Diverse p120RasGAP interactions with doubly phosphorylated partners EphB4, p190RhoGAP, and Dok1.

Autor:	Vish KJ; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA., Stiegler AL; Department of Pharmacology, Yale University, New Haven, Connecticut, USA., Boggon TJ; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA; Department of Pharmacology, Yale University, New Haven, Connecticut, USA; Department of Yale Cancer Center, Yale University, New Haven, Connecticut, USA. Electronic address: titus.boggon@yale.edu.
Jazyk:	angličtina
Zdroj:	The Journal of biological chemistry [J Biol Chem] 2023 Sep; Vol. 299 (9), pp. 105098. Date of Electronic Publication: 2023 Jul 27.
DOI:	10.1016/j.jbc.2023.105098
Abstrakt:	RasGAP (p120RasGAP), the founding member of the GTPase-activating protein (GAP) family, is one of only nine human proteins to contain two SH2 domains and is essential for proper vascular development. Despite its importance, its interactions with key binding partners remains unclear. In this study we provide a detailed viewpoint of RasGAP recruitment to various binding partners and assess their impact on RasGAP activity. We reveal the RasGAP SH2 domains generate distinct binding interactions with three well-known doubly phosphorylated binding partners: p190RhoGAP, Dok1, and EphB4. Affinity measurements demonstrate a 100-fold weakened affinity for RasGAP-EphB4 binding compared to RasGAP-p190RhoGAP or RasGAP-Dok1 binding, possibly driven by single versus dual SH2 domain engagement with a dominant N-terminal SH2 interaction. Small-angle X-ray scattering reveals conformational differences between RasGAP-EphB4 binding and RasGAP-p190RhoGAP binding. Importantly, these interactions do not impact catalytic activity, implying RasGAP utilizes its SH2 domains to achieve diverse spatial-temporal regulation of Ras signaling in a previously unrecognized fashion. Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article. (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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