scholarly journals Domain structure of proteoheparan sulphate from confluent cultures of human embryonic skin fibroblasts

1985 ◽  
Vol 231 (3) ◽  
pp. 683-687 ◽  
Author(s):  
L Å Fransson ◽  
L Cöster ◽  
I Carlstedt ◽  
A Malmström
Keyword(s):  
Cell Surface ◽  
Domain Structure ◽  
Culture Medium ◽  
Hydrophobic Interactions ◽  
Core Protein ◽  
Heparan Sulphate ◽  
Disulphide Bond ◽  
Disulphide Bonds ◽  
Embryonic Skin ◽  
Spent Media

Radiolabelled proteoheparan sulphates were isolated from confluent monolayers of fibroblasts and from their spent media. The cell-surface-associated proteoglycan (Mr 350 000) has a core protein of Mr 180 000 that is cleaved by reduction of disulphide bonds into polypeptides of Mr 90 000, both of which can bind transferrin [Fransson, Carlstedt, Cöster & Malmström (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 5657-5661]. Thrombin digestion of the proteoglycan yielded two major fragments. The larger one contained the heparan sulphate chains and glycoprotein-type oligosaccharides, whereas the smaller one contained interchain disulphide bond(s) and had affinity for transferrin as well as for octyl-Sepharose. The larger thrombic fragment was cleaved by trypsin into fragments containing the heparan sulphate chains and the oligosaccharides respectively. The smaller proteoheparan sulphate derived from the culture medium (Mr 150 000) had a core protein of Mr 30 000, which contained heparan sulphate-attachment and oligosaccharide-attachment regions, but no domains for binding of transferrin or for hydrophobic interactions.

Cell surface heparan sulphate and adhesive property of sublines of rat ascites hepatoma AH7974

1988 ◽  
Vol 90 (4) ◽  
pp. 683-689 ◽  
Author(s):  
A. Kimura ◽  
T. Kawaguchi ◽  
T. Ono ◽  
A. Sakuma ◽  
Y. Yokoya ◽  
...  
Keyword(s):  
Cell Surface ◽  
Culture Medium ◽  
Heparan Sulphate ◽  
Soluble Form ◽  
Foetal Calf Serum ◽  
Serum Free Medium ◽  
Free Medium ◽  
Ascites Hepatoma ◽  
Serum Free ◽  
Rat Ascites Hepatoma

Two variants (74AD and 74FL) established from rat ascites hepatoma AH7974 were examined for the production of glycosaminoglycans in culture. There was no difference between the adhesive (74AD) and the floating (74FL) variants in quantity of glycosaminoglycans produced by their cultivation in minimum essential medium supplemented with 10% foetal calf serum. However, they were distinctly different in the distribution patterns of heparan sulphate. In 74FL, about 70% of total heparan sulphate was found in the culture medium in soluble form, whereas in 74AD, only 7% was found in the medium and the rest was in the cell-substratum complex. In a serum-free medium, 74AD cells grew without adhering to the substratum. After cultivation, more than 90% of total heparan sulphate was found in the cell-associated fractions and the rest in the substratum fractions. No heparan sulphate was detected in the culture medium. On the other hand, 74FL cells released heparan sulphate to the serum-free medium as much as to the serum-containing medium. The increase in amount of heparan sulphate in the culture medium of 74FL cells was supposed to be caused by failure of the cells to deposit heparan sulphate at the cell surface and not caused by increased production. Cell-substratum adhesion mechanisms involving cell surface heparan sulphate (heparan sulphate proteoglycan) and some serum intermediate(s) are discussed for 74AD cells.

scholarly journals Recent Insights into Cell Surface Heparan Sulphate Proteoglycans and Cancer

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 1541 ◽  
Author(s):  
John R Couchman ◽  
Hinke Multhaupt ◽  
Ralph D. Sanderson
Keyword(s):  
Cell Surface ◽  
Core Protein ◽  
Tumour Progression ◽  
Heparan Sulphate ◽  
Cell Behaviour ◽  
Surface Receptors ◽  
Protein Ligands ◽  
Proliferation And Differentiation ◽  
Cell Processes ◽  
Heparan Sulphate Proteoglycans

