scholarly journals Clostridium perfringens iota toxin: characterization of the cell-associated iota b complex

2002 ◽  
Vol 367 (3) ◽  
pp. 801-808 ◽  
Author(s):  
Bradley G. STILES ◽  
Martha L. HALE ◽  
Jean Christophe MARVAUD ◽  
Michel R. POPOFF
Keyword(s):  
Cell Surface ◽  
Molecular Mass ◽  
Clostridium Perfringens ◽  
Surface Protein ◽  
Protein S ◽  
Vero Cells ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Neutralizing Monoclonal Antibody ◽  
A Cell

Clostridium perfringens type E iota toxin consists of two unlinked proteins designated as iota a (Ia; molecular mass47kDa), an ADP-ribosyltransferase and iota b (Ib; molecular mass81kDa) which binds to the cell surface and facilitates Ia entry into the cytosol. By Western-blot analysis, Ib incubated with Vero cells at 37°C generated a cell-associated, SDS-insoluble oligomer of Ib (molecular mass>220kDa) within 15s, which was still evident 110min after washing cells. Ib oligomerization was temperature, but not pH, dependent and was facilitated by a cell-surface protein(s). Within 5min at 37°C, cell-bound Ib generated Na+/K+ permeable channels that were blocked by Ia. However, Ib-induced channels or oligomers were not formed at 4°C. Two monoclonal antibodies raised against Ib that recognize unique, neutralizing epitopes within residues 632—655 either inhibited Ib binding to cells and/or oligomerization, unlike a non-neutralizing monoclonal antibody that binds within Ib residues 28—66. The Ib protoxin (molecular mass98kDa), which does not facilitate iota cytotoxicity but binds to Vero cells, did not oligomerize or form ion-permeable channels on cells, and neither trypsin nor chymotrypsin treatment of cell-bound Ib protoxin induced large complex formation. The link between Ib oligomers and iota toxicity was also apparent with a resistant cell line (MRC-5), which bound to Ib with no evidence of oligomerization. Overall, these studies revealed that the biological activity of iota toxin is dependent on a long-lived, cell-associated Ib complex that rapidly forms ion-permeable channels in cell membranes. These results further reveal the similarities of C. perfringens iota toxin with other bacterial binary toxins produced by Bacillus anthracis and C. botulinum.

scholarly journals Leukocytes with chromosome Y loss have reduced abundance of the cell surface immunoprotein CD99

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonas Mattisson ◽  
Marcus Danielsson ◽  
Maria Hammond ◽  
Hanna Davies ◽  
Caroline J. Gallant ◽  
...  
Keyword(s):  
Cell Surface ◽  
Single Cells ◽  
Surface Protein ◽  
Protein Abundance ◽  
Blood Leukocytes ◽  
Chromosome Y ◽  
Increased Risk ◽  
A Cell ◽  
Pseudoautosomal Regions ◽  
Male Specific

AbstractMosaic loss of chromosome Y (LOY) in immune cells is a male-specific mutation associated with increased risk for morbidity and mortality. The CD99 gene, positioned in the pseudoautosomal regions of chromosomes X and Y, encodes a cell surface protein essential for several key properties of leukocytes and immune system functions. Here we used CITE-seq for simultaneous quantification of CD99 derived mRNA and cell surface CD99 protein abundance in relation to LOY in single cells. The abundance of CD99 molecules was lower on the surfaces of LOY cells compared with cells without this aneuploidy in all six types of leukocytes studied, while the abundance of CD proteins encoded by genes located on autosomal chromosomes were independent from LOY. These results connect LOY in single cells with immune related cellular properties at the protein level, providing mechanistic insight regarding disease vulnerability in men affected with mosaic chromosome Y loss in blood leukocytes.

Localization and expression of msp130, a primary mesenchyme lineage-specific cell surface protein in the sea urchin embryo

Development ◽  
1987 ◽  
Vol 101 (2) ◽  
pp. 255-265 ◽  
Author(s):  
J.A. Anstrom ◽  
J.E. Chin ◽  
D.S. Leaf ◽  
A.L. Parks ◽  
R.A. Raff
Keyword(s):  
Cell Surface ◽  
Sea Urchin ◽  
Sea Water ◽  
Surface Protein ◽  
Specific Cell ◽  
Cell Surface Protein ◽  
Sea Urchin Embryo ◽  
A Cell ◽  
Mesenchyme Cells ◽  
Primary Mesenchyme Cells

