scholarly journals The thick waxy coat of mycobacteria, a protective layer against antibiotics and the host's immune system

2020 ◽  
Vol 477 (10) ◽  
pp. 1983-2006 ◽  
Author(s):  
Sarah M. Batt ◽  
David E. Minnikin ◽  
Gurdyal S. Besra
Keyword(s):  
Infectious Disease ◽  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Immune System ◽  
Mortality Rate ◽  
Cell Envelope ◽  
Protective Layer ◽  
Structure And Function ◽  
Complex Lipids ◽  
And Function

Tuberculosis, caused by the pathogenic bacterium Mycobacterium tuberculosis (Mtb), is the leading cause of death from an infectious disease, with a mortality rate of over a million people per year. This pathogen's remarkable resilience and infectivity is largely due to its unique waxy cell envelope, 40% of which comprises complex lipids. Therefore, an understanding of the structure and function of the cell wall lipids is of huge indirect clinical significance. This review provides a synopsis of the cell envelope and the major lipids contained within, including structure, biosynthesis and roles in pathogenesis.

scholarly journals Characterization of Phosphopantetheinyl Hydrolase from Mycobacterium tuberculosis

2021 ◽  
Author(s):  
Shilpika Pandey ◽  
Amrita Singh ◽  
Guangli Yang ◽  
Felipe B. d’Andrea ◽  
Xiuju Jiang ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Posttranslational Modification ◽  
Content Type ◽  
Protein Encoding ◽  
And Function ◽  
Encoding Genes

Tuberculosis (TB), caused by Mycobacterium tuberculosis , was the leading cause of death from an infectious disease before COVID, yet the in vivo essentiality and function of many of the protein-encoding genes expressed by M. tuberculosis are not known. We biochemically characterize M. tuberculosis ’s phosphopantetheinyl hydrolase, PptH, a protein unique to mycobacteria that removes an essential posttranslational modification on proteins involved in synthesis of lipids important for the bacterium’s cell wall and virulence.

PMR4-dependent cell wall depositions are a consequence but not the cause of temperature-induced autoimmunity

2021 ◽  
Author(s):  
Giuliana Hessler ◽  
Stephan Michael Portheine ◽  
Eva-Maria Gerlach ◽  
Tim Lienemann ◽  
Gerald Koch ◽  
...  
Keyword(s):  
Cell Wall ◽  
Immune System ◽  
Severe Damage ◽  
Temperature Dependent ◽  
Callose Synthase ◽  
Ambient Temperatures ◽  
Point Of No Return ◽  
Dependent Cell ◽  
And Function ◽  
Reduced Temperature

Abstract Plants possess a well-balanced immune system that is required for defense against pathogen infections. In autoimmune mutants or necrotic crosses, an intrinsic temperature-dependent imbalance leads to constitutive immune activation, resulting in severe damage or even death of plants. Recently, cell wall depositions were described as one of the symptoms following induction of the autoimmune phenotype in Arabidopsis saul1-1 mutants. However, the regulation and function of these depositions remained unclear. Here, we show that cell wall depositions, containing lignin and callose, were a common autoimmune feature and were deposited in proportion to the severity of the autoimmune phenotype at reduced ambient temperatures. When plants were exposed to reduced temperature for periods insufficient to induce an autoimmune phenotype, the cell wall depositions were not present. After low temperature intervals, sufficient to induce autoimmune responses, cell wall depositions correlated with a point of no return in saul1-1 autoimmunity. Although cell wall depositions were largely abolished in saul1-1 pmr4-1 double mutants lacking SAUL1 and the callose synthase gene GSL5/PMR4, their phenotype remained unchanged compared to that of the saul1-1 single mutant. Our data showed that cell wall depositions generally occur in autoimmunity, but appear not to be the cause of autoimmune phenotypes.

Structure and Function of the Immune System

2021 ◽  
Author(s):  
Mona Sadeghalvad ◽  
Hamid-Reza Mohammadi-Motlagh ◽  
Nima Rezaei
Keyword(s):  
Immune System ◽  
Structure And Function ◽  
And Function

Structure and function studies of plant cell wall polysaccharides

1994 ◽  
Vol 22 (2) ◽  
pp. 374-378 ◽  
Author(s):  
Peter Albersheim ◽  
Jinhua An ◽  
Glenn Freshour ◽  
Melvin S. Fuller ◽  
Rafael Guillen ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Structure And Function ◽  
Cell Wall Polysaccharides ◽  
And Function

Structure and function of wall appositions. 1. General histochemistry of papillae in barley coleoptiles attacked by Erysiphe graminis f. sp. hordei

1986 ◽  
Vol 64 (4) ◽  
pp. 793-801 ◽  
Author(s):  
Michael G. Smart ◽  
James R. Aist ◽  
Herbert W. Israel
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Cell Walls ◽  
Structure And Function ◽  
Erysiphe Graminis ◽  
Wall Appositions ◽  
And Function

Penetration pegs of Erysiphe graminis D.C. f. sp. hordei Em. Marchal are usually not impeded by normal papillae of barley coleoptiles, whereas oversize papillae are impenetrable to appressoria of the pathogen. We investigated the chemical composition of these papillae and the cell walls by classical histochemistry, in part to extend the fragmented knowledge of these structures and in part to find out if there are differences between normal and oversize papillae which would account for their different efficacies in resisting penetration. These papillae were indistinguishable from one another histochemically and contained protein, carbohydrate other than pectin, and a phenolic which was not lignin. We report also a definitive proof of callose in papillae. They do not contain cutin or suberin. The cell wall did not contain callose or cutin–suberin but did contain protein, pectin, and a phenolic (also not lignin). The results imply that different linkages between molecules in oversize papillae, or some other differences not revealed in this study, are responsible for their ability to prevent fungal penetration.

Cell Wall Glycoproteins: Structure and Function

1985 ◽  
Vol 1985 (Supplement 2) ◽  
pp. 105-127 ◽  
Author(s):  
K. ROBERTS ◽  
C. GRIEF ◽  
G. J. HILLS ◽  
P. J. SHAW
Keyword(s):  
Cell Wall ◽  
Structure And Function ◽  
And Function

scholarly journals Structure and Function of the Immune System

1987 ◽  
Vol 15 (3) ◽  
pp. 262-264 ◽  
Author(s):  
Kevin T. Schultz ◽  
Franziska Grieder
Keyword(s):  
Immune System ◽  
Structure And Function ◽  
And Function
Sign in / Sign up

Export Citation Format

Share Document