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Barrio-Alonso E, Lituma PJ, Notaras MJ, Albero R, Bouchekioua Y, Wayland N, Stankovic IN, Jain T, Gao S, Calderon DP, Castillo PE, Colak D. Circadian protein TIMELESS regulates synaptic function and memory by modulating cAMP signaling. Cell Rep 2023; 42:112375. [PMID: 37043347 PMCID: PMC10564971 DOI: 10.1016/j.celrep.2023.112375] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 03/07/2023] [Accepted: 03/24/2023] [Indexed: 04/13/2023] Open
Abstract
The regulation of neurons by circadian clock genes is thought to contribute to the maintenance of neuronal functions that ultimately underlie animal behavior. However, the impact of specific circadian genes on cellular and molecular mechanisms controlling synaptic plasticity and cognitive function remains elusive. Here, we show that the expression of the circadian protein TIMELESS displays circadian rhythmicity in the mammalian hippocampus. We identify TIMELESS as a chromatin-bound protein that targets synaptic-plasticity-related genes such as phosphodiesterase 4B (Pde4b). By promoting Pde4b transcription, TIMELESS negatively regulates cAMP signaling to modulate AMPA receptor GluA1 function and influence synaptic plasticity. Conditional deletion of Timeless in the adult forebrain impairs working and contextual fear memory in mice. These cognitive phenotypes were accompanied by attenuation of hippocampal Schaffer-collateral synapse long-term potentiation. Together, these data establish a neuron-specific function of mammalian TIMELESS by defining a mechanism that regulates synaptic plasticity and cognitive function.
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Affiliation(s)
- Estibaliz Barrio-Alonso
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, Cornell University, New York, NY, USA
| | - Pablo J Lituma
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, Cornell University, New York, NY, USA
| | - Michael J Notaras
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, Cornell University, New York, NY, USA
| | - Robert Albero
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Youcef Bouchekioua
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY, USA
| | - Natalie Wayland
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, Cornell University, New York, NY, USA
| | - Isidora N Stankovic
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, Cornell University, New York, NY, USA
| | - Tanya Jain
- Program of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Sijia Gao
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY, USA
| | | | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Dilek Colak
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, Cornell University, New York, NY, USA; Gale & Ira Drukier Institute for Children's Health, Weill Cornell Medical College, Cornell University, New York, NY, USA.
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2
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Clyne CD, Kusnadi KP, Cowcher A, Morgan J, Yang J, Fuller PJ, Young MJ. Regulation of mineralocorticoid receptor activation by circadian protein TIMELESS. J Mol Endocrinol 2023; 70:JME-21-0279. [PMID: 36099062 DOI: 10.1530/jme-21-0279] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 09/13/2022] [Indexed: 01/19/2023]
Abstract
The mineralocorticoid receptor (MR) is a ligand-activated transcription factor that regulates cardiorenal physiology and disease. Ligand-dependent MR transactivation involves a conformational change in the MR and recruitment of coregulatory proteins to form a unique DNA-binding complex at the hormone response element in target gene promoters. Differences in the recruitment of coregulatory proteins can promote tissue-, ligand- or gene-specific transcriptional outputs. The goal of this study was to evaluate the circadian protein TIMELESS as a selective regulator of MR transactivation. TIMELESS has an established role in cell cycle regulation and DNA repair. TIMELESS may not be central to mammalian clock function and does not bind DNA; however, RNA and protein levels oscillate over 24 h. Co-expression of TIMELESS down-regulated MR transactivation of an MR-responsive reporter in HEK293 cells, yet enhanced transactivation mediated by other steroid receptors. TIMELESS markedly inhibited MR transactivation of synthetic and native gene promoters and expression of MR target genes in H9c2 cardiac myoblasts. Immunofluorescence showed aldosterone induces colocalisation of TIMELESS and MR, although a direct interaction was not confirmed by coimmunoprecipitation. Potential regulation of circadian clock targets cryptochrome 1 and 2 by TIMELESS was not detected. However, our data suggest that these effects may involve TIMELESS coactivation of oestrogen receptor alpha (ERα). Taken together, these data suggest that TIMELESS may contribute to MR transcriptional outputs via enhancing ERα inhibitory actions on MR transactivation. Given the variable expression of TIMELESS in different cell types, these data offer new opportunities for the development of MR modulators with selective actions.
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Affiliation(s)
- Colin D Clyne
- Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, Australia
| | - Kevin P Kusnadi
- Cardiovascular Endocrinology Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Alexander Cowcher
- Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, Australia
| | - James Morgan
- Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, Australia
| | - Jun Yang
- Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, Australia
| | - Peter J Fuller
- Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, Australia
| | - Morag J Young
- Cardiovascular Endocrinology Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
- University of Melbourne and Baker HDI Department of Cardiometabolic Health and Disease, Melbourne, Australia
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Hosseini K, Beirami SM, Forouhandeh H, Vahed SZ, Eyvazi S, Ramazani F, Tarhriz V, Ardalan M. The role of circadian gene timeless in gastrointestinal cancers. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Neba Ambe GNN, Breda C, Bhambra AS, Arroo RRJ. Effect of the Citrus Flavone Nobiletin on Circadian Rhythms and Metabolic Syndrome. Molecules 2022; 27:molecules27227727. [PMID: 36431828 PMCID: PMC9695244 DOI: 10.3390/molecules27227727] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/06/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
Abstract
The importance of the circadian clock in maintaining human health is now widely acknowledged. Dysregulated and dampened clocks may be a common cause of age-related diseases and metabolic syndrome Thus, circadian clocks should be considered as therapeutic targets to mitigate disease symptoms. This review highlights a number of dietary compounds that positively affect the maintenance of the circadian clock. Notably the polymethoxyflavone nobiletin has shown some encouraging results in pre-clinical experiments. Although many more experiments are needed to fully elucidate its exact mechanism of action, it is a promising candidate with potential as a chronotherapeutic agent.
