scholarly journals The melanoma proteoglycan: restricted expression on microspikes, a specific microdomain of the cell surface.

1986 ◽  
Vol 103 (5) ◽  
pp. 1699-1710 ◽  
Author(s):  
H J Garrigues ◽  
M W Lark ◽  
S Lara ◽  
I Hellström ◽  
K E Hellström ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Surface ◽  
Chondroitin Sulfate ◽  
Chondroitin Sulfate Proteoglycan ◽  
Immunogold Electron Microscopy ◽  
Cell Contact ◽  
Cell Periphery ◽  
Sulfate Proteoglycan ◽  
Whole Mount ◽  
Specific Localization

A cell surface chondroitin sulfate proteoglycan associated with human melanomas and defined by mAb's F24.47 and 48.7 has been characterized biochemically and localized by indirect immunogold electron microscopy. These antibodies recognize distinct epitopes on the intact proteoglycan. In addition, mAb 48.7 also recognizes an epitope on a 250,000-D glycoprotein and is therefore similar to antibody 9.2.27 (described by Bumol, T.F., and R.A. Reisfeld, 1982, Proc. Natl. Acad. Sci. USA., 79:1245-1249). Furthermore, it was shown that the glycosaminoglycan chains released by alkaline borohydride treatment of the proteoglycan recognized by mAb 48.7 had a size of approximately 60,000 D. Since the intact proteoglycan was estimated to be 420,000 D, there are probably three chondroitin sulfate chains attached to the 250,000-D core glycoprotein. Furthermore, an oligosaccharide fraction containing 42% of the 3H activity (glucosamine as precursor) was isolated. Immunolocalization studies using whole-mount electron microscopy revealed that the chondroitin sulfate proteoglycan was present almost exclusively on microspikes, a microdomain of the melanoma cell surface. These processes were present as 1-2-micron structures on the upper cell surface and as longer (up to 20 micron) structures at the cell periphery. Peripheral microspikes were involved in the initial interactions between adjacent cells and formed complex footpads that made contact with the substratum. Immunogold-labeled cells were also thin sectioned and the specific localization of the chondroitin sulfate proteoglycan antigen was quantitated. The data confirmed the results of whole-mount microscopy and demonstrated a statistically significant association of the antigen with the microspike processes as compared with other areas of the cell surface. By using two different mAb's (48.7 and F24.47) that recognize epitopes on either the core glycoprotein or the intact proteoglycan, respectively, we have demonstrated that both molecules have the same restricted distribution at the cell surface. The specific localization of the antigen to microspikes at the cell surface suggests it may play a role in cell-cell contact and cell-substratum adhesion, which could be important in the metastatic process.

scholarly journals Brevican, a Chondroitin Sulfate Proteoglycan of Rat Brain, Occurs as Secreted and Cell Surface Glycosylphosphatidylinositol-anchored Isoforms

1995 ◽  
Vol 270 (45) ◽  
pp. 27206-27212 ◽  
Author(s):  
Constanze I. Seidenbecher ◽  
Karin Richter ◽  
Uwe Rauch ◽  
Reinhard Fässler ◽  
Craig C. Garner ◽  
...  
Keyword(s):  
Cell Surface ◽  
Chondroitin Sulfate ◽  
Rat Brain ◽  
Chondroitin Sulfate Proteoglycan ◽  
Sulfate Proteoglycan

scholarly journals Interaction of the NG2 chondroitin sulfate proteoglycan with type VI collagen.

