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SPARC  -  secreted protein, acidic, cysteine-rich...

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Disease relevance of SPARC


High impact information on SPARC


Chemical compound and disease context of SPARC


Biological context of SPARC

  • The nucleotide sequence predicts that osteonectin contains 304 amino acids, including a 17-residue signal peptide [11].
  • The 27,900-Mr fragment did not bind Ca2+, and since biosynthetic studies with 32PO4(3-) did not show phosphorylation of porcine osteonectin, this fragment is likely to be highly acidic [12].
  • We propose that SPARC regulates endothelial barrier function through F-actin-dependent changes in cell shape, coincident with the appearance of intercellular gaps, that provide a paracellular pathway for extravasation of macromolecules [13].
  • In this study we show that SPARC modulates the progression of bovine aortic endothelial cells through the cell cycle [14].
  • Active preparations of SPARC bind to specific components of the extracellular matrix and cause mesenchymal cells to assume a rounded phenotype [14].

Anatomical context of SPARC

  • Osteonectin cDNA sequence reveals potential binding regions for calcium and hydroxyapatite and shows homologies with both a basement membrane protein (SPARC) and a serine proteinase inhibitor (ovomucoid) [11].
  • Finally, the osteonectin sequence shows near identity (greater than 90%) with another protein, SPARC (secreted protein, acidic and rich in cysteine), secreted by mouse parietal endoderm [11].
  • On the other hand, osteonectin message was observed in tendon, a tissue in which little or no osteonectin protein is found in vivo [1].
  • To determine whether SPARC might influence endothelial permeability, we studied the effect of exogenous SPARC on the movement of 14C-labeled bovine serum albumin across postconfluent bovine pulmonary artery endothelial cells [13].
  • Moreover, early passage rat aortic smooth muscle cells which have high levels of cGMP-dependent protein kinase were sensitive to hep I treatment, in contrast to passaged cGMP-dependent protein kinase deficient cells which were refractory to hep I or TNfnA-D treatment, but were sensitive to SPARC [15].

Associations of SPARC with chemical compounds

  • Eleven mg of 125I-osteonectin bound to 1.0 g of hydroxyapatite with a Kd of 8 X 10(-8) M [16].
  • However, unlike the bovine protein, porcine osteonectin did not bind selectively to hydroxyapatite when EDTA tissue extracts were used [12].
  • The purified protein migrated with an Mr of 40,300 on SDS/polyacrylamide gels and was similar to bovine osteonectin in both amino acid composition and in its ability to bind to hydroxyapatite in the presence of 4 M-guanidinium hydrochloride (GdmCl) [12].
  • However, bovine SPARC NH2-terminal sequence (1-56 residues) antibodies did not react with gp60, indicating that the endothelial cell-surface-associated albumin-binding protein gp60 was different from the secreted albumin-binding protein SPARC [17].
  • SPARC, a Ca(2+)-binding glycoprotein that is expressed during tissue morphogenesis and functions as an inhibitor of cell spreading in vitro, was found to induce the secretion of an Mr = 45,000 protein in bovine aortic endothelial (BAE) cells [18].

Physical interactions of SPARC

  • Further, osteoblastic cells on the grooved surfaces also displayed a strong labelling for fibronectin at the cytoplasmic extensions coupled with intense osteonectin expression in comparison to the rough surfaced implants [19].

Regulatory relationships of SPARC

  • SPARC stimulated the secretion of PAI-1 protein into the medium of subconfluent BAE cells, but not confluent BAE cells, in a dose- and time-dependent manner [18].
  • SPARC induces the expression of type 1 plasminogen activator inhibitor in cultured bovine aortic endothelial cells [18].

