Gβγ signaling from an eponymous past to a specific future

An abiding issue has been parsing out the cellular impact of multiple Gβ and Gγ subtypes. In an article in this Cell Systems, Masuho et al. use a system developed to probe how distinct Gβγ combinations respond GPCR stimulation adopt trafficking itineraries cell. Since their discovery, subunits have suffered shadow more famous partners Gα heterotrimeric G proteins. Even now, we often refer them simply as “Gβγ subunits”—ignoring complexities having 5 12 mammals. The specificity signaling is (Tennakoon al., 2021Tennakoon M. Senarath K. Kankanamge D. Ratnayake Wijayaratna Olupothage Ubeysinghe S. Martins-Cannavino Hébert T.E. Karunarathne A. Subtype-dependent regulation signalling.Cell. Signal. 2021; 82: 109947Crossref PubMed Scopus (3) Google Scholar; Khan 2016Khan S.M. Sung J.Y. subunits-Different spaces, different faces.Pharmacol. Res. 2016; 111: 434-441Crossref (28) Smrcka Fisher, 2019Smrcka A.V. Fisher I. G-protein βγ multi-functional scaffolds transducers G-protein-coupled receptor signaling.Cell. Mol. Life Sci. 2019; 76: 4447-4459Crossref (30) Scholar) tools approach it are indeed useful. This especially true now that know occurs many sites mobility individual pairs likely associated with effects at distal plasma membrane, becomes important understand where they go, get there, who travel with, on what timescales these events occur. interesting timely article, 2021Masuho Skamangas N.K. Muntean B.S. Martemyanov K.A. Diversity complexes defines spatial temporal bias signaling.Cell Syst. (this issue): 324-337Abstract Full Text PDF (7) Scholar comprehensively profile entire range 60 using combination bimolecular fluorescence complementation (BiFC) bioluminescence resonance energy transfer (BRET) for ability be activated by protein-coupled (GPCR), dissociate from move about cell sites. Initially, BiFC, demonstrate abilities form perhaps not surprisingly most distinctive Gβ5 subunit least able subunits. Given studies suggested prefers RGS proteins over (reviewed Slepak, 2009Slepak V.Z. Structure, function, localization Gβ5-RGS complexes.Prog. Biol. Transl. 2009; 86: 157-203Crossref (24) Scholar), actually good way show platform reflects biological reality even when tags used BiFC could principle compromise or constrain functionality protein fusions. resolved follow-up types alternative proteomic approaches. initial screen, authors also co-expressed GαoA provide stoichiometrically relevant amount third member heterotrimer. It would quite see effect assembly With screen developed, some mysteries heterotrimer formation stability, subject future article. They next added mix, BiFC/BRET assay previous (Masuho 2015Masuho Ostrovskaya O. Kramer G.M. Jones C.D. Xie Distinct profiles functional discrimination among determine actions receptors.Sci. 2015; 8: ra123https://doi.org/10.1126/scisignal.aab4068Crossref (124) track release following activation D2 dopamine receptor. Here, found kinetic differences association released nanoluciferase-tagged GRK partner. Whether kinetics clarified. However, four similar magnitude BRET responses each was paired Again, one wonders happen if swapped other subunits, further, GPCR. While we’re it, ask switched type toolkit primary cells? possibilities pretty exciting. toggling networks identified such screens knockdown approaches (Krumins Gilman, 2006Krumins A.M. Gilman A.G. Targeted selectively prevents receptor-mediated modulation effectors reveals complex changes non-targeted proteins.J. Chem. 2006; 281: 10250-10262Abstract (94) 2015Khan Min Gora Houranieh Campden R. Robitaille Trieu P. Pétrin Jacobi Behlke M.A. al.Gβ4γ1 modulator M3 muscarinic signalling novel roles Gβ1 27: 1597-1608Crossref (12) cells endogenous systems standard lines HEK 293 here. Another finding noted inverse relationship between efficacy proximal outcome membrane. I suppose surprising sense “stay home” might better persistent drivers membrane-delimited events. fact, aspects study seen began appearance internal destinations. targeting early endosomes, mitochondria, Golgi apparatus, endoplasmic reticulum (ER) revealed texture our understanding downstream (Figure 1). work highlights kinetically second wave (or waves) sites—which seems vary depending composition dimer. Interestingly, deactivation comparing same pair either membrane ER. One site didn’t nucleus, already number demonstrated presence (Robitaille 2010Robitaille Wang Y. Goupil E. Del Duca Villeneuve L.R. Allen B.G. Laporte S.A. Bernard D.J. Gbetagamma negative regulator AP-1 mediated transcription.Cell. 2010; 22: 1254-1266Crossref (25) Scholar, reviewed Scholar). ignore cytosolic compartment potential target At point, will generate post-translational modifications particular isoprenylation, impacts movement combinations. What remain solved here? Plenty. For starters, return journey itinerant pairs? Are targeted back sent fate involving degradation can shuttled tertiary subcellular sites? If fact after appearing secondary sites, does work? How surface resupplied proper partners? needs considered carefully birth until death pieces seem around great deal, yet somehow balance plasticity fidelity struck. When you tour, there lot destinations see! happens once reach leaving membrane? do meet along both voyages pair? Do unique sets additional play into and/or time spent destinations? tagging versions GFP change color (Chudakov 2010Chudakov D.M. Matz M.V. Lukyanov Fluorescent applications imaging living tissues.Physiol. Rev. 90: 1103-1163Crossref (922) All said, stage new view actors, which may finally lead textbook eponymous one-note signaling. supported grant Canadian Institutes Health Research ( PJT-159687 ). T.E.H. holder Pacific Chair Biotechnology. signalingMasuho al.Cell SystemsMarch 4, 2021In BriefMasuho functionally tested all theoretically possible transduce signals report major role diversity differential organelles fine-tuning Full-Text Open Archive