scholarly journals Bgs3p, a Putative 1,3-β-Glucan Synthase Subunit, Is Required for Cell Wall Assembly in Schizosaccharomyces pombe

2003 ◽  
Vol 2 (1) ◽  
pp. 159-169 ◽  
Author(s):  
Victoria Martín ◽  
Blanca García ◽  
Elena Carnero ◽  
Angel Durán ◽  
Yolanda Sánchez
Keyword(s):  
Cell Wall ◽  
Fission Yeast ◽  
Green Fluorescence Protein ◽  
Cell Wall Biosynthesis ◽  
Calcofluor White ◽  
Fungal Cell ◽  
Glucan Synthase ◽  
Cell Wall Assembly ◽  
Main Components ◽  
Wall Assembly

ABSTRACT β-Glucans are the main components of the fungal cell wall. Fission yeast possesses a family of β-glucan synthase-related genes. We describe here the cloning and characterization of bgs3 +, a new member of this family. bgs3 + was cloned as a suppressor of a mutant hypersensitive to Echinocandin and Calcofluor White, drugs that interfere with cell wall biosynthesis. Disruption of the gene is lethal, and a decrease in Bgs3p levels leads to rounded cells with thicker walls, slightly reduces the amount of the β-glucan, and raises the amount of α-glucan polymer. These cells finally died. bgs3 + is expressed in vegetative cells grown in different conditions and during mating and germination and is not enhanced by stress situations. Consistent with the observed expression pattern, Bgs3-green fluorescence protein (GFP-Bgs3p) was found at the growing tips during interphase and at the septum prior to cytokinesis, always localized to growth areas. We also found GFP-Bgs3p in mating projections, during the early stages of zygote formation, and at the growing pole during ascospore germination. We conclude that Bgs3p localization is restricted to growth areas and that Bgs3p is a glucan synthase homologue required for cell wall biosynthesis and cell elongation in the fission yeast life cycle.

scholarly journals Length Specificity and Polymerization Mechanism of (1,3)-β-d-Glucan Synthase in Fungal Cell Wall Biosynthesis

Biochemistry ◽  
2020 ◽  
Vol 59 (5) ◽  
pp. 682-693 ◽  
Author(s):  
Abhishek Chhetri ◽  
Anna Loksztejn ◽  
Hai Nguyen ◽  
Kaila M. Pianalto ◽  
Mi Jung Kim ◽  
...  
Keyword(s):  
Cell Wall ◽  
Fungal Cell Wall ◽  
Cell Wall Biosynthesis ◽  
Fungal Cell ◽  
Glucan Synthase ◽  
Polymerization Mechanism

scholarly journals The Role of Glucosidase I (Cwh41p) in the Biosynthesis of Cell Wall β-1,6-Glucan Is Indirect

1998 ◽  
Vol 9 (10) ◽  
pp. 2729-2738 ◽  
Author(s):  
Claudia Abeijon ◽  
Ling Yun Chen
Keyword(s):  
Cell Wall ◽  
Double Mutant ◽  
Biosynthetic Pathway ◽  
Slow Growth ◽  
Wild Type ◽  
Glucose Residue ◽  
Calcofluor White ◽  
Cell Wall Assembly ◽  
Wall Assembly

CWH41, a gene involved in the assembly of cell wall β-1,6-glucan, has recently been shown to be the structural gene forSaccharomyces cerevisiae glucosidase I that is responsible for initiating the trimming of terminal α-1,2-glucose residue in the N-glycan processing pathway. To distinguish between a direct or indirect role of Cwh41p in the biosynthesis of β-1,6-glucan, we constructed a double mutant, alg5Δ(lacking dolichol-P-glucose synthase) cwh41Δ, and found that it has the same phenotype as the alg5Δsingle mutant. It contains wild-type levels of cell wall β-1,6-glucan, shows moderate underglycosylation of N-linked glycoproteins, and grows at concentrations of Calcofluor White (which interferes with cell wall assembly) that are lethal tocwh41Δ single mutant. The strong genetic interactions of CWH41 with KRE6 andKRE1, two other genes involved in the β-1,6-glucan biosynthetic pathway, disappear in the absence of dolichol-P-glucose synthase (alg5Δ). The triple mutantalg5Δcwh41Δkre6Δ is viable, whereas the double mutant cwh41Δkre6Δ in the same genetic background is not. The severe slow growth phenotype and 75% reduction in cell wall β-1,6-glucan, characteristic of the cwh41Δkre1Δdouble mutant, are not observed in the triple mutantalg5Δcwh41Δkre1Δ. Kre6p, a putative Golgi glucan synthase, is unstable in cwh41Δ strains, and its overexpression renders these cells Calcofluor White resistant. These results demonstrate that the role of glucosidase I (Cwh41p) in the biosynthesis of cell wall β-1,6-glucan is indirect and that dolichol-P-glucose is not an intermediate in this pathway.