1990 ◽  
Vol 111 (6) ◽  
pp. 3177-3188 ◽  
Author(s):  
W B Stallcup ◽  
K Dahlin ◽  
P Healy
Keyword(s):  
Cell Surface ◽  
Chondroitin Sulfate ◽  
Cell Lines ◽  
Intervertebral Discs ◽  
Chondroitin Sulfate Proteoglycan ◽  
Cellular Interactions ◽  
Sulfate Proteoglycan ◽  
Type Vi Collagen ◽  
Double Labeling ◽  
Parallel Change

The NG2 chondroitin sulfate proteoglycan is a membrane-associated molecule of approximately 500 kD with a core glycoprotein of 300 kD. Both the complete proteoglycan and a smaller quantity of the 300-kD core are immunoprecipitable with polyclonal and monoclonal antibodies against purified NG2. From some cell lines, the antibodies coprecipitate NG2 and type VI collagen, the latter appearing on SDS-PAGE as components of 140 and 250 kD under reducing conditions. The immunoprecipitation of type VI collagen does not seem to be due to recognition of the collagen by the antibodies, but rather to binding of the collagen to NG2. Studies on the NG2-type VI collagen complex suggest that binding between the two molecules is mediated by protein-protein interactions rather than by ionic interactions involving the glycosaminoglycans. Immunofluorescence double labeling in frozen sections of embryonic rat shows that NG2 and type VI collagen are colocalized in structures such as the intervertebral discs and arteries of the spinal column. In vitro the two molecules are highly colocalized on the surface of several cell lines. Treatment of these cells resulting in a change in the distribution of NG2 on the cell surface also causes a parallel change in type VI collagen distribution. Our results suggest that cell surface NG2 may mediate cellular interactions with the extracellular matrix by binding to type VI collagen.

scholarly journals Codistribution of heparan sulfate proteoglycan, laminin, and fibronectin in the extracellular matrix of normal rat kidney cells and their coordinate absence in transformed cells.

1982 ◽  
Vol 94 (1) ◽  
pp. 28-35 ◽  
Author(s):  
E G Hayman ◽  
A Oldberg ◽  
G R Martin ◽  
E Ruoslahti
Keyword(s):  
Cell Surface ◽  
Heparan Sulfate ◽  
Chondroitin Sulfate ◽  
Rat Kidney ◽  
Heparan Sulfate Proteoglycan ◽  
Chondroitin Sulfate Proteoglycan ◽  
Transformed Cells ◽  
Kidney Cells ◽  
Sulfate Proteoglycan ◽  
Normal Rat

We used antibodies raised against both a heparan sulfate proteoglycan purified from a mouse sarcoma and a chondroitin sulfate proteoglycan purified from a rat yolk sac carcinoma to study the appearance and distribution of proteoglycans in cultured cells. Normal rat kidney cells displayed a fibrillar network of immunoreactive material at the cell surface when stained with antibodies to heparan sulfate proteoglycan, while virally transformed rat kidney cells lacked such a surface network. Antibodies to chondroitin sulfate proteoglycan revealed a punctate pattern on the surface of both cell types. The distribution of these two proteoglycans was compared to that of fibronectin by double-labeling immunofluorescent staining. The heparan sulfate proteoglycan was found to codistribute with fibronectin, and fibronectin and laminin gave coincidental stainings. The distribution of chondroitin sulfate proteoglycan was not coincidental with that of fibronectin. Distinct fibers containing fibronectin but lacking chondroitin sulfate proteoglycan were observed. When the transformed cells were cultured in the presence of sodium butyrate, their morphology changed, and fibronectin, laminin, and heparan sulfate proteoglycan appeared at the cell surface in a pattern resembling that of normal cells. These results suggest that fibronectin, laminin, and heparan sulfate proteoglycan may be complexed at the cell surface. The proteoglycan may play a central role in assembly of such complexes since heparan sulfate has been shown to interact with both fibronectin and laminin.

scholarly journals Chondroitin sulfate proteoglycan Windpipe modulates Hedgehog signaling in Drosophila

2018 ◽  
Author(s):  
Masahiko Takemura ◽  
Fredrik Noborn ◽  
Jonas Nilsson ◽  
Eriko Nakato ◽  
Tsu-Yi Su ◽  
...  
Keyword(s):  
Cell Surface ◽  
Chondroitin Sulfate ◽  
Hedgehog Signaling ◽  
Transmembrane Protein ◽  
Wing Disc ◽  
Chondroitin Sulfate Proteoglycan ◽  
Growth Factor Signaling ◽  
Sulfate Proteoglycan ◽  
Sugar Chain ◽  
Hh Signaling

