Identification and isolation of a 140 kd cell surface glycoprotein with properties expected of a fibronectin receptor.
Affinity chromatography was used to identify a putative cell surface receptor for fibronectin. A large cell-attachment-promoting fibronectin fragment was used as the affinity matrix, and specific elution was effected by using synthetic peptides containing the sequence Arg-Gly-Asp, which is derived from the cell recognition sequence in the fibronectin cell attachment site. A 140 kd protein was bound by the affinity matrix from octylglucoside extracts of MG-63 human osteosarcoma cells and specifically eluted with the synthetic peptide Gly-Arg-Gly-Asp-Ser-Pro. The 140 kd protein was labeled by cell surface specific radioiodination and became incorporated into liposomes at a high efficiency. Liposomes containing this protein showed specific affinity toward fibronectin-coated surfaces, and this binding could be selectively inhibited by the synthetic cell-attachment peptide but not by inactive peptides. Affinity chromatography on wheat germ agglutinin-Sepharose showed that the 140 kd protein is a glycoprotein and, in combination with the fibronectin fragment chromatography, gave highly enriched preparations of the 140 kd protein. These properties suggest that the 140 kd glycoprotein is a membrane-embedded cell surface protein directly involved in the initial step of cell adhesion to fibronectin substrates.
Pytela
R
R
Pierschbacher
M D
MD
Ruoslahti
E
E
D001345:Autoradiography; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002846:Chromatography, Affinity / Q000379:methods; D004220:Disulfides / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005353:Fibronectins / Q000378:metabolism; D006023:Glycoproteins / Q000302:isolation & purification* / Q000378:metabolism; D006801:Humans; D007457:Iodine Radioisotopes; D008081:Liposomes; D046911:Macromolecular Substances; D012516:Osteosarcoma; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic / Q000302:isolation & purification* / Q000378:metabolism
D004220:Disulfides; D005353:Fibronectins; D006023:Glycoproteins; D007457:Iodine Radioisotopes; D008081:Liposomes; D046911:Macromolecular Substances; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic