The Cell Wall of Filamentous Fungi

2014 ◽  
pp. 224-237 ◽  
Author(s):  
Nir Osherov ◽  
Oded Yarden
Keyword(s):  
Cell Wall ◽  
Filamentous Fungi

scholarly journals A Chitin Synthase with a Myosin-Like Motor Domain Is Essential for Hyphal Growth, Appressorium Differentiation, and Pathogenicity of the Maize Anthracnose Fungus Colletotrichum graminicola

2007 ◽  
Vol 20 (12) ◽  
pp. 1555-1567 ◽  
Author(s):  
Stefan Werner ◽  
Janyce A. Sugui ◽  
Gero Steinberg ◽  
Holger B. Deising
Keyword(s):  
Cell Wall ◽  
Filamentous Fungi ◽  
Hyphal Growth ◽  
Motor Domain ◽  
Plant Colonization ◽  
Colletotrichum Graminicola ◽  
Wild Type ◽  
Chitin Synthesis ◽  
Cell Wall Biogenesis ◽  
Host Cell Wall

Chitin synthesis contributes to cell wall biogenesis and is essential for invasion of solid substrata and pathogenicity of filamentous fungi. In contrast to yeasts, filamentous fungi contain up to 10 chitin synthases (CHS), which might reflect overlapping functions and indicate their complex lifestyle. Previous studies have shown that a class VI CHS of the maize anthracnose fungus Colletotrichum graminicola is essential for cell wall synthesis of conidia and vegetative hyphae. Here, we report on cloning and characterization of three additional CHS genes, CgChsI, CgChsIII, and CgChsV, encoding class I, III, and V CHS, respectively. All CHS genes are expressed during vegetative and pathogenic development. ΔCgChsI and ΔCgChsIII mutants did not differ significantly from the wild-type isolate with respect to hyphal growth and pathogenicity. In contrast, null mutants in the CgChsV gene, which encodes a CHS with an N-terminal myosin-like motor domain, are strongly impaired in vegetative growth and pathogenicity. Even in osmotically stabilized media, vegetative hyphae of ΔCgChsV mutants exhibited large balloon-like swellings, appressorial walls appeared to disintegrate during maturation, and infection cells were nonfunctional. Surprisingly, ΔCgChsV mutants were able to form dome-shaped hyphopodia that exerted force and showed host cell wall penetration rates comparable with the wild type. However, infection hyphae that formed within the plant cells exhibited severe swellings and were not able to proceed with plant colonization efficiently. Consequently, ΔCgChsV mutants did not develop macroscopically visible anthracnose disease symptoms and, thus, were nonpathogenic.

Cell Wall Biosynthesis in Filamentous Fungi

2015 ◽  
pp. 151-168 ◽  
Author(s):  
Takuji Oka ◽  
Taiki Futagami ◽  
Masatoshi Goto
Keyword(s):  
Cell Wall ◽  
Filamentous Fungi ◽  
Cell Wall Biosynthesis

scholarly journals Octyl Gallate as an Intervention Catalyst to Augment Antifungal Efficacy of Caspofungin

J ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Jong Kim ◽  
Kathleen Chan ◽  
Luisa Cheng
Keyword(s):  
Cell Wall ◽  
Filamentous Fungi ◽  
Fungal Pathogens ◽  
Intervention Strategy ◽  
Cell Wall Integrity ◽  
Fungal Resistance ◽  
Alternative Intervention ◽  
Invasive Infections ◽  
Application Of Cas

Filamentous fungi such as Aspergillus spp. are opportunistic pathogens, which cause highly invasive infections, especially in immunocompromised individuals. Control of such fungal pathogens is increasingly problematic due to the small number of effective drugs available for treatment. Moreover, the increased incidence of fungal resistance to antifungal agents makes this problem a global human health issue. The cell wall integrity system of fungi is the target of antimycotic drugs echinocandins, such as caspofungin (CAS). However, echinocandins cannot completely inhibit the growth of filamentous fungal pathogens, which results in survival/escape of fungi during treatment. Chemosensitization was developed as an alternative intervention strategy, where co-application of CAS with the intervention catalyst octyl gallate (OG; chemosensitizer) greatly enhanced CAS efficacy, thus achieved ≥99.9% elimination of filamentous fungi in vitro. Based on hypersensitive responses of Aspergillus antioxidant mutants to OG, it is hypothesized that, besides destabilizing cell wall integrity, the redox-active characteristic of OG may further debilitate the fungal antioxidant system.

