The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Jörg Vogel - One of the best experts on this subject based on the ideXlab platform.
-
a 3 utr derived small rna provides the regulatory noncoding arm of the inner Membrane Stress response
Molecular Cell, 2016Co-Authors: Yanjie Chao, Jörg VogelAbstract:Small RNAs (sRNAs) from conserved noncoding genes are crucial regulators in bacterial signaling pathways but have remained elusive in the Cpx response to inner Membrane Stress. Here we report that an alternative biogenesis pathway releasing the conserved mRNA 3' UTR of Stress chaperone CpxP as an ∼60-nt sRNA provides the noncoding arm of the Cpx response. This so-called CpxQ sRNA, generated by general mRNA decay through RNase E, acts as an Hfq-dependent repressor of multiple mRNAs encoding extracytoplasmic proteins. Both CpxQ and the Cpx pathway are required for cell survival under conditions of dissipation of Membrane potential. Our discovery of CpxQ illustrates how the conversion of a transcribed 3' UTR into an sRNA doubles the output of a single mRNA to produce two factors with spatially segregated functions during inner Membrane Stress: a chaperone that targets problematic proteins in the periplasm and a regulatory RNA that dampens their synthesis in the cytosol.
-
A 3′ UTR-Derived Small RNA Provides the Regulatory Noncoding Arm of the Inner Membrane Stress Response
Molecular cell, 2016Co-Authors: Yanjie Chao, Jörg VogelAbstract:Small RNAs (sRNAs) from conserved noncoding genes are crucial regulators in bacterial signaling pathways but have remained elusive in the Cpx response to inner Membrane Stress. Here we report that an alternative biogenesis pathway releasing the conserved mRNA 3' UTR of Stress chaperone CpxP as an ∼60-nt sRNA provides the noncoding arm of the Cpx response. This so-called CpxQ sRNA, generated by general mRNA decay through RNase E, acts as an Hfq-dependent repressor of multiple mRNAs encoding extracytoplasmic proteins. Both CpxQ and the Cpx pathway are required for cell survival under conditions of dissipation of Membrane potential. Our discovery of CpxQ illustrates how the conversion of a transcribed 3' UTR into an sRNA doubles the output of a single mRNA to produce two factors with spatially segregated functions during inner Membrane Stress: a chaperone that targets problematic proteins in the periplasm and a regulatory RNA that dampens their synthesis in the cytosol.
-
σe dependent small rnas of salmonella respond to Membrane Stress by accelerating global omp mrna decay
Molecular Microbiology, 2006Co-Authors: Kai Papenfort, Verena Pfeiffer, Franziska Mika, Sacha Lucchini, Jay C D Hinton, Jörg VogelAbstract:The bacterial envelope Stress response (ESR) is triggered by the accumulation of misfolded outer Membrane proteins (OMPs) upon envelope damage or excessive OMP synthesis, and is mediated by the alternative sigma factor, σE. Activation of the σE pathway causes a rapid downregulation of major omp mRNAs, which prevents further build-up of unassembled OMPs and liberates the translocation and folding apparatus under conditions that require envelope remodelling. The factors that facilitate the rapid removal of the unusually stable omp mRNAs in the ESR were previously unknown. We report that in Salmonella the ESR relies upon two highly conserved, σE-controlled small non-coding RNAs, RybB and MicA. By using a transcriptomic approach and kinetic analyses of target mRNA decay in vivo, RybB was identified as the factor that selectively accelerates the decay of multiple major omp mRNAs upon induction of the ESR, while MicA is proposed to facilitate rapid decay of the single ompA mRNA. In unStressed bacterial cells, the two σE-dependent small RNAs function within a surveillance loop to maintain envelope homeostasis and to achieve autoregulation of σE.
Martin Buck - One of the best experts on this subject based on the ideXlab platform.
-
anionic lipids and the cytoskeletal proteins mreb and rodz define the spatio temporal distribution and function of Membrane Stress controller pspa in escherichia coli
Microbiology, 2014Co-Authors: Goran Jovanovic, Parul Mehta, Liming Ying, Martin BuckAbstract:All cell types must maintain the integrity of their Membranes. The conserved bacterial Membrane-associated protein PspA is a major effector acting upon extracytoplasmic Stress and is implicated in protection of the inner Membrane of pathogens, formation of biofilms and multi-drug-resistant persister cells. PspA and its homologues in Gram-positive bacteria and archaea protect the cell envelope whilst also supporting thylakoid biogenesis in cyanobacteria and higher plants. In enterobacteria, PspA is a dual function protein negatively regulating the Psp system in the absence of Stress and acting as an effector of Membrane integrity upon Stress. We show that in Escherichia coli the low-order oligomeric PspA regulatory complex associates with cardiolipin-rich, curved polar inner Membrane regions. There, cardiolipin and the flotillin 1 homologue YqiK support the PspBC sensors in transducing a Membrane Stress signal to the PspA-PspF inhibitory complex. After Stress perception, PspA high-order oligomeric effector complexes initially assemble in polar Membrane regions. Subsequently, the discrete spatial distribution and dynamics of PspA effector(s) in lateral Membrane regions depend on the actin homologue MreB and the peptidoglycan machinery protein RodZ. The consequences of loss of cytoplasmic Membrane anionic lipids, MreB, RodZ and/or YqiK suggest that the mode of action of the PspA effector is closely associated with cell envelope organization.
