scholarly journals Evolutionary Overview of Molecular Interactions and Enzymatic Activities in the Yeast Cell Walls

2020 ◽  
Vol 21 (23) ◽  
pp. 8996
Author(s):  
Renata Teparić ◽  
Mateja Lozančić ◽  
Vladimir Mrša
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Individual Component ◽  
Building Blocks ◽  
Fungal Cell ◽  
Environmental Signals ◽  
Identification And Characterization ◽  
Wall Components ◽  
Fungal Cell Walls

Fungal cell walls are composed of a polysaccharide network that serves as a scaffold in which different glycoproteins are embedded. Investigation of fungal cell walls, besides simple identification and characterization of the main cell wall building blocks, covers the pathways and regulations of synthesis of each individual component of the wall and biochemical reactions by which they are cross-linked and remodeled in response to different growth phase and environmental signals. In this review, a survey of composition and organization of so far identified and characterized cell wall components of different yeast genera including Saccharomyces, Candida, Kluyveromyces, Yarrowia, and Schizosaccharomyces are presented with the focus on their cell wall proteomes.

scholarly journals An Assessment of Infrared Spectra as Indicators of Fungal Cell Wall Composition

1970 ◽  
Vol 23 (2) ◽  
pp. 345 ◽  
Author(s):  
A JMichell ◽  
G Sourfield
Keyword(s):  
Cell Wall ◽  
Infrared Spectroscopy ◽  
Infrared Spectra ◽  
Cell Walls ◽  
Cell Wall Composition ◽  
Fungal Cell Wall ◽  
Fungal Cell ◽  
Chemical Treatments ◽  
Wall Components ◽  
Fungal Cell Walls

Infrared spectroscopy is assessed as a technique for identifying polymers derived from fungal cell walls, both as isolated materials and in mixtures with one another. The technique is then applied to a study of the composition of fungal cell walls and the conclusion reached that infrared spectra provide a rapid and valuable indication of the major components of such walls. They can also be used to follow the effect of chemical treatments designed to separate major wall components.

Isolation and Characterization of Plant Cell Walls and Cell Wall Components

1988 ◽  
pp. 3-40 ◽  
Author(s):  
WILLIAM S. YORK ◽  
ALAN G. DARVILL ◽  
MICHAEL MCNEIL ◽  
THOMAS T. STEVENSON ◽  
PETER ALBERSHEIM
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Walls ◽  
Cell Wall Components ◽  
Isolation And Characterization ◽  
Wall Components

Isolation and characterization of plant cell walls and cell wall components

1986 ◽  
pp. 3-40 ◽  
Author(s):  
William S. York ◽  
Alan G. Darvill ◽  
Michael McNeil ◽  
Thomas T. Stevenson ◽  
Peter Albersheim
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Walls ◽  
Cell Wall Components ◽  
Isolation And Characterization ◽  
Wall Components

scholarly journals Screening and Antifungal Activity of a β-Carboline Derivative against Cryptococcus neoformans and C. gattii

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Kátia Santana Cruz ◽  
Emerson Silva Lima ◽  
Marcia de Jesus Amazonas da Silva ◽  
Erica Simplício de Souza ◽  
Andreia Montoia ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Cryptococcus Neoformans ◽  
Active Compound ◽  
Cell Walls ◽  
Human Fibroblasts ◽  
Lead Compound ◽  
Fungal Cell ◽  
Fungal Cell Walls

Background. Cryptococcosis is a fungal disease of bad prognosis due to its pathogenicity and the toxicity of the drugs used for its treatment. The aim of this study was to investigate the medicinal potential of carbazole and β-carboline alkaloids and derivatives against Cryptococcus neoformans and C. gattii. Methods. MICs were established in accordance with the recommendations of the Clinical and Laboratory Standards Institute for alkaloids and derivatives against C. neoformans and C. gattii genotypes VNI and VGI, respectively. A single active compound was further evaluated against C. neoformans genotypes VNII, VNIII, and VNIV, C. gattii genotypes VGI, VGIII, and VGIV, Candida albicans ATCC 36232, for cytotoxicity against the MRC-5 lineage of human fibroblasts and for effects on fungal cells (cell wall, ergosterol, and leakage of nucleic acids). Results. Screening of 11 compounds revealed 8-nitroharmane as a significant inhibitor (MIC 40 μg/mL) of several C. neoformans and C. gattii genotypes. It was not toxic to fibroblasts (IC50 > 50 µg/mL) nor did it alter fungal cell walls or the concentration of ergosterol in C. albicans or C. neoformans. It increased leakage of substances that absorb at 260 nm. Conclusions. The synthetic β-carboline 8-nitroharmane significantly inhibits pathogenic Cryptococcus species and is interesting as a lead compound towards new therapy for Cryptococcus infections.

