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Phosphorylation of G Protein-Coupled Receptors: From the Barcode Hypothesis to the Flute Model

Zhao Yang1, Fan Yang1, Daolai Zhang1

  • 1Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology (Z.Y., Z.L., C.L., P.X., J.-P.S.), Department of Physiology (F.Y., X.Y.), Shandong University School of Medicine, Jinan, Shandong, People's Republic of China; School of Pharmacy, Binzhou Medical University, Yantai, Shandong, People's Republic of China (D.Z.); School of Medicine, Duke University, Durham, North Carolina (A.L., J.-P.S.).

Molecular Pharmacology
|March 2, 2017
PubMed

Insights

The phospho-barcode hypothesis suggests specific receptor phosphorylation patterns dictate distinct G protein-coupled receptor (GPCR) functions. Our flute model reveals how arrestins interpret these patterns to regulate GPCR signaling pathways.

Area of Science:

  • Molecular and Cellular Biology
  • Biochemistry
  • Pharmacology

Background:

  • Seven transmembrane G protein-coupled receptors (GPCRs) are crucial cell surface receptors involved in numerous physiological processes.
  • GPCRs are regulated by phosphorylation, primarily at the C terminus and intracellular loops, influencing their interaction with arrestin proteins.
  • Arrestins modulate GPCR signaling by mediating desensitization, internalization, and activating G protein-independent pathways.

Purpose of the Study:

  • To investigate the molecular mechanisms underlying GPCR phosphorylation pattern recognition by arrestins.
  • To explore how specific phosphorylation patterns translate into distinct downstream signaling outcomes.
  • To elucidate the role of the "phospho-barcode hypothesis" in GPCR regulation.

Main Methods:

  • Unnatural amino acid incorporation into GPCRs.
  • Fluorine-19 nuclear magnetic resonance (19F-NMR) spectroscopy.
  • Development of the "flute model" to describe receptor-arrestin interactions.

Main Results:

  • The "flute model" provides preliminary insights into how arrestins recognize specific GPCR phosphorylation patterns.
  • Arrestin's phosphate-binding pockets translate phosphorylation patterns into distinct conformational states.
  • These arrestin conformations are subsequently recognized by various downstream effector molecules.

Conclusions:

  • The "phospho-barcoding mechanism" allows arrestins to interpret a diverse range of GPCR phosphorylation patterns.
  • This mechanism contributes significantly to the functional diversity of GPCRs.
  • Understanding this code is key to deciphering complex GPCR signaling networks.

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