Proteoglycans families

K. Schwarz, B. Breuer, and H.Kresse, Biosynthesis and properties of a further member of the small chondroitin/dermatan sulfate proteoglycan family. J. Biol. Chem., 256 (1990) 22,023-22,028. 

Bost F, Diarra-Mehrpour M, Martin JP. Inter-alpha-trypsin inhibitor proteoglycan family—a group of proteins binding and stabilizing the extracellular matrix. Eur J Biochem 1998 252 339-346. 

Macromolecular complexes of proteins and carbohydrate present in the ECM serve not only as adhesive keeping cells in their correct positions but also facilitate control of cell activity by signalling through membrane proteins such as the integrin family of receptors. Glycoproteins are mainly protein with covalently attached carbohydrate whereas proteoglycans are predominantly complex carbohydrates secured on a protein framework. 

Type I collagen can interact with various other molecules in the extracellular matrix and on the cell surface. Cell receptors of type I collagen have been identified and include the heterodimeric integrin family receptors, ctl, 0 2, olO, and ol 1, especially o2/3l, the receptor tyrosine kinase discoidin domain receptor (DDR), and the heparan sulfate membrane proteoglycan syndecan family... 

The syndecan family of heparin sulfate proteoglycans (HSPGs) plays critical roles in several signal transduction pathways, and syndecan 3 intramembrane proteolysis is presenilin/y-secretase dependent (357). COX2 and COXl potentiate ABP formation through mechanisms that involve y-secretase activity. Sulindac sulfide and other NSAIDs (ibuprofen, indomethacin, R-flurbiprofen) selectively decrease the secretion of ABP independently of COX activity, probably via y-secretase inhibition (358-360). Pepstatin A methylester, sulfonamides, and benzodiazepines can also act as potent, noncompetitive, y-secretase inhibitors (335). These are but a few examples of the potential repercussions and biochemical consequences that the pharmacological manipulation of secretases in AD may bring about. 

These conformations were subjected to a combined MD/EM refinement using the NOESY derived constraints as pseudoenergy functions. Families of conformations for the whole molecule were then constructed from the structures derived for each linkage. This procedure was demonstrated on a fragment from the carbohydrate-protein linkage region of connective tissue proteoglycans. 

G. Westergren-Thorsson, P. Antonsson, A. MalrastrOra, D. Heine-g rd, and A. Oldberg, The synthesis of a family of structurally related proteoglycans in fibroblasts is differentially regulated by TGF-fi. Matrix, 11 (1991) 177-183. 

Leucine-rich repeats represent binding motifs found in a wide variety of both plant and mammalian proteins (Kobe and Kajava, 2001). These are involved in a multitude of protein-protein interactions. The sequence of porcine ribonuclease inhibitor, for example, displays a leucine-rich repeat (LRR) of length 27-29 residues that occurs 15 times in tandem (Fig. 9). Likewise, the family of small leucine-rich proteoglycans that includes biglycan, decorin, epiphycan, fibromodulin, keratocan, and lumican... 

The MMPs are a family of zinc-dependent neutral endopep-tidases that share structural domains but differ in substrate specificity, cellular sources, and inductivity (Table I). All the MMPs are important for remodeling of the extra cellular matrix and share the following functional features (/) they degrade extracellular matrix components, including fibronectin, collagen, elastin, proteoglycans, and laminin, (//) they are secreted in a latent proform and require activation for proteolytic activity, (///) they contain zinc at their active site and need calcium for stability, (/V) they function at neutral pH, and (v) they are inhibited by specific tissue inhibitors of metalloproteinases (TIMPs). 

In every tissue of the body cells are cemented into place by a variety of proteins and proteoglycans which constitute the extracellular matrix (ECM). This protein mat provides a secure foundation for the cells, but its components also have effects on cell function and differentiation. Cellular attachment is mediated by a family of matrix receptors found on the cell surface called integrins. Integrins secure the cell to the matrix, and determine cell shape, migration and spread. 

Bennett EP, Clausen H. Cloning and expression of a proteoglycan 80. UDP-galactose P-xylose 31,4-galactosyltransferase I - A seventh member of the human 34-galactosyltransferase gene family. J. 

Proteoglycans are major components of the extracellular matrix in animal cells. They are composed of core proteins and glycosaminoglycan polysaccharides. Heparin and heparan sulfate are the most complex glycosaminoglycans, a family of molecules that also includes chon-... 

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