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Goity A, Dovzhenok A, Lim S, Hong C, Loros J, Dunlap JC, Larrondo LF. Transcriptional rewiring of an evolutionarily conserved circadian clock. EMBO J 2024; 43:2015-2034. [PMID: 38627599 PMCID: PMC11099105 DOI: 10.1038/s44318-024-00088-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 03/05/2024] [Accepted: 03/08/2024] [Indexed: 05/18/2024] Open
Abstract
Circadian clocks temporally coordinate daily organismal biology over the 24-h cycle. Their molecular design, preserved between fungi and animals, is based on a core-oscillator composed of a one-step transcriptional-translational-negative-feedback-loop (TTFL). To test whether this evolutionarily conserved TTFL architecture is the only plausible way for achieving a functional circadian clock, we adopted a transcriptional rewiring approach, artificially co-opting regulators of the circadian output pathways into the core-oscillator. Herein we describe one of these semi-synthetic clocks which maintains all basic circadian features but, notably, it also exhibits new attributes such as a "lights-on timer" logic, where clock phase is fixed at the end of the night. Our findings indicate that fundamental circadian properties such as period, phase and temperature compensation are differentially regulated by transcriptional and posttranslational aspects of the clockworks.
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Affiliation(s)
- Alejandra Goity
- Millennium Institute for Integrative Biology (iBio), Santiago, Chile
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Andrey Dovzhenok
- Department of Mathematical Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Sookkyung Lim
- Department of Mathematical Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Christian Hong
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, OH, USA
| | - Jennifer Loros
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, 03755, USA
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, 03755, USA
| | - Jay C Dunlap
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, 03755, USA
| | - Luis F Larrondo
- Millennium Institute for Integrative Biology (iBio), Santiago, Chile.
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
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2
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Tariq D, Maurici N, Bartholomai BM, Chandrasekaran S, Dunlap JC, Bah A, Crane BR. Phosphorylation, disorder, and phase separation govern the behavior of Frequency in the fungal circadian clock. eLife 2024; 12:RP90259. [PMID: 38526948 PMCID: PMC10963029 DOI: 10.7554/elife.90259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2024] Open
Abstract
Circadian clocks are composed of transcription-translation negative feedback loops that pace rhythms of gene expression to the diurnal cycle. In the filamentous fungus Neurospora crassa, the proteins Frequency (FRQ), the FRQ-interacting RNA helicase (FRH), and Casein-Kinase I (CK1) form the FFC complex that represses expression of genes activated by the white-collar complex (WCC). FRQ orchestrates key molecular interactions of the clock despite containing little predicted tertiary structure. Spin labeling and pulse-dipolar electron spin resonance spectroscopy provide domain-specific structural insights into the 989-residue intrinsically disordered FRQ and the FFC. FRQ contains a compact core that associates and organizes FRH and CK1 to coordinate their roles in WCC repression. FRQ phosphorylation increases conformational flexibility and alters oligomeric state, but the changes in structure and dynamics are non-uniform. Full-length FRQ undergoes liquid-liquid phase separation (LLPS) to sequester FRH and CK1 and influence CK1 enzymatic activity. Although FRQ phosphorylation favors LLPS, LLPS feeds back to reduce FRQ phosphorylation by CK1 at higher temperatures. Live imaging of Neurospora hyphae reveals FRQ foci characteristic of condensates near the nuclear periphery. Analogous clock repressor proteins in higher organisms share little position-specific sequence identity with FRQ; yet, they contain amino acid compositions that promote LLPS. Hence, condensate formation may be a conserved feature of eukaryotic clocks.
