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International Journal of Molecular... Apr 2020Plant cell walls surround cells and provide both external protection and a means of cell-to-cell communication [...].
Plant cell walls surround cells and provide both external protection and a means of cell-to-cell communication [...].
Topics: Cell Membrane; Cell Wall; Plant Cells; Plant Development; Plant Proteins
PubMed: 32326416
DOI: 10.3390/ijms21082731 -
Microbiology Spectrum May 2017The molecular composition of the cell wall is critical for the biology and ecology of each fungal species. Fungal walls are composed of matrix components that are... (Review)
Review
The molecular composition of the cell wall is critical for the biology and ecology of each fungal species. Fungal walls are composed of matrix components that are embedded and linked to scaffolds of fibrous load-bearing polysaccharides. Most of the major cell wall components of fungal pathogens are not represented in humans, other mammals, or plants, and therefore the immune systems of animals and plants have evolved to recognize many of the conserved elements of fungal walls. For similar reasons the enzymes that assemble fungal cell wall components are excellent targets for antifungal chemotherapies and fungicides. However, for fungal pathogens, the cell wall is often disguised since key signature molecules for immune recognition are sometimes masked by immunologically inert molecules. Cell wall damage leads to the activation of sophisticated fail-safe mechanisms that shore up and repair walls to avoid catastrophic breaching of the integrity of the surface. The frontiers of research on fungal cell walls are moving from a descriptive phase defining the underlying genes and component parts of fungal walls to more dynamic analyses of how the various components are assembled, cross-linked, and modified in response to environmental signals. This review therefore discusses recent advances in research investigating the composition, synthesis, and regulation of cell walls and how the cell wall is targeted by immune recognition systems and the design of antifungal diagnostics and therapeutics.
Topics: Adaptation, Biological; Animals; Antifungal Agents; Antigens, Fungal; Biofilms; Cell Wall; Chitin; Ecology; Fungal Proteins; Fungi; Glucans; Humans; Hydrolases; Immune System; Mannans; Melanins; Mycoses; Plants; Polysaccharides; Stress, Physiological
PubMed: 28513415
DOI: 10.1128/microbiolspec.FUNK-0035-2016 -
Microbiology Spectrum Dec 2015Bacterial endospores possess multiple integument layers, one of which is the cortex peptidoglycan wall. The cortex is essential for the maintenance of spore core... (Review)
Review
Bacterial endospores possess multiple integument layers, one of which is the cortex peptidoglycan wall. The cortex is essential for the maintenance of spore core dehydration and dormancy and contains structural modifications that differentiate it from vegetative cell peptidoglycan and determine its fate during spore germination. Following the engulfment stage of sporulation, the cortex is synthesized within the intermembrane space surrounding the forespore. Proteins responsible for cortex synthesis are produced in both the forespore and mother cell compartments. While some of these proteins also contribute to vegetative cell wall synthesis, others are sporulation specific. In order for the bacterial endospore to germinate and resume metabolism, the cortex peptidoglycan must first be degraded through the action of germination-specific lytic enzymes. These enzymes are present, yet inactive, in the dormant spore and recognize the muramic-δ-lactam modification present in the cortex. Germination-specific lytic enzymes across Bacillaceae and Clostridiaceae share this specificity determinant, which ensures that the spore cortex is hydrolyzed while the vegetative cell wall remains unharmed. Bacillus species tend to possess two redundant enzymes, SleB and CwlJ, capable of sufficient cortex degradation, while the clostridia have only one, SleC. Additional enzymes are often present that cannot initiate the cortex degradation process, but which can increase the rate of release of small fragments into the medium. Between the two families, the enzymes also differ in the enzymatic activities they possess and the mechanisms acting to restrict their activation until germination has been initiated.
Topics: Bacteria; Bacterial Proteins; Cell Wall; Peptidoglycan; Spores, Bacterial
PubMed: 27337277
DOI: 10.1128/microbiolspec.TBS-0005-2012 -
ELife Nov 2014Bacteria that grow and proliferate despite having been stripped of their cell wall may provide insights into how primordial cells could have propagated billions of years...
