scholarly journals Kinetics of intracellular processing of chondroitin sulfate proteoglycan core protein and other matrix components.

1988 ◽  
Vol 106 (6) ◽  
pp. 2191-2202 ◽  
Author(s):  
S C Campbell ◽  
N B Schwartz
Keyword(s):  
Core Protein ◽  
Type Ii Collagen ◽  
Subcellular Fractionation ◽  
Type Ii ◽  
Link Protein ◽  
The Core ◽  
Intracellular Processing ◽  
Collagen Secretion ◽  
Golgi Region ◽  
Kinetics Of

Pulse-chase labeling techniques are used in conjunction with subcellular fractionation and quantitative immunoprecipitation to define the kinetics of intracellular translocation and secretion of proteoglycan core protein, along with link protein and type II collagen. In embryonic chick chondrocytes the core protein is processed very rapidly, exhibiting a t 1/2 in both the rough endoplasmic reticulum and golgi region of less than 10 min. Link protein appears to be processed as rapidly as the core protein, but the kinetics of type II collagen secretion is 3-4 times slower. These results are consistent with possible segregation and coordinate intracellular processing of link protein and core protein, macromolecules which are known to associate extracellularly. In contrast, rat chondrosarcoma chondrocytes translocated and secreted the core protein much more slowly (t 1/2 = 40 min) than the chick cells, perhaps due to the significantly reduced levels of galactosyltransferase I observed in the transformed chondrocytes.

The Formation of Cartilage Extracellular Matrix

1988 ◽  
Vol 46 ◽  
pp. 230-231
Author(s):  
B.M. Vertel
Keyword(s):  
Extracellular Matrix ◽  
Hyaline Cartilage ◽  
Core Protein ◽  
Type Ii Collagen ◽  
Type Ii ◽  
Structural Components ◽  
Normal Cartilage ◽  
Link Protein ◽  
Cartilage Extracellular Matrix ◽  
Compression Type

Normal cartilage function is dependent upon the unique structural properties of the extensive extracellular matrix (ECM). In final assembled form, the ECM of hyaline cartilage is composed of abundant amounts of proteoglycan (PG) and type II collagen. Additional collagens and glycoproteins may be important structural components as well. Through their concentration of negative charges, PGs confer upon the cartilage ECM the ability to retain high levels of hydration and thereby resist compression. Type II collagen fibers contribute to the tensile strength of cartilage.In the cartilage ECM, PG monomers associate with hyaluronic acid and link protein to form large aggregates. In turn, PG aggregates are associated with the fibrous meshwork of type II collagen. Interactions with other ECM molecules may occur as well. The cartilage matrix constituents are themselves large and complex. For example, the PG monomer is 1-5 x 106 daltons in size and contains a core protein of Mr >300K (comprising only 8-10% of the complete monomer).

scholarly journals Specific inhibition of type I and type II collagen fibrillogenesis by the small proteoglycan of tendon

1984 ◽  
Vol 223 (3) ◽  
pp. 587-597 ◽  
Author(s):  
K G Vogel ◽  
M Paulsson ◽  
D Heinegård
Keyword(s):  
Chemical Structure ◽  
Core Protein ◽  
Alkali Treatment ◽  
Type Ii Collagen ◽  
Type I ◽  
Type Ii ◽  
Dermatan Sulphate ◽  
The Core ◽  
Small Proteoglycan

The small dermatan sulphate proteoglycan of bovine tendon demonstrated a unique ability to inhibit fibrillogenesis of both type I and type II collagen from bovine tendon and cartilage respectively in an assay performed in vitro. None of the other proteoglycan populations from cartilage, tendon or aorta, even those similar in size and chemical structure, had this effect. Alkali treatment of the small proteoglycan of tendon eliminated its ability to inhibit fibrillogenesis, whereas chondroitinase digestion did not. This indicates that its interaction with collagen depends on the core protein. Fibrillogenesis of pepsin-digested collagens was affected similarly, indicating that interaction with the collagen telopeptides is not involved. The results suggest that interactions between collagen and proteoglycans may be quite specific both for the type of proteoglycan and its tissue of origin.

