scholarly journals Identification of the Major Expressed S-Layer and Cell Surface-Layer-Related Proteins in the Model Methanogenic Archaea:Methanosarcina barkeriFusaro andMethanosarcina acetivoransC2A

Archaea ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Lars Rohlin ◽  
Deborah R. Leon ◽  
Unmi Kim ◽  
Joseph A. Loo ◽  
Rachel R. Ogorzalek Loo ◽  
...  
Keyword(s):  
Surface Layer ◽  
Cell Surface ◽  
Structural Integrity ◽  
Lipid Membrane ◽  
Expression Patterns ◽  
Methanosarcina Barkeri ◽  
Protein Glycosylation ◽  
Methanosarcina Acetivorans ◽  
Genome Annotations ◽  
Cell Envelopes

Many archaeal cell envelopes contain a protein coat or sheath composed of one or more surface exposed proteins. These surface layer (S-layer) proteins contribute structural integrity and protect the lipid membrane from environmental challenges. To explore the species diversity of these layers in the Methanosarcinaceae, the major S-layer protein inMethanosarcina barkeristrain Fusaro was identified using proteomics. The Mbar_A1758 gene product was present in multiple forms with apparent sizes of 130, 120, and 100 kDa, consistent with post-translational modifications including signal peptide excision and protein glycosylation. A protein with features related to the surface layer proteins found inMethanosarcina acetivoransC2A andMethanosarcina mazeiGoel was identified in theM. barkerigenome. These data reveal a distinct conserved protein signature with features and implied cell surface architecture in the Methanosarcinaceae that is absent in other archaea. Paralogous gene expression patterns in twoMethanosarcinaspecies revealed abundant expression of a single S-layer paralog in each strain. Respective promoter elements were identified and shown to be conserved in mRNA coding and upstream untranslated regions. PriorM. acetivoransgenome annotations assigned S-layer or surface layer associated roles of eighty genes: however, of 68 examined none was significantly expressed relative to the experimentally determined S-layer gene.

scholarly journals Proteoglycans contribute to the functional integrity of the glomerular endothelial cell surface layer and are regulated in diabetic kidney disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alina Khramova ◽  
Roberto Boi ◽  
Vincent Fridén ◽  
Anna Björnson Granqvist ◽  
Ulf Nilsson ◽  
...  
Keyword(s):  
Surface Layer ◽  
Kidney Disease ◽  
Cell Surface ◽  
Diabetic Kidney Disease ◽  
Exchange Chromatography ◽  
Diabetic Kidney ◽  
Endothelial Cell Surface ◽  
Filtration Barrier ◽  
Essential Components

AbstractAll capillary endothelia, including those of the glomeruli, have a luminal cell surface layer (ESL) consisting of glycoproteins, glycolipids, proteoglycans (PGs) and glycosaminoglycans. Previous results have demonstrated that an intact ESL is necessary for a normal filtration barrier and damage to the ESL coupled to proteinuria is seen for example in diabetic kidney disease (DKD). We used the principles of ion exchange chromatography in vivo to elute the highly negatively charged components of the ESL with a 1 M NaCl solution in rats. Ultrastructural morphology and renal function were analyzed and 17 PGs and hyaluronan were identified in the ESL. The high salt solution reduced the glomerular ESL thickness, led to albuminuria and reduced GFR. To assess the relevance of ESL in renal disease the expression of PGs in glomeruli from DKD patients in a next generation sequencing cohort was investigated. We found that seven of the homologues of the PGs identified in the ESL from rats were differently regulated in patients with DKD compared to healthy subjects. The results show that proteoglycans and glycosaminoglycans are essential components of the ESL, maintaining the permselective properties of the glomerular barrier and thus preventing proteinuria.

scholarly journals A general approach to explore prokaryotic protein glycosylation reveals the unique surface layer modulation of an anammox bacterium

2021 ◽  
Author(s):  
Martin Pabst ◽  
Denis S. Grouzdev ◽  
Christopher E. Lawson ◽  
Hugo B. C. Kleikamp ◽  
Carol de Ram ◽  
...  
Keyword(s):  
Surface Layer ◽  
Protein Glycosylation ◽  
Anammox Bacterium ◽  
Prokaryotic Protein ◽  
Unique Surface

Facing extremes: archaeal surface-layer (glyco)proteins

Microbiology ◽  
2003 ◽  
Vol 149 (12) ◽  
pp. 3347-3351 ◽  
Author(s):  
Jerry Eichler
Keyword(s):  
Surface Layer ◽  
Structural Integrity ◽  
Elevated Temperatures ◽  
Protein Biosynthesis ◽  
Extreme Environments ◽  
Archaeal Protein ◽  
The Face ◽  
Micro Organisms ◽  
Physical Challenges ◽  
Insight Into

Archaea are best known in their capacities as extremophiles, i.e. micro-organisms able to thrive in some of the most drastic environments on Earth. The protein-based surface layer that envelopes many archaeal strains must thus correctly assemble and maintain its structural integrity in the face of the physical challenges associated with, for instance, life in high salinity, at elevated temperatures or in acidic surroundings. Study of archaeal surface-layer (glyco)proteins has thus offered insight into the strategies employed by these proteins to survive direct contact with extreme environments, yet has also served to elucidate other aspects of archaeal protein biosynthesis, including glycosylation, lipid modification and protein export. In this mini-review, recent advances in the study of archaeal surface-layer (glyco)proteins are discussed.

Neural induction and the structure of the target cell surface

Development ◽  
1982 ◽  
Vol 70 (1) ◽  
pp. 171-187
Author(s):  
A. M. Duprat ◽  
L. Gualandris ◽  
P. Rouge
Keyword(s):  
Cell Surface ◽  
Structural Integrity ◽  
Neural Induction ◽  
Active Role ◽  
Target Cells ◽  
Similar Treatment ◽  
Structural Modifications ◽  
Pleurodeles Waltl

Lectins (SBA and PSA) were used to provoke crowding and structural modifications of the presumptive ectoderm cell surface in order to investigate the role of the membrane organization of the competent target cells in neural induction. Are specific characteristics of the cell surface essential for this phenomenon to occur? From amphibian gastrulae, it is possible to obtain neural induction in vitro by association of presumptive ectoderm (target cells) with chordamesoderm (inductor tissue): 4 h of contact is sufficient in Pleurodeles waltl for transmission of the inductive signal. Very quickly, the treatment of the normal ectoderm by lectins (SBA-FITC or PSA-FITC) provoked surface modifications. Lectin-treatment (50 µg ml1−, 30 min) of presumptive ectoderm did not result in any neural induction. Lectin-treatment (50 µg ml1−, 30 min) of presumptive ectoderm previous to its association with the natural inductor for 4 h, disturbed the phenomenon: no induction. Similar treatment followed by association with the inductor for 24 h: induction. Treatment of SBA or PSA with their respective hapten inhibitors prior to addition to ectodermal cells completely blocked the suppressive effects on induction. The structural integrity of the membrane of competent target cells is necessary for neural induction to occur. The cell membrane could thus play, directly or indirectly, an active role in the specificity of this process

scholarly journals The Structural Integrity of the Model Lipid Membrane during Induced Lipid Peroxidation: The Role of Flavonols in the Inhibition of Lipid Peroxidation

Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 430 ◽  
Author(s):  
Anja Sadžak ◽  
Janez Mravljak ◽  
Nadica Maltar-Strmečki ◽  
Zoran Arsov ◽  
Goran Baranović ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Structural Changes ◽  
Structural Integrity ◽  
Lipid Membrane ◽  
Membrane Properties ◽  
Structural Reorganization ◽  
Unsaturated Lipids ◽  
Oxidative Attack

The structural integrity, elasticity, and fluidity of lipid membranes are critical for cellular activities such as communication between cells, exocytosis, and endocytosis. Unsaturated lipids, the main components of biological membranes, are particularly susceptible to the oxidative attack of reactive oxygen species. The peroxidation of unsaturated lipids, in our case 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), induces the structural reorganization of the membrane. We have employed a multi-technique approach to analyze typical properties of lipid bilayers, i.e., roughness, thickness, elasticity, and fluidity. We compared the alteration of the membrane properties upon initiated lipid peroxidation and examined the ability of flavonols, namely quercetin (QUE), myricetin (MCE), and myricitrin (MCI) at different molar fractions, to inhibit this change. Using Mass Spectrometry (MS) and Fourier Transform Infrared Spectroscopy (FTIR), we identified various carbonyl products and examined the extent of the reaction. From Atomic Force Microscopy (AFM), Force Spectroscopy (FS), Small Angle X-Ray Scattering (SAXS), and Electron Paramagnetic Resonance (EPR) experiments, we concluded that the membranes with inserted flavonols exhibit resistance against the structural changes induced by the oxidative attack, which is a finding with multiple biological implications. Our approach reveals the interplay between the flavonol molecular structure and the crucial membrane properties under oxidative attack and provides insight into the pathophysiology of cellular oxidative injury.

scholarly journals Physiological Evidence for Isopotential Tunneling in the Electron Transport Chain of Methane-Producing Archaea