In this report, we use a monoclonal antibody (B2C2) and antibodies against a fusion protein (Leaf et al. 1987) to characterize msp130, a cell surface protein specific to the primary mesenchyme cells of the sea urchin embryo. This protein first appears on the surface of these cells upon ingression into the blastocoel. Immunoelectronmicroscopy shows that msp130 is present in the trans side of the Golgi apparatus and on the extracellular surface of primary mesenchyme cells. Four precursor proteins to msp130 are identified and we show that B2C2 recognizes only the mature form of msp130. We demonstrate that msp130 contains N-linked carbohydrate groups and that the B2C2 epitope is sensitive to endoglycosidase F digestion. Evidence that msp130 is apparently a sulphated glycoprotein is presented. The recognition of the B2C2 epitope of msp130 is disrupted when embryos are cultured in sulphate-free sea water. In addition, two-dimensional immunoblots show that msp130 is an acidic protein that becomes substantially less acidic in the absence of sulphate. We also show that two other independently derived monoclonal antibodies, IG8 (McClay et al. 1983; McClay, Matranga & Wessel, 1985) and 1223 (Carson et al. 1985), recognize msp130, and suggest this protein to be a major cell surface antigen of primary mesenchyme cells.

scholarly journals A cell surface protein controls endocrine ring gland morphogenesis and steroid production

2019 ◽  
Vol 445 (1) ◽  
pp. 16-28 ◽  
Author(s):  
Yanina-Yasmin Pesch ◽  
Ricarda Hesse ◽  
Tariq Ali ◽  
Matthias Behr
Keyword(s):  
Cell Surface ◽  
Surface Protein ◽  
Cell Surface Protein ◽  
Steroid Production ◽  
Ring Gland ◽  
A Cell ◽  
Gland Morphogenesis

scholarly journals A monoclonal anti-DNA antibody also binds to cell-surface protein(s).

1984 ◽  
Vol 81 (12) ◽  
pp. 3843-3845 ◽  
Author(s):  
L. Jacob ◽  
F. Tron ◽  
J. F. Bach ◽  
D. Louvard
Keyword(s):  
Cell Surface ◽  
Surface Protein ◽  
Protein S ◽  
Cell Surface Protein

scholarly journals Detergent-Resistant Membrane Microdomains Facilitate Ib Oligomer Formation and Biological Activity of Clostridium perfringens Iota-Toxin

2004 ◽  
Vol 72 (4) ◽  
pp. 2186-2193 ◽  
Author(s):  
Martha L. Hale ◽  
Jean-Christophe Marvaud ◽  
Michel R. Popoff ◽  
Bradley G. Stiles
Keyword(s):  
Clostridium Perfringens ◽  
Cell Types ◽  
Cell Receptor ◽  
Vero Cells ◽  
Membrane Microdomains ◽  
Oligomer Formation ◽  
A Cell ◽  
Clostridium Perfringens Iota Toxin ◽  
Detergent Resistant Membrane ◽  
Soluble Fractions

ABSTRACT Clostridium perfringens iota-toxin consists of two separate proteins identified as a cell binding protein, iota b (Ib), which forms high-molecular-weight complexes on cells generating Na+/K+-permeable pores through which iota a (Ia), an ADP-ribosyltransferase, presumably enters the cytosol. Identity of the cell receptor and membrane domains involved in Ib binding, oligomer formation, and internalization is currently unknown. In this study, Vero (toxin-sensitive) and MRC-5 (toxin-resistant) cells were incubated with Ib, after which detergent-resistant membrane microdomains (DRMs) were extracted with cold Triton X-100. Western blotting revealed that Ib oligomers localized in DRMs extracted from Vero, but not MRC-5, cells while monomeric Ib was detected in the detergent-soluble fractions of both cell types. The Ib protoxin, previously shown to bind Vero cells but not form oligomers or induce cytotoxicity, was detected only in the soluble fractions. Vero cells pretreated with phosphatidylinositol-specific phospholipase C before addition of Ib indicated that glycosylphosphatidyl inositol-anchored proteins were minimally involved in Ib binding or oligomer formation. While pretreatment of Vero cells with filipin (which sequesters cholesterol) had no effect, methyl-β-cyclodextrin (which extracts cholesterol) reduced Ib binding and oligomer formation and delayed iota-toxin cytotoxicity. These studies showed that iota-toxin exploits DRMs for oligomer formation to intoxicate cells.

scholarly journals Cytoskeletal-membrane interactions: a stable interaction between cell surface glycoconjugates and doublet microtubules of the photoreceptor connecting cilium.