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Affiliation(s)
- Gael N. N. Neba Ambe
- Leicester School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9BH, UK
| | - Carlo Breda
- School of Allied Health Sciences, De Montfort University, The Gateway, Leicester LE1 9BH, UK
| | - Avninder Singh Bhambra
- School of Allied Health Sciences, De Montfort University, The Gateway, Leicester LE1 9BH, UK
| | - Randolph R. J. Arroo
- Leicester School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9BH, UK
- Correspondence:
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Liu C, Tang X, Gong Z, Zeng W, Hou Q, Lu R. Circadian Rhythm Sleep Disorders: Genetics, Mechanisms, and Adverse Effects on Health. Front Genet 2022; 13:875342. [PMID: 35571019 PMCID: PMC9099045 DOI: 10.3389/fgene.2022.875342] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 03/29/2022] [Indexed: 01/14/2023] Open
Abstract
Nearly all living organisms, from cyanobacteria to humans, have an internal circadian oscillation with a periodicity of approximately 24 h. In mammals, circadian rhythms regulate diverse physiological processes including the body temperature, energy metabolism, immunity, hormone secretion, and daily sleep-wake cycle. Sleep is tightly regulated by circadian rhythms, whereas a misalignment between the circadian rhythms and external environment may lead to circadian rhythm sleep disorders (CRSD). CRSD includes four main kinds of disorders: the advanced sleep-wake phase disorder (ASPD), the delayed sleep-wake phase disorder (DSPD), the irregular sleep-wake rhythm disorder and the non-24-h sleep-wake rhythm disorder. Recent studies have begun to shed light on the genetic basis of CRSD. Deciphering the genetic codes for ASPD and DSPD has so far been more successful than the other CRSDs, which allow for the development of animal models and understanding of the pathological mechanisms for these disorders. And studies from humans or animal models implicate CRSDs are associated with adverse health consequences, such as cancer and mental disorders. In this review, we will summarize the recent advances in the genetics, underlying mechanisms and the adverse effects on health of ASPD and DSPD.
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Affiliation(s)
| | - Xiangrong Tang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Zishan Gong
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Wang Zeng
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Qiao Hou
- Department of Rehabilitation Medicine, Xiangya Third Hospital, Central South University, Changsha, China
- *Correspondence: Renbin Lu, ; Qiao Hou,
| | - Renbin Lu
- Hunan Key Laboratory of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geratric Disorder, Xiangya Hospital, Central South University, Changsha, China
- *Correspondence: Renbin Lu, ; Qiao Hou,
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Grabarczyk DB. The Fork Protection Complex: A Regulatory Hub at the Head of the Replisome. Subcell Biochem 2022; 99:83-107. [PMID: 36151374 DOI: 10.1007/978-3-031-00793-4_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
As well as accurately duplicating DNA, the eukaryotic replisome performs a variety of other crucial tasks to maintain genomic stability. For example, organizational elements, like cohesin, must be transferred from the front of the fork to the new strands, and when there is replication stress, forks need to be protected and checkpoint signalling activated. The Tof1-Csm3 (or Timeless-Tipin in humans) Fork Protection Complex (FPC) ensures efficient replisome progression and is required for a range of replication-associated activities. Recent studies have begun to reveal the structure of this complex, and how it functions within the replisome to perform its diverse roles. The core of the FPC acts as a DNA grip on the front of the replisome to regulate fork progression. Other flexibly linked domains and motifs mediate interactions with proteins and specific DNA structures, enabling the FPC to act as a hub at the head of the replication fork.
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Affiliation(s)
- Daniel B Grabarczyk
- Rudolf Virchow Center for Integrative and Translational Bioimaging, Institute for Structural Biology, University of Würzburg, Würzburg, Germany.
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria.
