Key points are not available for this paper at this time.
Integrin-associated protein (IAP; CD47) is a thrombospondin receptor that forms a signaling complex with β3 integrins resulting in enhanced αvβ3-dependent cell spreading and chemotaxis and, in platelets, αIIbβ3-dependent spreading and aggregation. These actions of CD47 are all specifically abrogated by pertussis toxin treatment of cells. Here we report that CD47, its β3 integrin partner, and Gi proteins form a stable, detergent-soluble complex that can be recovered by immunoprecipitation and affinity chromatography. Giα is released from this complex by treatment with GTP or AlF4. GTP and AlF4 also reduce the binding of CD47 to its agonist peptide (4N1K) derived from thrombospondin, indicating a direct association of CD47 with Gi. 4N1K peptide causes a rapid decrease in intraplatelet cyclic AMP levels, a Gi-dependent event necessary for aggregation. Finally, 4N1K stimulates the binding of GTPγ35S to membranes from cells expressing IAP and αvβ3. This functional coupling of CD47 to heterotrimeric G proteins provides a mechanistic explanation for the biological effects of CD47 in a wide variety of systems. Integrin-associated protein (IAP; CD47) is a thrombospondin receptor that forms a signaling complex with β3 integrins resulting in enhanced αvβ3-dependent cell spreading and chemotaxis and, in platelets, αIIbβ3-dependent spreading and aggregation. These actions of CD47 are all specifically abrogated by pertussis toxin treatment of cells. Here we report that CD47, its β3 integrin partner, and Gi proteins form a stable, detergent-soluble complex that can be recovered by immunoprecipitation and affinity chromatography. Giα is released from this complex by treatment with GTP or AlF4. GTP and AlF4 also reduce the binding of CD47 to its agonist peptide (4N1K) derived from thrombospondin, indicating a direct association of CD47 with Gi. 4N1K peptide causes a rapid decrease in intraplatelet cyclic AMP levels, a Gi-dependent event necessary for aggregation. Finally, 4N1K stimulates the binding of GTPγ35S to membranes from cells expressing IAP and αvβ3. This functional coupling of CD47 to heterotrimeric G proteins provides a mechanistic explanation for the biological effects of CD47 in a wide variety of systems. The thrombospondins (TSPs) 1The abbreviations used are:TSP, thrombospondin; IAP, integrin-associated protein; mAb, monoclonal antibody; PAGE, polyacrylamide gel electrophoresis; NTA, nitrilotriacetic acid; 7TMS, seven-transmembrane segment; GDPβS, guanyl-5′-yl thiophosphate; GTPγS, guanosine 5′-3-O-(thio)triphosphate.1The abbreviations used are:TSP, thrombospondin; IAP, integrin-associated protein; mAb, monoclonal antibody; PAGE, polyacrylamide gel electrophoresis; NTA, nitrilotriacetic acid; 7TMS, seven-transmembrane segment; GDPβS, guanyl-5′-yl thiophosphate; GTPγS, guanosine 5′-3-O-(thio)triphosphate. are a family of multidomain, secreted glycoproteins whose production is differentially regulated during development, wound repair, inflammation, tumorigenesis, and other states in which rapid changes occur in cell proliferation and migration (1Bornstein P. J. Cell Biol. 1995; 130: 503-506Crossref PubMed Scopus (577) Google Scholar, 2Adams J.C. Tucker R.P. Lawler J. The Thrombospondin Gene Family. R. G. Landes Co., Austin, TX1995Google Scholar). Many of the apparently diverse effects of TSP proteins can be ascribed to the presence of different complements of receptors for the several domains of TSP on different cell types. Integrin-associated protein (IAP or CD47) is a receptor for the carboxyl-terminal cell binding domain of TSP1, which contains the active CD47 agonist peptide RFYVVMWK (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar, 4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar). This sequence is well conserved among species and TSP isoforms (2Adams J.C. Tucker R.P. Lawler J. The Thrombospondin Gene Family. R. G. Landes Co., Austin, TX1995Google Scholar), suggesting that all TSP family members use CD47 as a receptor. CD47 is an unusual member of the IgG superfamily of receptors. It consists of a single IgGv extracellular domain and five transmembrane segments terminating in a short, alternatively spliced cytoplasmic tail (5Lindberg F.P. Gresham