2017 ◽  
Vol 83 (18) ◽  
Author(s):  
Nikolas Duszenko ◽  
Nicole R. Buan
Keyword(s):  
Escherichia Coli ◽  
Electron Transport ◽  
Stationary Phase ◽  
Exponential Growth ◽  
Electron Transport Chain ◽  
Methanosarcina Barkeri ◽  
Metabolic Efficiency ◽  
Methanosarcina Acetivorans ◽  
Content Type ◽  
Transport Chain

ABSTRACT Many, but not all, organisms use quinones to conserve energy in their electron transport chains. Fermentative bacteria and methane-producing archaea (methanogens) do not produce quinones but have devised other ways to generate ATP. Methanophenazine (MPh) is a unique membrane electron carrier found in Methanosarcina species that plays the same role as quinones in the electron transport chain. To extend the analogy between quinones and MPh, we compared the MPh pool sizes between two well-studied Methanosarcina species, Methanosarcina acetivorans C2A and Methanosarcina barkeri Fusaro, to the quinone pool size in the bacterium Escherichia coli. We found the quantity of MPh per cell increases as cultures transition from exponential growth to stationary phase, and absolute quantities of MPh were 3-fold higher in M. acetivorans than in M. barkeri. The concentration of MPh suggests the cell membrane of M. acetivorans, but not of M. barkeri, is electrically quantized as if it were a single conductive metal sheet and near optimal for rate of electron transport. Similarly, stationary (but not exponentially growing) E. coli cells also have electrically quantized membranes on the basis of quinone content. Consistent with our hypothesis, we demonstrated that the exogenous addition of phenazine increases the growth rate of M. barkeri three times that of M. acetivorans. Our work suggests electron flux through MPh is naturally higher in M. acetivorans than in M. barkeri and that hydrogen cycling is less efficient at conserving energy than scalar proton translocation using MPh. IMPORTANCE Can we grow more from less? The ability to optimize and manipulate metabolic efficiency in cells is the difference between commercially viable and nonviable renewable technologies. Much can be learned from methane-producing archaea (methanogens) which evolved a successful metabolic lifestyle under extreme thermodynamic constraints. Methanogens use highly efficient electron transport systems and supramolecular complexes to optimize electron and carbon flow to control biomass synthesis and the production of methane. Worldwide, methanogens are used to generate renewable methane for heat, electricity, and transportation. Our observations suggest Methanosarcina acetivorans, but not Methanosarcina barkeri, has electrically quantized membranes. Escherichia coli, a model facultative anaerobe, has optimal electron transport at the stationary phase but not during exponential growth. This study also suggests the metabolic efficiency of bacteria and archaea can be improved using exogenously supplied lipophilic electron carriers. The enhancement of methanogen electron transport through methanophenazine has the potential to increase renewable methane production at an industrial scale.

scholarly journals Identification of novel therapeutic targets for histone 3 mutated children’s brain tumour, using unique tumour cell surface proteomic signatures

2021 ◽  
Vol 23 (Supplement_4) ◽  
pp. iv9-iv9
Author(s):  
Anya Snary ◽  
Richard Grundy ◽  
Rob Layfield ◽  
Ruman Rahman ◽  
Farhana Haque
Keyword(s):  
Membrane Proteins ◽  
Cell Membrane ◽  
Cell Surface ◽  
Brain Tumours ◽  
Expression Patterns ◽  
Surface Membrane ◽  
Therapeutic Targets ◽  
Molecular Signature ◽  
Histone 3 ◽  
Cell Membrane Proteins

Abstract Aims Improvements in the treatments for childhood and adolescent brain tumours, High-Grade Glioma (pHGG) and Diffuse Intrinsic Pontine Glioblastoma (DIPG), have not advanced much and they continue to carry a very poor prognosis. These brain tumours are now defined by mutations affecting histone 3 proteins, indeed 80% of DIPGs harbour histone H3.1 and H3.3 K27M somatic mutations whilst 30% of pHGGs exhibit H3.3 G34R or G34V mutations. We hypothesized that the histone 3 mutant tumours will have distinct mutation specific surfactome (cell membrane proteins) signature. Method We therefore analysed the cell surface proteomics of pHGG and DIPG, in order to identify novel targets for therapy. We have at first isolated the cell membrane fractions from a range of patient cells carrying different histone 3 mutations (G34R, G34V), relative to wild type histone 3. A comparative quantitative mass-spectrometry analyses of these cell surface membrane fractions is then performed. Results The results obtained to date demonstrated unique differential cell membrane expression patterns which correlated to specific mutation type. For example, increased expression of Ras-related proteins Rab-3, Rab-3D is detected only in histone H3.3-G34R mutated cell line in comparison. Conclusion Identification and analyses of these unique cell membrane proteins’ association with specific in H3.3 mutation in pHGG, will help to identify precise mutation specific therapeutic targets, benefiting the patients to receive therapy based on tumour’s molecular signature.