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Cai YD, Chiu JC. Timeless in animal circadian clocks and beyond. FEBS J 2021; 289:6559-6575. [PMID: 34699674 PMCID: PMC9038958 DOI: 10.1111/febs.16253] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 10/09/2021] [Accepted: 10/26/2021] [Indexed: 12/13/2022]
Abstract
TIMELESS (TIM) was first identified as a molecular cog in the Drosophila circadian clock. Almost three decades of investigations have resulted in an insightful model describing the critical role of Drosophila TIM (dTIM) in circadian timekeeping in insects, including its function in mediating light entrainment and temperature compensation of the molecular clock. Furthermore, exciting discoveries on its sequence polymorphism and thermosensitive alternative RNA splicing have also established its role in regulating seasonal biology. Although mammalian TIM (mTIM), its mammalian paralog, was first identified as a potential circadian clock component in 1990s due to sequence similarity to dTIM, its role in clock regulation has been more controversial. Mammalian TIM has now been characterized as a DNA replication fork component and has been shown to promote fork progression and participate in cell cycle checkpoint signaling in response to DNA damage. Despite defective circadian rhythms displayed by mtim mutants, it remains controversial whether the regulation of circadian clocks by mTIM is direct, especially given the interconnection between the cell cycle and circadian clocks. In this review, we provide a historical perspective on the identification of animal tim genes, summarize the roles of TIM proteins in biological timing and genomic stability, and draw parallels between dTIM and mTIM despite apparent functional divergence.
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Affiliation(s)
- Yao D Cai
- Department of Entomology and Nematology, College of Agricultural and Environmental Sciences, University of California Davis, CA, USA
| | - Joanna C Chiu
- Department of Entomology and Nematology, College of Agricultural and Environmental Sciences, University of California Davis, CA, USA
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Wang J, Yang Y, Wang Z, Xu K, Xiao X, Mu W. Comparison of effects in sustained and diel-cycling hypoxia on hypoxia tolerance, histology, physiology and expression of clock genes in high latitude fish Phoxinus lagowskii. Comp Biochem Physiol A Mol Integr Physiol 2021; 260:111020. [PMID: 34166835 DOI: 10.1016/j.cbpa.2021.111020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/19/2021] [Accepted: 06/19/2021] [Indexed: 01/26/2023]
Abstract
Phoxinus lagowskii is a popular fish in Chinese cuisine. Though it is found mainly in China's high-latitude regions, where diel-cycling hypoxia (DCH) is known to have unique impacts on aquatic organisms, there is little known about its response to hypoxia. Currently, nothing is known about the changes in blood parameters, gill and liver morphology, glucose and lipid metabolism, or expression of genes involved in clock and glucose metabolism in response to sustained hypoxia (SH) and diel-cycling hypoxia (DCH). To elucidate the influence of sustained and diel-cycling hypoxia on fish hypoxia tolerance, resting oxygen consumption (MO2) analysis was performed after ten days of hypoxia. This analysis revealed that hypoxia tolerance profoundly improved after ten days of either sustained or diel-cycling hypoxia acclimation, with DCH groups showing greater improvements than SH groups. Additionally, an increase in RBCs was found in P. lagowskii, suggesting an increase in the O2-carrying capacity of the blood to tolerate hypoxia. Hemoglobin (Hb) concentrations in P. lagowskii were increased at four days of diel-cycling hypoxia, confirming that physiological and metabolic adaptation to hypoxia is based on the duration of O2 exposure. Increased Hb and hematocrit (Hct) were found in DCH-exposed fish, both of which have been directly linked to high-latitude hypoxia tolerance. In the gills, lamella surface area increased in SH-exposed fish more than DCH-exposed fish, and these increases were accompanied by a decrease in the volume of interlamellar cell mass (ILCM). Histology changes in the liver showed a higher frequency of cytoplasmic vacuolization in DCH-exposed fish. PK increases in SH-exposed fish suggest that fish can use more energy sources in persistent hypoxia. Meanwhile, DCH-exposed fish use TG as an energy source. In SH-exposed fish, self-regulation of Cry1a was observed, whereas Cry1b gene was up-regulated significantly. In DCH-exposed fish, three of eight clock genes studied had increased expression, including Per1a, Clocka, and Cry1b, suggesting that SH and DCH result in different hypoxic responses. This study presents a novel approach to the study of fish responses to hypoxia in high latitude and shows that sustained hypoxia and diel-cycling hypoxia induce large differences in fish physiology.
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Affiliation(s)
- Jing Wang
- Key Laboratory of Biodiversity of Aquatic Organisms, College of Life Science and Technology, Harbin Normal University, Harbin 150025, China
| | - Yuting Yang
- Key Laboratory of Biodiversity of Aquatic Organisms, College of Life Science and Technology, Harbin Normal University, Harbin 150025, China
| | - Zhen Wang
- Key Laboratory of Biodiversity of Aquatic Organisms, College of Life Science and Technology, Harbin Normal University, Harbin 150025, China
| | - Kexin Xu
- Key Laboratory of Biodiversity of Aquatic Organisms, College of Life Science and Technology, Harbin Normal University, Harbin 150025, China
| | - Xin Xiao
- Key Laboratory of Biodiversity of Aquatic Organisms, College of Life Science and Technology, Harbin Normal University, Harbin 150025, China
| | - Weijie Mu
- Key Laboratory of Biodiversity of Aquatic Organisms, College of Life Science and Technology, Harbin Normal University, Harbin 150025, China.
