G Protein-coupled Receptor 30 (GPR30) Forms a Plasma Membrane Complex With Membrane-associated Guanylate Kinases (MAGUKs) and AKAP5 That Constitutively Inhibits cAMP Production.
Research output: Contribution to journal › Article
GPR30, or G protein-coupled estrogen receptor (GPER), is a GPCR reported to bind 17β-estradiol (E2), couple to the G proteins Gs and Gi/o, and mediate non-genomic estrogenic responses. However, controversies exist regarding the receptor pharmacological profile, effector coupling, and subcellular localization. We addressed the role of the type I PSD-95/Discs-large/ZO-1 homology (PDZ) motif at the receptor C-terminus in receptor trafficking and coupling to cAMP production in HEK293 cells and CHO cells ectopically expressing the receptor, and in MDCK cells expressing native receptor. GPR30 was localized both intracellularly and in the plasma membrane and subject to limited basal endocytosis. E2 and G-1, reported GPR30 agonists, neither stimulated nor inhibited cAMP production through GPR30, nor influenced receptor localization. Instead, GPR30 constitutively inhibited cAMP production stimulated by a heterologous agonist independently of Gi/o. Moreover, siRNA knockdown of native GPR30 increased cAMP production. Deletion of the receptor PDZ motif interfered with inhibition of cAMP production and increased basal receptor endocytosis. GPR30 interacted with membrane-associated guanylate kinases (MAGUKs), including SAP97 and PSD-95, and A-kinase anchoring protein (AKAP) 5 in the plasma membrane in a PDZ-dependent manner. Knockdown of AKAP5 or St-Ht31 treatment, to disrupt AKAP interaction with protein kinase A (PKA) RIIβ regulatory subunit, decreased inhibition of cAMP production, and St-Ht31 increased basal receptor endocytosis. Thus, GPR30 forms a plasma membrane complex with a MAGUK and AKAP5, which constitutively attenuates cAMP production in response to heterologous agonists independently of Gi/o and retains receptors in the plasma membrane.
|Research areas and keywords||
Subject classification (UKÄ) – MANDATORY
|Journal||Journal of Biological Chemistry|
|Publication status||Published - 2014|
Related research output
The G protein-coupled receptor GPR30 signalosome - A novel G protein-independent mechanism regulating cAMP signaling and receptor traffickingStefan Broselid, 2014, Drug Target Discovery. 100 p.
Research output: Thesis › Doctoral Thesis (compilation)