H.D. Schwarz E. Brown E.J. J. Cell Biol. 1993; 123: 485-496Crossref PubMed Scopus (295) Google Scholar). Monoclonal antibodies (mAbs) against CD47 block signaling events such as the increase in intracellular Ca2+ that occurs when endothelial cells spread on matrix proteins containing RGD sequences (6Schwartz M.A. Brown E.J. Fazeli B. J. Biol. Chem. 1993; 268: 19931-19934Abstract Full Text PDF PubMed Google Scholar). Further, anti-CD47 mAbs can block the transendothelial (7Cooper D. Lindberg F.P. Gamble G.R. Brown E.J. Vadas M.A. Proc. Natl. Acad. Sci. U. S. A. 1995; 92: 3978-3982Crossref PubMed Scopus (183) Google Scholar) and transepithelial (8Parkos C.A. Colgan S.P. Liang T.W. Nusrat A. Bacarra A.E. Carnes D.K. Madara J.L. J. Cell Biol. 1996; 132: 437-450Crossref PubMed Scopus (181) Google Scholar) migration of polymorphonuclear nucleophiles, and CD47 knockout mice have a severe host defense defect (9Lindberg F.P. Bullard D.C. Caver T.E. Gresham H.D. Beaudet A.L. Brown E.J. Science. 1996; 274: 795-798Crossref PubMed Scopus (292) Google Scholar). CD47 appears to be involved in processes related to integrin-mediated cell spreading (4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar, 10Chung J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar) and motility (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar, 11Wang X.Q. Frazier W.A. Mol. Biol. Cell. 1998; 9: 865-874Crossref PubMed Scopus (139) Google Scholar) in a number of cell types.In several biological settings, the binding to CD47 of TSP1, its cell binding domain, or the agonist peptide 4N1K (KRFYVVMWKK) can stimulate the “activation” of integrins to a higher affinity/avidity state. For example, the 4N1K peptide stimulates spreading on and of of the integrin as by the enhanced binding of the J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar). cells to a and 4N1K stimulate the of αvβ3-dependent cell spreading (4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar). Further, 4N1K peptide is a of endothelial cells on a matrix to which (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar). The chemotaxis of cells is also by this a is by CD47 X.Q. Frazier W.A. Mol. Biol. Cell. 1998; 9: 865-874Crossref PubMed Scopus (139) Google Scholar). of the of integrin is by of the cells with pertussis which signaling heterotrimeric G proteins of the Gi to the complex with a pertussis G The that such an association functional for the of GTP binding and cyclic AMP a of and AlF4 on binding to CD47 that the association of the complex with Gi is coupling of CD47 to Gi protein is with of the biological actions of TSP and CD47 as a chemotaxis receptor (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar) for TSP and and receptors for are receptors that are to G proteins A.G. J. Biol. Chem. Full Text PDF PubMed Google Scholar). CD47 on is a receptor for J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar). receptors that and are receptors to heterotrimeric Gi proteins Cell Biol. PubMed Scopus Google Scholar). of all of receptors in to a in intraplatelet levels, an event for and Cell Biol. PubMed Scopus Google Scholar). in of CD47 on in an and decrease in signaling events to from CD47 Ca2+ (6Schwartz M.A. Brown E.J. Fazeli B. J. Biol. Chem. 1993; 268: 19931-19934Abstract Full Text PDF PubMed Google Scholar) and of protein and (4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar). of events are regulated by receptors to heterotrimeric G proteins E.J. Cell. 1995; Full Text PDF PubMed Scopus Google Scholar). all of have also in integrin in a variety of M.A. Cell Biol. 1995; PubMed Scopus Google Scholar). that CD47 can with integrins of the X.Q. Frazier W.A. Mol. Biol. Cell. 1998; 9: 865-874Crossref PubMed Scopus (139) Google Scholar) and E. Brown E.J. S.D. J. 1993; Google S. J. PubMed Scopus Google Scholar), A. J. J. E. J. P. and E. as well as β3 (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar, 4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar, 10Chung J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar). all of biological the effects of the CD47 4N1K and on cell and are by pertussis toxin treatment of the cells in (4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar). A. J. J. E. J. P. and E. and A. in appears that different