Background information
The Thrombospondin proteins, Thrombospondins 1-4 and Thrombospondin 5 (also designated COMP), compose a family of glycoproteins that are involved in cell-to-cell and cell-to-matrix signaling. These extracellular, cell-surface proteins form complexes of both homo- and heteromultimers. Spondin-2, or Mindin, is also designated DIL-1 for its differential expression in cancerous and non-cancerous lung cells. Full-length SPON2 cDNA encodes a 331 amino acid protein with a domain arrangement similar to zebrafish F-Spondin and Mindin-1/Mindin-2: an FS1 domain, an FS2 domain, a hydrophobic signal sequence in the N-terminus and a Thrombospondin type I repeat. Immunoblot analysis demonstrates expression of dimers and oligomers in a concentration-dependent manner under nonreducing conditions.