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Keshvari M, Nejadtaghi M, Hosseini-Beheshti F, Rastqar A, Patel N. Exploring the role of circadian clock gene and association with cancer pathophysiology. Chronobiol Int 2019; 37:151-175. [PMID: 31791146 DOI: 10.1080/07420528.2019.1681440] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Most of the processes that occur in the mind and body follow natural rhythms. Those with a cycle length of about one day are called circadian rhythms. These rhythms are driven by a system of self-sustained clocks and are entrained by environmental cues such as light-dark cycles as well as food intake. In mammals, the circadian clock system is hierarchically organized such that the master clock in the suprachiasmatic nuclei of the hypothalamus integrates environmental information and synchronizes the phase of oscillators in peripheral tissues.The circadian system is responsible for regulating a variety of physiological and behavioral processes, including feeding behavior and energy metabolism. Studies revealed that the circadian clock system consists primarily of a set of clock genes. Several genes control the biological clock, including BMAL1, CLOCK (positive regulators), CRY1, CRY2, PER1, PER2, and PER3 (negative regulators) as indicators of the peripheral clock.Circadian has increasingly become an important area of medical research, with hundreds of studies pointing to the body's internal clocks as a factor in both health and disease. Thousands of biochemical processes from sleep and wakefulness to DNA repair are scheduled and dictated by these internal clocks. Cancer is an example of health problems where chronotherapy can be used to improve outcomes and deliver a higher quality of care to patients.In this article, we will discuss knowledge about molecular mechanisms of the circadian clock and the role of clocks in physiology and pathophysiology of concerns.
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Affiliation(s)
- Mahtab Keshvari
- Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Canada
| | - Mahdieh Nejadtaghi
- Department of Medical Genetics, faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | | | - Ali Rastqar
- Department of Psychiatry and Neuroscience, Université Laval, Quebec, Canada
| | - Niraj Patel
- Centre de Recherche CERVO, Université Laval, Québec, Canada
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Kurien P, Hsu PK, Leon J, Wu D, McMahon T, Shi G, Xu Y, Lipzen A, Pennacchio LA, Jones CR, Fu YH, Ptáček LJ. TIMELESS mutation alters phase responsiveness and causes advanced sleep phase. Proc Natl Acad Sci U S A 2019; 116:12045-12053. [PMID: 31138685 PMCID: PMC6575169 DOI: 10.1073/pnas.1819110116] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Many components of the circadian molecular clock are conserved from flies to mammals; however, the role of mammalian Timeless remains ambiguous. Here, we report a mutation in the human TIMELESS (hTIM) gene that causes familial advanced sleep phase (FASP). Tim CRISPR mutant mice exhibit FASP with altered photic entrainment but normal circadian period. We demonstrate that the mutation prevents TIM accumulation in the nucleus and has altered affinity for CRY2, leading to destabilization of PER/CRY complex and a shortened period in nonmature mouse embryonic fibroblasts (MEFs). We conclude that TIM, when excluded from the nucleus, can destabilize the negative regulators of the circadian clock, alter light entrainment, and cause FASP.
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Affiliation(s)
- Philip Kurien
- Department of Anesthesiology, University of California, San Francisco, CA 94143
| | - Pei-Ken Hsu
- Department of Neurology, University of California, San Francisco, CA 94143
| | - Jacy Leon
- Department of Anesthesiology, University of California, San Francisco, CA 94143
| | - David Wu
- Department of Neurology, University of California, San Francisco, CA 94143
| | - Thomas McMahon
- Department of Neurology, University of California, San Francisco, CA 94143
| | - Guangsen Shi
- Department of Neurology, University of California, San Francisco, CA 94143
| | - Ying Xu
- Center for Systems Biology, Soochow University, Suzhou 215000, China
| | - Anna Lipzen
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Department of Energy Joint Genome Institute, Walnut Creek, CA 94598
| | - Len A Pennacchio
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Department of Energy Joint Genome Institute, Walnut Creek, CA 94598
| | | | - Ying-Hui Fu
- Department of Neurology, University of California, San Francisco, CA 94143;
- Weill Neuroscience Institute, University of California, San Francisco, CA 94143
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA 94143
| | - Louis J Ptáček
- Department of Neurology, University of California, San Francisco, CA 94143;
- Weill Neuroscience Institute, University of California, San Francisco, CA 94143
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA 94143
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COOK GEOFFREYM, GRUEN ANNAE, MORRIS JOHN, PANKEY MSABRINA, SENATORE ADRIANO, KATZ PAULS, WATSON WINSORH, NEWCOMB JAMESM. Sequences of Circadian Clock Proteins in the Nudibranch Molluscs Hermissenda crassicornis, Melibe leonina, and Tritonia diomedea. THE BIOLOGICAL BULLETIN 2018; 234:207-218. [PMID: 29949437 PMCID: PMC6180908 DOI: 10.1086/698467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
While much is known about the genes and proteins that make up the circadian clocks in vertebrates and several arthropod species, much less is known about the clock genes in many other invertebrates, including nudibranchs. The goal of this project was to identify the RNA and protein products of putative clock genes in the central nervous system of three nudibranchs, Hermissenda crassicornis, Melibe leonina, and Tritonia diomedea. Using previously published transcriptomes (Hermissenda and Tritonia) and a new transcriptome (Melibe), we identified nudibranch orthologs for the products of five canonical clock genes: brain and muscle aryl hydrocarbon receptor nuclear translocator like protein 1, circadian locomotor output cycles kaput, non-photoreceptive cryptochrome, period, and timeless. Additionally, orthologous sequences for the products of five related genes-aryl hydrocarbon receptor nuclear translocator like, photoreceptive cryptochrome, cryptochrome DASH, 6-4 photolyase, and timeout-were determined. Phylogenetic analyses confirmed that the nudibranch proteins were most closely related to known orthologs in related invertebrates, such as oysters and annelids. In general, the nudibranch clock proteins shared greater sequence similarity with Mus musculus orthologs than Drosophila melanogaster orthologs, which is consistent with the closer phylogenetic relationships recovered between lophotrochozoan and vertebrate orthologs. The suite of clock-related genes in nudibranchs includes both photoreceptive and non-photoreceptive cryptochromes, as well as timeout and possibly timeless. Therefore, the nudibranch clock may resemble the one exhibited in mammals, or possibly even in non-drosopholid insects and oysters. The latter would be evidence supporting this as the ancestral clock for bilaterians.
