Optical Control of Dopamine Receptors Using a Photoswitchable Tethered Inverse Agonist

J Am Chem Soc. 2017 Dec 27;139(51):18522-18535. doi: 10.1021/jacs.7b07659. Epub 2017 Dec 13.

Abstract

Family A G protein-coupled receptors (GPCRs) control diverse biological processes and are of great clinical relevance. Their archetype rhodopsin becomes naturally light sensitive by binding covalently to the photoswitchable tethered ligand (PTL) retinal. Other GPCRs, however, neither bind covalently to ligands nor are light sensitive. We sought to impart the logic of rhodopsin to light-insensitive Family A GPCRs in order to enable their remote control in a receptor-specific, cell-type-specific, and spatiotemporally precise manner. Dopamine receptors (DARs) are of particular interest for their roles in motor coordination, appetitive, and aversive behavior, as well as neuropsychiatric disorders such as Parkinson's disease, schizophrenia, mood disorders, and addiction. Using an azobenzene derivative of the well-known DAR ligand 2-(N-phenethyl-N-propyl)amino-5-hydroxytetralin (PPHT), we were able to rapidly, reversibly, and selectively block dopamine D1 and D2 receptors (D1R and D2R) when the PTL was conjugated to an engineered cysteine near the dopamine binding site. Depending on the site of tethering, the ligand behaved as either a photoswitchable tethered neutral antagonist or inverse agonist. Our results indicate that DARs can be chemically engineered for selective remote control by light and provide a template for precision control of Family A GPCRs.

Publication types

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

MeSH terms

  • Binding Sites
  • Cysteine / chemistry
  • Dopamine / metabolism
  • Dopamine D2 Receptor Antagonists / pharmacology*
  • Dopamine D2 Receptor Antagonists / radiation effects*
  • Drug Inverse Agonism*
  • Humans
  • Ligands
  • Receptors, Dopamine D1 / antagonists & inhibitors
  • Receptors, Dopamine D1 / metabolism*
  • Receptors, Dopamine D1 / radiation effects*
  • Receptors, Dopamine D2 / metabolism*
  • Receptors, Dopamine D2 / radiation effects*

Substances

  • Dopamine D2 Receptor Antagonists
  • Ligands
  • Receptors, Dopamine D1
  • Receptors, Dopamine D2
  • Cysteine
  • Dopamine