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 Modulation of aggrecan and link-protein synthesis in articular cartilage

1992 ◽  
Vol 288 (3) ◽  
pp. 721-726 ◽  
Author(s):  
A J Curtis ◽  
R J Devenish ◽  
C J Handley
Keyword(s):  
Articular Cartilage ◽  
Half Life ◽  
Core Protein ◽  
Calf Serum ◽  
Cartilage Explants ◽  
Dependent Manner ◽  
Link Protein ◽  
The Core ◽  
Explant Cultures ◽  
Igf I

The addition of serum or insulin-like growth factor-I (IGF-I) to the medium of explant cultures of bovine articular cartilage is known to stimulate the synthesis of aggrecan in a dose-dependent manner. The half-life of the pool of proteoglycan core protein was measured in adult articular cartilage cultured for 6 days in the presence and absence of 20 ng of IGF-I/ml and shown to be 24 min under both sets of conditions. The half-life of the mRNA pool coding for aggrecan was also determined and shown to be approx. 4 h in cartilage maintained in culture with or without IGF-I. The pool size of mRNA coding for aggrecan core protein increased 5-6-fold in cartilage explants maintained in culture in medium containing 20% (v/v) fetal-calf serum; however, in tissue maintained with medium containing IGF-I there was no increase in the cellular levels of this mRNA. This suggests that aggrecan synthesis is stimulated by IGF-I at the level of translation of mRNA coding for the core protein of this proteoglycan and that other growth factors are present in serum that stimulate aggrecan synthesis at the level of transcription of the core-protein gene. Inclusion of serum or IGF-I in the medium of cartilage explant cultures induced increases in the amounts of mRNA coding for type II collagen and link protein, whereas only serum enhanced the amount of mRNA for the core protein of decorin.

scholarly journals Influence of a Putative Intermolecular Interaction between Core and the Pre-S1 Domain of the Large Envelope Protein on Hepatitis B Virus Secretion

2002 ◽  
Vol 76 (13) ◽  
pp. 6510-6517 ◽  
Author(s):  
Sophie Le Pogam ◽  
Chiaho Shih
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Wild Type ◽  
The Core ◽  
Virion Release ◽  
Naturally Occurring ◽  
B Virus ◽  
Kinetics Of ◽  
Viral Reverse Transcription

ABSTRACT Virion release of hepatitis B virus (HBV) from hepatocytes is a tightly regulated event. It is a dogma that only the mature HBV genome is preferentially allowed to export from the intracellular compartment (J. Summers and W. S. Mason, Cell 29:403-415, 1982). Recently, an “immature secretion” phenotype of a highly frequent naturally occurring HBV variant containing a leucine residue at amino acid 97 of the core protein was identified. Unlike wild-type HBV, this variant secretes almost equal amounts of mature and immature genomes. This phenomenon is not caused by any instability of core particles or by any deficiency in viral reverse transcription (T. T. Yuan, P. C. Tai, and C. Shih, J. Virol. 73:10122-10128, 1999). In this study, our kinetic analysis of virion secretion of the mutant F97L (phenylalanine to leucine) indicates that the secretion of its immature genome does not occur earlier than that of its mature genome. In addition, the secretion kinetics of the mature genomes are comparable between the wild-type HBV and the mutant F97L. Therefore, the immature secretion phenomenon of mutant F97L is not caused by premature secretion or more efficient secretion. Previously, we hypothesized that the immature secretion phenotype is probably caused by the aberrant interaction between its mutant core and wild-type envelope proteins. Here, we further demonstrated that a pre-S1 envelope mutation at position 119, changing an alanine (A) to a phenylalanine (F), can offset the immature secretion phenotype of the mutant I97L (isoleucine to leucine) and successfully restore the wild-type-like selective export of the mature genome of the double mutant pre-S1-A119F/core-I97L.