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Key Words
- ARNTL, aryl hydrocarbon receptor nuclear translocator like
- BMAL1, brain and muscle aryl hydrocarbon receptor nuclear translocator like protein 1
- CLOCK, circadian locomotor output cycles kaput
- CNS, central nervous system
- CRY DASH, cryptochrome DASH
- FAD, flavin adenine dinucleotide
- G+I, gamma-distributed and invariant
- ML, maximum likelihood
- MSA, multiple sequence alignments
- NCBI, National Center for Biotechnology Information
- NPCRY, non-photoreceptive cryptochrome
- PAC, Per-Arnt-Sim-associated C-terminal
- PAS, Per-Arnt-Sim
- PCRY, photoreceptive cryptochrome
- PHR, 6-4 photolyase
- TSA, transcriptome shotgun assembly
- bHLH, basic helix-loop-helix
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Affiliation(s)
- GEOFFREY M. COOK
- Department of Biology and Health Science, New England College, Henniker, New Hampshire 03242
| | - ANNA E. GRUEN
- Department of Biological Sciences, University of New Hampshire, Durham, New Hampshire 03824
| | - JOHN MORRIS
- Department of Biology and Health Science, New England College, Henniker, New Hampshire 03242
| | - M. SABRINA PANKEY
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire 03824
| | - ADRIANO SENATORE
- Department of Biology, University of Massachusetts, Amherst, Massachusetts 01003
- Present address: Department of Biology, University of Toronto, Mississauga, Ontario L5L 1C6, Canada
| | - PAUL S. KATZ
- Department of Biology, University of Massachusetts, Amherst, Massachusetts 01003
| | - WINSOR H. WATSON
- Department of Biological Sciences, University of New Hampshire, Durham, New Hampshire 03824
| | - JAMES M. NEWCOMB
- Department of Biology and Health Science, New England College, Henniker, New Hampshire 03242
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Chapman EC, O’Dell AR, Meligi NM, Parsons DR, Rotchell JM. Seasonal expression patterns of clock-associated genes in the blue mussel Mytilus edulis. Chronobiol Int 2017; 34:1300-1314. [DOI: 10.1080/07420528.2017.1363224] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Emma C. Chapman
- School of Environmental Sciences, University of Hull, Hull, UK
| | | | - Noha M. Meligi
- Zoology Department, Faculty of Science, Minia University, Minia, Egypt
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Bhadra U, Thakkar N, Das P, Pal Bhadra M. Evolution of circadian rhythms: from bacteria to human. Sleep Med 2017; 35:49-61. [DOI: 10.1016/j.sleep.2017.04.008] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/07/2017] [Accepted: 04/18/2017] [Indexed: 12/20/2022]
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14
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Chi L, Zou Y, Qin L, Ma W, Hao Y, Tang Y, Luo R, Wu Z. TIMELESS contributes to the progression of breast cancer through activation of MYC. Breast Cancer Res 2017; 19:53. [PMID: 28464854 PMCID: PMC5414141 DOI: 10.1186/s13058-017-0838-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/18/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Breast cancer is the most common malignancy and the leading cause of cancer death among women. TIMELESS (TIM), a circadian rhythm regulator, has been recently implicated in the progression of human cancer. However, the role of TIM in the progression of breast cancer has not been well-characterized. METHODS Immunohistochemistry (IHC) staining was used to examine TIM levels in breast cancer specimens. Mammosphere formation analysis and side population analysis were used to examine the effect of TIM on the self-renewal of breast cancer stem cells. A wound healing assay and a Transwell assay were used to determine the role of TIM in breast cancer cell migration and invasion. A soft agar growth assay in vitro and tumorigenicity in vivo were used to determine the role of TIM in tumorigenicity. RESULTS TIM levels in both breast cancer cell lines and tissues were significantly upregulated. Patients with high TIM had poorer prognosis than patients with low TIM. Overexpression of TIM dramatically enhanced, while knockdown of TIM suppressed the self-renewal of cancer stem cells (CSCs), cell invasion and migration abilities of breast cancer cells in vitro. Moreover, overexpression of TIM significantly augmented, while knockdown of TIM reduced the tumorigenicity of breast cancer cells in vivo. Mechanism studies revealed that TIM upregulated the expression and the trans-activity of the well-known oncogene MYC. Inhibition of MYC significantly blocked the effects of TIM on CSC population, cell invasion and anchor-independent cell growth. CONCLUSION TIM plays an important role in promoting breast cancer progression and may represent a novel therapeutic target for breast cancer.