integrin with CD47 can all to Gi This of the integrins that can with and be regulated by CD47 of the variety of to TSP proteins (1Bornstein P. J. Cell Biol. 1995; 130: 503-506Crossref PubMed Scopus (577) Google Scholar, 2Adams J.C. Tucker R.P. Lawler J. The Thrombospondin Gene Family. R. G. Landes Co., Austin, TX1995Google Scholar). The agonist peptide sequence RFYVVMWK is well conserved in all five TSP CD47 is a receptor for all TSP family from the association of CD47, and Gi other the of a functional association in which CD47 with Gi. treatment of with 4N1K a in intraplatelet cyclic AMP This signaling event is to all of the that G receptors Cell Biol. PubMed Scopus Google Scholar). have also a in intracellular cyclic AMP in other cell that to with integrin the agonist peptide 4N1K stimulates GTPγ35S binding to membranes These membranes of a CD47 and Gi and are a direct CD47 and Gi is by the of G protein and on the binding of 4N1K to on the we a for CD47 in which the as an or of the integrin transmembrane and CD47 its receptor heterotrimeric G proteins in the as receptors. This from a number of as The of the complex is with the of a the of the The complex with several different and the with affinity chromatography. of from the 4N1K the integrin and CD47 as the and A. that of protein from and membranes or protein complex when to cell A. J. J. E. J. P. and E. cells CD47 and Gi proteins integrins Gresham H.D. Brown E.J. J. Google Scholar), suggesting that the integrin be necessary to the protein be actions of CD47 in other cells such as cells Lindberg F.P. Brown E.J. J. 1997; PubMed Scopus Google Scholar). The of transmembrane segments be for G receptors to and G of the receptor in transmembrane segments of signaling J. Biol. Chem. Full Text PDF PubMed Google Scholar). a functional receptor by of containing transmembrane segments and the other containing segments and Science. PubMed Scopus Google Scholar). conserved the receptor superfamily have in These the which occurs the of the transmembrane of the sequence in transmembrane and in cytoplasmic domains involved in G protein coupling Scholar). are to the of G protein coupling in CD47 and this The CD47 agonist peptide 4N1K is in sequence to peptide for other G receptors. For example, the which can to peptide P. The Google Scholar). is with the sequence which is to the sequence of that a functional heterotrimeric be from the and of an integrin with the five segments of This is we report that the complex or heterotrimeric Gi functional that is a direct CD47 and the G protein as by the a of GTP and AlF4 on the binding of 4N1K by the that 4N1K treatment of cells causes a pertussis in intracellular cyclic and 4N1K specifically stimulates the binding of a GTP to membranes in a the of CD47, and TSP family a for of the biological actions of TSP proteins and a for G protein to the of integrin in systems. The thrombospondins (TSPs) 1The abbreviations used are:TSP, thrombospondin; IAP, integrin-associated protein; mAb, monoclonal antibody; PAGE, polyacrylamide gel electrophoresis; NTA, nitrilotriacetic acid; 7TMS, seven-transmembrane segment; GDPβS, guanyl-5′-yl thiophosphate; GTPγS, guanosine 5′-3-O-(thio)triphosphate.1The abbreviations used are:TSP, thrombospondin; IAP, integrin-associated protein; mAb, monoclonal antibody; PAGE, polyacrylamide gel electrophoresis; NTA, nitrilotriacetic acid; 7TMS, seven-transmembrane segment; GDPβS, guanyl-5′-yl thiophosphate; GTPγS, guanosine 5′-3-O-(thio)triphosphate. are a family of multidomain, secreted glycoproteins whose production is differentially regulated during development, wound repair, inflammation, tumorigenesis, and other states in which rapid changes occur in cell proliferation and migration (1Bornstein P. J. Cell Biol. 1995; 130: 503-506Crossref PubMed Scopus (577) Google Scholar, 2Adams J.C. Tucker R.P. Lawler J. The Thrombospondin Gene Family. R. G. Landes Co., Austin, TX1995Google Scholar). Many of the apparently diverse effects of TSP proteins can be ascribed to the presence of different complements of receptors for the several domains of TSP on different cell types. Integrin-associated protein (IAP or CD47) is a receptor for the carboxyl-terminal cell binding domain of TSP1, which contains the active CD47 agonist peptide