Molecular organization of selected prokaryotic S-layer proteins

2005 ◽  
Vol 51 (9) ◽  
pp. 731-743 ◽  
Author(s):  
Harald Claus ◽  
Erol Akça ◽  
Tony Debaerdemaeker ◽  
Christine Evrard ◽  
Jean-Paul Declercq ◽  
...  
Keyword(s):  
Cell Wall ◽  
Molecular Sieves ◽  
Extracellular Enzymes ◽  
Protein Stabilization ◽  
Proteolytic Processing ◽  
Molecular Organization ◽  
Wall Structures ◽  
Attachment Sites ◽  
Archaeal Species ◽  
Molecular Masses

Regular crystalline surface layers (S-layers) are widespread among prokaryotes and probably represent the earliest cell wall structures. S-layer genes have been found in approximately 400 different species of the prokaryotic domains bacteria and archaea. S-layers usually consist of a single (glyco-)protein species with molecular masses ranging from about 40 to 200 kDa that form lattices of oblique, tetragonal, or hexagonal architecture. The primary sequen ces of hyperthermophilic archaeal species exhibit some characteristic signatures. Further adaptations to their specific environments occur by various post-translational modifications, such as linkage of glycans, lipids, phosphate, and sulfate groups to the protein or by proteolytic processing. Specific domains direct the anchoring of the S-layer to the underlying cell wall components and transport across the cytoplasma membrane. In addition to their presumptive original role as protective coats in archaea and bacteria, they have adapted new functions, e.g., as molecular sieves, attachment sites for extracellular enzymes, and virulence factors.Key words: prokaryotes, cell walls, S-layer (glyco-) proteins, protein stabilization.

Proteolytic release of membrane-bound endo-(1,4)-β-glucanase activity associated with cell wall softening inAchlya ambisexualis

2002 ◽  
Vol 48 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Terry W Hill ◽  
Darlene M Loprete ◽  
Kim N Vu ◽  
Susan P. Bayat Mokhtari ◽  
L Vanessa Hardin
Keyword(s):  
Cell Wall ◽  
Membrane Vesicles ◽  
Cysteine Proteases ◽  
Proteolytic Processing ◽  
Cysteine Protease Inhibitor ◽  
Glucanase Activity ◽  
Molecular Masses ◽  
Detergent Treatment ◽  
Membrane Bound

Branching and other cell wall softening events in fungi and oomycetes are thought to involve the activity of secreted enzymes, which are packaged in membrane vesicles and delivered to sites of cell expansion, there to work in a carefully regulated manner upon the structure of the wall. Here we demonstrate a latent endo-(1,4)-β-glucanase activity in a mixed membrane fraction of the oomycete Achlya ambisexualis, which can be released by cysteine proteases with an increase of apparent activity. In addition, a similar endogenous process is strongly inhibited by the cysteine protease inhibitor iodoacetamide, while inhibitors of other types of proteases have a much smaller effect. Detergent treatment of membranes releases two glucanases detectable by electrophoretic activity staining, with apparent molecular masses of about 164 and 35 kDa. Proteolysis produces several activity bands, with major species having apparent molecular masses of about 149, 133, 48, 35, and 25 kDa. The ca. 35- and 25-kDa bands migrate in parallel with glucanases secreted during wall softening in vivo. We propose that the initiation of wall softening in Achlya involves the proteolytic processing and solubilization of at least some secreted endoglucanases. We also propose that the solubilization component of this process functions not just to provide the enzymes with access to wall matrix substrates but also may provide a mechanism for the eventual termination of their biological function.Key words: apical growth, hyphal branching, proteases, cell walls, protein secretion.

Chitinase production during interaction of Trichoderma aggressivum and Agaricus bisporus

2006 ◽  
Vol 52 (10) ◽  
pp. 961-967 ◽  
Author(s):  
Jennifer L Guthrie ◽  
Alan J Castle
Keyword(s):  
Cell Wall ◽  
Agaricus Bisporus ◽  
Extracellular Enzymes ◽  
Important Predictor ◽  
Cell Wall Degrading Enzymes ◽  
Trichoderma Species ◽  
Dual Cultures ◽  
Molecular Masses ◽  
Chitinase Production ◽  
Green Mould

The competitor fungus Trichoderma aggressivum causes green mould disease, a potentially devastating problem of the commercial mushroom Agaricus bisporus. Due to the recent appearance of this problem, very little is known about the mechanisms by which T. aggressivum interacts with and inhibits A. bisporus. A mechanism generally used by Trichoderma species in the antagonism of other fungi is the secretion of cell wall degrading enzymes. In this study, we determined the activities of chitinases produced in dual cultures of these fungi over a 2 week period. Both intracellular and extracellular enzymes were studied. Agaricus bisporus produced N-acetylglucosaminidases with apparent molecular masses of 111, 105, and 96 kDa. Two resistant brown strains produced greater activities of the 96 kDa N-acetylglucosaminidase than susceptible off-white and white strains. This result suggested that this enzyme might have a role in the resistance of commercial brown strains to green mould disease. Trichoderma aggressivum produced three N-acetylglucosaminidases with apparent molecular masses of 131, 125, and 122 kDa, a 40 kDa chitobiosidase, and a 36 kDa endochitinase. The 122 kDa N-acetylglucosaminidase showed the greatest activity and may be an important predictor of antifungal activity.Key words: mushrooms, chitinases, Trichoderma, Agaricus.

