Transmembrane peptide 4 and 5 of APJ are essential for its heterodimerization with OX1R

Biochem Biophys Res Commun. 2020 Jan 8;521(2):408-413. doi: 10.1016/j.bbrc.2019.10.146. Epub 2019 Oct 25.

Abstract

Increasing evidence indicates some G protein-coupled receptors function as a heterodimer, which provide a novel target for therapeutics investigation. However, study on the receptor-receptor interaction interface, a potent target on interfering dimer formation, are still limited. Here, using bioluminescence resonance energy transfer (BRET) combined with co-immunoprecipitation (Co-IP), we found a new constitutive GPCR heterodimer, apelin receptor (APJ)-orexin receptor type 1 (OX1R). Both APJ and OX1R co-internalized when constantly subjected to cognate agonist (apelin-13 or orexin-A) specific to either protomer. Combined with BRET and immunostaining, the in vitro synthesized transmembrane peptides (TMs) interfering experiments suggests that TM4 and 5 of APJ act as the interaction interface of the APJ-OX1R heterodimer, and co-internalization could be disrupted by these peptides as well. Our study not only provide new evidence on GPCR heterodimerization, but address a novel heterodimerization interface, which can be severed as a potential pharmacological target.

Keywords: APJ; Co-internalization; GPCR; Heterodimerization; Interface; OX1R.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apelin Receptors / chemistry*
  • Apelin Receptors / metabolism
  • Fluorescence Resonance Energy Transfer
  • Humans
  • Immunoprecipitation
  • Orexin Receptors / metabolism*
  • Peptides / metabolism
  • Protein Interaction Domains and Motifs
  • Protein Multimerization
  • Receptors, G-Protein-Coupled / chemistry*

Substances

  • Apelin Receptors
  • Orexin Receptors
  • Peptides
  • Receptors, G-Protein-Coupled