RFYVVMWK (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar, 4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar). This sequence is well conserved among species and TSP isoforms (2Adams J.C. Tucker R.P. Lawler J. The Thrombospondin Gene Family. R. G. Landes Co., Austin, TX1995Google Scholar), suggesting that all TSP family members use CD47 as a receptor. CD47 is an unusual member of the IgG superfamily of receptors. It consists of a single IgGv extracellular domain and five transmembrane segments terminating in a short, alternatively spliced cytoplasmic tail (5Lindberg F.P. Gresham H.D. Schwarz E. Brown E.J. J. Cell Biol. 1993; 123: 485-496Crossref PubMed Scopus (295) Google Scholar). Monoclonal antibodies (mAbs) against CD47 block signaling events such as the increase in intracellular Ca2+ that occurs when endothelial cells spread on matrix proteins containing RGD sequences (6Schwartz M.A. Brown E.J. Fazeli B. J. Biol. Chem. 1993; 268: 19931-19934Abstract Full Text PDF PubMed Google Scholar). Further, anti-CD47 mAbs can block the transendothelial (7Cooper D. Lindberg F.P. Gamble G.R. Brown E.J. Vadas M.A. Proc. Natl. Acad. Sci. U. S. A. 1995; 92: 3978-3982Crossref PubMed Scopus (183) Google Scholar) and transepithelial (8Parkos C.A. Colgan S.P. Liang T.W. Nusrat A. Bacarra A.E. Carnes D.K. Madara J.L. J. Cell Biol. 1996; 132: 437-450Crossref PubMed Scopus (181) Google Scholar) migration of polymorphonuclear nucleophiles, and CD47 knockout mice have a severe host defense defect (9Lindberg F.P. Bullard D.C. Caver T.E. Gresham H.D. Beaudet A.L. Brown E.J. Science. 1996; 274: 795-798Crossref PubMed Scopus (292) Google Scholar). CD47 appears to be involved in processes related to integrin-mediated cell spreading (4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar, 10Chung J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar) and motility (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar, 11Wang X.Q. Frazier W.A. Mol. Biol. Cell. 1998; 9: 865-874Crossref PubMed Scopus (139) Google Scholar) in a number of cell types. several biological settings, the binding to CD47 of TSP1, its cell binding domain, or the agonist peptide 4N1K (KRFYVVMWKK) can stimulate the “activation” of integrins to a higher affinity/avidity state. For example, the 4N1K peptide stimulates spreading on and of of the integrin as by the enhanced binding of the J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar). cells to a and 4N1K stimulate the of αvβ3-dependent cell spreading (4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar). Further, 4N1K peptide is a of endothelial cells on a matrix to which (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar). The chemotaxis of cells is also by this a is by CD47 X.Q. Frazier W.A. Mol. Biol. Cell. 1998; 9: 865-874Crossref PubMed Scopus (139) Google Scholar). of the of integrin is by of the cells with pertussis which signaling heterotrimeric G proteins of the Gi The to the complex with a pertussis G The that such an association functional for the of GTP binding and cyclic AMP a of and AlF4 on binding to CD47 that the association of the complex with Gi is coupling of CD47 to Gi protein is with of the biological actions of TSP and CD47 as a chemotaxis receptor (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar) for TSP and and receptors for are receptors that are to G proteins A.G. J. Biol. Chem. Full Text PDF PubMed Google Scholar). CD47 on is a receptor for J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar). receptors that and are receptors to heterotrimeric Gi proteins Cell Biol. PubMed Scopus Google Scholar). of all of receptors in to a in intraplatelet levels, an event for and Cell Biol. PubMed Scopus Google Scholar). in of CD47 on in an and decrease in signaling events to from CD47 Ca2+ (6Schwartz M.A. Brown E.J. Fazeli B. J. Biol. Chem. 1993; 268: 19931-19934Abstract Full Text PDF PubMed Google Scholar) and of protein and (4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar). of events are regulated by receptors to heterotrimeric G proteins E.J. Cell. 1995; Full Text PDF PubMed Scopus Google Scholar). all of have also in integrin in a variety of M.A. Cell Biol. 1995; PubMed Scopus Google Scholar). that CD47 can with integrins of the X.Q. Frazier