1987 ◽  
Vol 105 (6) ◽  
pp. 2973-2987 ◽  
Author(s):  
C J Horst ◽  
D M Forestner ◽  
J C Besharse
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Molecular Mass ◽  
Lipid Bilayer ◽  
Neonatal Rat ◽  
Sds Page ◽  
A Cell ◽  
The Cross ◽  
Triton X ◽  
Cell Surface Glycoconjugates

The ciliary base is marked by a transition zone in which Y-shaped cross-linkers extend from doublet microtubules to the plasma membrane. Our goal was to investigate the hypothesis that the cross-linkers form a stable interaction between membrane or cell surface components and the underlying microtubule cytoskeleton. We have combined Triton X-100 extraction with lectin cytochemistry in the photoreceptor sensory cilium to investigate the relationship between cell surface glycoconjugates and the underlying cytoskeleton, and to identify the cell surface components involved. Wheat germ agglutinin (WGA) binds heavily to the cell surface in the region of the Y-shaped cross-linkers of the neonatal rat photoreceptor cilium. WGA binding is not removed by prior digestion with neuraminidase and succinyl-WGA also binds the proximal cilium, suggesting a predominance of N-acetylglucosamine containing glycoconjugates. Extraction of the photoreceptor plasma membrane with Triton X-100 removes the lipid bilayer, leaving the Y-shaped crosslinkers associated with the axoneme. WGA-binding sites are found at the distal ends of the crosslinkers after Triton X-100 extraction, indicating that the microtubule-membrane cross-linkers retain both a transmembrane and a cell surface component after removal of the lipid bilayer. To identify glycoconjugate components of the cross-linkers we used a subcellular fraction enriched in axonemes from adult bovine retinas. Isolated, detergent-extracted bovine axonemes show WGA binding at the distal ends of the cross-linkers similar to that seen in the neonatal rat. Proteins of the axoneme fraction were separated by SDS-PAGE and electrophoretically transferred to nitrocellulose. WGA labeling of the nitrocellulose transblots reveals three glycoconjugates, all of molecular mass greater than 400 kD. The major WGA-binding glycoconjugate has an apparent molecular mass of approximately 600 kD and is insensitive to prior digestion with neuraminidase. This glycoconjugate may correspond to the dominant WGA-binding component seen in cytochemical experiments.

scholarly journals The in silico human surfaceome

2018 ◽  
Vol 115 (46) ◽  
pp. E10988-E10997 ◽  
Author(s):  
Damaris Bausch-Fluck ◽  
Ulrich Goldmann ◽  
Sebastian Müller ◽  
Marc van Oostrum ◽  
Maik Müller ◽  
...  
Keyword(s):  
Cell Surface ◽  
In Silico ◽  
Embryonic Stem ◽  
Surface Protein ◽  
Surface Proteins ◽  
Cell Surface Protein ◽  
Cell Surface Proteins ◽  
A Cell ◽  
Visualization Tools ◽  
Protein Classes

Cell-surface proteins are of great biomedical importance, as demonstrated by the fact that 66% of approved human drugs listed in the DrugBank database target a cell-surface protein. Despite this biomedical relevance, there has been no comprehensive assessment of the human surfaceome, and only a fraction of the predicted 5,000 human transmembrane proteins have been shown to be located at the plasma membrane. To enable analysis of the human surfaceome, we developed the surfaceome predictor SURFY, based on machine learning. As a training set, we used experimentally verified high-confidence cell-surface proteins from the Cell Surface Protein Atlas (CSPA) and trained a random forest classifier on 131 features per protein and, specifically, per topological domain. SURFY was used to predict a human surfaceome of 2,886 proteins with an accuracy of 93.5%, which shows excellent overlap with known cell-surface protein classes (i.e., receptors). In deposited mRNA data, we found that between 543 and 1,100 surfaceome genes were expressed in cancer cell lines and maximally 1,700 surfaceome genes were expressed in embryonic stem cells and derivative lines. Thus, the surfaceome diversity depends on cell type and appears to be more dynamic than the nonsurface proteome. To make the predicted surfaceome readily accessible to the research community, we provide visualization tools for intuitive interrogation (wlab.ethz.ch/surfaceome). The in silico surfaceome enables the filtering of data generated by multiomics screens and supports the elucidation of the surfaceome nanoscale organization.

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