scholarly journals Oligomeric forms of the 148 kDa cartilage matrix protein

1997 ◽  
Vol 328 (2) ◽  
pp. 665-668 ◽  
Author(s):  
Reema ZEINELDIN ◽  
Suzanne EKBORG ◽  
John BAKER
Keyword(s):  
Molecular Mass ◽  
Matrix Protein ◽  
Type Ii Collagen ◽  
Cartilage Matrix ◽  
Type Ii ◽  
Age Related ◽  
Sds Page ◽  
Self Association ◽  
Chromatography Step ◽  
Oligomeric Forms

The 148 kDa cartilage matrix protein (CMP), composed of three disulphide-bonded subunits, is a cartilage-specific glycoprotein found in association with fibrils of type II collagen and possibly with aggrecan. It is probable that CMP serves a structural role. As cartilage ages, an increasing proportion of the CMP becomes insoluble and resistant to extraction. In the present study, the isolation of CMP has been improved by inclusion of a hydrophobic chromatography step, thereby removing the remaining traces of collagen and proteoglycan. Evidence of self-association of CMP is presented. Higher-molecular-mass forms of CMP, ranging in apparent molecular mass from 270 to 510 kDa and separated by SDS/PAGE, were located using a specific anti-CMP monoclonal antibody. Both CMP and its oligomeric forms are reducible to 52 kDa subunits, and only trace amounts of other proteins. The formation of oligomers, which may constitute 23% of the total cartilage matrix protein, could occur as a byproduct of the normal biosynthetic trimerization of subunits. Alternatively, the oligomers may represent a step toward the age-related cross-linking and insolubilization of CMP.

scholarly journals Cartilage matrix protein forms a type II collagen-independent filamentous network: analysis in primary cell cultures with a retrovirus expression system.

1995 ◽  
Vol 6 (12) ◽  
pp. 1743-1753 ◽  
Author(s):  
Q Chen ◽  
D M Johnson ◽  
D R Haudenschild ◽  
M M Tondravi ◽  
P F Goetinck
Keyword(s):  
Growth Factor ◽  
Matrix Protein ◽  
Expression System ◽  
Type Ii Collagen ◽  
Cartilage Matrix ◽  
Type Ii ◽  
Tail Domain ◽  
Filament Formation ◽  
Wild Type ◽  
Epidermal Growth

Cartilage matrix protein (CMP) is expressed specifically in mature cartilage and consists of two von Willebrand factor A domains (CMP-A1 and CMP-A2) that are separated by an epidermal growth factor-like domain, and a coiled-coil tail domain at the carboxyl terminal end. We have shown previously that CMP interacts with type II collagen-containing fibrils in cartilage. In this study, we describe a type II collagen-independent CMP filament and we analyze the structural requirement for the formation of this type of filament. Recombinant wild-type CMP and two mutant forms were expressed in chick primary cell cultures using a retrovirus expression system. In chondrocytes, the wild-type virally encoded CMP is able to form disulfide bonded trimers and to assemble into filaments. Filaments also form with CMP whose Cys455 and Cys457 in the tail domain were mutagenized to prevent interchain disulfide bond formation. Therefore, intermolecular disulfide bonds are not necessary for the assembly of CMP into filaments. Both the wild-type and the double cysteine mutant also form filaments in fibroblasts, indicating that chondrocyte-specific factors are not required for filament formation. A truncated form of CMP that consists only of the CMP-A2 domain and the tail domain can form trimers but fails to form filaments, indicating that the deleted CMP-A1 domain and/or the epidermal growth factor domain are necessary for filament assembly but not for trimer formation. Furthermore, the expression of the virally encoded truncated CMP in chondrocyte culture disrupts endogenous CMP filament formation. Together these data suggest a role for CMP in cartilage matrix assembly by forming filamentous networks that require participation and coordination of individual domains of CMP.

Gene regulation during cartilage differentiation: temporal and spatial expression of link protein and cartilage matrix protein in the developing limb

Development ◽  
1989 ◽  
Vol 107 (1) ◽  
pp. 23-33
Author(s):  
N.S. Stirpe ◽  
P.F. Goetinck
Keyword(s):  
Matrix Protein ◽  
Core Protein ◽  
Type Ii Collagen ◽  
Cartilage Matrix ◽  
Type Ii ◽  
Spatial Expression ◽  
Link Protein ◽  
Genes Encoding ◽  
Temporal And Spatial ◽  
And Cartilage

The temporal and spatial expression of link protein and cartilage matrix protein genes was defined during chondrogenesis in the developing chick embryonic wing bud, using RNA in situ hybridization. For comparison, the expression of genes encoding type II collagen and cartilage proteoglycan core protein was also examined. Link protein transcripts are first detected at stage 25 of Hamburger and Hamilton, together with proteoglycan core protein transcripts. Type II collagen transcripts were first detected as early as stage 23 whereas cartilage matrix protein transcripts could not be detected before stage 26. The results of the study indicate that the temporal expression of the genes for cartilage matrix protein and type II collagen are independent of each other and also independent of that for link protein and proteoglycan core protein.

scholarly journals Integrin α2β1 Is a Receptor for the Cartilage Matrix Protein Chondroadherin

1997 ◽  
Vol 138 (5) ◽  
pp. 1159-1167 ◽  
Author(s):  
Lisbet Camper ◽  
Dick Heinegård ◽  
Evy Lundgren-Åkerlund
Keyword(s):  
Cell Adhesion ◽  
Matrix Protein ◽  
Collagen Type ◽  
Human Fibroblasts ◽  
Cartilage Matrix ◽  
Affinity Column ◽  
Integrin Subunit ◽  
Β1 Integrin ◽  
Type Ii ◽  
Collagen Type Ii

