PubMed:9452454 JSONTXT

{"project":"sentences","denotations":[{"id":"T1","span":{"begin":0,"end":95},"obj":"Sentence"},{"id":"T2","span":{"begin":96,"end":254},"obj":"Sentence"},{"id":"T3","span":{"begin":255,"end":368},"obj":"Sentence"},{"id":"T4","span":{"begin":369,"end":379},"obj":"Sentence"},{"id":"T5","span":{"begin":380,"end":478},"obj":"Sentence"},{"id":"T6","span":{"begin":479,"end":615},"obj":"Sentence"},{"id":"T7","span":{"begin":616,"end":630},"obj":"Sentence"},{"id":"T8","span":{"begin":631,"end":647},"obj":"Sentence"},{"id":"T9","span":{"begin":648,"end":668},"obj":"Sentence"},{"id":"T10","span":{"begin":669,"end":697},"obj":"Sentence"},{"id":"T11","span":{"begin":698,"end":866},"obj":"Sentence"},{"id":"T12","span":{"begin":867,"end":944},"obj":"Sentence"},{"id":"T13","span":{"begin":945,"end":959},"obj":"Sentence"},{"id":"T14","span":{"begin":960,"end":976},"obj":"Sentence"},{"id":"T15","span":{"begin":977,"end":997},"obj":"Sentence"},{"id":"T16","span":{"begin":998,"end":1131},"obj":"Sentence"},{"id":"T17","span":{"begin":1132,"end":1337},"obj":"Sentence"},{"id":"T18","span":{"begin":1338,"end":1529},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"The I domain of integrin LFA-1 interacts with ICAM-1 domain 1 at residue Glu-34 but not Gln-73.\nUsing a solid phase assay, we show that isolated LFA-1 I domain binds ICAM-1 in a Mg2+-dependent manner and is blocked by anti-I domain monoclonal antibodies. This activity mirrors that of the intact receptor (Dransfield, I., Cabañas, C., Craig, A., and Hogg, N. (1992) J. Cell Biol. 116, 219-226) and suggests that the I domain controls divalent cation-dependent receptor function. In ICAM-1, domain 1 residues Glu-34 and Gln-73 have been identified as critical for binding of LFA-1 as an intact receptor (Staunton, D. E., Dustin, M. L., Erickson, H. P., and Springer, T. A. (1990) Cell 61, 243-254). For the first time, we show that isolated I domain binds to domain 1 of ICAM-1 and that this interaction is inhibited partially by mutation of Glu-34 but not by Gln-73. The anti-ICAM-1 monoclonal antibody RR1/1, which maps to Gln-73 (Staunton, D. E., Dustin, M. L., Erickson, H. P., and Springer, T. A. (1990) Cell 61, 243-254), enhances I domain binding, suggesting potential allosteric control or coordinate binding by this region. Finally, I domain binding inhibited by Glu-34 ICAM-1 mutation correlates with divalent cation dependence, indicating that this residue might be in direct contact with the metal ion-dependent adhesion site. Thus, we describe the interaction between the LFA-1 I domain and ICAM-1, an event that controls the function of the intact receptor but includes only part of the complete ligand binding site."}