W.A. Mol. Biol. Cell. 1998; 9: 865-874Crossref PubMed Scopus (139) Google Scholar) and E. Brown E.J. S.D. J. 1993; Google S. J. PubMed Scopus Google Scholar), A. J. J. E. J. P. and E. as well as β3 (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar, 4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar, 10Chung J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar). all of biological the effects of the CD47 4N1K and on cell and are by pertussis toxin treatment of the cells in (4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar). A. J. J. E. J. P. and E. and A. in appears that different integrin with CD47 can all to Gi This of the integrins that can with and be regulated by CD47 of the variety of to TSP proteins (1Bornstein P. J. Cell Biol. 1995; 130: 503-506Crossref PubMed Scopus (577) Google Scholar, 2Adams J.C. Tucker R.P. Lawler J. The Thrombospondin Gene Family. R. G. Landes Co., Austin, TX1995Google Scholar). The agonist peptide sequence RFYVVMWK is well conserved in all five TSP CD47 is a receptor for all TSP family from the association of CD47, and Gi other the of a functional association in which CD47 with Gi. treatment of with 4N1K a in intraplatelet cyclic AMP This signaling event is to all of the that G receptors Cell Biol. PubMed Scopus Google Scholar). have also a in intracellular cyclic AMP in other cell that to with integrin the agonist peptide 4N1K stimulates GTPγ35S binding to membranes These membranes of a CD47 and Gi and are a direct CD47 and Gi is by the of G protein and on the binding of 4N1K to on the we a for CD47 in which the as an or of the integrin transmembrane and CD47 its receptor heterotrimeric G proteins in the as receptors. This from a number of as The of the complex is with the of a the of the The complex with several different and the with affinity chromatography. of from the 4N1K the integrin and CD47 as the and A. that of protein from and membranes or protein complex when to cell A. J. J. E. J. P. and E. cells CD47 and Gi proteins integrins Gresham H.D. Brown E.J. J. Google Scholar), suggesting that the integrin be necessary to the protein be actions of CD47 in other cells such as cells Lindberg F.P. Brown E.J. J. 1997; PubMed Scopus Google Scholar). The of transmembrane segments be for G receptors to and G of the receptor in transmembrane segments of signaling J. Biol. Chem. Full Text PDF PubMed Google Scholar). a functional receptor by of containing transmembrane segments and the other containing segments and Science. PubMed Scopus Google Scholar). conserved the receptor superfamily have in These the which occurs the of the transmembrane of the sequence in transmembrane and in cytoplasmic domains involved in G protein coupling Scholar). are to the of G protein coupling in CD47 and this The CD47 agonist peptide 4N1K is in sequence to peptide for other G receptors. For example, the which can to peptide P. The Google Scholar). is with the sequence which is to the sequence of that a functional heterotrimeric be from the and of an integrin with the five segments of This is we report that the complex or heterotrimeric Gi functional that is a direct CD47 and the G protein as by the a of GTP and AlF4 on the binding of 4N1K by the that 4N1K treatment of cells causes a pertussis in intracellular cyclic and 4N1K specifically stimulates the binding of a GTP to membranes in a the of CD47, and TSP family a for of the biological actions of TSP proteins and a for G protein to the of integrin in systems. The coupling of CD47 to Gi protein is with of the biological actions of TSP and CD47 as a chemotaxis receptor (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar) for TSP and and receptors for are receptors that are to G proteins A.G. J. Biol. Chem. Full Text PDF PubMed Google Scholar). CD47 on is a receptor for J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar). receptors that and are receptors to heterotrimeric Gi proteins Cell Biol. PubMed Scopus Google Scholar). of all of receptors in to a in intraplatelet levels, an event for and Cell Biol. PubMed Scopus Google Scholar). in of CD47 on in an and decrease in signaling events to from CD47 Ca2+ (6Schwartz M.A. Brown E.J. Fazeli B. J. Biol. Chem. 1993; 268: 19931-19934Abstract Full Text PDF PubMed Google Scholar) and of protein