Interactions of proteins with other wall components: a pivotal step in fungal cell wall construction

1995 ◽  
Vol 73 (S1) ◽  
pp. 384-387 ◽  
Author(s):  
R. Sentandreu ◽  
M. Sentandreu ◽  
M. V. Elorza ◽  
M. Iranzo ◽  
S. Mormeneo
Keyword(s):  
Cell Wall ◽  
Protein Interactions ◽  
Cell Walls ◽  
Noncovalent Interactions ◽  
Fungal Cell Wall ◽  
Fungal Cell ◽  
Covalent Bonds ◽  
Viscoelastic Composite ◽  
Wall Construction ◽  
Wall Components

Following synthesis of its individual components, the cell wall of Candida albicans is assembled extracellularly in two steps. First, a viscoelastic composite is formed by noncovalent interactions between mannoproteins and other wall components. Second, the initial network is consolidated by formation of covalent cross-linkages among the wall polymers. In both processes, specific proteins may regulate the final yeast or mycelial morphology. These proteins might carry out part of what could be called a morphogenetic code. Experimental results have shown that some mannoproteins form supramolecular complexes. They are secreted independently, but released together from cell walls by hydrolases. In C. albicans cell walls a transglutaminase activity has been detected that could be responsible for the formation of covalent bonds between structural proteins. Key words: fungal cell wall, construction, morphogenesis, protein interactions, noncovalent linkages, covalent linkages.

scholarly journals Unconventional Constituents and Shared Molecular Architecture of the Melanized Cell Wall of C. neoformans and Spore Wall of S. cerevisiae

2020 ◽  
Vol 6 (4) ◽  
pp. 329
Author(s):  
Christine Chrissian ◽  
Coney Pei-Chen Lin ◽  
Emma Camacho ◽  
Arturo Casadevall ◽  
Aaron M. Neiman ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Building Blocks ◽  
Cell Types ◽  
Resistant Cell ◽  
Spore Wall ◽  
Fungal Species ◽  
Resonance Spectroscopy ◽  
Molecular Architecture ◽  
Fungal Cell

The fungal cell wall serves as the interface between the cell and the environment. Fungal cell walls are composed largely of polysaccharides, primarily glucans and chitin, though in many fungi stress-resistant cell types elaborate additional cell wall structures. Here, we use solid-state nuclear magnetic resonance spectroscopy to compare the architecture of cell wall fractions isolated from Saccharomyces cerevisiae spores and Cryptococcus neoformans melanized cells. The specialized cell walls of these two divergent fungi are highly similar in composition. Both use chitosan, the deacetylated derivative of chitin, as a scaffold on which a polyaromatic polymer, dityrosine and melanin, respectively, is assembled. Additionally, we demonstrate that a previously identified but uncharacterized component of the S. cerevisiae spore wall is composed of triglycerides, which are also present in the C. neoformans melanized cell wall. Moreover, we identify a tyrosine-derived constituent in the C. neoformans wall that, although it is not dityrosine, is a non-pigment constituent of the cell wall. The similar composition of the walls of these two phylogenetically distant species suggests that triglycerides, polyaromatics, and chitosan are basic building blocks used to assemble highly stress-resistant cell walls and the use of these constituents may be broadly conserved in other fungal species.

scholarly journals Localization of chitin in algal and fungal cell walls by light and electron microscopy.