scholarly journals Hepatitis C Virus Infection Activates the Immunologic (Type II) Isoform of Nitric Oxide Synthase and Thereby Enhances DNA Damage and Mutations of Cellular Genes

2004 ◽  
Vol 78 (16) ◽  
pp. 8835-8843 ◽  
Author(s):  
Keigo Machida ◽  
Kevin T.-H. Cheng ◽  
Vicky M.-H. Sung ◽  
Ki Jeong Lee ◽  
Alexandra M. Levine ◽  
...  
Keyword(s):  
Mutation Frequency ◽  
Core Protein ◽  
Hcv Infection ◽  
Type Ii ◽  
Dna Breaks ◽  
The Core ◽  
Cellular Genes ◽  
Nos Inhibitors ◽  
Inos Promoter ◽  
Infected Cells

ABSTRACT Hepatitis C virus (HCV) infection causes hepatitis, hepatocellular carcinoma, and B-cell lymphomas in a significant number of patients. Previously we have shown that HCV infection causes double-stranded DNA breaks and enhances the mutation frequency of cellular genes, including proto-oncogenes and immunoglobulin genes. To determine the mechanisms, we studied in vitro HCV infection of cell culture. Here we report that HCV infection activated the immunologic (type II) isoform of nitric oxide (NO) synthase (NOS), i.e., inducible NOS (iNOS), thereby inducing NO, which in turn induced DNA breaks and enhanced the mutation frequencies of cellular genes. Treatment of HCV-infected cells with NOS inhibitors or small interfering RNA specific for iNOS abolished most of these effects. Expression of the core protein or nonstructural protein 3 (NS3), but not the other viral proteins, in B cells or hepatocytes induced iNOS and DNA breaks, which could be blocked by NOS inhibitors. The core protein also enhanced the mutation frequency of cellular genes in hepatocytes derived from HCV core transgenic mice compared with that in control mice. The iNOS promoter was activated more than fivefold in HCV-infected cells, as revealed by a luciferase reporter assay driven by the iNOS promoter. Similarly, the core and NS3 proteins also induced the same effects. Therefore, we conclude that HCV infection can stimulate the production of NO through activation of the gene for iNOS by the viral core and NS3 proteins. NO causes DNA breaks and enhances DNA mutation. This sequence of events provides a mechanism for HCV pathogenesis and oncogenesis.

scholarly journals Identification of a Minimum Enhancer Sequence for the Type II Collagen Gene Reveals Several Core Sequence Motifs in Common with the Link Protein Gene

1996 ◽  
Vol 271 (8) ◽  
pp. 4298-4303 ◽  
Author(s):  
Paul H. Krebsbach ◽  
Ken Nakata ◽  
Suzanne M. Bernier ◽  
Osamu Hatano ◽  
Tomoyuki Miyashita ◽  
...  
Keyword(s):  
Protein Gene ◽  
Type Ii Collagen ◽  
Collagen Gene ◽  
Type Ii ◽  
Sequence Motifs ◽  
Enhancer Sequence ◽  
Link Protein ◽  
Core Sequence

scholarly journals Correction of abnormal matrix formed by cmd/cmd chondrocytes in culture by exogenously added cartilage proteoglycan.