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Affiliation(s)
- Daniyal Tariq
- Department of Chemistry & Chemical Biology, Cornell UniversityIthacaUnited States
| | - Nicole Maurici
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Bradley M Bartholomai
- Department of Molecular and Systems Biology, Geisel School of Medicine at DartmouthHanoverUnited States
| | | | - Jay C Dunlap
- Department of Molecular and Systems Biology, Geisel School of Medicine at DartmouthHanoverUnited States
| | - Alaji Bah
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Brian R Crane
- Department of Chemistry & Chemical Biology, Cornell UniversityIthacaUnited States
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3
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Bakker MJ, Mládek A, Semrád H, Zapletal V, Pavlíková Přecechtělová J. Improving IDP theoretical chemical shift accuracy and efficiency through a combined MD/ADMA/DFT and machine learning approach. Phys Chem Chem Phys 2022; 24:27678-27692. [PMID: 36373847 DOI: 10.1039/d2cp01638a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This work extends the multi-scale computational scheme for the quantum mechanics (QM) calculations of Nuclear Magnetic Resonance (NMR) chemical shifts (CSs) in proteins that lack a well-defined 3D structure. The scheme couples the sampling of an intrinsically disordered protein (IDP) by classical molecular dynamics (MD) with protein fragmentation using the adjustable density matrix assembler (ADMA) and density functional theory (DFT) calculations. In contrast to our early investigation on IDPs (Pavlíková Přecechtělová et al., J. Chem. Theory Comput., 2019, 15, 5642-5658) and the state-of-the art NMR calculations for structured proteins, a partial re-optimization was implemented on the raw MD geometries in vibrational normal mode coordinates to enhance the accuracy of the MD/ADMA/DFT computational scheme. In addition, machine-learning based cluster analysis was performed on the scheme to explore its potential in producing protein structure ensembles (CLUSTER ensembles) that yield accurate CSs at a reduced computational cost. The performance of the cluster-based calculations is validated against results obtained with conventional structural ensembles consisting of MD snapshots extracted from the MD trajectory at regular time intervals (REGULAR ensembles). CS calculations performed with the refined MD/ADMA/DFT framework employed the 6-311++G(d,p) basis set that outperformed IGLO-III calculations with the same density functional approximation (B3LYP) and both explicit and implicit solvation. The partial geometry optimization did not universally improve the agreement of computed CSs with the experiment but substantially decreased errors associated with the ensemble averaging. A CLUSTER ensemble with 50 structures yielded ensemble averages close to those obtained with a REGULAR ensemble consisting of 500 MD frames. The cluster based calculations thus required only a fraction of the computational time.
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Affiliation(s)
- Michael J Bakker
- Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic.
| | - Arnošt Mládek
- Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic.
| | - Hugo Semrád
- Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic. .,Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic
| | - Vojtěch Zapletal
- Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic.
| | - Jana Pavlíková Přecechtělová
- Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic.
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4
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Tyler J, Lu Y, Dunlap J, Forger DB. Evolution of the repression mechanisms in circadian clocks. Genome Biol 2022; 23:17. [PMID: 35012616 PMCID: PMC8751359 DOI: 10.1186/s13059-021-02571-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 12/07/2021] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Circadian (daily) timekeeping is essential to the survival of many organisms. An integral part of all circadian timekeeping systems is negative feedback between an activator and repressor. However, the role of this feedback varies widely between lower and higher organisms. RESULTS Here, we study repression mechanisms in the cyanobacterial and eukaryotic clocks through mathematical modeling and systems analysis. We find a common mathematical model that describes the mechanism by which organisms generate rhythms; however, transcription's role in this has diverged. In cyanobacteria, protein sequestration and phosphorylation generate and regulate rhythms while transcription regulation keeps proteins in proper stoichiometric balance. Based on recent experimental work, we propose a repressor phospholock mechanism that models the negative feedback through transcription in clocks of higher organisms. Interestingly, this model, when coupled with activator phosphorylation, allows for oscillations over a wide range of protein stoichiometries, thereby reconciling the negative feedback mechanism in Neurospora with that in mammals and cyanobacteria. CONCLUSIONS Taken together, these results paint a picture of how circadian timekeeping may have evolved.
