Development of novel biosensors to study receptor-mediated activation of the G-protein α subunits G s and G olf

J Biol Chem. 2017 Dec 8;292(49):19989-19998. doi: 10.1074/jbc.M117.800698. Epub 2017 Oct 17.

Abstract

s (Gs) and Gαolf (Golf) are highly homologous G-protein α subunits that activate adenylate cyclase, thereby serving as crucial mediators of intracellular signaling. Because of their dramatically different brain expression patterns, we studied similarities and differences between their activation processes with the aim of comparing their receptor coupling mechanisms. We engineered novel luciferase- and Venus-fused Gα constructs that can be used in bioluminescence resonance energy transfer assays. In conjunction with molecular simulations, these novel biosensors were used to determine receptor activation-induced changes in conformation. Relative movements in Gs were consistent with the crystal structure of β2 adrenergic receptor in complex with Gs Conformational changes in Golf activation are shown to be similar to those in Gs Overall the current study reveals general similarities between Gs and Golf activation at the molecular level and provides a novel set of tools to search for Gs- and Golf-specific receptor pharmacology. In view of the wide functional and pharmacological roles of Gs- and Golf-coupled dopamine D1 receptor and adenosine A2A receptor in the brain and other organs, elucidating their differential structure-function relationships with Gs and Golf might provide new approaches for the treatment of a variety of neuropsychiatric disorders. In particular, these novel biosensors can be used to reveal potentially therapeutic dopamine D1 receptor and adenosine A2A receptor ligands with functionally selective properties between Gs and Golf signaling.

Keywords: G protein; G-protein–coupled receptor (GPCR); bioluminescence resonance energy transfer (BRET); dopamine receptor; pharmacology.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylyl Cyclases / metabolism
  • Animals
  • Bioluminescence Resonance Energy Transfer Techniques
  • Biosensing Techniques / instrumentation
  • Biosensing Techniques / methods*
  • GTP-Binding Protein alpha Subunits / metabolism*
  • GTP-Binding Protein alpha Subunits, Gs / metabolism*
  • Humans
  • Ligands
  • Protein Conformation
  • Receptor, Adenosine A2A / metabolism
  • Receptors, Dopamine D1 / metabolism
  • Signal Transduction

Substances

  • GTP-Binding Protein alpha Subunits
  • Ligands
  • Receptor, Adenosine A2A
  • Receptors, Dopamine D1
  • olfactory G protein subunit alpha olf
  • GTP-Binding Protein alpha Subunits, Gs
  • Adenylyl Cyclases

Associated data

  • PDB/1AZT
  • PDB/3SN6