scholarly journals Characterization of the interactions between human high-molecular-mass kininogen and cell wall proteins of pathogenic yeasts, Candida tropicalis

2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Justyna Karkowska-Kuleta ◽  
Dorota Zajac ◽  
Grazyna Bras ◽  
Oliwia Bochenska ◽  
Karolina Seweryn ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Molecular Mass ◽  
Candida Tropicalis ◽  
Dissociation Constants ◽  
High Molecular Mass ◽  
Biologically Active ◽  
Phosphoglycerate Mutase ◽  
Cell Wall Proteins ◽  
Effective Prevention

Candida tropicalis is one of the most frequent causes of serious, disseminated candidiasis in human patients infected by non-albicans Candida species, but still relatively little is known about its virulence mechanisms. In our current study, the interactions between the cell surface of this species and a multifunctional human protein—high-molecular-mass kininogen (HK), an important component of the plasma contact system involved in the development of the inflammatory state—were characterized at the molecular level. The quick release of biologically active kinins from candidal cell wall-adsorbed HK was presented and the HK-binding ability was assigned to several cell wall-associated proteins. Predicted hyphally regulated cell wall protein (Hyr) and some housekeeping enzymes exposed at the cell surface (known as “moonlighting proteins”) were found to be the major HK binders. Accordingly, after purification of selected proteins, the dissociation constants of the complexes of HK with Hyr, enolase and phosphoglycerate mutase were determined using surface plasmon resonance measurements, giving the values of 2.20 x 10-7 M, 1.42 x 10-7 M and 5.81 x 10-7 M, respectively. Therefore, in this work, for the first time, the interactions between C. tropicalis cell wall proteins and HK were characterized in molecular terms. Our findings may be useful for designing more effective prevention and treatment approaches against infections caused by this dangerous fungal pathogen.

Hydrophobic cell wall protein glycosylation by the pathogenic fungus Candida albicans

1994 ◽  
Vol 40 (4) ◽  
pp. 266-272 ◽  
Author(s):  
Kevin C. Hazen ◽  
Pati M. Glee
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Cell Surface ◽  
Molecular Mass ◽  
Pathogenic Fungus ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Protein Glycosylation ◽  
Yeast Cells ◽  
Cell Wall Proteins

Cell surface hydrophobicity influences adhesion and virulence of the opportunistic fungal pathogen Candida albicans. Previous studies have shown that cell surface hydrophobicity is due to specific proteins that are exposed on hydrophobic cells but are masked by long fibrils on hydrophilic cells. This observation suggests that hydrophobic cell wall proteins may contain little or no mannosylation. In the present study, the glycosylation levels of three hydrophobic cell wall proteins (molecular mass range between 36 and 40 kDa) derived from yeast cells were examined. One hydrophilic protein (90 kDa) was also tested. Various endoglycosidases (endoglycosidase F – N-glycosidase F, O-glycosidase, β-mannosidase, N-glycosidase F), an exoglycosidase (α-mannosidase), and trifluoromethane sulfonic acid were used to deglycosylate the proteins. All four proteins were reactive to the lectin concanavalin A, demonstrating that they were mannoproteins. However, gel electrophoresis of the control and treated proteins revealed that mannosyl groups of hydrophobic proteins were less than 2 kDa in size, while the mannosyl group of the hydrophilic protein had a molecular mass of approximately 20 kDa. These results suggest that unlike many hydrophilic proteins, hydrophobic proteins may have low levels of glycosylation. Changes in glycosylation may determine exposure of hydrophobic protein regions at the cell surface.Key words: Candida albicans, cell wall, mannoproteins, hydrophobicity, fibrils.

scholarly journals A high-molecular-mass cell wall protein released fromClostridium tyrobutyricumby heat treatment

FEBS Letters ◽  
1984 ◽  
Vol 174 (2) ◽  
pp. 284-288 ◽  
Author(s):  
Hélène Hayes ◽  
Jacqueline Commissaire ◽  
Jean-Louis Bergere
Keyword(s):  
Heat Treatment ◽  
Cell Wall ◽  
Molecular Mass ◽  
High Molecular Mass ◽  
Cell Wall Protein

scholarly journals Flagellar adhesion in chlamydomonas induces synthesis of two high molecular weight cell surface proteins