and (4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar). of events are regulated by receptors to heterotrimeric G proteins E.J. Cell. 1995; Full Text PDF PubMed Scopus Google Scholar). all of have also in integrin in a variety of M.A. Cell Biol. 1995; PubMed Scopus Google Scholar). that CD47 can with integrins of the X.Q. Frazier W.A. Mol. Biol. Cell. 1998; 9: 865-874Crossref PubMed Scopus (139) Google Scholar) and E. Brown E.J. S.D. J. 1993; Google S. J. PubMed Scopus Google Scholar), A. J. J. E. J. P. and E. as well as β3 (3Gao A.G. Lindberg F.P. Finn M.B. Blystone S.D. Brown E.J. Frazier W.A. J. Biol. Chem. 1996; 271: 21-24Abstract Full Text Full Text PDF PubMed Scopus (330) Google Scholar, 4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google Scholar, 10Chung J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar). all of biological the effects of the CD47 4N1K and on cell and are by pertussis toxin treatment of the cells in (4Gao A.G. Lindberg F.P. Dimitry J.M. Brown E.J. Frazier W.A. J. Cell Biol. 1996; 135: 533-544Crossref PubMed Scopus (184) Google J. Gao A.G. Frazier W.A. J. Biol. Chem. 1997; 272: 14740-14746Abstract Full Text Full Text PDF PubMed Scopus (171) Google Scholar). A. J. J. E. J. P. and E. and A. in appears that different integrin with CD47 can all to Gi This of the integrins that can with and be regulated by CD47 of the variety of to TSP proteins (1Bornstein P. J. Cell Biol. 1995; 130: 503-506Crossref PubMed Scopus (577) Google Scholar, 2Adams J.C. Tucker R.P. Lawler J. The Thrombospondin Gene Family. R. G. Landes Co., Austin, TX1995Google Scholar). The agonist peptide sequence RFYVVMWK is well conserved in all five TSP CD47 is a receptor for all TSP family from the association of CD47, and Gi other the of a functional association in which CD47 with Gi. treatment of with 4N1K a in intraplatelet cyclic AMP This signaling event is to all of the that G receptors Cell Biol. PubMed Scopus Google Scholar). have also a in intracellular cyclic AMP in other cell that to with integrin the agonist peptide 4N1K stimulates GTPγ35S binding to membranes These membranes of a CD47 and Gi and are a direct CD47 and Gi is by the of G protein and on the binding of 4N1K to on the we a for CD47 in which the as an or of the integrin transmembrane and CD47 its receptor heterotrimeric G proteins in the as receptors. This from a number of as The of the complex is with the of a the of the The complex with several different and the with affinity chromatography. of from the 4N1K the integrin and CD47 as the and A. that of protein from and membranes or protein complex when to cell A. J. J. E. J. P. and E. cells CD47 and Gi proteins integrins Gresham H.D. Brown E.J. J. Google Scholar), suggesting that the integrin be necessary to the protein be actions of CD47 in other cells such as cells Lindberg F.P. Brown E.J. J. 1997; PubMed Scopus Google Scholar). The of transmembrane segments be for G receptors to and G of the receptor in transmembrane segments of signaling J. Biol. Chem. Full Text PDF PubMed Google Scholar). a functional receptor by of containing transmembrane segments and the other containing segments and Science. PubMed Scopus Google Scholar). conserved the receptor superfamily have in These the which occurs the of the transmembrane of the sequence in transmembrane and in cytoplasmic domains involved in G protein coupling Scholar). are to the of G protein coupling in CD47 and this The CD47 agonist peptide 4N1K is in sequence to peptide for other G receptors. For example, the which can to peptide P. The Google Scholar). is with the sequence which is to the sequence of that a functional heterotrimeric be from the and of an integrin with the five segments of This is we report that the complex or heterotrimeric Gi functional that is a direct CD47 and the G protein as by the a of GTP and AlF4 on the binding of 4N1K by the that 4N1K treatment of cells causes a pertussis in intracellular cyclic and 4N1K specifically stimulates the binding of a GTP to membranes in a the of CD47, and TSP family a for of the biological actions of TSP proteins and a for G protein to the of integrin in systems. and for antibodies and and the of the and for peptide and and for of the and
Frazier et al. (Mon,) studied this question.