A small group of cell surface receptors are proteoglycans, possessing a core protein with one or more covalently attached glycosaminoglycan chains. They are virtually ubiquitous and their chains are major sites at which protein ligands of many types interact. These proteoglycans can signal and regulate important cell processes, such as adhesion, migration, proliferation, and differentiation. Since many protein ligands, such as growth factors, morphogens, and cytokines, are also implicated in tumour progression, it is increasingly apparent that cell surface proteoglycans impact tumour cell behaviour. Here, we review some recent advances, emphasising that many tumour-related functions of proteoglycans are revealed only after their modification in processes subsequent to synthesis and export to the cell surface. These include enzymes that modify heparan sulphate structure, recycling of whole or fragmented proteoglycans into exosomes that can be paracrine effectors or biomarkers, and lateral interactions between some proteoglycans and calcium channels that impact the actin cytoskeleton.

scholarly journals Binding of perlecan to transthyretin qin vitro

1997 ◽  
Vol 326 (3) ◽  
pp. 829-836 ◽  
Author(s):  
Sigbjørn SMELAND ◽  
Svein Olav KOLSET ◽  
Malcolm LYON ◽  
Kaare R. NORUM ◽  
Rune BLOMHOFF
Keyword(s):  
Hepg2 Cells ◽  
Hydrophobic Interactions ◽  
Core Protein ◽  
Chondroitin Sulphate ◽  
Binding Protein ◽  
Heparan Sulphate ◽  
Retinol Binding Protein ◽  
Affinity Column ◽  
Serum Retinol ◽  
Binding Studies

Transthyretin is one of two specific proteins involved in the transport of thyroid hormones in plasma; it possesses two binding sites for serum retinol-binding protein. In the present study we demonstrate that transthyretin also interacts in vitro with [35S]sulphate-labelled material from the medium of HepG2 cells. By using the same strategy as for purifying serum retinol-binding protein, [35S]sulphate-labelled medium was specifically eluted from a transthyretin-affinity column. Ion-exchange chromatography showed that the material was highly polyanionic, and its size and alkali susceptibility suggested that it was a proteoglycan. Structural analyses with chondroitinase ABC lyase and nitrous acid revealed that approx. 20% was chondroitin sulphate and 80% heparan sulphate. Immunoprecipitation showed that the [35S]sulphate-labelled material contained perlecan. Further analysis by binding studies revealed specific and saturable binding of 125I-transthyretin to perlecan-enriched Matrigel. Because inhibition of sulphation by treating HepG2 cells with sodium chlorate increased the affinity of the perlecan for transthyretin, and [3H]heparin was not retained by the transthyretin affinity column, the binding is probably mediated by the core protein and is not a protein–glycosaminoglycan interaction. Because perlecan is released from transthyretin in water, the binding might be due to hydrophobic interactions.

Proteoglycans, ion channels and cell–matrix adhesion

2017 ◽  
Vol 474 (12) ◽  
pp. 1965-1979 ◽  
Author(s):  
Ioli Mitsou ◽  
Hinke A.B. Multhaupt ◽  
John R. Couchman
Keyword(s):  
Ion Channels ◽  
Cell Surface ◽  
Core Protein ◽  
Animal Cell ◽  
Heparan Sulphate ◽  
Matrix Adhesion ◽  
Cell Matrix ◽  
Neuropilin 1 ◽  
Core Proteins ◽  
Cell Matrix Adhesion