Chondroadherin (the 36-kD protein) is a leucine-rich, cartilage matrix protein known to mediate adhesion of isolated chondrocytes. In the present study we investigated cell surface proteins involved in the interaction of cells with chondroadherin in cell adhesion and by affinity purification. Adhesion of bovine articular chondrocytes to chondroadherin-coated dishes was dependent on Mg2+ or Mn2+ but not Ca2+. Adhesion was partially inhibited by an antibody recognizing β1 integrin subunit. Chondroadherin-binding proteins from chondrocyte lysates were affinity purified on chondroadherin-Sepharose. The β1 integrin antibody immunoprecipitated two proteins with molecular mass ∼110 and 140 kD (nonreduced) from the EDTA-eluted material. These results indicate that a β1 integrin on chondrocytes interacts with chondroadherin. To identify the α integrin subunit(s) involved in interaction of cells with the protein, we affinity purified chondroadherin-binding membrane proteins from human fibroblasts. Immunoprecipitation of the EDTA-eluted material from the affinity column identified α2β1 as a chondroadherin-binding integrin. These results are in agreement with cell adhesion experiments where antibodies against the integrin subunit α2 partially inhibited adhesion of human fibroblast and human chondrocytes to chondroadherin. Since α2β1 also is a receptor for collagen type II, we tested the ability of different antibodies against the α2 subunit to inhibit adhesion of T47D cells to collagen type II and chondroadherin. The results suggested that adhesion to collagen type II and chondroadherin involves similar or nearby sites on the α2β1 integrin. Although α2β1 is a receptor for both collagen type II and chondroadherin, only adhesion of cells to collagen type II was found to mediate spreading.

scholarly journals Turnover of type II collagen and aggrecan in cartilage matrix at the onset of inflammatory arthritis in humans: Relationship to mediators of systemic and local inflammation

2003 ◽  
Vol 48 (11) ◽  
pp. 3085-3095 ◽  
Author(s):  
Alexander Fraser ◽  
Ursula Fearon ◽  
R. Clark Billinghurst ◽  
Mirela Ionescu ◽  
Richard Reece ◽  
...  
Keyword(s):  
Inflammatory Arthritis ◽  
Type Ii Collagen ◽  
Cartilage Matrix ◽  
Type Ii ◽  
Local Inflammation

Achondrogensis type II: A heterozygous point mutation prevents deposition of type II collagen into the cartilage matrix

1994 ◽  
Vol 14 (5) ◽  
pp. 389
Author(s):  
Danny Chan ◽  
C.W. Chow ◽  
William G. Cole ◽  
John F. Bateman
Keyword(s):  
Point Mutation ◽  
Type Ii Collagen ◽  
Cartilage Matrix ◽  
Type Ii

scholarly journals Murine fibromodulin: cDNA and genomic structure, and age-related expression and distribution in the knee joint

2001 ◽  
Vol 355 (3) ◽  
pp. 577-585 ◽  
Author(s):  
Anna-Marja K. SÄÄMÄNEN ◽  
Heli J. SALMINEN ◽  
A. Juho RANTAKOKKO ◽  
Dick HEINEGÅRD ◽  
Eero I. VUORIO
Keyword(s):  
Genomic Structure ◽  
Type Ii Collagen ◽  
Type I ◽  
Mrna Levels ◽  
Primary Role ◽  
Type Ii ◽  
Exon 2 ◽  
Collagen Fibrillogenesis ◽  
Calcified Cartilage ◽  
Age Related

The genomic structure of murine fibromodulin was determined, and its age-related expression and distribution were characterized in knee epiphyses, with decorin studied for reference. Fibromodulin, as well as decorin, have roles in collagen fibrillogenesis both in vitro and in vivo. The murine fibromodulin gene, Fmod, was similar with that in other species, with three exons and 86% of the translated sequence in exon 2. The 2.7kb long cDNA contains an open reading frame of 1131nt. Fibromodulin mRNA levels were highest in tissues rich in fibrillar collagens type I or type II. During growth, the distribution of fibromodulin mRNA was similar with that of type II collagen, with the highest levels between 5 days and 1 month of age. Thereafter, the expression of type II collagen declined to a level near the detection limit, whereas the fibromodulin expression decreased less markedly to a level of approx. 35% of maximum, and remained constant throughout the rest of the observation period. In contrast, decorin mRNA levels were the highest in old animals. Pericellular deposition of fibromodulin was strong around the late-hypertrophic chondrocytes of the secondary ossification centre and in the growth plate. In young epiphyses, both fibromodulin and decorin were found interterritorially, mainly in the uncalcified and deep-calcified cartilage. In the old mice, calcified cartilage became enriched with regard to fibromodulin, while, in contrast, decorin deposition diminished, particularly near the tidemark. In the subchondral bone trabeculae, decorin was found in the endosteum of growing, but not in the mature, epiphyses. Differences in the expression and distribution profiles suggest different roles for fibromodulin and decorin in the regulation of collagen fibrillogenesis, maintenance of the fibril organization and matrix mineralization. As fibromodulin is deposited closer to cells than decorin, it may have a primary role in collagen fibrillogenesis, whereas decorin might be involved in the maintenance of fibril structures in the interterritorial matrix.

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