scholarly journals FsFKS1, the 1,3-β-Glucan Synthase from the Caspofungin-Resistant Fungus Fusarium solani

2006 ◽  
Vol 5 (7) ◽  
pp. 1036-1042 ◽  
Author(s):  
Young-sil Ha ◽  
Sarah F. Covert ◽  
Michelle Momany
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Fusarium Solani ◽  
Cell Walls ◽  
Clinical Isolates ◽  
Fungal Cell ◽  
Spore Viability ◽  
Glucan Synthase ◽  
Main Components ◽  
Sensitive Fungus

ABSTRACT The cell wall, a mesh of carbohydrates and proteins, shapes and protects the fungal cell. The enzyme responsible for the synthesis of one of the main components of the fungal wall, 1,3-β-glucan synthase, is targeted by the antifungal caspofungin acetate (CFA). Clinical isolates of Candida albicans and Aspergillus fumigatus are much more sensitive to CFA than clinical isolates of Fusarium species. To better understand CFA resistance in Fusarium species, we cloned and sequenced FsFKS1, which encodes the Fusarium solani f. sp. pisi β(1,3)-d-glucan synthase, used RNA interference to reduce its expression and complemented deletion of the essential fks gene of the CFA-sensitive fungus A. fumigatus with FsFKS1. Reduction of the FsFKS1 message in F. solani f. sp. pisi reduced spore viability and caused lysis of spores and hyphae, consistent with cell wall defects. Compensating for the loss of A. fumigatus fks1 with FsFKS1 caused only a modest increase in the tolerance of A. fumigatus for CFA. Our results suggest that FsFKS1 is required for the proper construction of F. solani cell walls and that the resistance of F. solani to CFA is at best only partially due to resistance of the FsFKS1 enzyme to this antifungal agent.

scholarly journals PHR1, a pH-regulated gene of Candida albicans encoding a glucan-remodelling enzyme, is required for adhesion and invasion

Microbiology ◽  
2010 ◽  
Vol 156 (8) ◽  
pp. 2484-2494 ◽  
Author(s):  
Julia Calderon ◽  
Martin Zavrel ◽  
Enrico Ragni ◽  
William A. Fonzi ◽  
Steffen Rupp ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Crucial Role ◽  
Extracellular Enzymes ◽  
Hyphal Growth ◽  
Fungal Cell ◽  
Cell Monolayers ◽  
Cell Wall Assembly ◽  
Abiotic Surfaces ◽  
Wall Assembly

The fungal cell wall plays a crucial role in host–pathogen interactions. Its formation is the result of the coordinated activity of several extracellular enzymes, which assemble the constituents, and remodel and hydrolyse them in the extracellular space. Candida albicans Phr1 and Phr2 proteins belong to family GH72 of the β-(1,3)-glucanosyltransferases and play a crucial role in cell wall assembly. PHR1 and PHR2, homologues of Saccharomyces cerevisiae GAS1, are differently regulated by extracellular pH. PHR1 is expressed when ambient pH is 5.5 or higher, whereas PHR2 has the reverse expression pattern. Their deletion causes a pH-conditional defect in morphogenesis and virulence. In this work we explored whether PHR1 deletion affects the ability of C. albicans to adhere to and invade human epithelia. PHR1 null mutants exhibited a marked reduction in adhesion to both abiotic surfaces and epithelial cell monolayers. In addition, the mutant was unable to penetrate and invade reconstituted human epithelia. Transcription profiling of selected hyphal-specific and adhesin-encoding genes indicated that in the PHR1 null mutant, HWP1 and ECE1 transcript levels were similarly reduced in both adhesion and suspension conditions. These results, combined with microscopy analysis of the septum position, suggest that PHR1 is not required for the induction of hyphal development but plays a key role in the maintenance of hyphal growth. Thus, the β-(1,3)-glucan processing catalysed by Phr1p is of fundamental importance in the maintenance of the morphological state on which the adhesive and invasive properties of C. albicans greatly depend.

