scholarly journals Sophisticated Functions for a Simple Molecule: The Role of Glucosylceramides in Fungal Cells

2008 ◽  
Vol 2 ◽  
pp. LPI.S1014 ◽  
Author(s):  
Leonardo Nimrichter ◽  
Marcio L. Rodrigues ◽  
Eliana Barreto-Bergter ◽  
Luiz R. Travassos
Keyword(s):  
Cell Wall ◽  
Immune System ◽  
Building Block ◽  
Mammalian Cells ◽  
Recent Literature ◽  
Antifungal Drugs ◽  
Cell Wall Assembly ◽  
Wall Assembly ◽  
Ceramide Moiety

It is well known that mammalian glycosphingolipids (GSL) play key roles in different physiological and pathophysiological processes. The simplest GSL, glucosylceramide (GlcCer), is formed through the enzymatic transfer of glucose to a ceramide moiety. In mammalian cells this molecule is the building block for the synthesis of lactosylceramides and many other complex GSLs. In fungal cells GlcCer is a major neutral GSL that has been considered during decades merely as a structural component of cell membranes. The recent literature, however, describes the participation of fungal GlcCer in vital processes such as secretion, cell wall assembly, recognition by the immune system and regulation of virulence. In this review we discuss the most recent information regarding fungal GlcCer, including (i) new aspects of GlcCer metabolism, (ii) the involvement of these molecules in virulence mechanisms, (iii) their role as targets of new antifungal drugs and immunotherapeutic agents and, finally, (v) their potential participation on cellular signaling in response to different stimuli.

The role of the exocytic pathway in cell wall assembly in yeast

Yeast ◽  
2021 ◽  
Author(s):  
Qingguo Guo ◽  
Na Meng ◽  
Guanzhi Fan ◽  
Dong Sun ◽  
Yuan Meng ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Wall Assembly ◽  
Wall Assembly ◽  
Exocytic Pathway

scholarly journals Assemblies of DivIVA Mark Sites for Hyphal Branching and Can Establish New Zones of Cell Wall Growth in Streptomyces coelicolor

2008 ◽  
Vol 190 (22) ◽  
pp. 7579-7583 ◽  
Author(s):  
Antje Marie Hempel ◽  
Sheng-bing Wang ◽  
Michal Letek ◽  
José A. Gil ◽  
Klas Flärdh
Keyword(s):  
Cell Wall ◽  
Streptomyces Coelicolor ◽  
Time Lapse ◽  
Cell Wall Assembly ◽  
Peptidoglycan Synthesis ◽  
Wall Growth ◽  
Lateral Branches ◽  
Wall Assembly ◽  
Time Lapse Imaging

ABSTRACT Time-lapse imaging of Streptomyces hyphae revealed foci of the essential protein DivIVA at sites where lateral branches will emerge. Overexpression experiments showed that DivIVA foci can trigger establishment of new zones of cell wall assembly, suggesting a key role of DivIVA in directing peptidoglycan synthesis and cell shape in Streptomyces.

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.

Secondary cell-wall assembly in flax phloem fibres: role of galactans

Planta ◽  
2005 ◽  
Vol 223 (2) ◽  
pp. 149-158 ◽  
Author(s):  
Tatyana Gorshkova ◽  
Claudine Morvan
Keyword(s):  
Cell Wall ◽  
Secondary Cell Wall ◽  
Cell Wall Assembly ◽  
Wall Assembly

Dissecting the role of dolichol in cell wall assembly in the yeast mutants impaired in early glycosylation reactions

Yeast ◽  
2007 ◽  
Vol 24 (4) ◽  
pp. 239-252 ◽  
Author(s):  
Jacek Orłowski ◽  
Katarzyna Machula ◽  
Anna Janik ◽  
Ewa Zdebska ◽  
Grazyna Palamarczyk
Keyword(s):  
Cell Wall ◽  
Cell Wall Assembly ◽  
Wall Assembly ◽  
Yeast Mutants

scholarly journals The Role of Dimorphism Regulating Histidine Kinase (Drk1) in the Pathogenic Fungus Paracoccidioides brasiliensis Cell Wall

2021 ◽  
Vol 7 (12) ◽  
pp. 1014
Author(s):  
Marina Valente Navarro ◽  
Yasmin Nascimento de Barros ◽  
Wilson Dias Segura ◽  
Alison Felipe Alencar Chaves ◽  
Grasielle Pereira Jannuzzi ◽  
...  
Keyword(s):  
Cell Wall ◽  
Histidine Kinase ◽  
Mammalian Cells ◽  
Paracoccidioides Brasiliensis ◽  
Pathogenic Fungus ◽  
Fungal Resistance ◽  
Phagocytic Index ◽  
Mammalian Host ◽  
Control Group