1983 ◽  
Vol 96 (3) ◽  
pp. 589-597 ◽  
Author(s):  
WJ Snell ◽  
A Clausell ◽  
WS Moore
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Adhesion Molecules ◽  
Mating Type ◽  
Surface Proteins ◽  
Cell Wall Proteins ◽  
Intact Cells ◽  
Mating Reaction ◽  
Ionic Detergent ◽  
Flagellar Proteins

Because our previous studies (Snell, W.J., and W.S. Moore, 1980, J. Cell Biol. 84:203- 210) on the mating reaction of chlamydomonas reinhardtii showed that there was an adhesion-induced turnover of proteins whose synthesis is induced during aggregation. Analysis by SDS PAGE and autoradiography showed that proteins of 220,000 M(r) and 165, 000 M(r) (designated A(1) and A(2) respectively) consistently showed a high rate of synthesis only in flagella or flagellar membrane-enriched fractions prepared from aggregating gametes. Since the two proteins were soluble in the non-ionic detergent NP-40 and were removed from intact cells by a brief pronase treatment, it is likely that A(1) and A(2) are membrane proteins expose on the cell surface. A(1) and A(2) were each synthesized by gametes of both mating types (mt(-) and mt(+)) and synthesis of these two proteins could be detected in the normal mating reaction (wild type mt(-) and mt(+)), in mixtures of mt(-) and impotent mt(+) gametes (which could aggregate but not fuse), and in mixtures of gametes of a single mating type with isolated flagella of the opposite mating type. Cells aggregating in tunicamycin, an inhibitor of protein glycosylation, lost their adhesiveness during aggregation and did not synthesize the 220,000 M(r) protein but instead produced a protein (possibly an underglycosylated form of A(1)) of slightly lower mol wt. The 220,000 and 165,000 M(R) proteins appeared to be flagellar proteins and not cell wall proteins because A(1) and A(2) did not co-migrate with previously identified cell wall proteins, and synthesis of the two proteins could not be detected in flagella-less (bald-2) mutant cells. Analysis of the adhesive activity of sucrose gradient fraction of detergent (octyl glucoside)-solubilized flagellar membranes revealed that fractions containing A(1) and A(2) did not have detectable adhesive activity. The possibility remains that A(1) and A(2) are adhesion molecules whose activity could not be measured in the assay we used. Alternatively, the 220,000 and 165,000 M(r) proteins may be inactivated adhesion molecules or else they may be flagellar surface proteins involved only indirectly in the adhesion process.

scholarly journals Suppressive Effect on Activation of Macrophages by Lactobacillus casei Strain Shirota Genes Determining the Synthesis of Cell Wall-Associated Polysaccharides

2008 ◽  
Vol 74 (15) ◽  
pp. 4746-4755 ◽  
Author(s):  
Emi Yasuda ◽  
Masaki Serata ◽  
Tomoyuki Sako
Keyword(s):  
Cell Wall ◽  
Molecular Mass ◽  
Lactobacillus Casei ◽  
Gene Knockout ◽  
High Molecular Mass ◽  
Interleukin 12 ◽  
Raw 264.7 ◽  
Mouse Macrophage ◽  
Wild Type ◽  
Immune Modulator