AbstractProteoglycans, a class of carbohydrate-modified proteins, often modulate growth factor signaling on the cell surface. However, the molecular mechanism by which proteoglycans regulate signal transduction is largely unknown. In this study, using a recently-developed glycoproteomic method, we found that Windpipe (Wdp) is a novel chondroitin sulfate proteoglycan (CSPG) in Drosophila. Wdp is a single-pass transmembrane protein with leucin-rich repeat (LRR) motifs and bears three CS sugar chain attachment sites in the extracellular domain. Here we show that Wdp modulates the Hedgehog (Hh) pathway. Overexpression of wdp inhibits Hh signaling in the wing disc, which is dependent on its CS chains and the LRR motifs. Conversely, loss of wdp leads to the upregulation of Hh signaling. Furthermore, knockdown of wdp increase the cell surface accumulation of Smoothened (Smo), suggesting that Wdp inhibits Hh signaling by regulating Smo stability. Our study demonstrates a novel role of CSPG in regulating Hh signaling.

Chondroitin sulfate proteoglycan form of cellular and cell-surface Alzheimer amyloid precursor

1993 ◽  
Vol 154 (1-2) ◽  
pp. 121-124 ◽  
Author(s):  
Junichi Shioi ◽  
Lawrence M. Refolo ◽  
Spiros Efthimiopoulos ◽  
Nikolaos K. Robakis
Keyword(s):  
Cell Surface ◽  
Chondroitin Sulfate ◽  
Chondroitin Sulfate Proteoglycan ◽  
Sulfate Proteoglycan

scholarly journals The human homologue of rat NG2, a chondroitin sulfate proteoglycan, is not expressed on the cell surface of normal hematopoietic cells but is expressed by acute myeloid leukemia blasts from poor-prognosis patients with abnormalities of chromosome band 11q23

Blood ◽  
1996 ◽  
Vol 87 (3) ◽  
pp. 1123-1133 ◽  
Author(s):  
FO Smith ◽  
C Rauch ◽  
DE Williams ◽  
CJ March ◽  
D Arthur ◽  
...  
Keyword(s):  
Cell Surface ◽  
Chondroitin Sulfate ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Poor Prognosis ◽  
Hematopoietic Cells ◽  
Chondroitin Sulfate Proteoglycan ◽  
Chromosome Band ◽  
Sulfate Proteoglycan ◽  
Acute Myeloid

In our efforts to produce monoclonal antibodies that recognize cell- surface antigens expressed by hematopoietic precursor and stromal cells, we generated a monoclonal antibody, 7.1, which recognizes a 220- to 240-kD cell-surface protein whose N-terminal amino acid sequence is identical to the rat NG2 chondroitin sulfate proteoglycan molecule. This chondroitin sulfate proteoglycan, previously reported to be expressed by human melanoma cells, was not found to be expressed by normal hematopoietic cells, nor was it expressed on the cell surface of cell lines of hematopoietic origin including cell lines with 11q23 abnormalities. It was found on the cell surface of acute myeloid leukemia (AML) blasts and cell lines derived from nonhematopoietic tissues. Samples of leukemic marrow from 166 children with AML enrolled on Childrens Cancer Group protocol 213 were evaluated for cell-surface expression of this proteoglycan molecule. In 18 of 166 (11%) patient samples, greater than 25% of leukemic blasts expressed the NG2 molecule. These 18 patients had a poorer outcome with respect to survival (P = .002) and event-free survival (P = .035) with an actuarial survival at 4 years of 16.7%. Blast cell expression of the NG2 molecule was strongly associated with French-American-British M5 morphology (P < .0001) and abnormalities in chromosome band 11q23, site of the MLL gene. These results show that the NG2 molecule is expressed by malignant hematopoietic cells that have abnormalities in chromosome band 11q23, suggesting that antibody 7.1 may be useful in the rapid identification of this group of poor-prognosis patients.

scholarly journals Electron microscopic characterization of chick embryonic skeletal muscle proteoglycans.

