Abstract
Rap1 GTPases operate as molecular switches by cycling between a GDP-bound inactive state and a GTP-bound active state and regulate several cellular pathways in response to different stimuli. Circulating blood platelets express high levels of Rap1 proteins, mainly Rap1b, which plays a critical role in platelet adhesion and activation. Rap1 is a key element in the inside-out signaling pathway leading to the conversion of integrins into the high-affinity state for their ligands. In platelets, Rap1b regulates inside-out activation of both integrin αIIbβ3 and α2β1. In addition, Rap1b is also involved in integrin outside-in signaling. Integrin-mediated platelet adhesion leads to accumulation of GTP-bound Rap1b, which promotes integrin-mediated processes such as spreading and clot retraction. Rap1b is thus a bidirectional regulator of platelet integrin function. Here we describe a method to analyze Rap1b activation induced by platelet adhesion via integrin α2β1.
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Guidetti, G.F., Torti, M. (2014). Pull-Down Assay for Analysis of Integrin-Mediated Activation of Rap Proteins in Adherent Platelets. In: Trabalzini, L., Retta, S. (eds) Ras Signaling. Methods in Molecular Biology, vol 1120. Humana Press, Totowa, NJ. https://doi.org/10.1007/978-1-62703-791-4_11
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DOI: https://doi.org/10.1007/978-1-62703-791-4_11
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Publisher Name: Humana Press, Totowa, NJ
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