Regulation of Escherichia Coli Rnase R Under Stress Conditions

Regulation of Escherichia Coli Rnase R Under Stress Conditions PDF Author: Chenglu Chen
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Upon encountering stress conditions, cells must rapidly alter their gene expression and re-model their RNA complement to deal with the changing environment. As a consequence, both new RNA transcription as well as RNA degradation must take place. Accordingly, the RNA degradative machinery may adjust to the changes in RNA metabolism. Thus, a study of the response of the three major degradative exoribonucleases in Escherichia coli, polynucleotide phosphorylase, RNase II, and RNase R, to stress is of significant importance. RNase R, a processive 3' to 5' exoribonuclease, is unique among the known E. coli exoribonucleases in its ability to digest through RNAs containing extensive secondary structure without the aid of a helicase. In vivo, RNase R plays important roles in quality control of stable RNA, decay of mRNA with extensive repetitive extragenic palindromic (REP) sequences, cell-cycle regulated degradation of tmRNA in Caulobacter crescentus, as well as processing of rRNA under low temperature in P. syringae. In this dissertation, RNase R was shown to be unusual among the E. coli exoribonucleases in its dramatic response to a variety of stress conditions. Elevation of RNase R activity by as much as 10-fold was observed in response to entry into stationary phase, starvation and cold shock, and an ~3-fold increase was seen during growth in minimal medium compared to rich medium. The elevation in RNase R activity was associated with an increase in RNase R protein. Phenotypes of rnr mutants were also investigated, and RNase R was found to contribute to cell growth and viability. Further investigation of the regulation of RNase R during stress, primarily in stationary phase, revealed a novel regulation mechanism. Despite the large increase in RNase R protein and activity in stationary phase, rnr message actually decreased to only ~14% of its level in exponential phase. Further study revealed that RNase R is highly unstable in exponential phase and becomes stabilized during stationary phase, cold shock, and in minimal medium. Investigation of proteolysis on the unusual instability of RNase R indicated that both Lon and ClpXP play a role. In the absence of Lon, RNase R stability is increased ~10-fold. Based on these results, I propose that the increase in RNase R during stress is due to its enhanced stability under those conditions.

Regulation of Escherichia Coli Rnase R Under Stress Conditions

Regulation of Escherichia Coli Rnase R Under Stress Conditions PDF Author: Chenglu Chen
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Upon encountering stress conditions, cells must rapidly alter their gene expression and re-model their RNA complement to deal with the changing environment. As a consequence, both new RNA transcription as well as RNA degradation must take place. Accordingly, the RNA degradative machinery may adjust to the changes in RNA metabolism. Thus, a study of the response of the three major degradative exoribonucleases in Escherichia coli, polynucleotide phosphorylase, RNase II, and RNase R, to stress is of significant importance. RNase R, a processive 3' to 5' exoribonuclease, is unique among the known E. coli exoribonucleases in its ability to digest through RNAs containing extensive secondary structure without the aid of a helicase. In vivo, RNase R plays important roles in quality control of stable RNA, decay of mRNA with extensive repetitive extragenic palindromic (REP) sequences, cell-cycle regulated degradation of tmRNA in Caulobacter crescentus, as well as processing of rRNA under low temperature in P. syringae. In this dissertation, RNase R was shown to be unusual among the E. coli exoribonucleases in its dramatic response to a variety of stress conditions. Elevation of RNase R activity by as much as 10-fold was observed in response to entry into stationary phase, starvation and cold shock, and an ~3-fold increase was seen during growth in minimal medium compared to rich medium. The elevation in RNase R activity was associated with an increase in RNase R protein. Phenotypes of rnr mutants were also investigated, and RNase R was found to contribute to cell growth and viability. Further investigation of the regulation of RNase R during stress, primarily in stationary phase, revealed a novel regulation mechanism. Despite the large increase in RNase R protein and activity in stationary phase, rnr message actually decreased to only ~14% of its level in exponential phase. Further study revealed that RNase R is highly unstable in exponential phase and becomes stabilized during stationary phase, cold shock, and in minimal medium. Investigation of proteolysis on the unusual instability of RNase R indicated that both Lon and ClpXP play a role. In the absence of Lon, RNase R stability is increased ~10-fold. Based on these results, I propose that the increase in RNase R during stress is due to its enhanced stability under those conditions.

Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria

Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria PDF Author: Frans J. de Bruijn
Publisher: John Wiley & Sons
ISBN: 1119004896
Category : Science
Languages : en
Pages : 1472

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Book Description
Bacteria in various habitats are subject to continuously changing environmental conditions, such as nutrient deprivation, heat and cold stress, UV radiation, oxidative stress, dessication, acid stress, nitrosative stress, cell envelope stress, heavy metal exposure, osmotic stress, and others. In order to survive, they have to respond to these conditions by adapting their physiology through sometimes drastic changes in gene expression. In addition they may adapt by changing their morphology, forming biofilms, fruiting bodies or spores, filaments, Viable But Not Culturable (VBNC) cells or moving away from stress compounds via chemotaxis. Changes in gene expression constitute the main component of the bacterial response to stress and environmental changes, and involve a myriad of different mechanisms, including (alternative) sigma factors, bi- or tri-component regulatory systems, small non-coding RNA’s, chaperones, CHRIS-Cas systems, DNA repair, toxin-antitoxin systems, the stringent response, efflux pumps, alarmones, and modulation of the cell envelope or membranes, to name a few. Many regulatory elements are conserved in different bacteria; however there are endless variations on the theme and novel elements of gene regulation in bacteria inhabiting particular environments are constantly being discovered. Especially in (pathogenic) bacteria colonizing the human body a plethora of bacterial responses to innate stresses such as pH, reactive nitrogen and oxygen species and antibiotic stress are being described. An attempt is made to not only cover model systems but give a broad overview of the stress-responsive regulatory systems in a variety of bacteria, including medically important bacteria, where elucidation of certain aspects of these systems could lead to treatment strategies of the pathogens. Many of the regulatory systems being uncovered are specific, but there is also considerable “cross-talk” between different circuits. Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria is a comprehensive two-volume work bringing together both review and original research articles on key topics in stress and environmental control of gene expression in bacteria. Volume One contains key overview chapters, as well as content on one/two/three component regulatory systems and stress responses, sigma factors and stress responses, small non-coding RNAs and stress responses, toxin-antitoxin systems and stress responses, stringent response to stress, responses to UV irradiation, SOS and double stranded systems repair systems and stress, adaptation to both oxidative and osmotic stress, and desiccation tolerance and drought stress. Volume Two covers heat shock responses, chaperonins and stress, cold shock responses, adaptation to acid stress, nitrosative stress, and envelope stress, as well as iron homeostasis, metal resistance, quorum sensing, chemotaxis and biofilm formation, and viable but not culturable (VBNC) cells. Covering the full breadth of current stress and environmental control of gene expression studies and expanding it towards future advances in the field, these two volumes are a one-stop reference for (non) medical molecular geneticists interested in gene regulation under stress.

Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria, 2 Volume Set

Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria, 2 Volume Set PDF Author: Frans J. de Bruijn
Publisher: John Wiley & Sons
ISBN: 1119004888
Category : Science
Languages : en
Pages : 1460

