A Synthetic Intrabody-Based Selective and Generic Inhibitor of GPCR Endocytosis

Nat Nanotechnol. 2017 Dec;12(12):1190-1198. doi: 10.1038/nnano.2017.188. Epub 2017 Oct 2.

Abstract

Beta-arrestins (βarrs) critically mediate desensitization, endocytosis and signalling of G protein-coupled receptors (GPCRs), and they scaffold a large number of interaction partners. However, allosteric modulation of their scaffolding abilities and direct targeting of their interaction interfaces to modulate GPCR functions selectively have not been fully explored yet. Here we identified a series of synthetic antibody fragments (Fabs) against different conformations of βarrs from phage display libraries. Several of these Fabs allosterically and selectively modulated the interaction of βarrs with clathrin and ERK MAP kinase. Interestingly, one of these Fabs selectively disrupted βarr-clathrin interaction, and when expressed as an intrabody, it robustly inhibited agonist-induced endocytosis of a broad set of GPCRs without affecting ERK MAP kinase activation. Our data therefore demonstrate the feasibility of selectively targeting βarr interactions using intrabodies and provide a novel framework for fine-tuning GPCR functions with potential therapeutic implications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Clathrin / metabolism
  • Endocytosis / drug effects*
  • Enzyme Activation / drug effects
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • HEK293 Cells
  • Humans
  • Immunoglobulin Fab Fragments* / chemistry
  • Immunoglobulin Fab Fragments* / genetics
  • Immunoglobulin Fab Fragments* / pharmacology
  • Peptide Library*
  • Receptors, G-Protein-Coupled / metabolism*
  • Single-Chain Antibodies* / chemistry
  • Single-Chain Antibodies* / genetics
  • Single-Chain Antibodies* / pharmacology

Substances

  • Clathrin
  • Immunoglobulin Fab Fragments
  • Peptide Library
  • Receptors, G-Protein-Coupled
  • Single-Chain Antibodies
  • Extracellular Signal-Regulated MAP Kinases