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A molecular mechanism to diversify Ca(2+) signaling downstream of Gs protein-coupled receptors

Affiliations
  • 1Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany.
  • 2Research Training Group 1873, University of Bonn, Bonn, Germany.
  • 3Research Training Group 2873, University of Bonn, Bonn, Germany.
  • 4Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
  • 5Department of Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany.
  • 6Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany.
  • 7Amsterdam Institute for Molecular and Life Sciences (AIMMS), Division of Medicinal Chemistry, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.
  • 8Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan.
  • 9Komaba Institute for Science, The University of Tokyo, Meguro, Tokyo, 153-8505, Japan.
  • 10Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan.
  • 11Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany.
  • 12Institute of Pharmacology and Toxicology, University Hospital, University of Bonn, Bonn, Germany.
  • 13Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Institute of Drug Discovery, Purdue University, West Lafayette, IN, USA.
  • 14Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131, Padova, Italy.
  • 15Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany. kostenis@uni-bonn.de.

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September 3, 2024

Abstract

A long-held tenet in inositol-lipid signaling is that cleavage of membrane phosphoinositides by phospholipase Cβ (PLCβ) isozymes to increase cytosolic Ca in living cells is exclusive to Gq- and Gi-sensitive G protein-coupled receptors (GPCRs). Here we extend this central tenet and show that Gs-GPCRs also partake in inositol-lipid signaling and thereby increase cytosolic Ca. By combining CRISPR/Cas9 genome editing to delete Gα, the adenylyl cyclase isoforms 3 and 6, or the PLCβ1-4 isozymes, with pharmacological and genetic inhibition of Gq and G11, we pin down Gs-derived Gβγ as driver of a PLCβ2/3-mediated cytosolic Ca release module. This module does not require but crosstalks with Gα-dependent cAMP, demands Gα to release PLCβ3 autoinhibition, but becomes Gq-independent with mutational disruption of the PLCβ3 autoinhibited state. Our findings uncover the key steps of a previously unappreciated mechanism utilized by mammalian cells to finetune their calcium signaling regulation through Gs-GPCRs.

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