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Book Description
Bacteria in various habitats are subject to continuously changing environmental conditions, such as nutrient deprivation, heat and cold stress, UV radiation, oxidative stress, dessication, acid stress, nitrosative stress, cell envelope stress, heavy metal exposure, osmotic stress, and others. In order to survive, they have to respond to these conditions by adapting their physiology through sometimes drastic changes in gene expression. In addition they may adapt by changing their morphology, forming biofilms, fruiting bodies or spores, filaments, Viable But Not Culturable (VBNC) cells or moving away from stress compounds via chemotaxis. Changes in gene expression constitute the main component of the bacterial response to stress and environmental changes, and involve a myriad of different mechanisms, including (alternative) sigma factors, bi- or tri-component regulatory systems, small non-coding RNA’s, chaperones, CHRIS-Cas systems, DNA repair, toxin-antitoxin systems, the stringent response, efflux pumps, alarmones, and modulation of the cell envelope or membranes, to name a few. Many regulatory elements are conserved in different bacteria; however there are endless variations on the theme and novel elements of gene regulation in bacteria inhabiting particular environments are constantly being discovered. Especially in (pathogenic) bacteria colonizing the human body a plethora of bacterial responses to innate stresses such as pH, reactive nitrogen and oxygen species and antibiotic stress are being described. An attempt is made to not only cover model systems but give a broad overview of the stress-responsive regulatory systems in a variety of bacteria, including medically important bacteria, where elucidation of certain aspects of these systems could lead to treatment strategies of the pathogens. Many of the regulatory systems being uncovered are specific, but there is also considerable “cross-talk” between different circuits. Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria is a comprehensive two-volume work bringing together both review and original research articles on key topics in stress and environmental control of gene expression in bacteria. Volume One contains key overview chapters, as well as content on one/two/three component regulatory systems and stress responses, sigma factors and stress responses, small non-coding RNAs and stress responses, toxin-antitoxin systems and stress responses, stringent response to stress, responses to UV irradiation, SOS and double stranded systems repair systems and stress, adaptation to both oxidative and osmotic stress, and desiccation tolerance and drought stress. Volume Two covers heat shock responses, chaperonins and stress, cold shock responses, adaptation to acid stress, nitrosative stress, and envelope stress, as well as iron homeostasis, metal resistance, quorum sensing, chemotaxis and biofilm formation, and viable but not culturable (VBNC) cells. Covering the full breadth of current stress and environmental control of gene expression studies and expanding it towards future advances in the field, these two volumes are a one-stop reference for (non) medical molecular geneticists interested in gene regulation under stress.

Regulating with RNA in Bacteria and Archaea

Regulating with RNA in Bacteria and Archaea PDF Author: Gisela Storz
Publisher: John Wiley & Sons
ISBN: 1683672941
Category : Medical
Languages : en
Pages : 1065

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Book Description
Revealing the many roles of RNA in regulating gene expression For decades after the discoveries of messenger RNA, transfer RNA, and ribosomal RNA, it was largely assumed that the role of RNA in the cell was limited to shuttling the genomic message, chaperoning amino acids, and toiling in the ribosomes. Eventually, hints that RNA molecules might have regulatory roles began to appear. With the advent of genomics and bioinformatics, it became evident that numerous other RNA forms exist and have specific functions, including small RNAs (sRNA), RNA thermometers, and riboswitches to regulate core metabolic pathways, bacterial pathogenesis, iron homeostasis, quorum sensing, and biofilm formation. All of these functions, and more, are presented in Regulating with RNA in Bacteria and Archaea, written by RNA biologists from around the globe. Divided into eight sections-RNases and Helicases, Cis-Acting RNAs, Cis Encoded Base Pairing RNAs, Trans-Encoded Base Pairing RNAs, Protein Titration and Scaffolding, General Considerations, Emerging Topics, and Resources-this book serves as an excellent resource for established RNA biologists and for the many scientists who are studying regulated cellular systems. It is no longer a fair assumption that gene expression regulation is the provenance of proteins only or that control is exerted primarily at the level of transcription. This book makes clear that regulatory RNAs are key partners along with proteins in controlling the complex interactions and pathways found within prokaryotes.

Role in Cell Physiology

Role in Cell Physiology PDF Author: I.F. Pryme
Publisher: Elsevier
ISBN: 0080540678
Category : Science
Languages : en
Pages : 305

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Book Description
This volume deals with functions of the cytoskeleton in different cellular processes such as cell compartmentation and organelle transport, secretion and cell attachment.

Escherichia Coli and Salmonella

Escherichia Coli and Salmonella PDF Author: Frederick C. Neidhardt
Publisher:
ISBN: 9781555810849
Category : Escherichia coli
Languages : en
Pages : 2822

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Book Description
This is the long–awaited second edition of an invaluable classic! Escherichia coli occupies a central role in contemporary molecular biology. It is the unicellular organism about which most is known – all molecular and cellular biologists will want a copy of this book. In 154 chapters, 250 expert authors and editors present the state of the art. Completely rewritten and restructured, the second edition offers a whole new approach to the subject.