scholarly journals ChsVb, a Class VII Chitin Synthase Involved in Septation, Is Critical for Pathogenicity in Fusarium oxysporum

2007 ◽  
Vol 7 (1) ◽  
pp. 112-121 ◽  
Author(s):  
Magdalena Martín-Urdíroz ◽  
M. Isabel G. Roncero ◽  
José Antonio González-Reyes ◽  
Carmen Ruiz-Roldán
Keyword(s):  
Cell Wall ◽  
Fusarium Oxysporum ◽  
Tomato Fruit ◽  
Infection Process ◽  
Chitin Synthase ◽  
Fungal Cell ◽  
Myosin Motor ◽  
Cell Wall Assembly ◽  
Chitin Synthases ◽  
Wall Assembly

ABSTRACT A new myosin motor-like chitin synthase gene, chsVb, has been identified in the vascular wilt fungus Fusarium oxysporum f. sp. lycopersici. Phylogenetic analysis of the deduced amino acid sequence of the chsVb chitin synthase 2 domain (CS2) revealed that ChsVb belongs to class VII chitin synthases. The ChsVb myosin motor-like domain (MMD) is shorter than the MMD of class V chitin synthases and does not contain typical ATP-binding motifs. Targeted disrupted single (ΔchsVb) and double (ΔchsV ΔchsVb) mutants were unable to infect and colonize tomato plants or grow invasively on tomato fruit tissue. These strains were hypersensitive to compounds that interfere with fungal cell wall assembly, produced lemon-like shaped conidia, and showed swollen balloon-like structures in hyphal subapical regions, thickened walls, aberrant septa, and intrahyphal hyphae. Our results suggest that the chsVb gene is likely to function in polarized growth and confirm the critical importance of cell wall integrity in the complex infection process of this fungus.

scholarly journals A Conserved Machinery Underlies the Synthesis of a Chitosan Layer in the Candida Chlamydospore Cell Wall

mSphere ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Leo D. Bemena ◽  
Kyunghun Min ◽  
James B. Konopka ◽  
Aaron M. Neiman
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Drug Targets ◽  
Therapeutic Strategies ◽  
Effective Strategy ◽  
Fungal Cell ◽  
Detailed Understanding ◽  
Cell Wall Assembly ◽  
Wall Assembly ◽  
Potential Drug Targets

The cell wall is the interface between the fungal cell and its environment and disruption of cell wall assembly is an effective strategy for antifungal therapies. Therefore, a detailed understanding of how cell walls form is critical to identify potential drug targets and develop therapeutic strategies.

scholarly journals Identification of a putative alpha-glucan synthase essential for cell wall construction and morphogenesis in fission yeast

1998 ◽  
Vol 95 (16) ◽  
pp. 9161-9166 ◽  
Author(s):  
Frans Hochstenbach ◽  
Frans M. Klis ◽  
Herman van den Ende ◽  
Elly van Donselaar ◽  
Peter J. Peters ◽  
...  
Keyword(s):  
Cell Wall ◽  
Fission Yeast ◽  
Transmembrane Domain ◽  
Temperature Sensitive ◽  
Fungal Cell ◽  
Glucan Synthase ◽  
Catalytic Domains ◽  
Carbohydrate Polymer ◽  
Glucan Synthesis ◽  
Mutant Cells

