G protein-coupled receptors (GPCRs) transmit extracellular signals to the inside by activation of intracellular effector proteins. Different agonists can promote differential receptor-induced signaling responses - termed bias - potentially by eliciting different levels of recruitment of effector proteins. As activation and recruitment of effector proteins might influence each other, thorough analysis of bias is difficult. Here, we compared the efficacy of seven agonists to induce G protein, G protein-coupled receptor kinase 2 (GRK2), as well as arrestin3 binding to the muscarinic acetylcholine receptor M3 by utilizing FRET-based assays. In order to avoid interference between these interactions, we studied GRK2 binding in the presence of inhibitors of Gi and Gq proteins and analyzed arrestin3 binding to prestimulated M3 receptors to avoid differences in receptor phosphorylation influencing arrestin recruitment. We measured substantial differences in the agonist efficacies to induce M3R-arrestin3 versus M3R-GRK2 interaction. However, the rank order of the agonists for G protein- and GRK2-M3R interaction was the same, suggesting that G protein and GRK2 binding to M3R requires similar receptor conformations, whereas requirements for arrestin3 binding to M3R are distinct. Read full article

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A recent breakthrough study published in Nature by Makaía M. Papasergi-Scott, M. M. et al. Time-resolved cryo-EM of G-protein activation by a GPCR.

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The fission yeast Schizosaccharomyces pombe has two mating types, Plus (P) and Minus (M). investigated the stringency of the two GPCRs, Mam2 and Map3, for their respective pheromones, P-factor and M-factor acid residues of Map3, F214 and F215, are key residues important for discrimination of closely related M-factors

M. Aragay et al. 1998). Removal of G proteins by using CRISPR KO of Gαi (Gαi KO) or KO of all Gα subtypes (Gα_all KO) (M. constitutively internalize through clathrin-coated pits independently of phosphorylation and β-arrestin (M. M. Paing et al. 2022; J. L. Sapmaz et al. 2019, M. N. J. Seaman 2012).

M. et al. 2018; Manglik, A. et al. 2012). the formation of dimers and alter their function by destroying the interface between two receptors (M. structure of CB1R–5HT2AR heterodimers, preventing cognitive impairment while preserving analgesia in vivo (M.

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Franziska M Heydenreich, Michel Bouvier, Brian Kobilka, M Madan Babu, and their team's work on Molecular

M, et al. 2023).

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extinction by acute and chronic relaxin-3 receptor (RXFP3) activation in the rat retrosplenial cortex Sarah

Bouvier, M., Oligomerization of G-protein-coupled transmitter receptors.  

SMOOTHENED-PKA signaling in the Hedgehog cascade Elita Yuliantie , Arthur Christopoulos , Patrick M.

M., & Lefkowitz, R. J. (2003).

Continuing Study Addex Therapeutics in the 23rd BioEquity Europe Conference Simon Bekker-Jensen and Mette M

This week's highlight includes congrats to: Makaía M Papasergi-Scott, Peter Gmeiner, Brian K Kobilka,

Devki D Sukhtankar and Pina M Cardarelli's research: Burixafor Hydrobromide (GPC-100) effects on hematopoietic

K ´ onigstorfer, M. Mozhayeva, Y. Sara, T.C. Südhof, and ¨ E.T. Kavalali. 2001.

Anson, M., et al., Incidence of new onset type 2 diabetes in adults living with obesity treated with

Magdalena M Scharf, Antonella Di Pizio, Ines Liebscher, Hannes Schihada, and Gunnar Schulte et al. on

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Non-Peptide Small Molecule GLP-1 Receptor Agonist GSBR-1290 Crinetics Pharmaceuticals Appoints Robert M.