Peptidoglycan types of bacterial cell walls and their taxonomic implications.

▪ Abstract Nods are cytosolic proteins that contain a nucleotide-binding oligomerization domain (NOD). These proteins include key regulators of apoptosis and pathogen resistance in mammals and plants. A large number of Nods contain leucine-rich repeats (LRRs), hence referred to as NOD-LRR proteins. Genetic variation in several NOD-LRR proteins, including human Nod2, Cryopyrin, and CIITA, as well as mouse Naip5, is associated with inflammatory disease or increased susceptibility to microbial infections. Nod1, Nod2, Cryopyrin, and Ipaf have been implicated in protective immune responses against pathogens. Together with Toll-like receptors, Nod1 and Nod2 appear to play important roles in innate and acquired immunity as sensors of bacterial components. Specifically, Nod1 and Nod2 participate in the signaling events triggered by host recognition of specific motifs in bacterial peptidoglycan and, upon activation, induce the production of proinflammatory mediators. Naip5 is involved in host resistance to Legione...

NOD-LRR PROTEINS: Role in Host-Microbial Interactions and Inflammatory Disease

NOD1 and NOD2 are intracellular sensors of microbial components derived from bacterial peptidoglycan. This Review describes the signalling pathways of these NOD proteins and details their role in the maintenance of mucosal homeostasis and the induction of mucosal immunity. The NOD (nucleotide-binding oligomerization domain) proteins NOD1 and NOD2 have important roles in innate immunity as sensors of microbial components derived from bacterial peptidoglycan. The importance of these molecules is underscored by the fact that mutations in the gene that encodes NOD2 occur in a subpopulation of patients with Crohn's disease, and NOD1 has also been shown to participate in host defence against infection with Helicobacter pylori. Here, we focus on the molecular interactions between these NOD proteins and other intracellular molecules to elucidate the mechanisms by which NOD1 and NOD2 contribute to the maintenance of mucosal homeostasis and the induction of mucosal inflammation.

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Signalling pathways and molecular interactions of NOD1 and NOD2

Publisher Summary This chapter discusses the analysis of the chemical composition and primary structure of the murein. Murein (peptidoglycan, mucopeptide) is the main cell wall polymer of eubacteria and is common to both Gram-negative and Gram-positive bacteria. There are only a few prokaryotic organisms, such as mycoplasmas and archaebacteria, which lack murein. The glycan moiety is rather uniform and shows only a few variations such as O-acetylation or O-phosphorylation or the exceptional absence of peptide substituents. The peptide moiety of the murein shows, in contrast to the glycan part, a considerable variation. Extensive investigation of the chemical structure of murein has demonstrated the existence of almost 100 different variations of the peptide moiety. Depending on the mode of cross-linking two main groups of murein, named A and B, have been distinguished. The different structure of cell walls of Gram-positive and Gram-negative bacteria necessitates discrete methods for preparing cell walls. The cell walls of Gram-positive bacteria reveal in profile one thick and more or less homogeneous layer, whereas Gram-negative bacteria have thinner, but distinctly layered cell walls with an outer membrane resembling the cytoplasmic membrane in profile.

5 Analysis of the Chemical Composition and Primary Structure of Murein

Peptidoglycans from bacterial cell walls trigger immune responses in insects and mammals. A peptidoglycan recognition protein, PGRP, has been cloned from moths as well as vertebrates and has been s ...

https://www.pnas.org/content/pnas/97/25/13772.full.pdf

A family of peptidoglycan recognition proteins in the fruit fly Drosophila melanogaster.

http://www.jbc.org/content/247/19/6312.full.pdf

Occurrence of N-Nonsubstituted Glucosamine Residues in Peptidoglycan of Lysozyme-resistant Cell Walls from Bacillus cereus

Occurrence of non-N-substituted glucosamine residues in lysozyme-resistant peptidoglycan from Bacillus cereus cell walls

Isolation of glucosaminyl-β(1–4)-muramic acid and phosphoric acid ester of this disacoharide from acid hydrolysates of peptidoglycan of Bacillus cereus ahu 1356 cell walls

Tokuji Nakatani

Papers

Occurrence of N-Nonsubstituted Glucosamine Residues in Peptidoglycan of Lysozyme-resistant Cell Walls from Bacillus cereus

Occurrence of non-N-substituted glucosamine residues in lysozyme-resistant peptidoglycan from Bacillus cereus cell walls

Isolation of glucosaminyl-β(1–4)-muramic acid and phosphoric acid ester of this disacoharide from acid hydrolysates of peptidoglycan of Bacillus cereus ahu 1356 cell walls