Cryptochromes(CRYs)are photolyase-like bluelight receptors originally identified in Arabidopsis thaliana(Arabidopsis)and have since been identified across diverse evolutionary lineages.Cryptochromes not only transduce...Cryptochromes(CRYs)are photolyase-like bluelight receptors originally identified in Arabidopsis thaliana(Arabidopsis)and have since been identified across diverse evolutionary lineages.Cryptochromes not only transduce blue-light cues to the circadian clock but also maintain the temperature compensation of circadian clock.However,the precise mechanism by which CRYs integrate blue light signals into the circadian clock in Arabidopsis is still under investigation.This study revealed that,when blue light was filtered out from white light,the circadian period length in Col-0 was extended,but not in the cry1 cry2double mutant.This indicates that both blue light and CRYs are crucial for regulating the circadian rhythm.Furthermore,we discovered that CRY2 interacted with PSEUDORESPONSE REGULATOR 5(PRR5),a key component of the circadian clock under blue light,which suppressed PRR5's transcriptional inhibition ability on CCA1 and LHY.These findings illuminate the pathway through which blue light influences the circadian clock via the CRY2-PRR5 module.展开更多
Post-translational modifications play essential roles in finely modulating eukaryotic circadian clock systems.In plants,the effects of O-glycosylation on the circadian clock and the underlying mechanisms remain largel...Post-translational modifications play essential roles in finely modulating eukaryotic circadian clock systems.In plants,the effects of O-glycosylation on the circadian clock and the underlying mechanisms remain largely unknown.The O-fucosyltransferase SPINDLY(SPY)and the O-GIcNAc transferase SECRET AGENT(SEC)are two prominent O-glycosylation enzymes in higher plants,with both overlapped and unique functions in plant growth and development.Unlike the critical role of O-GIcNAc in regulating the animal circadian clock,here we report that nuclear-localized SPY,but not SEC,specifically modulates the pace of the Arabidopsis circadian clock.By identifying the interactome of SPY,we identified PSEUDORESPONSE REGULATOR 5(PRR5),one of the core circadian clock components,as a new SPY-interacting protein.PRR5 can be O-fucosylated by SPY in pianta,while point mutation in the catalytic domain of SPY abolishes the O-fucosylation of PRR5.The protein abundance of PRR5 is strongly increased in spy mutants,while the degradation rate of PRR5 is much reduced,suggesting that PRR5 proteolysis is promoted by SPY-mediated O-fucosylation.Moreover,multiple lines of genetic evidence indicate that PRR5 is a major downstream target of SPY to specifically mediate its modulation of the circadian clock.Collectively,our findings provide novel insights into the specific role of the O-fucosyltransferase activity of SPY in modulating the circadian clock and implicate that O-glycosylation might play an evolutionarily conserved role in modulating the circadian clock system,via O-GIcNAcylation in mammals,but via O-fuco-sylation in higher plants.展开更多
基金supported in part by the National Key R&D Program of China(2024YFA1306700)the National Natural Science Foundation of China(32330006,32150007,31825004,32200229,32170247)+1 种基金the Research Team Cultivation Program of Shenzhen University(2023DFT005to H.L.)the research fund from the Synthetic Biology Research Center of Shenzhen University。
文摘Cryptochromes(CRYs)are photolyase-like bluelight receptors originally identified in Arabidopsis thaliana(Arabidopsis)and have since been identified across diverse evolutionary lineages.Cryptochromes not only transduce blue-light cues to the circadian clock but also maintain the temperature compensation of circadian clock.However,the precise mechanism by which CRYs integrate blue light signals into the circadian clock in Arabidopsis is still under investigation.This study revealed that,when blue light was filtered out from white light,the circadian period length in Col-0 was extended,but not in the cry1 cry2double mutant.This indicates that both blue light and CRYs are crucial for regulating the circadian rhythm.Furthermore,we discovered that CRY2 interacted with PSEUDORESPONSE REGULATOR 5(PRR5),a key component of the circadian clock under blue light,which suppressed PRR5's transcriptional inhibition ability on CCA1 and LHY.These findings illuminate the pathway through which blue light influences the circadian clock via the CRY2-PRR5 module.
基金suppoded by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB27030206)National Natural Science Foundation of China(No.31770287)+1 种基金National Key Research and Development Program of China(2016YFD0100600)to L.W.the National Institutes of Health(R01 GM100051)to T.P.S.
文摘Post-translational modifications play essential roles in finely modulating eukaryotic circadian clock systems.In plants,the effects of O-glycosylation on the circadian clock and the underlying mechanisms remain largely unknown.The O-fucosyltransferase SPINDLY(SPY)and the O-GIcNAc transferase SECRET AGENT(SEC)are two prominent O-glycosylation enzymes in higher plants,with both overlapped and unique functions in plant growth and development.Unlike the critical role of O-GIcNAc in regulating the animal circadian clock,here we report that nuclear-localized SPY,but not SEC,specifically modulates the pace of the Arabidopsis circadian clock.By identifying the interactome of SPY,we identified PSEUDORESPONSE REGULATOR 5(PRR5),one of the core circadian clock components,as a new SPY-interacting protein.PRR5 can be O-fucosylated by SPY in pianta,while point mutation in the catalytic domain of SPY abolishes the O-fucosylation of PRR5.The protein abundance of PRR5 is strongly increased in spy mutants,while the degradation rate of PRR5 is much reduced,suggesting that PRR5 proteolysis is promoted by SPY-mediated O-fucosylation.Moreover,multiple lines of genetic evidence indicate that PRR5 is a major downstream target of SPY to specifically mediate its modulation of the circadian clock.Collectively,our findings provide novel insights into the specific role of the O-fucosyltransferase activity of SPY in modulating the circadian clock and implicate that O-glycosylation might play an evolutionarily conserved role in modulating the circadian clock system,via O-GIcNAcylation in mammals,but via O-fuco-sylation in higher plants.