SEM and fluorescence imaging of callose deposition in root hair tips and suspension cultures of Streptanthus tortuosus

1990 ◽  
Vol 48 (3) ◽  
pp. 698-699
Author(s):  
K.S. Walters ◽  
R.D. Sjolund ◽  
K.C. Moore
Keyword(s):  
Cell Wall ◽  
Root Hair ◽  
Cultured Cells ◽  
Root Hairs ◽  
Callus Cultures ◽  
Callose Deposition ◽  
Culture Cells ◽  
Wall Structures ◽  
Ultraviolet Illumination ◽  
Callose Formation

Callose, B-1,3-glucan, a component of cell walls, is associated with phloem sieve plates, plasmodesmata, and other cell wall structures that are formed in response to wounding or infection. Callose reacts with aniline blue to form a fluorescent complex that can be recognized in the light microscope with ultraviolet illumination. We have identified callose in cell wall protuberances that are formed spontaneously in suspension-cultured cells of S. tortuosus and in the tips of root hairs formed in sterile callus cultures of S. tortuosus. Callose deposits in root hairs are restricted to root hair tips which appear to be damaged or deformed, while normal root hair tips lack callose deposits. The callose deposits found in suspension culture cells are restricted to regions where unusual outgrowths or protuberances are formed on the cell surfaces, specifically regions that are the sites of new cell wall formation.Callose formation has been shown to be regulated by intracellular calcium levels.

In vitro assembly of 2-D crystals from partially purified EA1 protein secreted by Bacillus anthracis strain Delta Sterne-1

1994 ◽  
Vol 52 ◽  
pp. 276-277
Author(s):  
Mary Beth Downs ◽  
Wilson Ribot ◽  
Joseph W. Farchaus
Keyword(s):  
Cell Wall ◽  
Molecular Sieves ◽  
Cell Envelope ◽  
Single Species ◽  
Supporting Cell ◽  
Surface Layers ◽  
Rabbit Igg ◽  
In Vitro Assembly ◽  
Covalently Linked

Many bacteria possess surface layers (S-layers) that consist of a two-dimensional protein lattice external to the cell envelope. These S-layer arrays are usually composed of a single species of protein or glycoprotein and are not covalently linked to the underlying cell wall. When removed from the cell, S-layer proteins often reassemble into a lattice identical to that found on the cell, even without supporting cell wall fragments. S-layers exist at the interface between the cell and its environment and probably serve as molecular sieves that exclude destructive macromolecules while allowing passage of small nutrients and secreted proteins. Some S-layers are refractory to ingestion by macrophages and, generally, bacteria are more virulent when S-layers are present.When grown in rich medium under aerobic conditions, B. anthracis strain Delta Sterne-1 secretes large amounts of a proteinaceous extractable antigen 1 (EA1) into the growth medium. Immunocytochemistry with rabbit polyclonal anti-EAl antibody made against the secreted protein and gold-conjugated goat anti-rabbit IgG showed that EAI was localized at the cell surface (fig 1), which suggests its role as an S-layer protein.

scholarly journals THE LYSIS OF GROUP A HEMOLYTIC STREPTOCOCCI BY EXTRACELLULAR ENZYMES OF STREPTOMYCES ALBUS

1952 ◽  
Vol 96 (6) ◽  
pp. 569-580 ◽  
Author(s):  
Maclyn McCarty
Keyword(s):  
Cell Wall ◽  
Extracellular Enzymes ◽  
Group A Streptococci ◽  
Carbohydrate Component ◽  
Streptococcal Cell Wall ◽  
Intact Cells ◽  
Enzymatic Lysis ◽  
Streptomyces Albus ◽  
Group A ◽  
Isolated Cell

Cell wall preparations of uniform chemical constitution have been obtained from several strains of group A streptococci. The isolated cell walls are dissolved by the same fractions of the Streptomyces albus enzymes that are effective in the lysis of intact cells, and it is likely that enzymatic lysis of group A streptococci is effected by an attack on the cell wall. The streptococcal cell wall, as prepared in this study, consists of approximately two-thirds carbohydrate and one-third protein. Small amounts of other components may be present. The carbohydrate component, which is composed primarily of N-acetyl-glucosamine and rhamnose, is the group-specific C carbohydrate. The evidence indicates that one of the streptomyces enzymes is directed toward the carbohydrate component of the cell wall.

