| First Author | Shen B | Year | 2013 |
| Journal | Nature | Volume | 503 |
| Issue | 7474 | Pages | 131-5 |
| PubMed ID | 24162846 | Mgi Jnum | J:206751 |
| Mgi Id | MGI:5551939 | Doi | 10.1038/nature12613 |
| Citation | Shen B, et al. (2013) A directional switch of integrin signalling and a new anti-thrombotic strategy. Nature 503(7474):131-5 |
| abstractText | Integrins have a critical role in thrombosis and haemostasis. Antagonists of the platelet integrin alphaIIbbeta3 are potent anti-thrombotic drugs, but also have the life-threatening adverse effect of causing bleeding. It is therefore desirable to develop new antagonists that do not cause bleeding. Integrins transmit signals bidirectionally. Inside-out signalling activates integrins through a talin-dependent mechanism. Integrin ligation mediates thrombus formation and outside-in signalling, which requires Galpha13 and greatly expands thrombi. Here we show that Galpha13 and talin bind to mutually exclusive but distinct sites within the integrin beta3 cytoplasmic domain in opposing waves. The first talin-binding wave mediates inside-out signalling and also ligand-induced integrin activation, but is not required for outside-in signalling. Integrin ligation induces transient talin dissociation and Galpha13 binding to an EXE motif (in which X denotes any residue), which selectively mediates outside-in signalling and platelet spreading. The second talin-binding wave is associated with clot retraction. An EXE-motif-based inhibitor of Galpha13-integrin interaction selectively abolishes outside-in signalling without affecting integrin ligation, and suppresses occlusive arterial thrombosis without affecting bleeding time. Thus, we have discovered a new mechanism for the directional switch of integrin signalling and, on the basis of this mechanism, designed a potent new anti-thrombotic drug that does not cause bleeding. |