-
Managing Membrane Stress: the phage shock protein (Psp) response, from molecular mechanisms to physiology.
FEMS microbiology reviews, 2010Co-Authors: Nicolas Joly, Goran Jovanovic, Christoph Engl, Maxime Huvet, Tina Toni, Xia Sheng, Michael P. H. Stumpf, Martin BuckAbstract:The bacterial phage shock protein (Psp) response functions to help cells manage the impacts of agents impairing cell Membrane function. The system has relevance to biotechnology and to medicine. Originally discovered in Escherichia coli, Psp proteins and homologues are found in Gram-positive and Gram-negative bacteria, in archaea and in plants. Study of the E. coli and Yersinia enterocolitica Psp systems provides insights into how Membrane-associated sensory Psp proteins might perceive Membrane Stress, signal to the transcription apparatus and use an ATP-hydrolysing transcription activator to produce effector proteins to overcome the Stress. Progress in understanding the mechanism of signal transduction by the Membrane-bound Psp proteins, regulation of the psp gene-specific transcription activator and the cell biology of the system is presented and discussed. Many features of the action of the Psp system appear to be dominated by states of self-association of the master effector, PspA, and the transcription activator, PspF, alongside a signalling pathway that displays strong conditionality in its requirement.
-
In vivo localizations of Membrane Stress controllers PspA and PspG in Escherichia coli.
Molecular microbiology, 2009Co-Authors: Christoph Engl, Goran Jovanovic, Liming Ying, Louise J. Lloyd, Heath Murray, Martin Spitaler, Jeff Errington, Martin BuckAbstract:The phage shock protein (Psp) response in Gram-negative bacteria counteracts Membrane Stress. Transcription of the PspF regulon (pspABCDE and pspG) in Escherichia coli is induced upon Stresses that dissipate the proton motive force (pmf). Using GFP fusions we have visualized the subcellular localizations of PspA (a negative regulator and effector of Psp) and PspG (an effector of Psp). It has previously been proposed that PspA evenly coates the inner Membrane of the cell. We now demonstrate that instead of uniformly covering the entire cell, PspA (and PspG) is highly organized into what appear to be distinct functional classes (complexes at the cell pole and the lateral cell wall). Real-time observations revealed lateral PspA and PspG complexes are highly mobile, but absent in cells lacking MreB. Without the MreB cytoskeleton, induction of the Psp response is still observed, yet these cells fail to maintain pmf under Stress conditions. The two spatial subspecies therefore appear to be dynamically and functionally distinct with the polar clusters being associated with sensory function and the mobile complexes with maintenance of pmf.
Yanjie Chao - One of the best experts on this subject based on the ideXlab platform.
-
a 3 utr derived small rna provides the regulatory noncoding arm of the inner Membrane Stress response
Molecular Cell, 2016Co-Authors: Yanjie Chao, Jörg VogelAbstract:Small RNAs (sRNAs) from conserved noncoding genes are crucial regulators in bacterial signaling pathways but have remained elusive in the Cpx response to inner Membrane Stress. Here we report that an alternative biogenesis pathway releasing the conserved mRNA 3' UTR of Stress chaperone CpxP as an ∼60-nt sRNA provides the noncoding arm of the Cpx response. This so-called CpxQ sRNA, generated by general mRNA decay through RNase E, acts as an Hfq-dependent repressor of multiple mRNAs encoding extracytoplasmic proteins. Both CpxQ and the Cpx pathway are required for cell survival under conditions of dissipation of Membrane potential. Our discovery of CpxQ illustrates how the conversion of a transcribed 3' UTR into an sRNA doubles the output of a single mRNA to produce two factors with spatially segregated functions during inner Membrane Stress: a chaperone that targets problematic proteins in the periplasm and a regulatory RNA that dampens their synthesis in the cytosol.
-
A 3′ UTR-Derived Small RNA Provides the Regulatory Noncoding Arm of the Inner Membrane Stress Response
Molecular cell, 2016Co-Authors: Yanjie Chao, Jörg VogelAbstract:Small RNAs (sRNAs) from conserved noncoding genes are crucial regulators in bacterial signaling pathways but have remained elusive in the Cpx response to inner Membrane Stress. Here we report that an alternative biogenesis pathway releasing the conserved mRNA 3' UTR of Stress chaperone CpxP as an ∼60-nt sRNA provides the noncoding arm of the Cpx response. This so-called CpxQ sRNA, generated by general mRNA decay through RNase E, acts as an Hfq-dependent repressor of multiple mRNAs encoding extracytoplasmic proteins. Both CpxQ and the Cpx pathway are required for cell survival under conditions of dissipation of Membrane potential. Our discovery of CpxQ illustrates how the conversion of a transcribed 3' UTR into an sRNA doubles the output of a single mRNA to produce two factors with spatially segregated functions during inner Membrane Stress: a chaperone that targets problematic proteins in the periplasm and a regulatory RNA that dampens their synthesis in the cytosol.