1985 ◽  
Vol 100 (5) ◽  
pp. 1767-1776 ◽  
Author(s):  
D G Pechak ◽  
D A Carrino ◽  
A I Caplan
Keyword(s):  
Electron Microscopy ◽  
Chondroitin Sulfate ◽  
Biochemical Characterization ◽  
Core Protein ◽  
Chondroitin Sulfate Proteoglycan ◽  
Sulfate Proteoglycan ◽  
Protein Length ◽  
Core Proteins ◽  
Leg Muscle

In this article, proteoglycans from embryonic chick leg muscle are quantitatively and qualitatively compared with day 8 high density cell culture cartilage proteoglycans by electron microscopy of proteoglycan-cytochrome c monolayers. The visualized proteoglycan profiles were separated into four categories according to shape, size, and complexity. The two major categories were further characterized by lengths of core proteins, lengths of side projections, and distance between side projections. Two large proteoglycans are identifiable in spread leg muscle preparations. One group has a core protein (mean length of 205 nm) from which extend long thin side projections that we interpret to be groups of chondroitin sulfate glycosaminoglycans with a mean length of 79 nm. This large chondroitin sulfate proteoglycan is the only type found in muscle cultures as determined both biochemically in the past and now by electron microscopy and is referred to as muscle proteoglycan. The second large proteoglycan has a mean core protein length of 250 nm and side projections that are visibly shorter (mean length of 38 nm) and thicker than those of the muscle proteoglycan. This group is referred to as the mesenchymal proteoglycan since its biosynthetic origin is still uncertain. We compare these two profiles with the chick cartilage chondroitin sulfate proteoglycan that has a mean core protein length of 202 nm and side projections with a mean length of 50 nm. The data presented here substantiate the earlier biochemical characterization of these noncartilage proteoglycans and establish the unique structural features of the muscle proteoglycan as compared with the similar profiles of the cartilage and mesenchymal proteoglycans.

scholarly journals Arterial chondroitin sulfate proteoglycan: localization with a monoclonal antibody.

1988 ◽  
Vol 36 (10) ◽  
pp. 1211-1221 ◽  
Author(s):  
M W Lark ◽  
T K Yeo ◽  
H Mar ◽  
S Lara ◽  
I Hellström ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Chondroitin Sulfate ◽  
Chondroitin Sulfate Proteoglycan ◽  
Elastic Fibers ◽  
Immunogold Electron Microscopy ◽  
Sulfate Proteoglycan ◽  
Arterial Smooth Muscle ◽  
Matrix Components

We generated a monoclonal antibody (Mab) against a large chondroitin sulfate proteoglycan (CSPG) isolated from bovine aorta. This Mab (941) immunoprecipitates a CSPG synthesized by cultured monkey arterial smooth muscle cells. The immunoprecipitated CSPG is totally susceptible to chondroitinase ABC digestion and possesses a core glycoprotein of Mr approximately 400-500 KD. By use of immunofluorescence light microscopy and immunogold electron microscopy, the PG recognized by this Mab was shown to be deposited in the extracellular matrix of monkey arterial smooth muscle cell cultures in clusters which were not part of other fibrous matrix components and not associated with the cell's plasma membrane. With similar immunolocalization techniques, the CSPG antigen was found enriched in the intima and present in the medial portions of normal blood vessels, as well as in the interstitial matrix of thickened intimal lesions of atherosclerotic vessels. Immunoelectron microscopy revealed that this CSPG was confined principally to the space within the extracellular matrix not occupied by other matrix components, such as collagen and elastic fibers. These results indicate that this particular proteoglycan has a specific but restricted distribution in the extracellular matrix of arterial tissue.

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