Optogenetic interrogation reveals separable G-protein-dependent and -independent signalling linking G-protein-coupled receptors to the circadian oscillator

Helena J. Bailes, Nina Milosavljevic, Ling Yu Zhuang, Elliot J. Gerrard, Tomoki Nishiguchi, Takeaki Ozawa, Robert J. Lucas

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9 Citations (Scopus)


Background: Endogenous circadian oscillators distributed across the mammalian body are synchronised among themselves and with external time via a variety of signalling molecules, some of which interact with G-protein-coupled receptors (GPCRs). GPCRs can regulate cell physiology via pathways originating with heterotrimeric G-proteins or β-arrestins. We applied an optogenetic approach to determine the contribution of these two signalling modes on circadian phase. Results: We employed a photopigment (JellyOp) that activates Gαs signalling with better selectivity and higher sensitivity than available alternatives, and a point mutant of this pigment (F112A) biased towards β-arrestin signalling. When expressed in fibroblasts, both native JellyOp and the F112A arrestin-biased mutant drove light-dependent phase resetting in the circadian clock. Shifts induced by the two opsins differed in their circadian phase dependence and the degree to which they were associated with clock gene induction. Conclusions: Our data imply separable G-protein and arrestin inputs to the mammalian circadian clock and establish a pair of optogenetic tools suitable for manipulating Gαs-and β-arrestin-biased signalling in live cells.

Original languageEnglish
Article number40
Number of pages14
JournalBMC Biology
Issue number1
Publication statusPublished - 15 May 2017
Externally publishedYes


  • HEK293 cell
  • circadian clock
  • phase response curve
  • proximity ligation assay
  • rat1 fibroblast

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