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Affiliation(s)
- Limin Chi
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China
| | - Yujiao Zou
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China
| | - Ling Qin
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China
| | - Weifeng Ma
- Department of Microbiology, School of Public Health, Southern Medical University, Guangzhou, 510515, China
| | - Yanyan Hao
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China
| | - Yao Tang
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China
| | - Rongcheng Luo
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China.
| | - Ziqing Wu
- Cancer Center, TCM-Integrated Hospital, Southern Medical University, Guangzhou, 510315, China. .,Key Laboratory of Molecular Tumor Pathology of Guangdong Province, Southern Medical University, Guangzhou, 510515, China. .,Department of Pathology, School of Basic Medical Science, Southern Medical University, Guangzhou, 510515, China.
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Machicao F, Peter A, Machann J, Königsrainer I, Böhm A, Lutz SZ, Heni M, Fritsche A, Schick F, Königsrainer A, Stefan N, Häring HU, Staiger H. Glucose-Raising Polymorphisms in the Human Clock Gene Cryptochrome 2 (CRY2) Affect Hepatic Lipid Content. PLoS One 2016; 11:e0145563. [PMID: 26726810 PMCID: PMC4699770 DOI: 10.1371/journal.pone.0145563] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 12/04/2015] [Indexed: 01/22/2023] Open
Abstract
Circadian rhythms govern vital functions. Their disruption provokes metabolic imbalance favouring obesity and type-2 diabetes. The aim of the study was to assess the role of clock genes in human prediabetes. To this end, genotype-phenotype associations of 121 common single nucleotide polymorphisms (SNPs) tagging ARNTL, ARNTL2, CLOCK, CRY1, CRY2, PER1, PER2, PER3, and TIMELESS were assessed in a study population of 1,715 non-diabetic individuals metabolically phenotyped by 5-point oral glucose tolerance tests. In subgroups, hyperinsulinaemic-euglycaemic clamps, intravenous glucose tolerance tests, and magnetic resonance imaging/spectroscopy were performed. None of the tested SNPs was associated with body fat content, insulin sensitivity, or insulin secretion. Four CRY2 SNPs were associated with fasting glycaemia, as reported earlier. Importantly, carriers of these SNPs’ minor alleles revealed elevated fasting glycaemia and, concomitantly, reduced liver fat content. In human liver tissue samples, CRY2 mRNA expression was directly associated with hepatic triglyceride content. Our data may point to CRY2 as a novel switch in hepatic fuel metabolism promoting triglyceride storage and, concomitantly, limiting glucose production. The anti-steatotic effects of the glucose-raising CRY2 alleles may explain why these alleles do not increase type-2 diabetes risk.
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Affiliation(s)
- Fausto Machicao
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
| | - Andreas Peter
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, University Hospital Tübingen, Tübingen, Germany
| | - Jürgen Machann
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Department of Diagnostic and Interventional Radiology, Section on Experimental Radiology, University Hospital Tübingen, Tübingen, Germany
| | - Ingmar Königsrainer
- Department of General, Visceral, and Transplant Surgery, University Hospital Tübingen, Tübingen, Germany
| | - Anja Böhm
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, University Hospital Tübingen, Tübingen, Germany
| | - Stefan Zoltan Lutz
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, University Hospital Tübingen, Tübingen, Germany
| | - Martin Heni
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, University Hospital Tübingen, Tübingen, Germany
| | - Andreas Fritsche
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, University Hospital Tübingen, Tübingen, Germany
- Department of Internal Medicine, Division of Nutritional and Preventive Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Fritz Schick
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Department of Diagnostic and Interventional Radiology, Section on Experimental Radiology, University Hospital Tübingen, Tübingen, Germany
| | - Alfred Königsrainer
- Department of General, Visceral, and Transplant Surgery, University Hospital Tübingen, Tübingen, Germany
| | - Norbert Stefan
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, University Hospital Tübingen, Tübingen, Germany
| | - Hans-Ulrich Häring
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, University Hospital Tübingen, Tübingen, Germany
| | - Harald Staiger
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, University Hospital Tübingen, Tübingen, Germany
- * E-mail:
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16
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Li D, Su Y, Tu J, Wei R, Fan X, Yin H, Hu Y, Xu H, Yao Y, Yang D, Yang M. Evolutionary conservation of the circadian gene timeout in Metazoa. ANIM BIOL 2016. [DOI: 10.1163/15707563-00002482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Timeless (Tim) is considered to function as an essential circadian clock gene in Drosophila. Putative homologues of the Drosophila timeless gene have been identified in both mice and humans. While Drosophila contains two paralogs, timeless and timeout, acting in clock/light entrainment and chromosome integrity/photoreception, respectively, mammals contain only one Tim homolog. In this paper, we study the phylogeny of the timeless/timeout family in 48 species [including 1 protozoan (Guillardia theta), 1 nematode (Caenorhabditis elegans), 8 arthropods and 38 chordates], for which whole genome data are available by using MEGA (Molecular Evolutionary Genetics Analysis). Phylogenetic Analysis by Maximum Likelihood (PAML) was used to analyze the selective pressure acting on metazoan timeless/timeout genes. Our phylogeny clearly separates insect timeless and timeout lineages and shows that non-insect animal Tim genes are homologs of insect timeout. In this study, we explored the relatively rapidly evolving timeless lineage that was apparently lost from most deuterostomes, including chordates, and from Caenorhabditis elegans. In contrast, we found that the timeout protein, often confusingly called “timeless” in the vertebrate literature, is present throughout the available animal genomes. Selection results showed that timeout is under weaker negative selection than timeless. Finally, our phylogeny of timeless/timeout showed an evolutionary conservation of the circadian clock gene timeout in Metazoa. This conservation is in line with its multifunctionality, being essential for embryonic development and maintenance of chromosome integrity, among others.
