Polar‐biased localization of the cold stress‐induced RNA helicase, CrhC, in the Cyanobacterium <i>Anabaena</i> sp. strain PCC 7120

El-Fahmawi, Bassam; Owttrim, George W.

doi:10.1046/j.1365-2958.2003.03783.x

Cited by 22 publications

(20 citation statements)

References 56 publications

(85 reference statements)

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“…We have found the accumulation (ϩ2.3-folds) of the product Cre10.g427700.t1.1, a non-annotated gene with DExD/H box RNA helicase domains. The function of RNA helicases are still poorly understood in plants (109), but under cold temperature these helicases have been found to be possibly involved in mRNA export (110) and in increasing the translation efficiency altering the gene expression (112).…”

Section: Discussionmentioning

confidence: 99%

Systemic Cold Stress Adaptation of Chlamydomonas reinhardtii

Valledor

Furuhashi

Hanak

et al. 2013

Molecular & Cellular Proteomics

130

131

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Chlamydomonas reinhardtii is one of the most important model organisms nowadays phylogenetically situated between higher plants and animals (Merchant et al. 2007). Stress adaptation of this unicellular model algae is in the focus because of its relevance to biomass and biofuel production. Here, we have studied cold stress adaptation of C. reinhardtii hitherto not described for this algae whereas intensively studied in higher plants. Toward this goal, high throughput mass spectrometry was employed to integrate proteome, metabolome, physiological and cell-morphological changes during a time-course from 0 to 120 h. These data were complemented with RT-qPCR for target genes involved in central metabolism, signaling, and lipid biosynthesis. Using this approach dynamics in central metabolism were linked to cold-stress dependent sugar and autophagy pathways as well as novel genes in C. reinhardtii such as CKIN1, CKIN2 and a hitherto functionally not annotated protein named CKIN3. Cold stress affected extensively the physiology and the organization of the cell. Gluconeogenesis and starch biosynthesis pathways are activated leading to a pronounced starch and sugar accumulation. Quantitative lipid profiles indicate a sharp decrease in the lipophilic fraction and an increase in polyunsaturated fatty acids suggesting this as a mechanism of maintaining membrane fluidity. The proteome is completely remodeled during cold stress: specific candidates of the ribosome and the spliceosome indicate altered biosynthesis and degradation of proteins important for adaptation to low temperatures. Specific proteasome degradation may be mediated by the observed cold-specific changes in the ubiquitinylation system. Sparse partial least squares regression analysis was applied for protein correlation network analysis using proteins as predictors and Fv/Fm, FW, total lipids, and starch as responses. We applied also Granger causality analysis and revealed correlations between proteins and metabolites otherwise not detectable. Twenty percent of the proteins responsive to cold are uncharacterized proteins. This presents a considerable resource for new discoveries in cold stress biology in alga and plants. Molecular &

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Section: Discussionmentioning

confidence: 99%

Systemic Cold Stress Adaptation of Chlamydomonas reinhardtii

Valledor

Furuhashi

Hanak

et al. 2013

Molecular & Cellular Proteomics

130

131

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“…The three membranes present in Synechocystis cells were separated by discontinuous flotation sucrose gradient fractionation as initially described by Murata and Omata (36) and modified according to the method of El-Fahmawi and Owttrim (21). Cultures grown at 30°C or cold shocked at 20°C for 3 h were harvested at 7,500 ϫ g for 15 min at 4°C.…”

Section: Methodsmentioning

confidence: 99%

“…RhlB is RNA degradosome associated at the cytoplasmic membrane, and SrmB and DbpA are solubility and ribosome associated, while the multifunctional helicase DeaD is associated with all three functions (18). Although RNA helicases do not contain canonical membrane-spanning domains, they are membrane associated in some bacteria (12,21,22) but not all (13). For example, RNA helicases associated with RNA degradosomes localize to the cytoplasmic membrane via RNase E in E. coli (4,12) and RNase Y in B. subtilis (5) whereas CshA and CshB colocalize with CspB and ribosomes in areas surrounding the B. subtilis nucleoid, the localization being dependent on active transcription (23).…”

Section: Importancementioning

confidence: 99%

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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

et al. 2016

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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. IMPORTANCEThe 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. C ompartmentalization of metabolic processes is crucial for cells to avoid futile cycles. While this is efficiently achieved by lipid bilayers in eukaryotic cells, this solution does not generally apply in prokaryotes. Although prokaryotes have the ability to compartmentalize using invagination of the inner cell membrane, these compartments, for example, magnetosomes, tend to perform one specific function and are not widely used (1). Prokaryotes can also form proteinaceous microcompartments in which specific reactions occur, the primary cyanobacterial example being that of carboxysomes (2). Prokaryotes do not compartmentalize routine, everyday anabolic and catabolic processes such as transcription and translation or protein and RNA decay; however, there is a growing body of evidence indicating that prokaryotes spatially confine these cellular processes (3). A prime example is the localization of the RNA degradation complex, the degradosome, to the cytoplasmic membrane (CM) in Escherichia coli (4) and Bacillus subtilis (5).The E. coli degradosome consists of RNase E, polynucleotide phosphorylase (PNPase), enolase, and the DEAD box RNA he...

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“…The list includes chemotaxis proteins, parts of the chromosomal segregation apparatus, type IV pili, slime nozzles in gliding bacteria, twocomponent signaling proteins, septation regulators, flagella, actin polymerization nucleators, autotransporters, type II secretion proteins, a type III secretion system, a type IV apparatus, an RNA helicase, and a bacterial reverse transcriptase (38,67,143,147,194,293,297,340,374,378 (199), and the ActA protein congregates at future division sites in filaments of Listeria monocytogenes (250). All these behaviors identify an underlying heterogeneity in the cell envelope, one that is defined by and enhanced by the existence of polarities in cell shape.…”

Section: Sequestrationmentioning

confidence: 99%

The Selective Value of Bacterial Shape

Young

2006

Microbiol Mol Biol Rev

867

777

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SUMMARY Why do bacteria have shape? Is morphology valuable or just a trivial secondary characteristic? Why should bacteria have one shape instead of another? Three broad considerations suggest that bacterial shapes are not accidental but are biologically important: cells adopt uniform morphologies from among a wide variety of possibilities, some cells modify their shape as conditions demand, and morphology can be tracked through evolutionary lineages. All of these imply that shape is a selectable feature that aids survival. The aim of this review is to spell out the physical, environmental, and biological forces that favor different bacterial morphologies and which, therefore, contribute to natural selection. Specifically, cell shape is driven by eight general considerations: nutrient access, cell division and segregation, attachment to surfaces, passive dispersal, active motility, polar differentiation, the need to escape predators, and the advantages of cellular differentiation. Bacteria respond to these forces by performing a type of calculus, integrating over a number of environmental and behavioral factors to produce a size and shape that are optimal for the circumstances in which they live. Just as we are beginning to answer how bacteria create their shapes, it seems reasonable and essential that we expand our efforts to understand why they do so.

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Polar‐biased localization of the cold stress‐induced RNA helicase, CrhC, in the Cyanobacterium Anabaena sp. strain PCC 7120

Cited by 22 publications

References 56 publications

Systemic Cold Stress Adaptation of Chlamydomonas reinhardtii

Systemic Cold Stress Adaptation of Chlamydomonas reinhardtii

Cyanobacterial RNA Helicase CrhR Localizes to the Thylakoid Membrane Region and Cosediments with Degradosome and Polysome Complexes in Synechocystis sp. Strain PCC 6803

The Selective Value of Bacterial Shape

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