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Affiliation(s)
- Jonathan Tyler
- Department of Mathematics, University of Michigan, Ann Arbor, 48109 MI USA
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, University of Michigan, Ann Arbor, 48109 MI USA
| | - Yining Lu
- Department of Mathematics, University of Michigan, Ann Arbor, 48109 MI USA
| | - Jay Dunlap
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, 03755 NH USA
| | - Daniel B. Forger
- Department of Mathematics, University of Michigan, Ann Arbor, 48109 MI USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, 48109 MI USA
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5
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Philpott JM, Torgrimson MR, Harold RL, Partch CL. Biochemical mechanisms of period control within the mammalian circadian clock. Semin Cell Dev Biol 2021; 126:71-78. [PMID: 33933351 DOI: 10.1016/j.semcdb.2021.04.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 04/11/2021] [Accepted: 04/13/2021] [Indexed: 12/27/2022]
Abstract
Genetically encoded biological clocks are found broadly throughout life on Earth, where they generate circadian (about a day) rhythms that synchronize physiology and behavior with the daily light/dark cycle. Although the genetic networks that give rise to circadian timing are now fairly well established, our understanding of how the proteins that constitute the molecular 'cogs' of this biological clock regulate the intrinsic timing, or period, of circadian rhythms has lagged behind. New studies probing the biochemical and structural basis of clock protein function are beginning to reveal how assemblies of dedicated clock proteins form and evolve through post-translational regulation to generate circadian rhythms. This review will highlight some recent advances providing important insight into the molecular mechanisms of period control in mammalian clocks with an emphasis on structural analyses related to CK1-dependent control of PER stability.
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Affiliation(s)
- Jonathan M Philpott
- Department of Chemistry and Biochemistry, UC Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA.
| | - Megan R Torgrimson
- Department of Chemistry and Biochemistry, UC Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA.
| | - Rachel L Harold
- Department of Chemistry and Biochemistry, UC Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA.
| | - Carrie L Partch
- Department of Chemistry and Biochemistry, UC Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA; Center for Circadian Biology, UC San Diego, 9500 Gilman Drive, MC 0116, La Jolla, CA 92093, USA.
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6
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Kelliher CM, Lambreghts R, Xiang Q, Baker CL, Loros JJ, Dunlap JC. PRD-2 directly regulates casein kinase I and counteracts nonsense-mediated decay in the Neurospora circadian clock. eLife 2020; 9:64007. [PMID: 33295874 PMCID: PMC7746235 DOI: 10.7554/elife.64007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/08/2020] [Indexed: 01/22/2023] Open
Abstract
Circadian clocks in fungi and animals are driven by a functionally conserved transcription–translation feedback loop. In Neurospora crassa, negative feedback is executed by a complex of Frequency (FRQ), FRQ-interacting RNA helicase (FRH), and casein kinase I (CKI), which inhibits the activity of the clock’s positive arm, the White Collar Complex (WCC). Here, we show that the prd-2 (period-2) gene, whose mutation is characterized by recessive inheritance of a long 26 hr period phenotype, encodes an RNA-binding protein that stabilizes the ck-1a transcript, resulting in CKI protein levels sufficient for normal rhythmicity. Moreover, by examining the molecular basis for the short circadian period of upf-1prd-6 mutants, we uncovered a strong influence of the Nonsense-Mediated Decay pathway on CKI levels. The finding that circadian period defects in two classically derived Neurospora clock mutants each arise from disruption of ck-1a regulation is consistent with circadian period being exquisitely sensitive to levels of casein kinase I.
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Affiliation(s)
- Christina M Kelliher
- Department of Molecular & Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - Randy Lambreghts
- Department of Molecular & Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - Qijun Xiang
- Department of Molecular & Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - Christopher L Baker
- Department of Molecular & Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, United States.,The Jackson Laboratory, Bar Harbor, United States
| | - Jennifer J Loros
- Department of Biochemistry & Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - Jay C Dunlap
- Department of Molecular & Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, United States
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7
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Pelham JF, Dunlap JC, Hurley JM. Intrinsic disorder is an essential characteristic of components in the conserved circadian circuit. Cell Commun Signal 2020; 18:181. [PMID: 33176800 PMCID: PMC7656774 DOI: 10.1186/s12964-020-00658-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 09/06/2020] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION The circadian circuit, a roughly 24 h molecular feedback loop, or clock, is conserved from bacteria to animals and allows for enhanced organismal survival by facilitating the anticipation of the day/night cycle. With circadian regulation reportedly impacting as high as 80% of protein coding genes in higher eukaryotes, the protein-based circadian clock broadly regulates physiology and behavior. Due to the extensive interconnection between the clock and other cellular systems, chronic disruption of these molecular rhythms leads to a decrease in organismal fitness as well as an increase of disease rates in humans. Importantly, recent research has demonstrated that proteins comprising the circadian clock network display a significant amount of intrinsic disorder. MAIN BODY In this work, we focus on the extent of intrinsic disorder in the circadian clock and its potential mechanistic role in circadian timing. We highlight the conservation of disorder by quantifying the extent of computationally-predicted protein disorder in the core clock of the key eukaryotic circadian model organisms Drosophila melanogaster, Neurospora crassa, and Mus musculus. We further examine previously published work, as well as feature novel experimental evidence, demonstrating that the core negative arm circadian period drivers FREQUENCY (Neurospora crassa) and PERIOD-2 (PER2) (Mus musculus), possess biochemical characteristics of intrinsically disordered proteins. Finally, we discuss the potential contributions of the inherent biophysical principals of intrinsically disordered proteins that may explain the vital mechanistic roles they play in the clock to drive their broad evolutionary conservation in circadian timekeeping. CONCLUSION The pervasive conservation of disorder amongst the clock in the crown eukaryotes suggests that disorder is essential for optimal circadian timing from fungi to animals, providing vital homeostatic cellular maintenance and coordinating organismal physiology across phylogenetic kingdoms. Video abstract.