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Affiliation(s)
- Diyan Li
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Yuan Su
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Jianbo Tu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Ranlei Wei
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Xiaolan Fan
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Huadong Yin
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Yaodong Hu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Huailiang Xu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Yongfang Yao
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Deying Yang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Mingyao Yang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P. R. China
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17
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Inaguma Y, Ito H, Hara A, Iwamoto I, Matsumoto A, Yamagata T, Tabata H, Nagata KI. Morphological characterization of mammalian Timeless in the mouse brain development. Neurosci Res 2015; 92:21-8. [DOI: 10.1016/j.neures.2014.10.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 10/24/2014] [Accepted: 10/28/2014] [Indexed: 01/14/2023]
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18
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Kojima S, Green CB. Circadian genomics reveal a role for post-transcriptional regulation in mammals. Biochemistry 2015; 54:124-33. [PMID: 25303020 PMCID: PMC4302021 DOI: 10.1021/bi500707c] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 07/21/2014] [Indexed: 12/28/2022]
Abstract
To maintain daily cycles, the circadian clock must tightly regulate the rhythms of thousands of mRNAs and proteins with the correct period, phase, and amplitude to ultimately drive the wide range of rhythmic biological processes. Recent genomic approaches have revolutionized our view of circadian gene expression and highlighted the importance of post-transcriptional regulation in driving mRNA rhythmicity. Even after transcripts are made from DNA, subsequent processing and regulatory steps determine when, where, and how much protein will be generated. These post-transcriptional regulatory mechanisms can add flexibility to overall gene expression and alter protein levels rapidly without requiring transcript synthesis and are therefore beneficial for cells; however, the extent to which circadian post-transcriptional mechanisms contribute to rhythmic profiles throughout the genome and the mechanisms involved have not been fully elucidated. In this review, we will summarize how circadian genomics have revealed new insights into rhythmic post-transcriptional regulation in mammals and discuss potential implications of such regulation in controlling many circadian-driven physiologies.
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Affiliation(s)
- Shihoko Kojima
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9111, United States
| | - Carla B. Green
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9111, United States
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19
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Markova-Car EP, Jurišić D, Ilić N, Kraljević Pavelić S. Running for time: circadian rhythms and melanoma. Tumour Biol 2014; 35:8359-68. [PMID: 24729125 DOI: 10.1007/s13277-014-1904-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 03/27/2014] [Indexed: 12/22/2022] Open
Abstract
Circadian timing system includes an input pathway transmitting environmental signals to a core oscillator that generates circadian signals responsible for the peripheral physiological or behavioural events. Circadian 24-h rhythms regulate diverse physiologic processes. Deregulation of these rhythms is associated with a number of pathogenic conditions including depression, diabetes, metabolic syndrome and cancer. Melanoma is a less common type of skin cancer yet more aggressive often with a lethal ending. However, little is known about circadian control in melanoma and exact functional associations between core clock genes and development of melanoma skin cancer. This paper, therefore, comprehensively analyses current literature data on the involvement of circadian clock components in melanoma development. In particular, the role of circadian rhythm deregulation is discussed in the context of DNA repair mechanisms and influence of UV radiation and artificial light exposure on cancer development. The role of arylalkylamine N-acetyltransferase (AANAT) enzyme and impact of melatonin, as a major output factor of circadian rhythm, and its protective role in melanoma are discussed in details. We hypothesise that further understanding of clock genes' involvement and circadian regulation might foster discoveries in the field of melanoma diagnostics and treatment.
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Affiliation(s)
- Elitza P Markova-Car
- Department of Biotechnology, University of Rijeka, Radmile Matejčić 2, 51000, Rijeka, Croatia,
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20
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Zelinski EL, Deibel SH, McDonald RJ. The trouble with circadian clock dysfunction: multiple deleterious effects on the brain and body. Neurosci Biobehav Rev 2014; 40:80-101. [PMID: 24468109 DOI: 10.1016/j.neubiorev.2014.01.007] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 01/07/2014] [Accepted: 01/16/2014] [Indexed: 02/08/2023]
Abstract
This review consolidates research employing human correlational and experimental work across brain and body with experimental animal models to provide a more complete representation of how circadian rhythms influence almost all aspects of life. In doing so, we will cover the morphological and biochemical pathways responsible for rhythm generation as well as interactions between these systems and others (e.g., stress, feeding, reproduction). The effects of circadian disruption on the health of humans, including time of day effects, cognitive sequelae, dementia, Alzheimer's disease, diet, obesity, food preferences, mood disorders, and cancer will also be discussed. Subsequently, experimental support for these largely correlational human studies conducted in non-human animal models will be described.