ABSTRACT Although many Lactobacillus strains used as probiotics are believed to modulate host immune responses, the molecular natures of the components of such probiotic microorganisms directly involved in immune modulation process are largely unknown. We aimed to assess the function of polysaccharide moiety of the cell wall of Lactobacillus casei strain Shirota as a possible immune modulator which regulates cytokine production by macrophages. A gene survey of the genome sequence of L. casei Shirota hunted down a unique cluster of 10 genes, most of whose predicted amino acid sequences had similarities to various extents to known proteins involved in biosynthesis of extracellular or capsular polysaccharides from other lactic acid bacteria. Gene knockout mutants of eight genes from this cluster resulted in the loss of reactivity to L. casei Shirota-specific monoclonal antibody and extreme reduction of high-molecular-mass polysaccharides in the cell wall fraction, indicating that at least these genes are involved in biosynthesis of high-molecular-mass cell wall polysaccharides. By adding heat-killed mutant cells to mouse macrophage cell lines or to mouse spleen cells, the production of tumor necrosis factor alpha, interleukin-12 (IL-12), IL-10, and IL-6 was more stimulated than by wild-type cells. In addition, these mutants additively enhanced lipopolysaccharide-induced IL-6 production by RAW 264.7 mouse macrophage-like cells, while wild-type cells significantly suppressed the IL-6 production of RAW 264.7. Collectively, these results indicate that this cluster of genes of L. casei Shirota, which have been named cps1A, cps1B, cps1C, cps1D, cps1E, cps1F, cps1G, and cps1J, determine the synthesis of the high-molecular-mass polysaccharide moiety of the L. casei Shirota cell wall and that this polysaccharide moiety is the relevant immune modulator which may function to reduce excessive immune reactions during the activation of macrophages by L. casei Shirota.

Efficient cell surface display of Lip2 lipase using C-domains of glycosylphosphatidylinositol-anchored cell wall proteins of Yarrowia lipolytica

2011 ◽  
Vol 91 (3) ◽  
pp. 645-654 ◽  
Author(s):  
Evgeniya Y. Yuzbasheva ◽  
Tigran V. Yuzbashev ◽  
Ivan A. Laptev ◽  
Tatiana K. Konstantinova ◽  
Sergey P. Sineoky
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Yarrowia Lipolytica ◽  
Surface Display ◽  
Cell Surface Display ◽  
Cell Wall Proteins ◽  
Lip2 Lipase

scholarly journals Towards understanding the novel adhesin function of Candida albicans phosphoglycerate mutase at the pathogen cell surface: some structural analysis of the interactions with human host extracellular matrix proteins

2021 ◽  
Author(s):  
Dorota Satala ◽  
Aleksandra Zelazna ◽  
Grzegorz Satala ◽  
Michal Bukowski ◽  
Marcin Zawrotniak ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Cell Surface ◽  
Fungal Pathogens ◽  
Dissociation Constants ◽  
Molecular Model ◽  
Tight Binding ◽  
Phosphoglycerate Mutase ◽  
Sequence Motifs ◽  
Glycolysis Pathway ◽  
Moonlighting Proteins

Although many atypical proteinaceous cell wall components that belong to a group of multitasking, "moonlighting" proteins, have been repeatedly identified in numerous pathogenic microorganisms, their novel extracellular functions and secretion mechanisms remain largely unrecognized. In Candida albicans, one of the most common fungal pathogens in humans, phosphoglycerate mutase (Gpm1) - a cytoplasmic enzyme involved in the glycolysis pathway - has been shown to occur on the cell surface and has been identified as a potentially important virulence factor. In this study, we demonstrated tight binding of C. albicans Gpm1 to the candidal cell surface, thus suggesting that the readsorption of soluble Gpm1 from the external environment could be a likely mechanism leading to the presence of this moonlighting protein on the pathogen surface. Several putative Gpm1-binding receptors on the yeast surface were identified. The affinities of Gpm1 to human vitronectin (VTR) and fibronectin (FN) were characterized with surface plasmon resonance measurements, and the dissociation constants of the complexes formed were determined to be in the order of 10–8 M. The internal Gpm1 sequence motifs, directly interacting with VTR (aa 116-158) and FN (aa 138-175) were mapped using chemical crosslinking and mass spectrometry. Synthetic peptides with matching sequences significantly inhibited formation of the Gpm1-VTR and Gpm1-FN complexes. A molecular model of the Gpm1-VTR complex was developed. These results provide the first structural insights into the adhesin function of candidal surface-exposed Gpm1.

