose. Similar growth responses of the sll0528 knockout mutant and wild type under high light and mixotrophic growth indicated that sll0528 was dispensable for these conditions. Recombinant Sll0528 protein could cleave beta-casein into smaller fragments. These results together suggest that the Sll0528 metalloprotease plays a role in the stress response and lays the foundation for further investigation of its mechanism, as well as providing hints for the functional analysis of other S2Ps in cyanobacteria.
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Affiliation(s)
- Haijin Lei
- College of Light Industry and Food Sciences, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China.
| | - Gu Chen
- College of Light Industry and Food Sciences, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China.
| | - Yuling Wang
- College of Light Industry and Food Sciences, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China.
| | - Qinglong Ding
- College of Light Industry and Food Sciences, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China.
| | - Dong Wei
- College of Light Industry and Food Sciences, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China.
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Tiwari S, Tripathy BC, Jajoo A, Das AB, Murata N, Sane PV. Prasanna K. Mohanty (1934-2013): a great photosynthetiker and a wonderful human being who touched the hearts of many. PHOTOSYNTHESIS RESEARCH 2014; 122:235-260. [PMID: 25193504 DOI: 10.1007/s11120-014-0033-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 08/15/2014] [Indexed: 06/03/2023]
Abstract
Prasanna K. Mohanty, a great scientist, a great teacher and above all a great human being, left us more than a year ago (on March 9, 2013). He was a pioneer in the field of photosynthesis research; his contributions are many and wide-ranging. In the words of Jack Myers, he would be a "photosynthetiker" par excellence. He remained deeply engaged with research almost to the end of his life; we believe that generations of researchers still to come will benefit from his thorough and enormous work. We present here his life and some of his contributions to the field of Photosynthesis Research. The response to this tribute was overwhelming and we have included most of the tributes, which we received from all over the world. Prasanna Mohanty was a pioneer in the field of "Light Regulation of Photosynthesis", a loving and dedicated teacher-unpretentious, idealistic, and an honest human being.
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Affiliation(s)
- Swati Tiwari
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India,
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Prakash JSS, Tiwari S. Prasanna Mohanty (1934–2013): a pioneer and a loving teacher. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS 2013; 19:301-305. [PMCID: PMC3656183 DOI: 10.1007/s12298-013-0183-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- J. S. S. Prakash
- />Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad, 500 046 India
| | - Swati Tiwari
- />School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067 India
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21
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Abstract
Similar to proteins, RNA molecules must fold into the correct conformation and associate with protein complexes in order to be functional within a cell. RNA helicases rearrange RNA secondary structure and RNA-protein interactions in an ATP-dependent reaction, performing crucial functions in all aspects of RNA metabolism. In prokaryotes, RNA helicase activity is associated with roles in housekeeping functions including RNA turnover, ribosome biogenesis, translation and small RNA metabolism. In addition, RNA helicase expression and/or activity are frequently altered during cellular response to abiotic stress, implying they perform defined roles during cellular adaptation to changes in the growth environment. Specifically, RNA helicases contribute to the formation of cold-adapted ribosomes and RNA degradosomes, implying a role in alleviation of RNA secondary structure stabilization at low temperature. A common emerging theme involves RNA helicases acting as scaffolds for protein-protein interaction and functioning as molecular clamps, holding RNA-protein complexes in specific conformations. This review highlights recent advances in DEAD-box RNA helicase association with cellular response to abiotic stress in prokaryotes.
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Affiliation(s)
- George W Owttrim
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
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