Structural highlights
Function[GBG2_BOVIN] Guanine nucleotide-binding proteins (G proteins) are involved as a modulator or transducer in various transmembrane signaling systems. The beta and gamma chains are required for the GTPase activity, for replacement of GDP by GTP, and for G protein-effector interaction. [GBB1_BOVIN] Guanine nucleotide-binding proteins (G proteins) are involved as a modulator or transducer in various transmembrane signaling systems. The beta and gamma chains are required for the GTPase activity, for replacement of GDP by GTP, and for G protein-effector interaction. Publication Abstract from PubMedPIP3-dependent Rac exchanger 1 (P-Rex1) is activated downstream of G protein-coupled receptors to promote neutrophil migration and metastasis. The structure of more than half of the enzyme and its regulatory G protein binding site are unknown. Our 3.2 A cryo-EM structure of the P-Rex1-Gbetagamma complex reveals that the carboxyl-terminal half of P-Rex1 adopts a complex fold most similar to those of Legionella phosphoinositide phosphatases. Although catalytically inert, the domain coalesces with a DEP domain and two PDZ domains to form an extensive docking site for Gbetagamma. Hydrogen-deuterium exchange mass spectrometry suggests that Gbetagamma binding induces allosteric changes in P-Rex1, but functional assays indicate that membrane localization is also required for full activation. Thus, a multidomain assembly is key to the regulation of P-Rex1 by Gbetagamma and the formation of a membrane-localized scaffold optimized for recruitment of other signaling proteins such as PKA and PTEN. Cryo-electron microscopy structure and analysis of the P-Rex1-Gbetagamma signaling scaffold.,Cash JN, Urata S, Li S, Ravala SK, Avramova LV, Shost MD, Gutkind JS, Tesmer JJG, Cianfrocco MA Sci Adv. 2019 Oct 16;5(10):eaax8855. doi: 10.1126/sciadv.aax8855. eCollection, 2019 Oct. PMID:31663027[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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