A dolichol acyltransferase present in rat and human postheparin plasma

1992 ◽  
Vol 70 (6) ◽  
pp. 470-474 ◽  
Author(s):  
P. Sindelar ◽  
C. Valtersson
Keyword(s):  
Cell Surface ◽  
Molecular Mass ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
High Molecular Mass ◽  
Gel Chromatography ◽  
Heat Treated ◽  
A Cell ◽  
Small Unilamellar Vesicles ◽  
Plasma Heparin

Incubation of small unilamellar vesicles consisting of dioleoyl phosphatidylcholine – dioleoyl phosphatidylethanolamine (3:1) and 2 mol% [3H]dolichol-19 with postheparin plasma from rat resulted in the formation of dolichyl oleate. Normal plasma or heat-treated postheparin plasma contained no activity and, hence, the results indicate the presence of a cell surface associated dolichol acyltransferase that can be released into the blood by heparin. The reaction is strongly stimulated by phosphatidylethanolamine and Ca2+, whereas no stimulation with triglycerides or acyl-CoA was observed. Together with the fact that the only product formed was dolichyl oleate, these results strongly suggest that a transacylation mechanism from the phospholipids to dolichol is operative in the liposomes. Gel chromatography of postheparin plasma yielded a molecular mass of about 350 kilodaltons for the active enzyme and density gradient centrifugation indicated that this high molecular mass complex consists mainly of proteins. Finally, we conclude that this enzyme is not unique to the rat, but is also present in human postheparin plasma.Key words: phospholipids, dolichol, plasma, heparin, acyltransferase(s).

scholarly journals Functional insights into the high-molecular-mass penicillin-binding proteins of Streptococcus agalactiae revealed by gene deletion and transposon mutagenesis analysis

2021 ◽  
Author(s):  
Luchang Zhu ◽  
Prasanti Yerramilli ◽  
Layne Pruitt ◽  
Abhishek Mishra ◽  
Randall J. Olsen ◽  
...  
Keyword(s):  
Cell Wall ◽  
Molecular Mass ◽  
Binding Proteins ◽  
Bacterial Pathogen ◽  
High Molecular Mass ◽  
Isogenic Mutant ◽  
Penicillin Binding Proteins ◽  
Cell Wall Peptidoglycan ◽  
Mutant Strains ◽  
Group B

High-molecular-mass penicillin-binding proteins (PBPs) are enzymes that catalyze the biosynthesis of bacterial cell wall peptidoglycan. The Gram-positive bacterial pathogen Streptococcus agalactiae (group B streptococcus , or GBS) produces five high-molecular-mass PBPs, namely, PBP1A, PBP1B, PBP2A, PBP2B, and PBP2X. Among these, only PBP2X is essential for cell viability, whereas the other four PBPs are individually dispensable. The biological function of the four non-essential PBPs is poorly characterized in GBS. We deleted the pbp1a , pbp1b , pbp2a , and pbp2b genes individually from a genetically well-characterized serotype V GBS strain, and studied the phenotypes of the four isogenic mutant strains. Compared to the wild-type parental strain (i) none of the pbp isogenic mutant strains had a significant growth defect in THY rich medium, (ii) isogenic mutant strains Δ pbp1a and Δ pbp1b had significantly increased susceptibility to penicillin and ampicillin, and (iii) isogenic mutant strains Δ pbp1a and Δ pbp2b had significantly longer chain lengths. Using saturated transposon mutagenesis and transposon insertion site sequencing, we determined genes essential for the viability of wild-type GBS strain and each of the four isogenic pbp deletion mutant strains in THY rich medium. The pbp1a gene is essential for cell viability in the pbp2b deletion background. Reciprocally, pbp2b is essential in the pbp1a deletion background. Moreover, the gene encoding RodA, a peptidoglycan polymerase that works in conjunction with PBP2B, is also essential in the pbp1a deletion background. Together, our results suggest functional overlap between PBP1A and PBP2B-RodA complex in GBS cell wall peptidoglycan biosynthesis. IMPORTANCE High-molecular-mass penicillin-binding proteins (HMM-PBPs) are enzymes required for bacterial cell-wall biosynthesis. Bacterial pathogen group B streptococcus (GBS) produces five distinct HMM-PBPs. The biological functions of these proteins are not well characterized in GBS. In this study, we performed a comprehensive deletion analysis of genes encoding HMM-PBPs in GBS. We found that deleting certain PBP-encoding genes altered bacterial susceptibility to beta-lactam antibiotics, cell morphology, and the essentiality of other enzymes involved in cell-wall peptidoglycan synthesis. The results of our study shed new light on the biological functions of PBPs in GBS.

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