Cell surface proteoglycans comprise a transmembrane or membrane-associated core protein to which one or more glycosaminoglycan chains are covalently attached. They are ubiquitous receptors on nearly all animal cell surfaces. In mammals, the cell surface proteoglycans include the six glypicans, CD44, NG2 (CSPG4), neuropilin-1 and four syndecans. A single syndecan is present in invertebrates such as nematodes and insects. Uniquely, syndecans are receptors for many classes of proteins that can bind to the heparan sulphate chains present on syndecan core proteins. These range from cytokines, chemokines, growth factors and morphogens to enzymes and extracellular matrix (ECM) glycoproteins and collagens. Extracellular interactions with other receptors, such as some integrins, are mediated by the core protein. This places syndecans at the nexus of many cellular responses to extracellular cues in development, maintenance, repair and disease. The cytoplasmic domains of syndecans, while having no intrinsic kinase activity, can nevertheless signal through binding proteins. All syndecans appear to be connected to the actin cytoskeleton and can therefore contribute to cell adhesion, notably to the ECM and migration. Recent data now suggest that syndecans can regulate stretch-activated ion channels. The structure and function of the syndecans and the ion channels are reviewed here, along with an analysis of ion channel functions in cell–matrix adhesion. This area sheds new light on the syndecans, not least since evidence suggests that this is an evolutionarily conserved relationship that is also potentially important in the progression of some common diseases where syndecans are implicated.

scholarly journals Comparative study on glycosaminoglycans synthesized in peripheral and peritoneal polymorphonuclear leucocytes from guinea pigs

1984 ◽  
Vol 217 (1) ◽  
pp. 199-207 ◽  
Author(s):  
Y Ohhashi ◽  
F Hasumi ◽  
Y Mori
Keyword(s):  
Cell Surface ◽  
Guinea Pigs ◽  
Lysosomal Enzymes ◽  
Culture Medium ◽  
Chondroitin Sulphate ◽  
Alkali Treatment ◽  
Heparan Sulphate ◽  
Polymorphonuclear Leucocytes ◽  
Dermatan Sulphate ◽  
Cell Cell

Glycosaminoglycans synthesized in polymorphonuclear (PMN) leucocytes isolated from blood (peripheral PMN leucocytes) and in those induced intraperitoneally by the injection of caseinate (peritoneal PMN leucocytes) were compared. Both peripheral and peritoneal PMN leucocytes were incubated in medium containing [35S]sulphate and [3H]glucosamine. Each sample obtained after incubation was separated into cell, cell-surface and medium fractions by trypsin digestion and centrifugation. The glycosaminoglycans secreted from peripheral and peritoneal PMN leucocytes were decreased in size by alkali treatment, indicating that they existed in the form of proteoglycans. Descending paper chromatography of the unsaturated disaccharides obtained by the digestion of glycosaminoglycans with chondroitinase AC and chondroitinase ABC identified the labelled glycosaminoglycans of both the cell and the medium fractions in peripheral PMN leucocytes as 55-58% chondroitin 4-sulphate, 16-19% chondroitin 6-sulphate, 16-19% dermatan sulphate and 6-8% heparan sulphate. Oversulphated chondroitin sulphate and oversulphated dermatan sulphate were found only in the medium fraction. In peritoneal PMN leucocytes there is a difference in the composition of glycosaminoglycans between the cell and the medium fractions; the cell fraction was composed of 60% chondroitin 4-sulphate, 5.5% chondroitin 6-sulphate, 16.8% dermatan sulphate and 13.9% heparan sulphate, whereas the medium fraction consisted of 24.5% chondroitin 4-sulphate, 28.2% chondroitin 6-sulphate, 33.7% dermatan sulphate and 10% heparan sulphate. Oversulphated chondroitin sulphate and oversulphated dermatan sulphate were found in the cell, cell-surface and medium fractions. On the basis of enzymic assays with chondro-4-sulphatase and chondro-6-sulphatase, the positions of sulphation in the disulphated disaccharides were identified as 4- and 6-positions of N-acetylgalactosamine. Most of the 35S-labelled glycosaminoglycans synthesized in peripheral PMN leucocytes were retained within cells, whereas those in peritoneal PMN leucocytes were secreted into the culture medium. Moreover, the amount of glycosaminoglycans in peritoneal PMN leucocytes was significantly less than that in peripheral PMN leucocytes. Assay of lysosomal enzymes showed that these activities in peritoneal PMN leucocytes were 2-fold higher than those in peripheral PMN leucocytes.

