Thrombospondin 4 A1

Summary

Principal Investigator: JOHN LAWLER
Abstract: A detailed comprehension of the role of the thrombospondins (TSPs), including cartilage oligomeric matrix protein (COMP), in the regulation of extracellular matrix (ECM) structure and cellular behavior during tissue genesis and repair is the long-term goal of the proposed studies. Specific focus for the next period of support will be on the following areas. Specific Aim 1. To identify key amino acids for the interactions of COMP with proteins and proteoglycans (PGs). We have found that COMP binds to aggrecan, as well as to integrins in chondrocytes and fibroblasts. In addition, growth plate disorganization is observed in TSP-1-, TSP-3-, and COMP-null mice. We have recently solved the structure of the signature domain of COMP by X-ray crystallography. Based on these data, we plan to determine the molecular basis for the interaction of COMP with collagens, integrins, and glycosaminoglycans (GAGs) by site-directed mutagenesis within the context of the intact molecule and the recombinant signature domain. The aspartic acids that comprise the potential metal ion-dependent adhesion site (MIDAS) and the adjacent to MIDAS motif will be mutated to alanines to establish the importance of these sites in collagen and zinc binding, and matrix assembly. In addition, the specificity of the MIDAS will be explored using peptide libraries. The binding site for GAGs will be identified by X-ray crystallography. Existing structural data, naturally occurring mutations, and published synthetic peptide data will be used to identify amino acids for mutagenesis. This approach will enable us to probe the function of specific motifs within the context of the correctly folded protein. Specific Aim 2. To determine the effects of COMP on cellular phenotype and ECM structure. COMP orchestrates collagen fibril formation, ECM organization, and chondrocyte survival and differentiation during growth plate development. The importance of COMP is underscored by the fact that naturally occurring mutations in it result in skeletal dysplasias. In Aim 1, we will identify the integrin, collagen and GAG binding sites in the COMP molecule. In this aim, we will identify the integrin-mediated cellular responses to COMP in chondrocytes and fibroblasts. We will also explore the effect of the absence of COMP expression using primary cultures of chondrocytes from COMP-null mice. We hypothesize that wild-type COMP promotes cell adhesion, migration, proliferation and survival, while suppressing apoptosis. The specific signaling pathways that mediate the cellular responses to COMP in 2- and 3-D culture systems will be identified. In addition, proliferation, apoptosis and matrix structure in the growth plate of wild-type and COMP-null mice will be analyzed. We will also determine whether or not the integrin and GAG binding sites collaborate with the collagen-binding site to regulate ECM structure. Finally, we will explore the effect of some of the disease causing mutations on the ability of COMP to support cellular processes and matrix assembly. The data from these studies will provide key insights into the function of the signature domain of COMP in terms of its interactions with various proteins, PGs and cells.
Funding Period: ----------------2009 - ---------------2011-
more information: NIH RePORT

Top Publications

  1. pmc The structures of the thrombospondin-1 N-terminal domain and its complex with a synthetic pentameric heparin
    Kemin Tan
    Department of Medical Oncology, Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA
    Structure 14:33-42. 2006
  2. pmc The crystal structure of the heparin-binding reelin-N domain of f-spondin
    Kemin Tan
    Department of Medical Oncology, Dana Farber Cancer Institute, Boston, MA 02115, USA
    J Mol Biol 381:1213-23. 2008
  3. pmc Skeletal abnormalities in mice lacking extracellular matrix proteins, thrombospondin-1, thrombospondin-3, thrombospondin-5, and type IX collagen
    Karen L Posey
    Department of Pediatrics, University of Texas Medical School, 6431 Fannin, Houston, TX 77030, USA
    Am J Pathol 172:1664-74. 2008
  4. pmc Structures of thrombospondins
    C B Carlson
    Department of Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
    Cell Mol Life Sci 65:672-86. 2008
  5. pmc Thrombospondins in cancer
    S Kazerounian
    Division of Cancer Biology and Angiogenesis, Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachussetts 02215, USA
    Cell Mol Life Sci 65:700-12. 2008
  6. pmc Heparin-induced cis- and trans-dimerization modes of the thrombospondin-1 N-terminal domain
    Kemin Tan
    Department of Medical Oncology, Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA
    J Biol Chem 283:3932-41. 2008
  7. pmc Interaction of cartilage oligomeric matrix protein/thrombospondin 5 with aggrecan
    Faye Hui Chen
    Cartilage Biology and Orthopaedics Branch, NIAMS, National Institutes of Health, Bethesda, Maryland 20892, USA
    J Biol Chem 282:24591-8. 2007
  8. pmc Thrombospondin-based antiangiogenic therapy
    Xuefeng Zhang
    Department of Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
    Microvasc Res 74:90-9. 2007
  9. pmc A thrombospondin-dependent pathway for a protective ER stress response
    Jeffrey M Lynch
    Department of Pediatrics, Cincinnati Children s Hospital, University of Cincinnati, OH 45247, USA
    Cell 149:1257-68. 2012
  10. pmc The crystal structure of the signature domain of cartilage oligomeric matrix protein: implications for collagen, glycosaminoglycan and integrin binding
    Kemin Tan
    Midwest Center for Structural Genomics, Biosciences Division, Argonne National Laboratory, Argonne, Illinois, USA
    FASEB J 23:2490-501. 2009