Bacteria that grow and proliferate despite having been stripped of their cell wall may provide insights into how primordial cells could have propagated billions of years ago.
Topics: Bacteria; Cell Wall; L Forms
PubMed: 25427009
DOI: 10.7554/eLife.05427 -
Nature Communications Apr 2020Bacteria can produce membranous nanotubes that mediate contact-dependent exchange of molecules among bacterial cells. However, it is unclear how nanotubes cross the cell...
Bacteria can produce membranous nanotubes that mediate contact-dependent exchange of molecules among bacterial cells. However, it is unclear how nanotubes cross the cell wall to emerge from the donor or to penetrate into the recipient cell. Here, we report that Bacillus subtilis utilizes cell wall remodeling enzymes, the LytC amidase and its enhancer LytB, for efficient nanotube extrusion and penetration. Nanotube production is reduced in a lytBC mutant, and the few nanotubes formed appear deficient in penetrating into target cells. Donor-derived LytB molecules localize along nanotubes and on the surface of nanotube-connected neighbouring cells, primarily at sites of nanotube penetration. Furthermore, LytB from donor B. subtilis can activate LytC of recipient bacteria from diverse species, facilitating cell wall hydrolysis to establish nanotube connection. Our data provide a mechanistic view of how intercellular connecting devices can be formed among neighbouring bacteria.
Topics: Amidohydrolases; Bacillus subtilis; Bacterial Proteins; Cell Surface Extensions; Cell Wall; Conjugation, Genetic; Protein Transport
PubMed: 32321911
DOI: 10.1038/s41467-020-15605-1 -
Annual Review of Biochemistry Jun 2018Peptidoglycan is an essential component of the cell wall that protects bacteria from environmental stress. A carefully coordinated biosynthesis of peptidoglycan during... (Review)
Review
Peptidoglycan is an essential component of the cell wall that protects bacteria from environmental stress. A carefully coordinated biosynthesis of peptidoglycan during cell elongation and division is required for cell viability. This biosynthesis involves sophisticated enzyme machineries that dynamically synthesize, remodel, and degrade peptidoglycan. However, when and where bacteria build peptidoglycan, and how this is coordinated with cell growth, have been long-standing questions in the field. The improvement of microscopy techniques has provided powerful approaches to study peptidoglycan biosynthesis with high spatiotemporal resolution. Recent development of molecular probes further accelerated the growth of the field, which has advanced our knowledge of peptidoglycan biosynthesis dynamics and mechanisms. Here, we review the technologies for imaging the bacterial cell wall and its biosynthesis activity. We focus on the applications of fluorescent d-amino acids, a newly developed type of probe, to visualize and study peptidoglycan synthesis and dynamics, and we provide direction for prospective research.
Topics: Amino Acids; Bacteria; Cell Wall; Fluorescent Dyes; Microscopy, Atomic Force; Microscopy, Electron; Microscopy, Fluorescence; Peptidoglycan
PubMed: 29596002
DOI: 10.1146/annurev-biochem-062917-012921 -
Annals of the New York Academy of... Jul 2021Antibiotic tolerance-the ability of bacteria to survive for an extended time in the presence of bactericidal antibiotics-is an understudied contributor to antibiotic... (Review)
Review
Antibiotic tolerance-the ability of bacteria to survive for an extended time in the presence of bactericidal antibiotics-is an understudied contributor to antibiotic treatment failure. Herein, I review the manifestations, mechanisms, and clinical relevance of tolerance to cell wall-active (CWA) antibiotics, one of the most important groups of antibiotics at the forefront of clinical use. I discuss definitions of tolerance and assays for tolerance detection, comprehensively discuss the mechanism of action of β-lactams and other CWA antibiotics, and then provide an overview of how cells mitigate the potentially lethal effects of CWA antibiotic-induced cell damage to become tolerant. Lastly, I discuss evidence for a role of CWA antibiotic tolerance in clinical antibiotic treatment failure.
