Thrombospondins: structure and regulation of expression

作者：PAUL K. BORNSTEIN · 发表于：The FASEB Journal · 年份：1992 · DOI：10.1096/fasebj.6.14.1426766 · 被引用次数：350 · 研究领域：Angiogenesis and VEGF in Cancer、Cell Adhesion Molecules Research、Coagulation, Bradykinin, Polyphosphates, and Angioedema

Thrombospondin (TSP) is a large, trimeric, modular glycoprotein that is a major constituent of platelet alpha granules. TSP is also secreted by a wide variety of epithelial and mesenchymal cells in patterns that reflect developmental changes in the embryo and response to injury in the adult. In addition to its role in blood coagulation, TSP has been reported to serve both adhesive and anti-adhesive functions, to foster neurite outgrowth, stimulate and inhibit cell growth and migration, and inhibit angiogenesis. Although this diversity in apparent function can be attributed, in part, to the ability of a single TSP to interact with several different cell-surface receptors, it is now known that the TSPs are encoded by at least three homologous genes in both human and mouse. TSP1, the commonly recognized protein isolated from platelets, is similar to TSP2 in structure. Both proteins contain NH2-terminal, COOH-terminal, and procollagen homology domains, and type I (TSP or properdin), type II (EGF-like), and type III (Ca(2+)-binding) repeats. However, the two TSPs differ in amino acid sequence and in the regulation of their expression. TSP1 is rapidly induced by serum and growth factors. An SRE and a binding site for NF-Y have been shown to mediate the serum response of the human TSP1 gene. On the other hand, TSP2 is far less responsive to serum than TSP1 and lacks the promoter elements that mediate the serum responsiveness of TSP1. TSP3 resembles TSP1 and TSP2 in its COOH-terminal...