Dimorphic fungi of the Paracoccidioides genus are the causative agents of paracoccidioidomycosis (PCM), an endemic disease in Latin America with a high incidence in Brazil. This pathogen presents as infective mycelium at 25 °C in the soil, reverting to its pathogenic form when inhaled by the mammalian host (37 °C). Among these dimorphic fungal species, dimorphism regulating histidine kinase (Drk1) plays an essential role in the morphological transition. These kinases are present in bacteria and fungi but absent in mammalian cells and are important virulence and cellular survival regulators. Hence, the purpose of this study was to investigate the role of PbDrk1 in the cell wall modulation of P. brasiliensis. We observed that PbDrk1 participates in fungal resistance to different cell wall-disturbing agents by reducing viability after treatment with iDrk1. To verify the role of PbDRK1 in cell wall morphogenesis, qPCR results showed that samples previously exposed to iDrk1 presented higher expression levels of several genes related to cell wall modulation. One of them was FKS1, a β-glucan synthase that showed a 3.6-fold increase. Furthermore, confocal microscopy analysis and flow cytometry showed higher β-glucan exposure on the cell surface of P. brasiliensis after incubation with iDrk1. Accordingly, through phagocytosis assays, a significantly higher phagocytic index was observed in yeasts treated with iDrk1 than the control group, demonstrating the role of PbDrk1 in cell wall modulation, which then becomes a relevant target to be investigated. In parallel, the immune response profile showed increased levels of proinflammatory cytokines. Finally, our data strongly suggest that PbDrk1 modulates cell wall component expression, among which we can identify β-glucan. Understanding this signalling pathway may be of great value for identifying targets of antifungal molecular activity since HKs are not present in mammals.

scholarly journals Protein Glycosylation inAspergillus fumigatusIs Essential for Cell Wall Synthesis and Serves as a Promising Model of Multicellular Eukaryotic Development

2012 ◽  
Vol 2012 ◽  
pp. 1-21 ◽  
Author(s):  
Cheng Jin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Posttranslational Modification ◽  
Mammalian Cells ◽  
Protein Glycosylation ◽  
Cell Wall Synthesis ◽  
Fungal Cell ◽  
Multiple Functions ◽  
Significant Attention

Glycosylation is a conserved posttranslational modification that is found in all eukaryotes, which helps generate proteins with multiple functions. Our knowledge of glycosylation mainly comes from the investigation of the yeastSaccharomyces cerevisiaeand mammalian cells. However, during the last decade, glycosylation in the human pathogenic moldAspergillus fumigatushas drawn significant attention. It has been revealed that glycosylation inA. fumigatusis crucial for its growth, cell wall synthesis, and development and that the process is more complicated than that found in the budding yeastS. cerevisiae. The present paper implies that the investigation of glycosylation inA. fumigatusis not only vital for elucidating the mechanism of fungal cell wall synthesis, which will benefit the design of new antifungal therapies, but also helps to understand the role of protein glycosylation in the development of multicellular eukaryotes. This paper describes the advances in functional analysis of protein glycosylation inA. fumigatus.

scholarly journals Properties of Arabinogalactan Proteins (AGPs) in Apple (Malus × Domestica) Fruit at Different Stages of Ripening

Biology ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 225
Author(s):  
Agata Leszczuk ◽  
Justyna Cybulska ◽  
Tomasz Skrzypek ◽  
Artur Zdunek
Keyword(s):  
Cell Wall ◽  
Malus Domestica ◽  
Arabinogalactan Proteins ◽  
Ex Situ ◽  
Morphological Properties ◽  
Mature Stage ◽  
Fruit Storage ◽  
Cell Wall Assembly ◽  
Wall Assembly

Arabinogalactan proteins (AGPs) are constituents of the cell wall–plasma membrane continuum in fruit tissue. The aim of the study was to characterise AGPs contained in fruit by determination of their chemical structure and morphological properties. The results were obtained from in and ex situ investigations and a comparative analysis of AGPs present in Malus × domestica fruit at different stages of ripening from green fruit through the mature stage to over-ripening during fruit storage. The HPLC and colorimetric methods were used for analyses of the composition of monosaccharides and proteins in AGPs extracted from fruit. We have found that AGPs from fruit mainly consists of carbohydrate chains composed predominantly of arabinose, galactose, glucose, galacturonic acid, and xylose. The protein moiety accounts for 3.15–4.58%, which depends on the various phases of ripening. Taken together, our results show that the structural and morphological properties of AGPs and calcium concentration in AGPs are related to the progress of ripening, which is correlated with proper fruit cell wall assembly. In line with the existing knowledge, our data confirmed the typical carbohydrate composition of AGPs and may be the basis for studies regarding their presumed properties of binding calcium ions.

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