Topics: Anti-Bacterial Agents; Bacteria; Cell Wall; Microbial Sensitivity Tests
PubMed: 33274447
DOI: 10.1111/nyas.14541 -
Journal of Experimental Botany Nov 2023Years ago, a classic textbook would define plant cell walls based on passive features. For instance, a sort of plant exoskeleton of invariable polysaccharide... (Review)
Review
Years ago, a classic textbook would define plant cell walls based on passive features. For instance, a sort of plant exoskeleton of invariable polysaccharide composition, and probably painted in green. However, currently, this view has been expanded to consider plant cell walls as active, heterogeneous, and dynamic structures with a high degree of complexity. However, what do we mean when we refer to a cell wall as a dynamic structure? How can we investigate the different implications of this dynamism? While the first question has been the subject of several recent publications, defining the ideal strategies and tools needed to address the second question has proven to be challenging due to the myriad of techniques available. In this review, we will describe the capacities of several methodologies to study cell wall composition, structure, and other aspects developed or optimized in recent years. Keeping in mind cell wall dynamism and plasticity, the advantages of performing long-term non-invasive live-imaging methods will be emphasized. We specifically focus on techniques developed for Arabidopsis thaliana primary cell walls, but the techniques could be applied to both secondary cell walls and other plant species. We believe this toolset will help researchers in expanding knowledge of these dynamic/evolving structures.
Topics: Arabidopsis; Plants; Cell Wall; Cell Membrane; Protein Transport
PubMed: 37539735
DOI: 10.1093/jxb/erad310 -
Developmental Cell Apr 2021Organelles of the plant cell cooperate to synthesize and secrete a strong yet flexible polysaccharide-based extracellular matrix: the cell wall. Cell wall composition... (Review)
Review
Organelles of the plant cell cooperate to synthesize and secrete a strong yet flexible polysaccharide-based extracellular matrix: the cell wall. Cell wall composition varies among plant species, across cell types within a plant, within different regions of a single cell wall, and in response to intrinsic or extrinsic signals. This diversity in cell wall makeup is underpinned by common cellular mechanisms for cell wall production. Cellulose synthase complexes function at the plasma membrane and deposit their product into the cell wall. Matrix polysaccharides are synthesized by a multitude of glycosyltransferases in hundreds of mobile Golgi stacks, and an extensive set of vesicle trafficking proteins govern secretion to the cell wall. In this review, we discuss the different subcellular locations at which cell wall synthesis occurs, review the molecular mechanisms that control cell wall biosynthesis, and examine how these are regulated in response to different perturbations to maintain cell wall homeostasis.
Topics: Cell Membrane; Cell Wall; Endocytosis; Endoplasmic Reticulum; Glucosyltransferases; Golgi Apparatus; Homeostasis; Plant Cells; Polysaccharides
PubMed: 33761322
DOI: 10.1016/j.devcel.2021.03.004 -
Molecular Plant Mar 2011Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth, are major repositories for photosynthetically accumulated carbon, and, in... (Review)
Review
Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth, are major repositories for photosynthetically accumulated carbon, and, in addition, impact greatly on the human use of plants. Land plant cell walls contain in the region of a dozen major polysaccharide structures that are mostly encompassed by cellulose, hemicelluloses, and pectic polysaccharides. During the evolution of land plants, polysaccharide diversification appears to have largely involved structural elaboration and diversification within these polysaccharide groups. Cell wall chemistry is well advanced and a current phase of cell wall science is aimed at placing the complex polysaccharide chemistry in cellular contexts and developing a detailed understanding of cell wall biology. Imaging cell wall glycomes is a challenging area but recent developments in the establishment of cell wall molecular probe panels and their use in high throughput procedures are leading to rapid advances in the molecular understanding of the spatial heterogeneity of individual cell walls and also cell wall differences at taxonomic levels. The challenge now is to integrate this knowledge of cell wall heterogeneity with an understanding of the molecular and physiological mechanisms that underpin cell wall properties and functions.
Topics: Cell Wall; Fluorescent Antibody Technique; Plant Proteins; Plants
PubMed: 21199879
DOI: 10.1093/mp/ssq075