@article {291,
	title = {C-terminal threonines and serines play distinct roles in the desensitization of rhodopsin, a G protein-coupled receptor.},
	journal = {Elife},
	volume = {4},
	year = {2015},
	month = {2015 Apr 24},
	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>
},
	keywords = {Animals, Arrestin, Binding Sites, Mice, Mice, Inbred C57BL, Mice, Knockout, Phosphorylation, Receptors, G-Protein-Coupled, Retinal Rod Photoreceptor Cells, Rhodopsin, Serine, Threonine},
	issn = {2050-084X},
	doi = {10.7554/eLife.05981},
	author = {Azevedo, Anthony W and Doan, Thuy and Moaven, Hormoz and Sokal, Iza and Baameur, Faiza and Vishnivetskiy, Sergey A and Homan, Kristoff T and Tesmer, John J G and Gurevich, Vsevolod V and Chen, Jeannie and Rieke, Fred}
}
@article {726,
	title = {Multiple phosphorylation sites confer reproducibility of the rod{\textquoteright}s single-photon responses.},
	journal = {Science},
	volume = {313},
	year = {2006},
	month = {2006 Jul 28},
	pages = {530-3},
	abstract = {<p>Although signals controlled by single molecules are expected to be inherently variable, rod photoreceptors generate reproducible responses to single absorbed photons. We show that this unexpected reproducibility-the consistency of amplitude and duration of rhodopsin activity-varies in a graded and systematic manner with the number but not the identity of phosphorylation sites on rhodopsin{\textquoteright}s C terminus. These results indicate that each phosphorylation site provides an independent step in rhodopsin deactivation and that collectively these steps tightly control rhodopsin{\textquoteright}s active lifetime. Other G protein cascades may exploit a similar mechanism to encode accurately the timing and number of receptor activation.</p>
},
	keywords = {Animals, Arrestin, Electrophysiology, Mice, Mice, Transgenic, Models, Biological, Mutation, Patch-Clamp Techniques, Phosphorylation, Photons, Retinal Rod Photoreceptor Cells, Rhodopsin, Vision, Ocular},
	issn = {1095-9203},
	doi = {10.1126/science.1126612},
	author = {Doan, Thuy and Mendez, Ana and Detwiler, Peter B and Chen, Jeannie and Rieke, Fred}
}
