Identification of a bone sialoprotein receptor in osteosarcoma cells.
Bone sialoprotein (BSP) is an extracellular matrix glycoprotein associated with the mineral bone matrix. The amino acid sequence of BSP contains an Arg-Gly-Asp (RGD) sequence which confers to the protein cell binding properties (Oldberg, A., Franzén, A., and Heinegård, D. (1988) J. Biol. Chem. 263, 19430-19432). When BSP was used as an affinity matrix to isolate a cell surface receptor from rat osteosarcoma cells, a protein composed of polypeptides similar in size to those of a previously characterized vitronectin receptor was obtained. This putative BSP receptor, like the vitronectin receptor, bound also to an affinity matrix made of an RGD-containing heptapeptide. Moreover, similar patterns of inhibition of cell attachment to BSP and vitronectin was obtained with variant RGD-containing peptides, with BSP and with vitronectin. Finally, an anti-vitronectin receptor antiserum immunoprecipitated a receptor identical in size to the receptor bound to a BSP affinity matrix. These results show that BSP is recognized by an RGD-directed receptor and that both vitronectin and BSP can bind to this receptor.
Oldberg
A
A
Department of Physiological Chemistry, University of Lund, Sweden.
Franzén
A
A
Heinegård
D
D
Pierschbacher
M
M
Ruoslahti
E
E
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002846:Chromatography, Affinity; D000939:Epitopes / Q000032:analysis; D006023:Glycoproteins / Q000494:pharmacology; D008970:Molecular Weight; D012516:Osteosarcoma / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D011971:Receptors, Immunologic / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D019030:Receptors, Vitronectin; D019096:Vitronectin
D000939:Epitopes; D006023:Glycoproteins; D011971:Receptors, Immunologic; D019030:Receptors, Vitronectin; D019096:Vitronectin