The cell wall protects fungi against lysis and determines their cell shape. Alpha-glucan is a major carbohydrate component of the fungal cell wall, but its function is unknown and its synthase has remained elusive. Here, we describe a fission yeast gene,ags1+, which encodes a putative alpha-glucan synthase. In contrast to the structure of other carbohydrate polymer synthases, the predicted Ags1 protein consists of two probable catalytic domains for alpha-glucan assembly, namely an intracellular domain for alpha-glucan synthesis and an extracellular domain speculated to cross-link or remodel alpha-glucan. In addition, the predicted Ags1 protein contains a multipass transmembrane domain that might contribute to transport of alpha-glucan across the membrane. Loss of Ags1p function in a temperature-sensitive mutant results in cell lysis, whereas mutant cells grown at the semipermissive temperature contain decreased levels of cell wall alpha-glucan and fail to maintain rod shapes, causing rounding of the cells. These findings demonstrate that alpha-glucan is essential for fission yeast morphogenesis.

scholarly journals Pneumocystis carinii BCK1functions in a mitogen-activated protein kinase cascade regulating fungal cell-wall assembly

FEBS Letters ◽  
2003 ◽  
Vol 548 (1-3) ◽  
pp. 59-68 ◽  
Author(s):  
Charles F. Thomas ◽  
Pawan K. Vohra ◽  
John G. Park ◽  
Veenu Puri ◽  
Andrew H. Limper ◽  
...  
Keyword(s):  
Cell Wall ◽  
Protein Kinase ◽  
Pneumocystis Carinii ◽  
Mitogen Activated Protein Kinase ◽  
Fungal Cell ◽  
Cell Wall Assembly ◽  
Mitogen Activated Protein ◽  
Kinase Cascade ◽  
Wall Assembly ◽  
Protein Kinase Cascade

scholarly journals Medicinal genetics approach towards identifying the molecular target of a novel inhibitor of fungal cell wall assembly

2003 ◽  
Vol 48 (4) ◽  
pp. 1029-1042 ◽  
Author(s):  
Kappei Tsukahara ◽  
Katsura Hata ◽  
Kazutaka Nakamoto ◽  
Koji Sagane ◽  
Nao-aki Watanabe ◽  
...  
Keyword(s):  
Cell Wall ◽  
Molecular Target ◽  
Fungal Cell Wall ◽  
Fungal Cell ◽  
Cell Wall Assembly ◽  
Wall Assembly

scholarly journals The contractile ring coordinates curvature-dependent septum assembly during fission yeast cytokinesis

2015 ◽  
Vol 26 (1) ◽  
pp. 78-90 ◽  
Author(s):  
Zhou Zhou ◽  
Emilia Laura Munteanu ◽  
Jun He ◽  
Tristan Ursell ◽  
Mark Bathe ◽  
...  
Keyword(s):  
Cell Wall ◽  
Fission Yeast ◽  
Cleavage Furrow ◽  
Dependent Manner ◽  
Contractile Ring ◽  
Cell Wall Assembly ◽  
Ring Shape ◽  
Dependent Growth ◽  
Contractile Forces ◽  
Wall Assembly

The functions of the actin-myosin–based contractile ring in cytokinesis remain to be elucidated. Recent findings show that in the fission yeast Schizosaccharomyces pombe, cleavage furrow ingression is driven by polymerization of cell wall fibers outside the plasma membrane, not by the contractile ring. Here we show that one function of the ring is to spatially coordinate septum cell wall assembly. We develop an improved method for live-cell imaging of the division apparatus by orienting the rod-shaped cells vertically using microfabricated wells. We observe that the septum hole and ring are circular and centered in wild-type cells and that in the absence of a functional ring, the septum continues to ingress but in a disorganized and asymmetric manner. By manipulating the cleavage furrow into different shapes, we show that the ring promotes local septum growth in a curvature-dependent manner, allowing even a misshapen septum to grow into a more regular shape. This curvature-dependent growth suggests a model in which contractile forces of the ring shape the septum cell wall by stimulating the cell wall machinery in a mechanosensitive manner. Mechanical regulation of the cell wall assembly may have general relevance to the morphogenesis of walled cells.

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