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Affiliation(s)
- Jacqueline F. Pelham
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180 USA
| | - Jay C. Dunlap
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755 USA
| | - Jennifer M. Hurley
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180 USA
- Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy, NY 12018 USA
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8
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Abstract
Sleep is a fundamental property conserved across species. The homeostatic induction of sleep indicates the presence of a mechanism that is progressively activated by the awake state and that induces sleep. Several lines of evidence support that such function, namely, sleep need, lies in the neuronal assemblies rather than specific brain regions and circuits. However, the molecular mechanism underlying the dynamics of sleep need is still unclear. This review aims to summarize recent studies mainly in rodents indicating that protein phosphorylation, especially at the synapses, could be the molecular entity associated with sleep need. Genetic studies in rodents have identified a set of kinases that promote sleep. The activity of sleep-promoting kinases appears to be elevated during the awake phase and in sleep deprivation. Furthermore, the proteomic analysis demonstrated that the phosphorylation status of synaptic protein is controlled by the sleep-wake cycle. Therefore, a plausible scenario may be that the awake-dependent activation of kinases modifies the phosphorylation status of synaptic proteins to promote sleep. We also discuss the possible importance of multisite phosphorylation on macromolecular protein complexes to achieve the slow dynamics and physiological functions of sleep in mammals.
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Affiliation(s)
- Koji L Ode
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroki R Ueda
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics, Osaka, Japan
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9
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Beytebiere JR, Greenwell BJ, Sahasrabudhe A, Menet JS. Clock-controlled rhythmic transcription: is the clock enough and how does it work? Transcription 2019; 10:212-221. [PMID: 31595813 DOI: 10.1080/21541264.2019.1673636] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Circadian clocks regulate the rhythmic expression of thousands of genes underlying the daily oscillations of biological functions. Here, we discuss recent findings showing that circadian clock rhythmic transcriptional outputs rely on additional mechanisms than just clock gene DNA binding, which may ultimately contribute to the plasticity of circadian transcriptional programs.
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Affiliation(s)
- Joshua R Beytebiere
- Department of Biology, Center for Biological Clock Research, Texas A&M University, TX, USA
| | - Ben J Greenwell
- Department of Biology, Center for Biological Clock Research, Texas A&M University, TX, USA.,Program of Genetics, Texas A&M University, College Station, TX, USA
| | - Aishwarya Sahasrabudhe
- Department of Biology, Center for Biological Clock Research, Texas A&M University, TX, USA
| | - Jerome S Menet
- Department of Biology, Center for Biological Clock Research, Texas A&M University, TX, USA.,Program of Genetics, Texas A&M University, College Station, TX, USA
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10
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FRQ-CK1 interaction determines the period of circadian rhythms in Neurospora. Nat Commun 2019; 10:4352. [PMID: 31554810 PMCID: PMC6761100 DOI: 10.1038/s41467-019-12239-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 08/28/2019] [Indexed: 01/25/2023] Open
Abstract
Circadian clock mechanisms have been extensively investigated but the main rate-limiting step that determines circadian period remains unclear. Formation of a stable complex between clock proteins and CK1 is a conserved feature in eukaryotic circadian mechanisms. Here we show that the FRQ-CK1 interaction, but not FRQ stability, correlates with circadian period in Neurospora circadian clock mutants. Mutations that specifically affect the FRQ-CK1 interaction lead to severe alterations in circadian period. The FRQ-CK1 interaction has two roles in the circadian negative feedback loop. First, it determines the FRQ phosphorylation profile, which regulates FRQ stability and also feeds back to either promote or reduce the interaction itself. Second, it determines the efficiency of circadian negative feedback process by mediating FRQ-dependent WC phosphorylation. Our conclusions are further supported by mathematical modeling and in silico experiments. Together, these results suggest that the FRQ-CK1 interaction is a major rate-limiting step in circadian period determination. Circadian clocks control daily rhythms of molecular and physiological activities. Here, the authors show that the interaction between proteins FRQ and CK1, rather than FRQ stability, is a major rate-limiting step in circadian period determination in the model fungus Neurospora.
