J. Biol. Chem.-2014-Butcher-18451-65.pdf (2.54 MB)

Concomitant action of structural elements and receptor phosphorylation determines arrestin-3 interaction with the free fatty acid receptor FFA4

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journal contribution
posted on 24.02.2016 by Adrian J. Butcher, B. D. Hudson, B. Shimpukade, E. Alvarez-Curto, Rudi Prihandoko, T. Ulven, G. Milligan, Andrew B. Tobin
In addition to being nutrients, free fatty acids act as signaling molecules by activating a family of G protein-coupled receptors. Among these is FFA4, previously called GPR120, which responds to medium and long chain fatty acids, including health-promoting ω-3 fatty acids, which have been implicated in the regulation of metabolic and inflammatory responses. Here we show, using mass spectrometry, mutagenesis, and phosphospecific antibodies, that agonist-regulated phosphorylation of the human FFA4 receptor occurred primarily at five residues (Thr(347), Thr(349), Ser(350), Ser(357), and Ser(360)) in the C-terminal tail. Mutation of these residues reduced both the efficacy and potency of ligand-mediated arrestin-3 recruitment as well as affecting recruitment kinetics. Combined mutagenesis of all five of these residues was insufficient to fully abrogate interaction with arrestin-3, but further mutagenesis of negatively charged residues revealed additional structural components for the interaction with arrestin-3 within the C-terminal tail of the receptor. These elements consist of the acidic residues Glu(341), Asp(348), and Asp(355) located close to the phosphorylation sites. Receptor phosphorylation thus operates in concert with structural elements within the C-terminal tail of FFA4 to allow for the recruitment of arrestin-3. Importantly, these mechanisms of arrestin-3 recruitment operate independently from Gq/11 coupling, thereby offering the possibility that ligands showing stimulus bias could be developed that exploit these differential coupling mechanisms. Furthermore, this provides a strategy for the design of biased receptors to probe physiologically relevant signaling.

History

Citation

Journal of Biological Chemistry, 2014, 289 (26), pp. 18451-18465

Author affiliation

/Organisation/COLLEGE OF MEDICINE, BIOLOGICAL SCIENCES AND PSYCHOLOGY/MBSP Non-Medical Departments/Molecular & Cell Biology

Version

VoR (Version of Record)

Published in

Journal of Biological Chemistry

Publisher

American Society for Biochemistry and Molecular Biology

issn

0021-9258

eissn

1083-351X

Acceptance date

05/05/2014

Copyright date

2014

Available date

24/02/2016

Publisher version

http://www.jbc.org/content/289/26/18451

Language

en

Exports