C-propeptide of type ii procollagen; a protein associated with cartilage mineralization

1986 ◽  
Vol 44 ◽  
pp. 272-273
Author(s):  
E.R. Lee ◽  
A.R. Poole
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Matrix Protein ◽  
Type Ii Collagen ◽  
Collagen Molecule ◽  
Type Ii ◽  
Amino Acid Sequencing ◽  
Procollagen Type ◽  
Matrix Distribution ◽  
The Matrix

A matrix protein has been identified in both calcifying and noncalcifying cartilage during development, and named chondrocalcin. The concentration of this protein is greatly increased in calcifying cartilage and it appears in the matrix when and where mineralization occurs. Amino acid sequencing has recently shown that chondrocalcin is identical to the C-propeptide of type II procollagen. Type II procollagen is a high molecular weight precursor of type II collagen and it is characterized by amino (NH2) and carboxy (C) propeptide extensions. These nonhelical extensions are normally cleaved extracellularly by proteinases to give the collagen molecule. To investigate the synthesis, secretion and matrix distribution of the C-propeptide, particularly during mineralization, this protein has been localized at the EM level with immunogold techniques.

scholarly journals Two amino acid residues in the matrix protein M1 contribute to the virulence difference of H5N1 avian influenza viruses in mice

Virology ◽  
2009 ◽  
Vol 384 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Shufang Fan ◽  
Guohua Deng ◽  
Jiasheng Song ◽  
Guobin Tian ◽  
Yongbing Suo ◽  
...  
Keyword(s):  
Amino Acid ◽  
Avian Influenza ◽  
Matrix Protein ◽  
Influenza Viruses ◽  
Amino Acid Residues ◽  
Avian Influenza Viruses ◽  
H5n1 Avian Influenza ◽  
The Matrix ◽  
Matrix Protein M1

scholarly journals Matrix and Envelope Coevolution Revealed in a Patient Monitored since Primary Infection with Human Immunodeficiency Virus Type 1

2009 ◽  
Vol 83 (19) ◽  
pp. 9875-9889 ◽  
Author(s):  
Elodie Beaumont ◽  
Daniela Vendrame ◽  
Bernard Verrier ◽  
Emmanuelle Roch ◽  
François Biron ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Matrix Protein ◽  
Immunodeficiency Virus ◽  
The Matrix ◽  
Hiv 1

ABSTRACT Lentiviruses, including human immunodeficiency virus type 1 (HIV-1), typically encode envelope glycoproteins (Env) with long cytoplasmic tails (CTs). The strong conservation of CT length in primary isolates of HIV-1 suggests that this factor plays a key role in viral replication and persistence in infected patients. However, we report here the emergence and dominance of a primary HIV-1 variant carrying a natural 20-amino-acid truncation of the CT in vivo. We demonstrated that this truncation was deleterious for viral replication in cell culture. We then identified a compensatory amino acid substitution in the matrix protein that reversed the negative effects of CT truncation. The loss or rescue of infectivity depended on the level of Env incorporation into virus particles. Interestingly, we found that a virus mutant with defective Env incorporation was able to spread by cell-to-cell transfer. The effects on viral infectivity of compensation between the CT and the matrix protein have been suggested by in vitro studies based on T-cell laboratory-adapted virus mutants, but we provide here the first demonstration of the natural occurrence of similar mechanisms in an infected patient. Our findings provide insight into the potential of HIV-1 to evolve in vivo and its ability to overcome major structural alterations.