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11
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Guo G, Wang K, Hu SS, Tian T, Liu P, Mori T, Chen P, Johnson CH, Qin X. Autokinase Activity of Casein Kinase 1 δ/ε Governs the Period of Mammalian Circadian Rhythms. J Biol Rhythms 2019; 34:482-496. [PMID: 31392916 DOI: 10.1177/0748730419865406] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Circadian rhythms exist in nearly all organisms. In mammals, transcriptional and translational feedback loops (TTFLs) are believed to underlie the mechanism of the circadian clock. Casein kinase 1δ/ε (CK1δ/ε) are key kinases that phosphorylate clock components such as PER proteins, determining the pace of the clock. Most previous studies of the biochemical properties of the key kinases CK1ε and CK1δ in vitro have focused on the properties of the catalytic domains from which the autoinhibitory C-terminus has been deleted (ΔC); those studies ignored the significance of self-inhibition by autophosphorylation. By comparing the properties of the catalytic domain of CK1δ/ε with the full-length kinase that can undergo autoinhibition, we found that recombinant full-length CK1 showed a sequential autophosphorylation process that induces conformational changes to affect the overall kinase activity. Furthermore, a direct relationship between the period change and the autokinase activity among CK1δ, CK1ε, and CK1ε-R178C was observed. These data implicate the autophosphorylation activity of CK1δ and CK1ε kinases in setting the pace of mammalian circadian rhythms and indicate that the circadian period can be modulated by tuning the autophosphorylation rates of CK1δ/ε.
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Affiliation(s)
- Gaili Guo
- Department of Health Sciences, Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui Province, China
| | - Kankan Wang
- Department of Health Sciences, Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui Province, China
| | - Shan-Shan Hu
- Department of Health Sciences, Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui Province, China
| | - Tian Tian
- Department of Health Sciences, Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui Province, China
| | - Peng Liu
- Department of Health Sciences, Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui Province, China
| | - Tetsuya Mori
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Peng Chen
- Department of Health Sciences, Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui Province, China
| | | | - Ximing Qin
- Department of Health Sciences, Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui Province, China
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12
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Loros JJ. Principles of the animal molecular clock learned from Neurospora. Eur J Neurosci 2019; 51:19-33. [PMID: 30687965 DOI: 10.1111/ejn.14354] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 12/10/2018] [Accepted: 12/13/2018] [Indexed: 12/28/2022]
Abstract
Study of Neurospora, a model system evolutionarily related to animals and sharing a circadian system having nearly identical regulatory architecture to that of animals, has advanced our understanding of all circadian rhythms. Work on the molecular bases of the Oscillator began in Neurospora before any clock genes were cloned and provided the second example of a clock gene, frq, as well as the first direct experimental proof that the core of the Oscillator was built around a transcriptional translational negative feedback loop (TTFL). Proof that FRQ was a clock component provided the basis for understanding how light resets the clock, and this in turn provided the generally accepted understanding for how light resets all animal and fungal clocks. Experiments probing the mechanism of light resetting led to the first identification of a heterodimeric transcriptional activator as the positive element in a circadian feedback loop, and to the general description of the fungal/animal clock as a single step TTFL. The common means through which DNA damage impacts the Oscillator in fungi and animals was first described in Neurospora. Lastly, the systematic study of Output was pioneered in Neurospora, providing the vocabulary and conceptual framework for understanding how Output works in all cells. This model system has contributed to the current appreciation of the role of Intrinsic Disorder in clock proteins and to the documentation of the essential roles of protein post-translational modification, as distinct from turnover, in building a circadian clock.