1986 ◽  
Vol 103 (4) ◽  
pp. 1605-1614 ◽  
Author(s):  
M Takeda ◽  
H Iwata ◽  
S Suzuki ◽  
K S Brown ◽  
K Kimata
Keyword(s):  
Hyaluronic Acid ◽  
Culture Medium ◽  
Core Protein ◽  
Type Ii Collagen ◽  
Type Ii ◽  
Intact Cartilage ◽  
The Matrix ◽  
Mutant Cells ◽  
Hyaluronic Acid Binding

The cartilage matrix deficiency (cmd/cmd) mouse fails to synthesize the core protein of cartilage-characteristic proteoglycan (cartilage PG). Chondrocytes from the cmd/cmd cartilage cultured in vitro produced nodules with greatly reduced extracellular matrix. Immunofluorescence staining revealed that the nodules of mutant cells differed from the normal in lacking cartilage PG and in uneven and reduced deposition of type II collagen. Exogenously added cartilage PG prepared from either normal mouse cartilage or Swarm rat chondrosarcoma to the culture medium was incorporated exclusively into the extracellular matrices of the nodules, with a concurrent correction of the abnormal distribution pattern of type II collagen. The incorporation of cartilage PG into the matrix was disturbed by hyaluronic acid or decasaccharide derived therefrom, suggesting that the incorporation process involves the interaction of added proteoglycan with hyaluronic acid. Both the hyaluronic acid-binding region and the protein-enriched core molecule prepared from rat chondrosarcoma cartilage PG could also be incorporated but, unlike the intact cartilage PG, they were distributed equally in the surrounding zones where fibroblast-like cells predominate. The results indicate that the intact form of cartilage PG is required for specific incorporation into the chondrocyte nodules, and further suggest that cartilage PG plays a regulatory role in the assembly of the matrix macromolecules.

Differential co-expression of long and short form type IX collagen transcripts during avian limb chondrogenesis in ovo

Development ◽  
1992 ◽  
Vol 115 (1) ◽  
pp. 169-179
Author(s):  
R.E. Swiderski ◽  
M. Solursh
Keyword(s):  
Core Protein ◽  
Short Form ◽  
Marker Gene ◽  
Type Ii Collagen ◽  
Marker Genes ◽  
Type Ii ◽  
Amino Terminal ◽  
Collagen Mrna ◽  
Long Form ◽  
Collagen Chain

Using RNA blot analysis of developmentally staged avian limb buds, we demonstrate that transcripts of several cartilage marker genes appear in limb tissue prior to overt chondrogenesis. Type II collagen mRNA, cartilage proteoglycan core protein mRNA, alpha 2(IX) collagen mRNA, and transcripts of the short form alpha 1(IX) collagen chain derived from the downstream promoter are co-expressed in limb tissue approximately 24–36 hours before the appearance of the respective polypeptides in differentiating cartilagenous tissue. Transcripts of the long form alpha 1(IX) collagen chain derived from the upstream promoter appear somewhat later in development; nearly coincident with the immunolocalization of type IX collagen in the cartilage elements of the limb. The spatial distribution of type II and type IX collagen transcripts was analyzed by in situ hybridization. Type II collagen and the long form alpha 1(IX) collagen transcripts co-localized in the chondrogenic elements of the developing forelimb. In contrast, short form alpha 1(IX) collagen transcripts which lack the 5′ region encoding the NC4 globular amino-terminal domain were distributed throughout the non-chondrogenic, non-myogenic mesenchymal regions of the limb and were not detectable above background levels in the limb chondrogenic elements. The precocious appearance of several cartilage marker gene transcripts prior to chondrogenesis suggests that multiple levels of gene regulation including alternative promoter use, alternative RNA splicing, alternative polyadenylation, and other post-transcriptional as well as translational mechanisms are active prior to, and during avian limb chondrogenesis.

Exclusion of human proteoglycan link protein (CRTL1) and type II collagen (COL2A1) genes in pseudoachondroplasia

1992 ◽  
Vol 44 (4) ◽  
pp. 420-424 ◽  
Author(s):  
Jacqueline T. Hecht ◽  
Susan H. Blanton ◽  
Yaping Wang ◽  
Steve P. Daiger ◽  
William A. Horton ◽  
...  
Keyword(s):  
Type Ii Collagen ◽  
Type Ii ◽  
Link Protein
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