Scientific Experts

  • Kemin Tan
  • Cagla Eroglu
  • Josephine C Adams
  • Jack Lawler
  • Jeffrey M Lynch
  • Karen L Posey
  • S Kazerounian
  • J Lawler
  • C B Carlson
  • Jacqueline T Hecht
  • Faye Hui Chen
  • Xuefeng Zhang
  • Michelle A Sargent
  • Kazutoshi Mori
  • N Scott Blair
  • Marjorie Maillet
  • Kaari A Lynch
  • Hanna Osinska
  • Jeffery D Molkentin
  • John N Lorenz
  • Bruce J Aronow
  • Davy Vanhoutte
  • Jeffrey Robbins
  • Ron Prywes
  • Tetsuya Okada
  • Aryn Schloemer
  • Kurt Hankenson
  • Alka C Veerisetty
  • K O Yee
  • D F Mosher
  • Paul Bornstein
  • Rocky S Tuan
  • Nichlesh Patel
  • Mary E Herndon

Detail Information

Publications13

  1. pmc The structures of the thrombospondin-1 N-terminal domain and its complex with a synthetic pentameric heparin
    Kemin Tan
    Department of Medical Oncology, Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA
    Structure 14:33-42. 2006
    ..The TSPN-1 structure and identified adjacent linker region provide a structural framework for the analysis of the TSPN domain of various molecules, including TSPs, NELLs, many collagens, TSPEAR, and kielin...
  2. pmc The crystal structure of the heparin-binding reelin-N domain of f-spondin
    Kemin Tan
    Department of Medical Oncology, Dana Farber Cancer Institute, Boston, MA 02115, USA
    J Mol Biol 381:1213-23. 2008
    ..The homophilic asymmetric dimer can potentially offer advantages in binding to ligands such as glycosaminoglycans, which may, in turn, bridge the two reelin-N domains and stabilize the dimer...
  3. pmc Skeletal abnormalities in mice lacking extracellular matrix proteins, thrombospondin-1, thrombospondin-3, thrombospondin-5, and type IX collagen
    Karen L Posey
    Department of Pediatrics, University of Texas Medical School, 6431 Fannin, Houston, TX 77030, USA
    Am J Pathol 172:1664-74. 2008
    ....
  4. pmc Structures of thrombospondins
    C B Carlson
    Department of Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
    Cell Mol Life Sci 65:672-86. 2008
    ..Part of a multi-author Review)...
  5. pmc Thrombospondins in cancer
    S Kazerounian
    Division of Cancer Biology and Angiogenesis, Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachussetts 02215, USA
    Cell Mol Life Sci 65:700-12. 2008
    ..Whereas the role of TSP-1 in the tumor microenvironment is the best characterized, the other TSPs may have similar functions. (Part of a Multi-author Review)...
  6. pmc Heparin-induced cis- and trans-dimerization modes of the thrombospondin-1 N-terminal domain
    Kemin Tan
    Department of Medical Oncology, Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA
    J Biol Chem 283:3932-41. 2008
    ..Dimer formation may also involve TSPN-1 domains from two separate TSP-1 molecules. This association would enable glycosaminoglycans to cluster TSP-1...
  7. pmc Interaction of cartilage oligomeric matrix protein/thrombospondin 5 with aggrecan
    Faye Hui Chen
    Cartilage Biology and Orthopaedics Branch, NIAMS, National Institutes of Health, Bethesda, Maryland 20892, USA
    J Biol Chem 282:24591-8. 2007
    ..Our results suggest that COMP/TSP5 may function to support matrix interactions in cartilage ECM...
  8. pmc Thrombospondin-based antiangiogenic therapy
    Xuefeng Zhang
    Department of Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
    Microvasc Res 74:90-9. 2007
    ..In this article, we review the progress in thrombospondin-based antiangiogenic therapy and discuss the perspectives on the significant challenges that remain...
  9. pmc A thrombospondin-dependent pathway for a protective ER stress response
    Jeffrey M Lynch
    Department of Pediatrics, Cincinnati Children s Hospital, University of Cincinnati, OH 45247, USA
    Cell 149:1257-68. 2012
    ..Hence, Thbs can function inside the cell during disease remodeling to augment ER function and protect through a mechanism involving regulation of Atf6α...
  10. pmc The crystal structure of the signature domain of cartilage oligomeric matrix protein: implications for collagen, glycosaminoglycan and integrin binding
    Kemin Tan
    Midwest Center for Structural Genomics, Biosciences Division, Argonne National Laboratory, Argonne, Illinois, USA
    FASEB J 23:2490-501. 2009
    ..The structure presented here and its unique molecular packing in the crystal identify potential interactive sites for glycosaminoglycans, integrins, and collagens, which are key to cartilage structure and function...
  11. pmc Gabapentin receptor alpha2delta-1 is a neuronal thrombospondin receptor responsible for excitatory CNS synaptogenesis
    Cagla Eroglu
    Duke University Medical Center, Cell Biology Department, Durham, NC 27710, USA
    Cell 139:380-92. 2009
    ..These findings identify alpha2delta-1 as a receptor involved in excitatory synapse formation and suggest that gabapentin may function therapeutically by blocking new synapse formation...
  12. pmc The structure of the Ca²+-binding, glycosylated F-spondin domain of F-spondin - A C2-domain variant in an extracellular matrix protein
    Kemin Tan
    Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
    BMC Struct Biol 11:22. 2011
    ..The FS domain is found in F-spondins, mindins, M-spondin and amphiF-spondin...
  13. pmc The thrombospondins
    Josephine C Adams
    School of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
    Cold Spring Harb Perspect Biol 3:a009712. 2011
    ..We discuss their roles in vivo, associations with human disease, and ongoing translational applications. In many respects, we are only beginning to appreciate the important roles of these proteins in physiology and pathology...