scholarly journals Proteolytic processing of the L-type Ca2+ channel alpha11.2 subunit in neurons

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1166 ◽  
Author(s):  
Olivia R. Buonarati ◽  
Peter B. Henderson ◽  
Geoffrey G. Murphy ◽  
Mary C. Horne ◽  
Johannes W. Hell
Keyword(s):  
Gene Expression ◽  
Brain Tissue ◽  
Neuronal Excitability ◽  
Central Element ◽  
Proteolytic Processing ◽  
Full Length ◽  
Hek293 Cells ◽  
Specific Antibodies ◽  
C Terminus ◽  
Molecular Masses

Background: The L-type Ca2+ channel Cav1.2 is a prominent regulator of neuronal excitability, synaptic plasticity, and gene expression. The central element of Cav1.2 is the pore-forming α11.2 subunit. It exists in two major size forms, whose molecular masses have proven difficult to precisely determine. Recent work suggests that α11.2 is proteolytically cleaved between the second and third of its four pore-forming domains (Michailidis et al,. 2014). Methods: To better determine the apparent molecular masses (MR)of the α11.2 size forms, extensive systematic immunoblotting of brain tissue as well as full length and C-terminally truncated α11.2 expressed in HEK293 cells was conducted using six different region–specific antibodies against α11.2. Results: The full length form of α11.2 migrated, as expected, with an apparent MR of ~250 kDa. A shorter form of comparable prevalence with an apparent MR of ~210 kDa could only be detected in immunoblots probed with antibodies recognizing α11.2 at an epitope 400 or more residues upstream of the C-terminus. Conclusions: The main two size forms of α11.2 are the full length form and a shorter form, which lacks ~350 distal C-terminal residues. Midchannel cleavage as suggested by Michailidis et al. (2014) is at best minimal in brain tissue.

scholarly journals AtSYP71 Is Important for Plant Cell Wall Biosynthesis and Stress Adaptation.

2021 ◽  
Author(s):  
Xiaoyue Kou ◽  
Hailong Zhang ◽  
Xiaonan Zhao ◽  
Mingjing Wang ◽  
Guochen Qin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Early Development ◽  
Plant Development ◽  
Plant Cell Wall ◽  
Cell Plate ◽  
Development Stage ◽  
Cell Wall Biosynthesis ◽  
Knockout Mutant ◽  
Wall Structures ◽  
Confocal Images

Abstract Background: SYP71, the plant-specific Qc-SNARE protein, is reported to regulate vesicle trafficking. SYP71 is localized on the ER, endosome, plasma membrane and cell plate, suggesting its multiple functions. Lotus SYP71 is essential for symbiotic nitrogen fixation in nodules. AtSYP71, GmSYP71 and OsSYP71 are implicated in plant resistance to pathogenesis. To date, SYP71 regulatory role on plant development remain unclear.Results: AtSYP71-knockout mutant atsyp71-4 was lethal at early development stage. Early development of AtSYP71-knockdown mutant atsyp71-2 was delayed, and stress response was also affected. Confocal images revealed that protein secretion was blocked in atsyp71-2. Transcriptomic analysis indicated that metabolism, response to environmental stimuli pathways and apoplast components were influenced in atsyp71-2. Moreover, the contents of lignin, cellulose and flavonoids as well as cell wall structures were also altered.Conclusion: Our findings suggested that AtSYP71 is essential for plant development. AtSYP71 probably regulates plant development, metabolism and environmental adaptation by affecting cell wall homeostasis via mediating secretion of materials and regulators required for cell wall biosynthesis and dynamics.

scholarly journals Downregulation of p‐COUMAROYL ESTER3‐HYDROXYLASEin rice leads to altered cell wall structures and improves biomass saccharification

2018 ◽  
Vol 95 (5) ◽  
pp. 796-811 ◽  
Author(s):  
Yuri Takeda ◽  
Yuki Tobimatsu ◽  
Steven D. Karlen ◽  
Taichi Koshiba ◽  
Shiro Suzuki ◽  
...  
Keyword(s):  
Cell Wall ◽  
Biomass Saccharification ◽  
Wall Structures ◽  
Altered Cell

Differential pulp cell wall structures lead to diverse fruit textures in apple (Malus domestica)

PROTOPLASMA ◽  
2022 ◽  
Author(s):  
Ling Yang ◽  
Peihua Cong ◽  
Jiali He ◽  
Haidong Bu ◽  
Sijun Qin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Malus Domestica ◽  
Pulp Cell ◽  
Wall Structures
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