In Gram-negative bacteria, outer-membrane integrity is essential for survival and is monitored by the σ(E) stress-response system, which initiates damage-repair pathways. One activating signal is unassembled outer-membrane proteins. Using biochemical and genetic experiments in Escherichia coli, we found that off-pathway intermediates in lipopolysaccharide transport and assembly provided an additional required signal. These distinct signals, arising from disruptions in the transport and assembly of the major outer-membrane components, jointly determined the rate of proteolytic destruction of a negative regulator of the σ(E) transcription factor, thereby modulating the expression of stress-response genes. This dual-signal system permits a rapid response to dysfunction in outer-membrane biogenesis, while buffering responses to transient fluctuations in individual components, and may represent a broad strategy for bacteria to monitor their interface with the environment.
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http://dx.doi.org/10.1126/science.1235358 | DOI Listing |
Small
January 2025
National Energy Metal Resources and New Materials Key Laboratory, Engineering Research Center of the Ministry of Education for Advanced Battery Materials, Hunan Provincial Key Laboratory of Nonferrous Value-Added Metallurgy, School of Metallurgy and Environment, Central South University, Changsha, 410083, P. R. China.
Electrochemical CO reduction (CORR) in membrane electrode assembly (MEA) represents a viable strategy for converting CO into value-added multi-carbon (C) compounds. Therefore, the microstructure of the catalyst layer (CL) affects local gas transport, charge conduction, and proton supply at three-phase interfaces, which is significantly determined by the solvent environment. However, the microenvironment of the CLs and the mechanism of the solvent effect on C selectivity remains elusive.
View Article and Find Full Text PDFLangmuir
January 2025
College of Physical Science and Technology, Yangzhou University, Yangzhou 225002, China.
Porous nanomaterials have shown great promise in many desalination applications. Zeolite nanotubes, featuring abundant but inhomogeneous nanopores on their surface, have been recently synthesized in experiments; however, their capacity for desalination is not yet understood. In this work, we use molecular dynamics simulations to investigate the capability of assembled zeolite nanotube membranes to perform in desalination applications due to their inherent multiscale porous properties.
View Article and Find Full Text PDFNanoscale Horiz
January 2025
Center for Research on Advanced Fiber Technologies (CRAFT), Materials Research Institute and Huck Institute of Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Molecular composites, such as bone and nacre, are everywhere in nature and play crucial roles, ranging from self-defense to carbon sequestration. Extensive research has been conducted on constructing inorganic layered materials at an atomic level inspired by natural composites. These layered materials exfoliated to 2D crystals are an emerging family of nanomaterials with extraordinary properties.
View Article and Find Full Text PDFGenome Med
January 2025
Otology & Neurotology Group CTS495, Instituto de Investigación Biosanitario, Ibs.GRANADA, Universidad de Granada, 18071, Granada, Spain.
Background: Familial Meniere's disease (FMD) is a rare polygenic disorder of the inner ear. Mutations in the connexin gene family, which encodes gap junction proteins, can also cause hearing loss, but their role in FMD is largely unknown.
Methods: We retrieved exome sequencing data from 94 individuals in 70 Meniere's disease (MD) families.
Sci China Life Sci
January 2025
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Mitochondrial Rho-GTPase 1 (MIRO1) is an outer mitochondrial membrane protein which regulates mitochondrial transport and mitophagy in mitosis. In present study, we reported the crucial roles of MIRO1 in mammalian oocyte meiosis and its potential relationship with aging. We found that MIRO1 expressed in mouse and porcine oocytes, and its expression decreased in aged mice.
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