Independent deposition of collagen types II and IX at epithelial-mesenchymal interfaces

Development ◽  
1989 ◽  
Vol 105 (1) ◽  
pp. 85-95 ◽  
Author(s):  
J.M. Fitch ◽  
A. Mentzer ◽  
R. Mayne ◽  
T.F. Linsenmayer
Keyword(s):  
Collagen Type ◽  
Immunohistochemical Study ◽  
Type Ii Collagen ◽  
The Other ◽  
Extracellular Matrices ◽  
Type Ii ◽  
Collagen Deposition ◽  
Collagen Types ◽  
Hind Limbs ◽  
The Matrix

Previous studies have demonstrated the presence of type II collagen (in mature chickens predominantly a ‘cartilage-specific’ collagen) in a variety of embryonic extracellular matrices that separate epithelia from mesenchyme. In an immunohistochemical study using collagen type-specific monoclonal antibodies, we asked whether type IX collagen, another ‘cartilage-specific’ collagen, is coexpressed along with type II at such interfaces. We confirmed that, in the matrix underlying a variety of cranial ectodermal derivatives and along the ventrolateral surfaces of neuroepithelia, type II collagen is codistributed with collagen types I and IV. Type IX collagen, however, was undetectable at those sites. We observed immunoreactivity for type IX collagen only within the notochordal sheath, where it first appeared at a later stage than did collagen types I and II. We also observed type II collagen (without type IX) beneath the dorsolateral ectoderm at stage 16; this correlates with the period during which limb ectoderm has been reported to induce the mesoderm to become chondrogenic. Finally, in older hind limbs we observed subepithelial type II collagen that was not associated with subsequent chondrogenesis, but appeared to parallel the formation of feathers and scales in the developing limb. These observations suggest that the deposition of collagen types II and IX into interfacial matrices is regulated independently, and that induction of mesenchymal chondrogenesis by such matrices does not involve type IX collagen. Subepithelial type IX collagen deposition, on the other hand, correlates with the assembly of a thick multilaminar fibrillar matrix, as present in the notochordal sheath and, as shown previously, in the corneal primary stroma.

Immunohistochemical Localization of Matrix Proteins in the Femoral Joint Cartilage of Growing Commercial Pigs

1992 ◽  
Vol 29 (6) ◽  
pp. 514-520 ◽  
Author(s):  
S. Ekman ◽  
D. Heinegård
Keyword(s):  
Subchondral Bone ◽  
Matrix Protein ◽  
Collagen Type ◽  
Immunohistochemical Localization ◽  
Matrix Composition ◽  
Type Ii ◽  
Collagen Type Ii ◽  
Chondrocyte Maturation ◽  
Proliferative Zone ◽  
The Matrix

The immunocytochemical localization of several matrix macromolecules, including collagen type II and proteoglycans, in the distal femoral articular-epiphyseal cartilage complex of 15 commercial pigs between the age of 6 and 18 weeks was studied. Early osteochondrotic lesions, i.e., chondronecrosis in the resting region of the growth cartilage, as well as extensions of necrotic cartilage into the subchondral bone, were present in all animals, except those 6 weeks old. A battery of antibodies were used for identification of macromolecules in the matrix at different stages of the disease. Chondrocyte involvement in the process could be studied by identifying the sequence of alterations in matrix macromolecules as the lesion developed. The immunostaining for aggrecan (large aggregating proteoglycans), cartilage oligomeric matrix protein, fibronectin, collagen type II, fibromodulin, and biglycan was more prominent in the areas of chondronecrosis, extending into the subchondral bone, than in the normal resting region. This altered pattern of matrix macromolecules resembled that of the matrix of the proliferative chondrocytes and suggests that the chondrocyte maturation had stopped in the proliferative zone. The matrix in the areas of chondronecrosis in the resting region resembled that in the normal resting region. Thus the chondronecrosis appears to have preceded alterations of the matrix composition. The antibody reactivity pattern was, however, altered in the matrix of the clustered chondrocytes in areas of chondronecrosis. Staining in these regions suggested a more prominent appearance of fibronectin and collagen type II than in the normal matrix of the resting region. These changes are suggestive of attempt to repair. The chondronecrotic areas restricted to the resting region have a matrix that is different from the matrix of the abnormal cartilage extending into the subchondral bone, which resembled the matrix of the proliferative region. Hence the osteochondrotic lesion may not start in the resting region, instead the maturation of chondrocytes seems to stop in the proliferative zone, which would result in impaired bone formation.

scholarly journals Chondrodysplasia in transgenic mice harboring a 15-amino acid deletion in the triple helical domain of pro alpha 1(II) collagen chain.

