G protein-coupled estrogen receptor 1 (GPER1)/GPR30 increases ERK1/2 activity through PDZ motif-dependent and -independent mechanisms

J Biol Chem. 2017 Jun 16;292(24):9932-9943. doi: 10.1074/jbc.M116.765875. Epub 2017 Apr 27.

Abstract

G protein-coupled receptor 30 (GPR30), also called G protein-coupled estrogen receptor 1 (GPER1), is thought to play important roles in breast cancer and cardiometabolic regulation, but many questions remain about ligand activation, effector coupling, and subcellular localization. We showed recently that GPR30 interacts through the C-terminal type I PDZ motif with SAP97 and protein kinase A (PKA)-anchoring protein (AKAP) 5, which anchor the receptor in the plasma membrane and mediate an apparently constitutive decrease in cAMP production independently of Gi/o Here, we show that GPR30 also constitutively increases ERK1/2 activity. Removing the receptor PDZ motif or knocking down specifically AKAP5 inhibited the increase, showing that this increase also requires the PDZ interaction. However, the increase was inhibited by pertussis toxin as well as by wortmannin but not by AG1478, indicating that Gi/o and phosphoinositide 3-kinase (PI3K) mediate the increase independently of epidermal growth factor receptor transactivation. FK506 and okadaic acid also inhibited the increase, implying that a protein phosphatase is involved. The proposed GPR30 agonist G-1 also increased ERK1/2 activity, but this increase was only observed at a level of receptor expression below that required for the constitutive increase. Furthermore, deleting the PDZ motif did not inhibit the G-1-stimulated increase. Based on these results, we propose that GPR30 increases ERK1/2 activity via two Gi/o-mediated mechanisms, a PDZ-dependent, apparently constitutive mechanism and a PDZ-independent G-1-stimulated mechanism.

Keywords: A-kinase-anchoring protein (AKAP); G protein; G protein-coupled receptor (GPCR); GPER1; GPR30; PDZ domain; calcineurin; extracellular signal-regulated kinase (ERK).

Publication types

  • Comparative Study

MeSH terms

  • A Kinase Anchor Proteins / antagonists & inhibitors
  • A Kinase Anchor Proteins / genetics
  • A Kinase Anchor Proteins / metabolism
  • Amino Acid Substitution
  • Cyclopentanes / pharmacology
  • Enzyme Activation / drug effects
  • Enzyme Inhibitors / pharmacology
  • GTP-Binding Protein alpha Subunits, Gi-Go / agonists*
  • GTP-Binding Protein alpha Subunits, Gi-Go / chemistry
  • GTP-Binding Protein alpha Subunits, Gi-Go / genetics
  • GTP-Binding Protein alpha Subunits, Gi-Go / metabolism
  • HEK293 Cells
  • Humans
  • MAP Kinase Signaling System* / drug effects
  • Mitogen-Activated Protein Kinase 1 / chemistry
  • Mitogen-Activated Protein Kinase 1 / genetics
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Mitogen-Activated Protein Kinase 3 / chemistry
  • Mitogen-Activated Protein Kinase 3 / genetics
  • Mitogen-Activated Protein Kinase 3 / metabolism*
  • Models, Molecular*
  • Mutation
  • PDZ Domains
  • Phosphatidylinositol 3-Kinase / chemistry
  • Phosphatidylinositol 3-Kinase / genetics
  • Phosphatidylinositol 3-Kinase / metabolism*
  • Phosphorylation / drug effects
  • Protein Processing, Post-Translational / drug effects
  • Quinolines / pharmacology
  • RNA Interference
  • Radioligand Assay
  • Receptors, Estrogen / chemistry
  • Receptors, Estrogen / genetics
  • Receptors, Estrogen / metabolism*
  • Receptors, G-Protein-Coupled / agonists
  • Receptors, G-Protein-Coupled / chemistry
  • Receptors, G-Protein-Coupled / genetics
  • Receptors, G-Protein-Coupled / metabolism*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Up-Regulation / drug effects

Substances

  • 1-(4-(6-bromobenzo(1,3)dioxol-5-yl)-3a,4,5,9b-tetrahydro-3H-cyclopenta(c)quinolin-8-yl)ethanone
  • A Kinase Anchor Proteins
  • AKAP5 protein, human
  • Cyclopentanes
  • Enzyme Inhibitors
  • GPER1 protein, human
  • Quinolines
  • Receptors, Estrogen
  • Receptors, G-Protein-Coupled
  • Recombinant Fusion Proteins
  • Phosphatidylinositol 3-Kinase
  • MAPK1 protein, human
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • GTP-Binding Protein alpha Subunits, Gi-Go