scholarly journals Putative Extracellular Electron Transfer in Methanogenic Archaea

2021 ◽  
Vol 12 ◽  
Author(s):  
Kailin Gao ◽  
Yahai Lu
Keyword(s):  
Electron Transfer ◽  
Methanogenic Archaea ◽  
Methanosarcina Barkeri ◽  
Extracellular Electron Transfer ◽  
Future Research ◽  
Methanosarcina Acetivorans ◽  
Geobacter Metallireducens ◽  
Methanosarcina Mazei ◽  
Current State ◽  
Electron Transfers

It has been suggested that a few methanogens are capable of extracellular electron transfers. For instance, Methanosarcina barkeri can directly capture electrons from the coexisting microbial cells of other species. Methanothrix harundinacea and Methanosarcina horonobensis retrieve electrons from Geobacter metallireducens via direct interspecies electron transfer (DIET). Recently, Methanobacterium, designated strain YSL, has been found to grow via DIET in the co-culture with Geobacter metallireducens. Methanosarcina acetivorans can perform anaerobic methane oxidation and respiratory growth relying on Fe(III) reduction through the extracellular electron transfer. Methanosarcina mazei is capable of electromethanogenesis under the conditions where electron-transfer mediators like H2 or formate are limited. The membrane-bound multiheme c-type cytochromes (MHC) and electrically-conductive cellular appendages have been assumed to mediate the extracellular electron transfer in bacteria like Geobacter and Shewanella species. These molecules or structures are rare but have been recently identified in a few methanogens. Here, we review the current state of knowledge for the putative extracellular electron transfers in methanogens and highlight the opportunities and challenges for future research.

scholarly journals Cell surface oligosaccharides on Dictyostelium during development

1991 ◽  
Vol 99 (3) ◽  
pp. 485-495
Author(s):  
SUPAVADEE AMATAYAKUL-CHANTLER ◽  
MICHAEL A. J. FERGUSON ◽  
RAYMOND A. DWEK ◽  
THOMAS W. RADEMACHER ◽  
RAJ B. PAREKH ◽  
...  
Keyword(s):  
Cell Surface ◽  
Time Frame ◽  
Protein Glycosylation ◽  
Developmental Studies ◽  
Plant Glycoproteins ◽  
Chemical Technique ◽  
Cell Surface Glycoproteins ◽  
Oligosaccharide Structures ◽  
Surface Glycoproteins

Developmental studies of the changes in protein glycosylation are useful in elucidating the role of oligosaccharides in biological events. We have used the chemical technique, hydrazinolysis, to release oligosaccharides from cell surface glycoproteins of Dictyostelium discoideum. Oligomannose type, xylose- and fucose-containing oligosaccharides were found to be present. The charged oligosaccharides contained sulphate and mannose 6-phosphate residues; no sialic acid was detected. The charged oligosaccharides also contained significant amounts of xylose, arabinose, fucose and galactose, as well as mannose and N-acetylglucosamine, which were the main constituents of the neutral glycans. By monitoring the chemical characteristics of the liberated oligosaccharides, dramatic changes in both the charge and size distribution of cell surface oligosaccharides were observed throughout the 24 h period of cell development. A comparison, however, between the neutral glycan structures of prestalk and prespore cells, over the same time frame showed no dramatic differences Discoidin, a lectin present on the cell surface of 8 h cells, was found not to be glycosylated. Affinity chromatography using immobilised discoidin was used to probe a sugar library made from the cell surface glycoproteins of 8h cells. Discoidin was found to bind selectively an oligosaccharide with the structure Manα3(Manα6)(Xylβ2)Manβ4GlcNAc. This oligosaccharide lacks a conventional N,N'-diacetylchitobiose core and has only been previously observed in plant glycoproteins. Peptide-N-glycosidase F treatment of horseradish peroxidase released an identical structure, confirming that the oligosaccharide was not a degradation fragment of the hydrazine. The oligosaccharide was found to inhibit discoidinmediated haemagglutination with a Kt of 0.75 mM, a concentration approximately 100 times lower than that for galactose The correlation between changes in the amoebal plasma membrane oligosaccharide structures and the biological events occurring at different stages of development such as cell-cell adhesion and cellsubstratum attachment suggest an important role for sugars in these processes

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