Ribonucleases, Part B: Artificial and Engineered Ribonucleases and Speicifc Applications

Ribonucleases, Part B: Artificial and Engineered Ribonucleases and Speicifc Applications PDF Author:
Publisher: Elsevier
ISBN: 0080522572
Category : Science
Languages : en
Pages : 555

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Book Description
This second volume on ribonucleases provides up-to-date, methods-related information on these enzymes. Of particular interest to researchers will be the discussion of artificial and engineered ribonucleases, as well as the application of ribonucleases in medicine and biotechnology.The critically acclaimed laboratory standard for more than forty years, Methods in Enzymology is one of the most highly respected publications in the field of biochemistry. Since 1955, each volume has been eagerly awaited, frequently consulted, and praised by researchers and reviewers alike. Now with more than 300 volumes (all of them still in print), the series contains much material still relevant today--truly an essential publication for researchers in all fields of life sciences.

Systems Biology and Biotechnology of Escherichia coli

Systems Biology and Biotechnology of Escherichia coli PDF Author: Sang Yup Lee
Publisher: Springer Science & Business Media
ISBN: 1402093942
Category : Science
Languages : en
Pages : 471

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Book Description
Systems biology is changing the way biological systems are studied by allowing us to examine the cell and organism as a whole. Systems biotechnology allows optimal design and development of upstream to downstream bioprocesses by taking a systems-approach. E. coli has been a model organism for almost all biological and biotechnological studies. This book brings together for the first time the state-of-the-art reviews by the world-leading experts on systems biology and biotechnological applications of E. coli. The topics covered include genomics and functional genomics, resources for systems biology, network analysis, genome-scale metabolic reconstruction, modelling and simulation, dynamic modelling and simulation, systems-level analysis of evolution, plasmids and expression systems, protein synthesis, production and export, engineering the central metabolism, synthetic biology, and systems metabolic engineering of E. coli. This book provides readers with guidance on how a complex biological system can be studied using E. coli as a model organism. It also presents how to perform synthetic biology and systems metabolic engineering studies on E. coli with successful examples, the approaches of which can be extended to other organisms. This book will be a complete resource for anyone interested in systems biology and biotechnology.

Ribosomes Structure, Function, and Dynamics

Ribosomes Structure, Function, and Dynamics PDF Author: Marina V. Rodnina
Publisher: Springer Science & Business Media
ISBN: 3709102154
Category : Medical
Languages : en
Pages : 428

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Book Description
The ribosome is a macromolecular machine that synthesizes proteins with a high degree of speed and accuracy. Our present understanding of its structure, function and dynamics is the result of six decades of research. This book collects over 40 articles based on the talks presented at the 2010 Ribosome Meeting, held in Orvieto, Italy, covering all facets of the structure and function of the ribosome. New high-resolution crystal structures of functional ribosome complexes and cryo-EM structures of translating ribosomes are presented, while partial reactions of translation are examined in structural and mechanistic detail, featuring translocation as a most dynamic process. Mechanisms of initiation, both in bacterial and eukaryotic systems, translation termination, and novel details of the functions of the respective factors are described. Structure and interactions of the nascent peptide within, and emerging from, the ribosomal peptide exit tunnel are addressed in several articles. Structural and single-molecule studies reveal a picture of the ribosome exhibiting the energy landscape of a processive Brownian machine. The collection provides up-to-date reviews which will serve as a source of essential information for years to come.

Prokaryotic Metabolism and Physiology

Prokaryotic Metabolism and Physiology PDF Author: Byung Hong Kim
Publisher: Cambridge University Press
ISBN: 1107171733
Category : Medical
Languages : en
Pages : 509

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Book Description
Extensive and up-to-date review of key metabolic processes in bacteria and archaea and how metabolism is regulated under various conditions.