Other interactions of SPARC


Analytical, diagnostic and therapeutic context of SPARC


  1. Osteonectin mRNA: distribution in normal and transformed cells. Young, M.F., Bolander, M.E., Day, A.A., Ramis, C.I., Robey, P.G., Yamada, Y., Termine, J.D. Nucleic Acids Res. (1986) [Pubmed]
  2. Immunological screening of SPARC/Osteonectin in nonmineralized tissues. Maillard, C., Malaval, L., Delmas, P.D. Bone (1992) [Pubmed]
  3. Renaturation of SPARC expressed in Escherichia coli requires isomerization of disulfide bonds for recovery of biological activity. Bassuk, J.A., Braun, L.P., Motamed, K., Baneyx, F., Sage, E.H. Int. J. Biochem. Cell Biol. (1996) [Pubmed]
  4. SPARC is expressed by ganglion cells and astrocytes in bovine retina. Yan, Q., Sage, E.H., Hendrickson, A.E. J. Histochem. Cytochem. (1998) [Pubmed]
  5. SPARC inhibits endothelial cell adhesion but not proliferation through a tyrosine phosphorylation-dependent pathway. Motamed, K., Sage, E.H. J. Cell. Biochem. (1998) [Pubmed]
  6. Expression of tissue transglutaminase in skeletal tissues correlates with events of terminal differentiation of chondrocytes. Aeschlimann, D., Wetterwald, A., Fleisch, H., Paulsson, M. J. Cell Biol. (1993) [Pubmed]
  7. Focal adhesion integrity is downregulated by the alternatively spliced domain of human tenascin. Murphy-Ullrich, J.E., Lightner, V.A., Aukhil, I., Yan, Y.Z., Erickson, H.P., Höök, M. J. Cell Biol. (1991) [Pubmed]
  8. SPARC, a secreted protein associated with cellular proliferation, inhibits cell spreading in vitro and exhibits Ca+2-dependent binding to the extracellular matrix. Sage, H., Vernon, R.B., Funk, S.E., Everitt, E.A., Angello, J. J. Cell Biol. (1989) [Pubmed]
  9. Secreted protein acidic, rich in cysteine (SPARC), mediates cellular survival of gliomas through AKT activation. Shi, Q., Bao, S., Maxwell, J.A., Reese, E.D., Friedman, H.S., Bigner, D.D., Wang, X.F., Rich, J.N. J. Biol. Chem. (2004) [Pubmed]
  10. Evidence for positive and negative regulatory elements in the 5'-flanking sequence of the mouse sparc (osteonectin) gene. Nomura, S., Hashmi, S., McVey, J.H., Ham, J., Parker, M., Hogan, B.L. J. Biol. Chem. (1989) [Pubmed]
  11. Osteonectin cDNA sequence reveals potential binding regions for calcium and hydroxyapatite and shows homologies with both a basement membrane protein (SPARC) and a serine proteinase inhibitor (ovomucoid). Bolander, M.E., Young, M.F., Fisher, L.W., Yamada, Y., Termine, J.D. Proc. Natl. Acad. Sci. U.S.A. (1988) [Pubmed]
  12. Characterization of porcine osteonectin extracted from foetal calvariae. Domenicucci, C., Goldberg, H.A., Hofmann, T., Isenman, D., Wasi, S., Sodek, J. Biochem. J. (1988) [Pubmed]
  13. SPARC (secreted protein acidic and rich in cysteine) regulates endothelial cell shape and barrier function. Goldblum, S.E., Ding, X., Funk, S.E., Sage, E.H. Proc. Natl. Acad. Sci. U.S.A. (1994) [Pubmed]
  14. The Ca2(+)-binding glycoprotein SPARC modulates cell cycle progression in bovine aortic endothelial cells. Funk, S.E., Sage, E.H. Proc. Natl. Acad. Sci. U.S.A. (1991) [Pubmed]
  15. Cyclic GMP-dependent protein kinase is required for thrombospondin and tenascin mediated focal adhesion disassembly. Murphy-Ullrich, J.E., Pallero, M.A., Boerth, N., Greenwood, J.A., Lincoln, T.M., Cornwell, T.L. J. Cell. Sci. (1996) [Pubmed]
  16. Isolation and characterization of native adult osteonectin. Romberg, R.W., Werness, P.G., Lollar, P., Riggs, B.L., Mann, K.G. J. Biol. Chem. (1985) [Pubmed]
  17. Isolation and characterization of a cell surface albumin-binding protein from vascular endothelial cells. Tiruppathi, C., Finnegan, A., Malik, A.B. Proc. Natl. Acad. Sci. U.S.A. (1996) [Pubmed]
  18. SPARC induces the expression of type 1 plasminogen activator inhibitor in cultured bovine aortic endothelial cells. Hasselaar, P., Loskutoff, D.J., Sawdey, M., Sage, E.H. J. Biol. Chem. (1991) [Pubmed]
  19. Influence of titanium surfaces on attachment of osteoblast-like cells in vitro. Jayaraman, M., Meyer, U., Bühner, M., Joos, U., Wiesmann, H.P. Biomaterials (2004) [Pubmed]
  20. Rat embryo fibroblasts transformed by c-Jun display highly metastatic and angiogenic activities in vivo and deregulate gene expression of both angiogenic and antiangiogenic factors. Kraemer, M., Tournaire, R., Dejong, V., Montreau, N., Briane, D., Derbin, C., Binétruy, B. Cell Growth Differ. (1999) [Pubmed]
  21. Gene expression profiling of peripheral blood mononuclear cells from cattle infected with Mycobacterium paratuberculosis. Coussens, P.M., Colvin, C.J., Wiersma, K., Abouzied, A., Sipkovsky, S. Infect. Immun. (2002) [Pubmed]
  22. Loss of insulin-like growth factor I receptor-dependent expression of p107 and cyclin A in cells that lack the extracellular matrix protein secreted protein acidic and rich in cysteine. Basu, A., Rodeck, U., Prendergast, G.C., Howe, C.C. Cell Growth Differ. (1999) [Pubmed]
  23. Diverse forms of stress result in changes in cellular levels of osteonectin/SPARC without altering mRNA levels in osteoligament cells. Sauk, J.J., Norris, K., Kerr, J.M., Somerman, M.J., Young, M.F. Calcif. Tissue Int. (1991) [Pubmed]
  24. Endotoxin alters the expression of extracellular matrix proteins by cultured endothelial cells. Sawhney, R.S., Bone, R.C. Cell. Mol. Biol. Res. (1993) [Pubmed]
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