Search results for "Membrane glycoprotein"

The cyclopentenone-type prostaglandin 15-deoxy-delta12,14-prostaglandin J2 inhibits CD95 ligand gene expression in T lymphocytes: interference with p…

2003

Abstract 15-Deoxy-Δ12,14-PGJ2 (15d-PGJ2) is a cyclopentenone-type PG endowed with anti-inflammatory properties and produced by different cells, including those of the immune system. 15d-PGJ2 is a natural ligand of the peroxisome proliferator-activated receptor (PPAR)-γ nuclear receptor, but relevant PPARγ-independent actions mediated by this prostanoid have been described. Fas (APO-1/CD95) and its ligand (Fas-L) are cell surface proteins whose interaction activates apoptosis of Fas-expressing targets. In T cells, the Fas-Fas-L system regulates activation-induced cell death and has been implicated in diseases in which lymphocyte homeostasis is compromised. Moreover, several studies have desc…

Changes in the cell wall glycoprotein composition of Candida albicans associated to the inhibition of germ tube formation by EDTA.

1994

Hyphal development in Candida albicans was blocked by EDTA. This effect was not due to a general growth inhibition since the chelator did not affect protein and DNA synthesis. Recovery of mycelial growth was observed when EDTA-grown cells were incubated at 37 degrees C in EDTA-free medium. High-molecular-weight mannoproteins (HMWM) that are mycelium-specific wall components, and particularly a 260-kDa species (HMWM-260), were absent in the wall of cells grown under germination conditions in the presence of EDTA. Synthesis of the HMWM-260 species was not inhibited but its incorporation (secretion) into the wall structure seemed to be blocked in EDTA-treated cells.

Sorting of a secretory protein (gp80) to the apical surface of Caco-2 cells

1994

We have investigated the synthesis and polarized secretion of the exogenous gp80 glycoprotein complex in the human epithelial adenocarcinoma cell line, Caco-2. gp80 is secreted at the apical surface of Madin-Darby canine kidney (MDCK) cells and should, therefore, display the signal(s) required for sorting into the apical exocytic pathway. In Caco-2 cells, no bona fide secretory protein released preferentially at the apical surface has been described so far. To address the question of whether Caco-2 cells possess a machinery capable of delivery of secretory proteins at the apical surface, we stably transfected the cells with a recombinant gene coding for the gp80 glycoprotein complex. Pulse-…

β1-Integrin Cytoplasmic Subdomains Involved in Dominant Negative Function

1998

The beta1-integrin cytoplasmic domain consists of a membrane proximal subdomain common to the four known isoforms ("common" region) and a distal subdomain specific for each isoform ("variable" region). To investigate in detail the role of these subdomains in integrin-dependent cellular functions, we used beta1A and beta1B isoforms as well as four mutants lacking the entire cytoplasmic domain (beta1TR), the variable region (beta1COM), or the common region (beta1 deltaCOM-B and beta1 deltaCOM-A). By expressing these constructs in Chinese hamster ovary and beta1 integrin-deficient GD25 cells (Wennerberg et al., J Cell Biol 132, 227-238, 1996), we show that beta1B, beta1COM, beta1 deltaCOM-B, a…

Dysbiosis and zonulin upregulation alter gut epithelial and vascular barriers in patients with ankylosing spondylitis

2017

BackgroundDysbiosis has been recently demonstrated in patients with ankylosing spondylitis (AS) but its implications in the modulation of intestinal immune responses have never been studied. The aim of this study was to investigate the role of ileal bacteria in modulating local and systemic immune responses in AS.MethodsIleal biopsies were obtained from 50 HLA-B27+ patients with AS and 20 normal subjects. Silver stain was used to visualise bacteria. Ileal expression of tight and adherens junction proteins was investigated by TaqMan real-time (RT)-PCR and immunohistochemistry. Serum levels of lipopolysaccharide (LPS), LPS-binding protein (LPS-BP), intestinal fatty acid-BP (iFABP) and zonulin…

Cystinuria subtype and nephrolithiasis

1999

Molecular organization of selected prokaryotic S-layer proteins.

2005

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 sulf…

Isolation and characterization of a 60-70-kD plasma membrane glycoprotein involved in the contact-dependent inhibition of growth

1990

Previous studies have shown that plasma membrane compounds are involved in the contact-dependent inhibition of growth of human diploid fibroblasts. The purification of the active plasma membrane glycoprotein is described in this report. The glycoprotein has an apparent molecular mass of 60-70 kD and, due to differential sialylation, isoelectric points between pH 5.5. and 6.2. Treatment with sialidase yielded one spot in two-dimensional gel electrophoresis with an isoelectric point of 6.3. After removal of the N-glycosidically linked oligosaccharide chains, the apparent molecular mass is reduced by approximately 22 kD. Treatment was diluted NaOH, which removes the O-glycosidically linked por…

Contact-dependent inhibition of growth of normal diploid human fibroblasts by plasma membrane glycoproteins.

1988

Homeostasis in vivo is maintained by a highly complex network of positive and negative signals. At the cellular level, this regulatory microenvironment can be divided, in a simplified fashion, into two major compartments: the humoral compartment, including compounds such as hormones, growth factors and nutrients, and the contact-environment compartment, including cell-cell and cell-matrix interactions. At least in cultures of diploid, non-transformed cells, cell-cell and cell-matrix interactions have been shown to be of major importance for the regulation of growth as well as of differentiation. Although until now the glycoprotein involved in the contact-dependent inhibition of growth has n…

Evidence for the formation of covalent bonds between macromolecules in the domain of the wall of Candida albicans mycelial cells

1989

An O-glycosylated mannoprotein, after its incorporation into the wall, showed an increase in its molecular weight, due at least to its association with N-glycosidic sugar chain(s). This was shown by rendering the material soluble after partial degradation of the wall structure. At present it is unknown whether this phenomenon is due to an additional transglycosylation process or whether the partial degradation of the wall solubilizes a supramolecular structure formed between the original O-glycosylated protein which becomes linked either directly or indirectly through a protein to the N-sugar chain(s).