Rolf D Hubmayr - One of the best experts on this subject based on the ideXlab platform.
-
Plasma Membrane Stress failure in ventilator-injured lungs. A hypothesis about osmoregulation and the pharmacologic protection of the lungs against deformation injury.
Biology of the neonate, 2004Co-Authors: Jose L. Mendez, Otis B. Rickman, Rolf D HubmayrAbstract:Cell injury and repair are invariable consequences of mechanical ventilation with large tidal volumes. Rate and amplitude of deforming Stress affect numerous cell metabolic functions including host defense and wound repair. Recently, we have focused on the role of plasma Membrane Stress failure as a trigger for a pro-inflammatory response in mechanically ventilated lungs. We have developed both cell- and organ-based models to study this problem. Alveolar epithelial cells that are exposed to deforming Stresses seek to maintain sublytic plasma Membrane tension and may activate mechanisms of cell surface area regulation to control Membrane tension. Interventions which either increase the amount of excess plasma Membrane or enhance lipid trafficking should be cytoprotective against deformation induced injury. Osmotic manipulation may be one such intervention. Preconditioning the lungs with anisosmotic solutions may allow the cells to recruit excess plasma Membrane and thus be more resistant to ventilator-induced lung injury.
-
Role of Deformation-induced Lipid Trafficking in the Prevention of Plasma Membrane Stress Failure
American journal of respiratory and critical care medicine, 2002Co-Authors: Nicholas E Vlahakis, Mark A. Schroeder, Richard E. Pagano, Rolf D HubmayrAbstract:Cells experience plasma Membrane Stress failure when the matrix to which they adhere undergoes large deformations. In the lung, such a mechanism might explain mechanical ventilation–associated cell injury. We have previously shown that in alveolar epithelial cells, deformation induces lipid trafficking to the plasma Membrane, thereby accommodating the required increase in the cell surface area. We now show that cell wounding is strain amplitude and rate dependent and that under conditions of impaired exocytosis strain-induced cell wounding is significantly increased. In addition, the susceptibility of cells to mechanical injury was not correlated with changes in cell stiffness. Using a dual-labeling technique, we differentiated between cell populations that were reversibly and irreversibly injured and showed that interventions that impair deformation-induced lipid trafficking also reduce the likelihood of plasma Membrane resealing. Our findings suggest that cell plasticity and remodeling responses such as...
-
invited review plasma Membrane Stress failure in alveolar epithelial cells
Journal of Applied Physiology, 2000Co-Authors: Nicholas E Vlahakis, Rolf D HubmayrAbstract:In this review, we examine the hypothesis that plasma Membrane Stress failure is a central event in the pathophysiology of injury from alveolar overdistension. This hypothesis leads us to consider alveolar micromechanics and specifically the mechanical interactions between lung matrix and alveolar epithelial cell cytoskeleton and plasma Membrane. We then explore events that are central to the regulation of plasma Membrane tension and detail the lipid-trafficking responses of in vitro deformed and/or injured cells. We conclude with a reference to upregulation of Stress-responsive genes after Membrane injury and resealing.
Zaixing Huang - One of the best experts on this subject based on the ideXlab platform.
-
the young laplace s equation for solid
arXiv: Materials Science, 2018Co-Authors: Zaixing HuangAbstract:The Young-Laplace's equation is established based on liquid Membrane without shearing resistance. It is not valid for solid. By taking into account the in-plane shearing and transverse shearing within the surface layer, we reconstruct the Young-Laplace's equation so as to characterize the surface of solid. A new version of the Young-Laplace's equation is proposed. It shows that the surface equilibrium of solid is determined by the bulk Stress, surface Membrane Stress and surface transverse Stress together. The transverse shear Stress depends on the gradient of the Gaussian curvature of surface and strain. The intrinsic Membrane Stress and surface transverse shear Stress cause the residual Stresses to appear in the interior of solid. The intrinsic surface transverse shear Stress only occurs in the non-spherical body.
-
The Young-Laplace equation associated with transverse shear Stress within the surface layer of a solid
Philosophical Magazine Letters, 2018Co-Authors: Zaixing HuangAbstract:The Young-Laplace's equation is established based on liquid Membrane without shearing resistance. It is not valid for solid. By taking into account the in-plane shearing and transverse shearing within the surface layer, we reconstruct the Young-Laplace's equation so as to characterize the surface of solid. A new version of the Young-Laplace's equation is proposed. It shows that the surface equilibrium of solid is determined by the bulk Stress, surface Membrane Stress and surface transverse Stress together. The transverse shear Stress depends on the gradient of the Gaussian curvature of surface and strain. The intrinsic Membrane Stress and surface transverse shear Stress cause the residual Stresses to appear in the interior of solid. The intrinsic surface transverse shear Stress only occurs in the non-spherical body.