@article{241,
  keywords = {Animals, Arrestin, Binding Sites, Mice, Mice, Inbred C57BL, Mice, Knockout, Phosphorylation, Receptors, G-Protein-Coupled, Retinal Rod Photoreceptor Cells, Rhodopsin, Serine, Threonine},
  author = {Anthony Azevedo and Thuy Doan and Hormoz Moaven and Iza Sokal and Faiza Baameur and Sergey Vishnivetskiy and Kristoff Homan and John Tesmer and Vsevolod Gurevich V and Jeannie Chen and Fred Rieke},
  title = {C-terminal threonines and serines play distinct roles in the desensitization of rhodopsin, a G protein-coupled receptor.},
  abstract = {<p>Rod photoreceptors generate measurable responses to single-photon activation of individual molecules of the G protein-coupled receptor (GPCR), 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 GPCR activity.</p>
},
  year = {2015},
  journal = {Elife},
  volume = {4},
  month = {2015 Apr 24},
  issn = {2050-084X},
  doi = {10.7554/eLife.05981},
  language = {eng},
}