Heparan sulphate proteoglycans on rat parathyroid cells recycle in low Ca2+ medium

1990 ◽  
Vol 18 (5) ◽  
pp. 816-818 ◽  
Author(s):  
YASUHIRO TAKEUCHI ◽  
KAZUSHIGE SAKAGUCHI ◽  
MASAKI YANAGISHITA ◽  
VINCENT C. HASCALL
Keyword(s):  
Cell Surface ◽  
Cell Line ◽  
Transport Process ◽  
Core Protein ◽  
Divalent Cations ◽  
Heparan Sulphate ◽  
Parathyroid Cell ◽  
Metabolic Fate ◽  
Membrane Compartment ◽  
Heparan Sulphate Proteoglycans

Summary A rat parathyroid cell line, with some differentiated properties of the parathyroid gland, synthesizes predominantly a heparan sulphate proteoglycan (HS-PG) typical of cell surface HS-PGs (core protein = ∼ 70 kDa, three to four HS chains of ∼ 30 kDa). A 10 min pulse-chase protocol was used to determine the metabolic fate of the HS-PGs for cells maintained in 2.1 mM-Ca2+ (high Ca) or in 0.05 mM-Ca2+ (low Ca). In low Ca, ∼ 60% of the labelled HS-PGs reach the cell surface (t1/2= ∼ 15 min) as determined by trypsin accessibility. This population of HS-PGs recycles (t1/2= ∼ 9 min) between the cell surface and an intracellular (presumably endosome) compartment. After ∼ 2 h, this population of HS-PGs is internalized and rapidly degraded in lysosomes. In high Ca, only ∼ 10% of the HS-PGs reach the cell surface, where they do not recycle. Changing from high to low Ca any time between 30–120 min of chase, rapidly (t1/2 less than 4 min) redistributes the HS-PGs to the cell surface where they begin recycling; conversely, changing from low to high Ca leads to a rapid sequestration of the cell surface HS-PGs within the cells. Other divalent cations fail to minic the response to Ca2+. The results suggest that most of the HS-PGs in this cell line are anchored in a membrane compartment involved in a transport process between endosomes and the cell surface which is regulated by the concentration of extracellular Ca2+.

scholarly journals Expression of NG2 proteoglycan causes retention of type VI collagen on the cell surface.

1993 ◽  
Vol 4 (11) ◽  
pp. 1097-1108 ◽  
Author(s):  
A Nishiyama ◽  
W B Stallcup
Keyword(s):  
Cell Surface ◽  
Culture Medium ◽  
Core Protein ◽  
Cell Surface Receptor ◽  
Neural Cells ◽  
Pericellular Matrix ◽  
Type Vi Collagen ◽  
Surface Receptor ◽  
A Cell ◽  
Ng2 Proteoglycan

NG2 is a membrane-associated chondroitin sulfate proteoglycan with a core protein of 300 kD. Previously it was shown immunochemically that the core protein of NG2 can bind type VI collagen (Stallcup, W., Dahlin, K., and P. Healy. 1990. J. Cell Biol. 111:3177-3188). We have extended our studies on the interaction of NG2 and type VI collagen by transfecting cells with the full-length rat NG2 cDNA. B28 rat neural cells and U251MG human glioma cells used for transfection do not synthesize NG2. Both cell lines secrete type VI collagen into tissue culture medium but do not anchor it at the cell surface. Upon transfection of these cells with the NG2 cDNA, NG2 was correctly localized to the cell surface. Furthermore, type VI collagen could now be detected on the surface of NG2-positive cells in a pattern that coincided with that of NG2. This ability of NG2 to anchor type VI collagen to the cell surface could be abolished by incubating the cells in the presence of anti-NG2 monoclonal antibodies. These findings indicate that NG2 functions as a cell surface receptor for type VI collagen and may play a role in modulating the assembly of pericellular matrix.