THE ENZYME COMPLEXES FOR THE DESTRUCTION OF THE CELL WALL OF FILAMENTOUS FUNGI - PRODUCERS OF INDUSTRIAL ENZYMES

2018 ◽  
Vol 2 (3) ◽  
pp. 31-35 ◽  
Author(s):  
A.S. Sereda ◽  
◽  
I.A. Velikoretskaya ◽  
D.O. Osipov ◽  
V.Yu. Matys ◽  
...  
Keyword(s):  
Cell Wall ◽  
Filamentous Fungi ◽  
Industrial Enzymes ◽  
Enzyme Complexes

scholarly journals Characterization and biological activities of polysaccharides extracted from the filamentous fungal cell wall: an updated literature review

2020 ◽  
Vol 9 (11) ◽  
pp. e62191110217
Author(s):  
Gildomar Lima Valasques Junior ◽  
Pâmala Évelin Pires Cedro ◽  
Tátilla Putumujú Santana Mendes ◽  
Alana Caise dos Anjos Miranda ◽  
Aldo Barbosa Côrtes Filho ◽  
...  
Keyword(s):  
Cell Wall ◽  
Biological Activity ◽  
Filamentous Fungi ◽  
Cell Walls ◽  
Biological Activities ◽  
Fungal Cell Wall ◽  
Gas Chromatography Mass Spectrometry ◽  
Infrared Spectrometry ◽  
Resonance Spectroscopy ◽  
Fungal Cell

Filamentous fungi are eukaryotic organisms with several industrial and pharmaceutical applications. Polysaccharides are the principal components of cell walls from Fungi and other organisms like diatoms, and have been reported in the industrial and medical fields as products with a huge number of different biological activities and applications. The objectives of this narrative review were to assess the characterization methods and and biological activities of polysaccharides extracted from the filamentous fungal cell wall. Glucans, chitin and galactomannans are the most common polysaccharide often found in the cell walls of fungi. These polysaccharides can contain different glycosidic linkage either an α or β-configuration and at various positions, such as (1-3,1-4, 1-6), as well as several molecular sizes. This leads to an almost limitless diversity in their structure and biological activity. There are many methods for polysaccharides characterization, among them; the methods commonly used involve Infrared Spectrometry (FT-IR), Nuclear Magnetic Resonance Spectroscopy (MRS), and gas chromatography-mass spectrometry (CG-MS). Typically, cell wall polysaccharides from filamentous fungi have been shown to possess complex, important and multifaceted biological activities including mainly antioxidant, anti-inflammatory, immunomodulatory, antinociceptive, antitumor and hypoglycemic activities. Due to the large number of filamentous fungi genus and species capable of producing useful polysaccharides, perform scientific researches, and produce novel scientific knowledge and information are particularly interesting in order to identify polysaccharides with potential biological activity and that can be used for medicinal purposes.

scholarly journals Octyl Gallate as an Intervention Catalyst to Augment Antifungal Efficacy of Caspofungin

2018 ◽  
Author(s):  
Jong H. Kim ◽  
Kathleen L. Chan ◽  
Luisa W. Cheng
Keyword(s):  
Cell Wall ◽  
Filamentous Fungi ◽  
Fungal Pathogens ◽  
Intervention Strategy ◽  
Cell Wall Integrity ◽  
Fungal Resistance ◽  
Alternative Intervention ◽  
Invasive Infections ◽  
Application Of Cas

Filamentous fungi such as Aspergillus spp. are opportunistic pathogens, which cause highly invasive infections, especially in immunocompromised individuals. Control of such fungal pathogens is increasingly problematic due to the small number of effective drugs available for treatment. Moreover, the increased incidence of fungal resistance to antifungal agents makes this problem a global human health issue. The cell wall integrity system of fungi is the target of antimycotic drugs echinocandins, such as caspofungin (CAS). However, echinocandins cannot completely inhibit the growth of filamentous fungal pathogens, which results in survival/escape of fungi during treatment. Chemosensitization was developed as an alternative intervention strategy, where co-application of CAS with the intervention catalyst octyl gallate (OG; chemosensitizer) greatly enhanced CAS efficacy, thus achieved ≥ 99.9% elimination of filamentous fungi in vitro. Based on hypersensitive responses of Aspergillus antioxidant mutants to OG, it is hypothesized that, besides destabilizing cell wall integrity, the redox-active characteristic of OG may further debilitate fungal antioxidant system.

scholarly journals Quantitative single molecule RNA-FISH and RNase-free cell wall digestion in Neurospora crassa.