1978 ◽  
Vol 26 (10) ◽  
pp. 782-791 ◽  
Author(s):  
N L Pearlmutter ◽  
C A Lembi
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Acetic Acid ◽  
Electron Microscope ◽  
Cell Walls ◽  
Potassium Hydroxide ◽  
Light And Electron Microscopy ◽  
Fungal Cell ◽  
Blastocladiella Emersonii ◽  
Fungal Cell Walls

Chitin was visualized in cell walls after hydrolysis with potassium hydroxide and subsequent postfixation of the deacetylated polysaccharide (chitosan) in OsO4. Areas of chitin deposition appeared dark borwn by light microscopy and electron dense in the electron microscope. With this method, the presence of chitin was demonstrated in the cell walls of the green alga Pithophora oedogonia (Montagne) Wittrock and two fungi, Ceratocystis ulmi Buism. (C. Moreau) and Blastocladiella emersonii Cantino and Hyatt. Most of the chitin in P. oedogonia ws found in the crosswall disk and small amounts occurred in the outer longitudinal walls. The septal disk of C. ulmi also contained chitin, but significant amounts were present in the inner and outer regions of longitudinal walls as well. Chitin was present throughout the walls of B. emersonii. Small amounts of chitin were not easily demonstrated by this technique, but removal of chitosan by exposure to dilute acetic acid before osmium fixation disrupted cell wall integrity, suggesting that small amounts of the structural polysaccharide had been removed.

scholarly journals Chitinases Are Essential for Sexual Development but Not Vegetative Growth in Cryptococcus neoformans

2009 ◽  
Vol 8 (11) ◽  
pp. 1692-1705 ◽  
Author(s):  
Lorina G. Baker ◽  
Charles A. Specht ◽  
Jennifer K. Lodge
Keyword(s):  
Cell Wall ◽  
Sexual Reproduction ◽  
Cryptococcus Neoformans ◽  
Vegetative Growth ◽  
Cell Walls ◽  
Cell Structure ◽  
Complex Structure ◽  
Hydrolytic Enzymes ◽  
Fungal Cell ◽  
Fungal Cell Walls

ABSTRACT Cryptococcus neoformans is an opportunistic pathogen that mainly infects immunocompromised individuals. The fungal cell wall of C. neoformans is an excellent target for antifungal therapies since it is an essential organelle that provides cell structure and integrity. Importantly, it is needed for localization or attachment of known virulence factors, including melanin, phospholipase, and the polysaccharide capsule. The polysaccharide fraction of the cryptococcal cell wall is a complex structure composed of chitin, chitosan, and glucans. Chitin is an indispensable component of many fungal cell walls that contributes significantly to cell wall strength and integrity. Fungal cell walls are very dynamic, constantly changing during cell division and morphogenesis. Hydrolytic enzymes, such as chitinases, have been implicated in the maintenance of cell wall plasticity and separation of the mother and daughter cells at the bud neck during vegetative growth in yeast. In C. neoformans we identified four predicted endochitinases, CHI2, CHI21, CHI22, and CHI4, and a predicted exochitinase, hexosaminidase, HEX1. Enzymatic analysis indicated that Chi2, Chi22, and Hex1 actively degraded chitinoligomeric substrates. Chi2 and Hex1 activity was associated mostly with the cellular fraction, and Chi22 activity was more prominent in the supernatant. The enzymatic activity of Hex1 increased when grown in media containing only N-acetylglucosamine as a carbon source, suggesting that its activity may be inducible by chitin degradation products. Using a quadruple endochitinase deletion strain, we determined that the endochitinases do not affect the growth or morphology of C. neoformans during asexual reproduction. However, mating assays indicated that Chi2, Chi21, and Chi4 are each involved in sexual reproduction. In summary, the endochitinases were found to be dispensable for routine vegetative growth but not sexual reproduction.

Melanin deposition in the hyphae of a species of Phomopsis

1975 ◽  
Vol 21 (4) ◽  
pp. 442-452 ◽  
Author(s):  
D. H. Ellis ◽  
D. A. Griffiths
Keyword(s):  
Cell Wall ◽  
Surface Analysis ◽  
Cell Walls ◽  
Lytic Enzymes ◽  
Fungal Cell ◽  
Ionizing Radiations ◽  
Dopa Melanin ◽  
Fungal Cell Walls ◽  
Cellular Organelles

Hyaline hyphae of Phomopsis become pigmented when exposed to short periods of light. Pigment was deposited in the form of melanin granules both within the cell wall and within mucilaginous excrescences that were developed irregularly over the hyphal surface. Analysis of the pigment showed it to have properties similar to that of "Dopa" melanin and to pigments previously isolated from fungal cell walls. Lysis of both hyaline and pigmented hyphal walls by means of lytic enzymes was minimal. It is suggested that the major role of melanin in this fungus is the protection of cellular organelles from harmful ionizing radiations.

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