Key phosphorylation sites in GPCRs orchestrate the contribution of β-Arrestin 1 in ERK1/2 activation

Mithu Baidya, Punita Kumari, Hemlata Dwivedi-Agnihotri, Shubhi Pandey, Madhu Chaturvedi, Tomasz Maciej Stepniewski, Kouki Kawakami, Yubo Cao, Stéphane A. Laporte, Jana Selent, Asuka Inoue, Arun K. Shukla

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)

Abstract

β-arrestins (βarrs) are key regulators of G protein-coupled receptor (GPCR) signaling and trafficking, and their knockdown typically leads to a decrease in agonist-induced ERK1/2 MAP kinase activation. Interestingly, for some GPCRs, knockdown of βarr1 augments agonist-induced ERK1/2 phosphorylation although a mechanistic basis for this intriguing phenomenon is unclear. Here, we use selected GPCRs to explore a possible correlation between the spatial positioning of receptor phosphorylation sites and the contribution of βarr1 in ERK1/2 activation. We discover that engineering a spatially positioned double-phosphorylation-site cluster in the bradykinin receptor (B2R), analogous to that present in the vasopressin receptor (V2R), reverses the contribution of βarr1 in ERK1/2 activation from inhibitory to promotive. An intrabody sensor suggests a conformational mechanism for this role reversal of βarr1, and molecular dynamics simulation reveals a bifurcated salt bridge between this double-phosphorylation site cluster and Lys294 in the lariat loop of βarr1, which directs the orientation of the lariat loop. Our findings provide novel insights into the opposite roles of βarr1 in ERK1/2 activation for different GPCRs with a direct relevance to biased agonism and novel therapeutics.

Original languageEnglish
Article numbere49886
JournalEMBO Reports
Volume21
Issue number9
DOIs
Publication statusPublished - 2020 Sep 3

Keywords

  • ERK1/2 MAP kinase
  • G protein-coupled receptors
  • biased agonism
  • cellular signaling
  • β-arrestins

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Genetics

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