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Affiliation(s)
- Jennifer J Loros
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire.,Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
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13
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Circadian Proteomic Analysis Uncovers Mechanisms of Post-Transcriptional Regulation in Metabolic Pathways. Cell Syst 2018; 7:613-626.e5. [PMID: 30553726 DOI: 10.1016/j.cels.2018.10.014] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 08/12/2018] [Accepted: 10/29/2018] [Indexed: 12/20/2022]
Abstract
Transcriptional and translational feedback loops in fungi and animals drive circadian rhythms in transcript levels that provide output from the clock, but post-transcriptional mechanisms also contribute. To determine the extent and underlying source of this regulation, we applied newly developed analytical tools to a long-duration, deeply sampled, circadian proteomics time course comprising half of the proteome. We found a quarter of expressed proteins are clock regulated, but >40% of these do not arise from clock-regulated transcripts, and our analysis predicts that these protein rhythms arise from oscillations in translational rates. Our data highlighted the impact of the clock on metabolic regulation, with central carbon metabolism reflecting both transcriptional and post-transcriptional control and opposing metabolic pathways showing peak activities at different times of day. The transcription factor CSP-1 plays a role in this metabolic regulation, contributing to the rhythmicity and phase of clock-regulated proteins.
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14
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Wong DCS, O’Neill JS. Non-transcriptional processes in circadian rhythm generation. CURRENT OPINION IN PHYSIOLOGY 2018; 5:117-132. [PMID: 30596188 PMCID: PMC6302373 DOI: 10.1016/j.cophys.2018.10.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
'Biological clocks' orchestrate mammalian biology to a daily rhythm. Whilst 'clock gene' transcriptional circuits impart rhythmic regulation to myriad cellular systems, our picture of the biochemical mechanisms that determine their circadian (∼24 hour) period is incomplete. Here we consider the evidence supporting different models for circadian rhythm generation in mammalian cells in light of evolutionary factors. We find it plausible that the circadian timekeeping mechanism in mammalian cells is primarily protein-based, signalling biological timing information to the nucleus by the post-translational regulation of transcription factor activity, with transcriptional feedback imparting robustness to the oscillation via hysteresis. We conclude by suggesting experiments that might distinguish this model from competing paradigms.
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15
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Larrondo LF, Canessa P. The Clock Keeps on Ticking: Emerging Roles for Circadian Regulation in the Control of Fungal Physiology and Pathogenesis. Curr Top Microbiol Immunol 2018; 422:121-156. [PMID: 30255278 DOI: 10.1007/82_2018_143] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Tic-tac, tic-tac, the sound of time is familiar to us, yet, it also silently shapes daily biological processes conferring 24-hour rhythms in, among others, cellular and systemic signaling, gene expression, and metabolism. Indeed, circadian clocks are molecular machines that permit temporal control of a variety of processes in individuals, with a close to 24-hour period, optimizing cellular dynamics in synchrony with daily environmental cycles. For over three decades, the molecular bases of these clocks have been extensively described in the filamentous fungus Neurospora crassa, yet, there have been few molecular studies in fungi other than Neurospora, despite evidence of rhythmic phenomena in many fungal species, including pathogenic ones. This chapter will revise the mechanisms underlying clock regulation in the model fungus N. crassa, as well as recent findings obtained in several fungi. In particular, this chapter will review the effect of circadian regulation of virulence and organismal interactions, focusing on the phytopathogen Botrytis cinerea, as well as several entomopathogenic fungi, including the behavior-manipulating species Ophiocordyceps kimflemingiae and Entomophthora muscae. Finally, this review will comment current efforts in the study of mammalian pathogenic fungi, while highlighting recent circadian lessons from parasites such as Trypanosoma and Plasmodium. The clock keeps on ticking, whether we can hear it or not.
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Affiliation(s)
- Luis F Larrondo
- Millennium Institute for Integrative Biology (iBio), Santiago, Chile. .,Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Paulo Canessa
- Millennium Institute for Integrative Biology (iBio), Santiago, Chile.,Facultad de Ciencias de la Vida, Centro de Biotecnologia Vegetal, Universidad Andres Bello, Santiago, Chile
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