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Key phosphorylation sites in GPCR s orchestrate the contribution of β‐Arrestin 1 in ERK 1/2 activation
Author(s) -
Baidya Mithu,
Kumari Punita,
DwivediAgnihotri Hemlata,
Pandey Shubhi,
Chaturvedi Madhu,
Stepniewski Tomasz Maciej,
Kawakami Kouki,
Cao Yubo,
Laporte Stéphane A,
Selent Jana,
Inoue Asuka,
Shukla Arun K
Publication year - 2020
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.15252/embr.201949886
Subject(s) - phosphorylation , g protein coupled receptor , arrestin , mapk/erk pathway , key (lock) , microbiology and biotechnology , chemistry , biology , signal transduction , ecology
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 ERK 1/2 MAP kinase activation. Interestingly, for some GPCR s, knockdown of βarr1 augments agonist‐induced ERK 1/2 phosphorylation although a mechanistic basis for this intriguing phenomenon is unclear. Here, we use selected GPCR s to explore a possible correlation between the spatial positioning of receptor phosphorylation sites and the contribution of βarr1 in ERK 1/2 activation. We discover that engineering a spatially positioned double‐phosphorylation‐site cluster in the bradykinin receptor (B 2 R), analogous to that present in the vasopressin receptor (V 2 R), reverses the contribution of βarr1 in ERK 1/2 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 Lys 294 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 ERK 1/2 activation for different GPCR s with a direct relevance to biased agonism and novel therapeutics.