C-terminal threonines and serines play distinct roles in the desensitization of rhodopsin, a G protein-coupled receptor

  1. Anthony W Azevedo
  2. Thuy Doan
  3. Hormoz Moaven
  4. Iza Sokal
  5. Faiza Baameur
  6. Sergey A Vishnivetskiy
  7. Kristoff T Homan
  8. John J G Tesmer
  9. Vsevolod V Gurevich
  10. Jeannie Chen
  11. Fred Rieke  Is a corresponding author
  1. University of Washington, United States
  2. Keck School of Medicine of University of Southern California, United States
  3. Vanderbilt University School of Medicine, United States
  4. University of Michigan, United States

Abstract

Rod photoreceptors generate measurable responses to single-photon activation of individual molecules of the G-protein-coupled receptor, rhodopsin. Timely rhodopsin desensitization depends on phosphorylation and arrestin binding, which quenches G-protein activation. Rhodopsin phosphorylation has been measured biochemically at C-terminal serine residues, suggesting that these residues are critical for producing fast, low noise responses. The role of native threonine residues is unclear. We compared single-photon responses from rhodopsin lacking native serine or threonine phosphorylation sites. Contrary to expectation, serine-only rhodopsin generated prolonged step-like single-photon responses that terminated abruptly and randomly, whereas threonine-only rhodopsin generated responses that were only modestly slower than normal. We show that the step-like responses of serine-only rhodopsin reflect slow and stochastic arrestin binding. Thus, threonine sites play a privileged role in promoting timely arrestin binding and rhodopsin desensitization. Similar coordination of phosphorylation and arrestin binding may more generally permit tight control of the duration of G-protein-coupled receptor activity.

Article and author information

Author details

  1. Anthony W Azevedo

    Department of Physiology and Biophysics, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Thuy Doan

    Department of Ophthalmology, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Hormoz Moaven

    Departments of Cell & Neurobiology and Ophthalmology, Zilkha Neurogenetic Institute, Keck School of Medicine of University of Southern California, Los Angeles, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Iza Sokal

    Department of Physiology and Biophysics, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Faiza Baameur

    Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Sergey A Vishnivetskiy

    Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Kristoff T Homan

    Life Sciences Institute, Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, United States
    Competing interests
    The authors declare that no competing interests exist.
  8. John J G Tesmer

    Life Sciences Institute, Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, United States
    Competing interests
    The authors declare that no competing interests exist.
  9. Vsevolod V Gurevich

    Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, United States
    Competing interests
    The authors declare that no competing interests exist.
  10. Jeannie Chen

    Departments of Cell & Neurobiology and Ophthalmology, Zilkha Neurogenetic Institute, Keck School of Medicine of University of Southern California, Los Angeles, United States
    Competing interests
    The authors declare that no competing interests exist.
  11. Fred Rieke

    Department of Physiology and Biophysics, University of Washington, Seattle, United States
    For correspondence
    rieke@u.washington.edu
    Competing interests
    The authors declare that no competing interests exist.

Ethics

Animal experimentation: This work was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All procedures followed protocols approved by the Institutional Animal Care and Use Committee (protocol 3030-01) of the University of Washington.

Reviewing Editor

  1. Ronald L Calabrese, Emory University, United States

Version history

  1. Received: December 9, 2014
  2. Accepted: April 23, 2015
  3. Accepted Manuscript published: April 24, 2015 (version 1)
  4. Version of Record published: May 20, 2015 (version 2)

Copyright

© 2015, Azevedo et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 1,877
    Page views
  • 480
    Downloads
  • 33
    Citations

Article citation count generated by polling the highest count across the following sources: Scopus, Crossref, PubMed Central.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Anthony W Azevedo
  2. Thuy Doan
  3. Hormoz Moaven
  4. Iza Sokal
  5. Faiza Baameur
  6. Sergey A Vishnivetskiy
  7. Kristoff T Homan
  8. John J G Tesmer
  9. Vsevolod V Gurevich
  10. Jeannie Chen
  11. Fred Rieke
(2015)
C-terminal threonines and serines play distinct roles in the desensitization of rhodopsin, a G protein-coupled receptor
eLife 4:e05981.
https://doi.org/10.7554/eLife.05981

Share this article

https://doi.org/10.7554/eLife.05981

Further reading

    1. Structural Biology and Molecular Biophysics
    Ekaterina Smirnova, Emmanuelle Bignon ... Adam Ben Shem
    Research Article

    Sirtuin 6 (SIRT6) is an NAD+-dependent histone H3 deacetylase that is prominently found associated with chromatin, attenuates transcriptionally active promoters and regulates DNA repair, metabolic homeostasis and lifespan. Unlike other sirtuins, it has low affinity to free histone tails but demonstrates strong binding to nucleosomes. It is poorly understood how SIRT6 docking on nucleosomes stimulates its histone deacetylation activity. Here, we present the structure of human SIRT6 bound to a nucleosome determined by cryogenic electron microscopy. The zinc finger domain of SIRT6 associates tightly with the acidic patch of the nucleosome through multiple arginine anchors. The Rossmann fold domain binds to the terminus of the looser DNA half of the nucleosome, detaching two turns of the DNA from the histone octamer and placing the NAD+ binding pocket close to the DNA exit site. This domain shows flexibility with respect to the fixed zinc finger and moves with, but also relative to, the unwrapped DNA terminus. We apply molecular dynamics simulations of the histone tails in the nucleosome to show that in this mode of interaction, the active site of SIRT6 is perfectly poised to catalyze deacetylation of the H3 histone tail and that the partial unwrapping of the DNA allows even lysines close to the H3 core to reach the enzyme.

    1. Structural Biology and Molecular Biophysics
    Bernhard Schuster
    Insight

    The surface layer of Sulfolobus acidocaldarius consists of a flexible but stable outer protein layer that interacts with an inner, membrane-bound protein.