SHEDDING OF SURFACE PROTEINS BY PORCINE THYROID CELLS

1980 ◽  
Vol 85 (2) ◽  
pp. 245-251 ◽  
Author(s):  
A. BRENNAN ◽  
P. M. POVEY ◽  
B. REES SMITH ◽  
R. HALL
Keyword(s):  
Cell Surface ◽  
Sodium Dodecyl Sulphate ◽  
Culture Medium ◽  
Cell Metabolism ◽  
Sodium Dodecyl ◽  
Surface Proteins ◽  
Half Time ◽  
Thyroid Cells ◽  
Peptide Cleavage ◽  
Membrane Bound

Isolated porcine thyroid cells were surface-labelled with 125I using the lactoperoxidase technique. Samples of the cells were then cultured and harvested at various intervals for up to 7 days. The labelled proteins remaining on the cells or shed into the culture medium were analysed by electrophoresis on polyacrylamide gels run in sodium dodecyl sulphate. These studies indicated that the several different surface proteins of the thyroid cells were lost from the cell surface at similar rates (half-time of approximately 28 h) as the result, at least in part, of a process which depended on active cell metabolism. In addition, the gel profiles obtained from analysis of both medium and membrane-bound labelled proteins were similar and this suggested that peptide cleavage was not involved in the shedding of the majority of these proteins.

Multimerization of monocyte chemoattractant protein-1 is not required for glycosaminoglycan-dependent transendothelial chemotaxis

2001 ◽  
Vol 358 (3) ◽  
pp. 737-745 ◽  
Author(s):  
Simi ALI ◽  
Adrian C. V. PALMER ◽  
Sarah J. FRITCHLEY ◽  
Yvonne MALEY ◽  
John A. KIRBY
Keyword(s):  
Cell Surface ◽  
Fusion Protein ◽  
Radioligand Binding ◽  
Heparan Sulphate ◽  
Placental Alkaline Phosphatase ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Monocyte Chemoattractant Protein 1 ◽  
Monocyte Chemoattractant ◽  
Monocyte Chemoattractant Protein

Chemokines interact with specific G-protein-coupled cell-surface receptors and with glycosaminoglycans (GAGs), such as heparan sulphate. Although chemokines often form multimers in solution, this process may be enhanced following interaction with GAGs on the cell surface, or within the extracellular matrix. However, the significance of multimerization for chemokine function remains controversial. In the present study, a fusion protein was prepared between the prototypical human CC chemokine, monocyte chemoattractant protein-1 (MCP-1; also known as CCL-2) and a large secreted placental alkaline phosphatase (SEAP) moiety. This fusion protein (MCP-1–SEAP) remained monomeric under conditions that promote oligomerization of the native chemokine. Radioligand binding showed that both native MCP-1 and MCP-1–SEAP competed for the same site on the surface of HEK-293 cells expressing the CCR2b chemokine receptor. The interaction between either chemokine species and endothelial cell surface GAGs was antagonized by the addition of the heparan sulphate-like molecule, heparin. Both MCP-1 and MCP-1–SEAP induced a Ca2+-flux in the THP-1 monocytic cell line, and were equally effective at promoting transendothelial chemotaxis of mononuclear immune cells, with maximal migration being produced by treatment with 12nM of either species. In each case this chemotactic response was almost completely antagonized by the addition of heparin. The importance of interaction between either native MCP-1 or MCP-1–SEAP and cell-surface GAGs for transcellular migration was demonstrated by the almost complete absence of leucocyte chemotaxis across monolayers of GAG-deficient mutant cells. In summary, this study shows that multimerization is neither necessary for, nor potentiates, the biological activity of MCP-1. However, the results do clearly demonstrate the importance of the interaction between MCP-1 and cell-surface heparan sulphate for transmonolayer leucocyte chemotaxis.

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