2021 ◽  
Author(s):  
Bradley Bartholomai ◽  
Amy S Gladfelter ◽  
Jennifer J Loros ◽  
Jay C. Dunlap
Keyword(s):  
Cell Wall ◽  
Filamentous Fungi ◽  
Single Molecule ◽  
Cell Imaging ◽  
Numerical Data ◽  
Free Cell ◽  
Spatial Patterning ◽  
Expression And Purification ◽  
Rna Fish ◽  
Fixed Cell

Single molecule RNA-FISH (smFISH) is a valuable tool for analysis of mRNA spatial patterning in fixed cells that is underutilized in filamentous fungi. A primary complication for fixed-cell imaging in filamentous fungi is the need for enzymatic cell wall permeabilization, which is compounded by considerable variability in cell wall composition between species. smFISH adds another layer of complexity due to a requirement for RNase free conditions. Here, we describe the cloning, expression, and purification of a chitinase suitable for supplementation of a commercially available RNase-free enzyme preparation for efficient permeabilization of the Neurospora cell wall. We further provide a method for smFISH in Neurospora which includes a tool for generating numerical data from images that can be used in downstream customized analysis protocols.

scholarly journals The Cell Wall Integrity Pathway Contributes to the Early Stages of Aspergillus fumigatus Asexual Development

2020 ◽  
Vol 86 (7) ◽  
Author(s):  
Marina Campos Rocha ◽  
João Henrique Tadini Marilhano Fabri ◽  
Isabelle Taira Simões ◽  
Rafael Silva-Rocha ◽  
Daisuke Hagiwara ◽  
...  
Keyword(s):  
Cell Wall ◽  
Aspergillus Fumigatus ◽  
Filamentous Fungi ◽  
Cell Wall Integrity ◽  
Asexual Development ◽  
Remarkable Feature ◽  
Susceptible Host ◽  
Content Type ◽  
Cell Wall Integrity Pathway ◽  
Cell Wall Remodeling

ABSTRACT Aspergillus fumigatus is a major cause of human disease. The survival of this fungus is dependent on the cell wall organization and function of its components. The cell wall integrity pathway (CWIP) is the primary signaling cascade that controls de novo synthesis of the cell wall in fungi. Abundant conidiation is a hallmark in A. fumigatus, and uptake of conidia by a susceptible host is usually the initial event in infection. The formation of conidia is mediated by the development of fungus-specific specialized structures, conidiophores, which are accompanied by cell wall remodeling. The molecular regulation of these changes in cell wall composition required for the rise of conidiophore from the solid surface and to disperse the conidia into the air is currently unknown. Here, we investigated the role of CWIP in conidiation. We show that CWIP pkcAG579R, ΔmpkA, and ΔrlmA mutants displayed reduced conidiation during synchronized asexual differentiation. The transcription factor RlmA directly regulated the expression of regulators of conidiation, including flbB, flbC, brlA, abaA, and rasB, as well as genes involved in cell wall synthesis and remodeling, and this affected the chitin content in aerial hyphae. Phosphorylation of RlmA and MpkA was increased during asexual differentiation. We also observed that MpkA physically associated with the proteins FlbB, FlbC, BrlA, and RasB during this process, suggesting another level of cross talk between the CWIP and asexual development pathways. In summary, our results support the conclusion that one function of the CWIP is the regulation of asexual development in filamentous fungi. IMPORTANCE A remarkable feature of the human pathogen Aspergillus fumigatus is its ability to produce impressive amounts of infectious propagules known as conidia. These particles reach immunocompromised patients and may initiate a life-threatening mycosis. The conidiation process in Aspergillus is governed by a sequence of proteins that coordinate the development of conidiophores. This process requires the remodeling of the cell wall so that the conidiophores can rise and withstand the chains of conidia. The events regulating cell wall remodeling during conidiation are currently unknown. Here, we show that the cell wall integrity pathway (CWIP) components RlmA and MpkA directly contribute to the activation of the conidiation cascade by enabling transcription or phosphorylation of critical proteins involved in asexual development. This study points to an essential role for the CWIP during conidiation and provides further insights into the complex regulation of asexual development in filamentous fungi.

Sign in / Sign up

Export Citation Format

Share Document