1992 ◽  
Vol 118 (1) ◽  
pp. 203-212 ◽  
Author(s):  
M Metsäranta ◽  
S Garofalo ◽  
G Decker ◽  
M Rintala ◽  
B de Crombrugghe ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Endochondral Ossification ◽  
Electron Microscopic Examination ◽  
Type Ii Collagen ◽  
Dominant Negative ◽  
Collagen Molecule ◽  
Type Ii ◽  
Electron Microscopic ◽  
Dominant Negative Mutation ◽  
Collagen Chain

We have generated transgenic mice by microinjection of a 39-kb mouse pro alpha 1(II) collagen gene construct containing a deletion of exon 7 and intron 7. This mutation was expected to disturb the assembly and processing of the homotrimeric type II collagen molecule in cartilage. Expression of transgene mRNA at levels equivalent or higher than the endogenous mRNA in the offspring of two founder animals resulted in a severe chondrodysplastic phenotype with short limbs, hypoplastic thorax, abnormal craniofacial development, and other skeletal deformities. The affected pups died at birth due to respiratory distress. Light microscopy of epiphyseal growth plates of transgenic pups demonstrated a marked reduction in cartilaginous extracellular matrix and disruption of the normal organization of the growth plate. The zone of proliferating chondrocytes was greatly reduced whereas the zone of hypertrophic chondrocytes was markedly increased extending deep into the diaphysis suggestive of a defect in endochondral ossification. Electron microscopic examination revealed chondrocytes with extended RER, a very severe reduction in the amount of cartilage collagen fibrils, and abnormalities in their structure. We postulate that the deletion in the alpha 1(II) collagen acts as a dominant negative mutation disrupting the assembly and secretion of type II collagen molecules. The consequences of the mutation include interference with normal endochondral ossification. These mice constitute a valuable model to study the mechanisms underlying human chondrodysplasias and normal bone formation.

scholarly journals Cellular heterogeneity in cultured human chondrocytes identified by antibodies specific for alpha 2(XI) collagen chains.

1989 ◽  
Vol 109 (3) ◽  
pp. 1363-1369 ◽  
Author(s):  
B Swoboda ◽  
R Holmdahl ◽  
H Stöss ◽  
K von der Mark
Keyword(s):  
Hyaline Cartilage ◽  
Type Ii Collagen ◽  
Cross Reactivity ◽  
Cellular Heterogeneity ◽  
Human Chondrocytes ◽  
Type I ◽  
Type Ii ◽  
Human Cartilage ◽  
The Matrix ◽  
Type Xi Collagen

Collagen type XI is a component of hyaline cartilage consisting of alpha 1(XI), alpha 2(XI), and alpha 3(XI) chains; with 5-10% of the total collagen content, it is a minor but significant component next to type II collagen, but its function and precise localization in cartilaginous tissues is still unclear. Owing to the homology of the alpha 3(XI) and alpha 1(II) collagen chains, attempts to prepare specific antibodies to native type XI collagen have been unsuccessful in the past. In this study, we report on the preparation and use for immunohistochemistry of a polyclonal antibody specific for alpha 2(XI) denatured collagen chains. The antibody was prepared by immunization with the isolated alpha 2(XI) chain and reacts neither with native type XI collagen nor type I, II, V, or IX by ELISA or immunoblotting, nor with alpha 1(XI) or alpha 3(XI), but with alpha 2(XI) chains. Using this antibody, it was possible to specifically localize alpha 2(XI) in cartilage by pretreating tissue sections with 6 M urea. In double immunofluorescence staining experiments, the distribution of alpha 2(XI) as indicative for type XI collagen in fetal bovine and human cartilage was compared with that of type II collagen, using a monoclonal antibody to alpha 1(II). Type XI collagen was found throughout the matrix of hyaline cartilage. However, owing to cross-reactivity of the monoclonal anti-alpha 1(II) with alpha 3(XI), both antibodies produced the same staining pattern. Cellular heterogeneity was, however, detected in monolayer cultures of human chondrocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

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