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Affiliation(s)
- Erin L Zelinski
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, AB, Canada.
| | - Scott H Deibel
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
| | - Robert J McDonald
- Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
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21
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Pereira DS, Tufik S, Pedrazzoli M. Moléculas que marcam o tempo: implicações para os fenótipos circadianos. BRAZILIAN JOURNAL OF PSYCHIATRY 2009; 31:63-71. [PMID: 19506779 DOI: 10.1590/s1516-44462009000100015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 11/14/2008] [Indexed: 12/12/2022]
Abstract
OBJETIVO: Revisar resumidamente a literatura dos últimos 36 anos de pesquisa em cronobiologia molecular a fim de informar aos profissionais de saúde os avanços obtidos nesta área e os potenciais para aplicação na clínica médica. MÉTODO: Buscas na literatura foram realizadas utilizando as bases de dados PubMed e Scopus usando como palavras-chave "clock genes, circadian rhythms, diurnal preference, delayed sleep phase syndrome, advanced sleep phase syndrome, photoperiod and mood disorder". DISCUSSÃO: Atualmente, o mecanismo molecular da regulação da ritmicidade circadiana é compreendido em grande detalhe. Muitos estudos publicados mostram associações de polimorfismos nos genes relógio com transtornos do ritmo circadiano e com transtornos do humor. CONCLUSÕES: De maneira geral, o progresso obtido na área de cronobiologia molecular traz um melhor entendimento da regulação do sistema de temporização biológico. O desenvolvimento de estudos nesta área tem o potencial de ser aplicável ao tratamento dos transtornos dos ritmos circadianos e certos transtornos do humor, além de prevenir riscos à saúde causados por viagens intercontinentais (Jet Lag) e por trabalhos noturnos e por turnos.
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22
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Kondratov RV, Antoch MP. Circadian proteins in the regulation of cell cycle and genotoxic stress responses. Trends Cell Biol 2007; 17:311-7. [PMID: 17644383 DOI: 10.1016/j.tcb.2007.07.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 05/02/2007] [Accepted: 07/02/2007] [Indexed: 12/31/2022]
Abstract
The mammalian circadian system has been implicated in the regulation of the genotoxic stress response of an organism; however, the underlying molecular mechanisms are not well understood. Recent data suggest that, in addition to circadian variations in the expression of genes involved in genotoxic stress responses, core circadian proteins PERIOD1 (PER1) and TIMELESS (TIM) interact with components of the cell cycle checkpoint system, such as ataxia telangiectasia mutated (ATM)-checkpoint kinase 2 (Chk2) and ataxia telangiectasia and Rad3-related (ATR)-Chk1, and are necessary for activation of Chk1 and Chk2 by DNA damage. Moreover, in complex with its recently identified partner, TIM-interacting protein (TIPIN), TIM interacts with components of the DNA replication system to regulate DNA replication processes under both normal and stress conditions. These discoveries shed new light on the role of core circadian proteins in various cellular and physiological processes.
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Affiliation(s)
- Roman V Kondratov
- Department of Biological, Geological and Environmental Sciences, Cleveland State University, Cleveland, OH 44115, USA
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23
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Ishida N. Circadian clock, cancer and lipid metabolism. Neurosci Res 2007; 57:483-90. [PMID: 17303272 DOI: 10.1016/j.neures.2006.12.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Revised: 12/22/2006] [Accepted: 12/25/2006] [Indexed: 10/23/2022]
Abstract
Genetic analysis has revealed that mammalian circadian oscillator is driven by a cell autonomous transcription/translation-based negative feedback loop, wherein positive elements (CLOCK and BMAL1) induce the expression of negative regulators (Periods, CRY1 and CRY2) that inhibit the transactivation of positive regulators. Recent research reveals that this clock feedback loop affects many aspects of our physiology, such as cell cycle and lipid metabolism. In this review, I summarize the molecular links between the circadian clock mechanism and the cell cycle, and between the clock and lipid metabolism. Recent studies of clock mutants also suggest that clock molecules play a role as stress sensors. Lastly, we propose the importance of sterol for entraining peripheral clocks.
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Affiliation(s)
- Norio Ishida
- Clock Cell Biology, Department of Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology (AIST), 6-5 Tsukuba Center, 1-1 Higashi, Tsukuba 305-8566, Japan.
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Yoshizawa-Sugata N, Masai H. Human Tim/Timeless-interacting Protein, Tipin, Is Required for Efficient Progression of S Phase and DNA Replication Checkpoint. J Biol Chem 2007; 282:2729-40. [PMID: 17102137 DOI: 10.1074/jbc.m605596200] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Tipin was originally isolated as a protein interacting with Timeless/Tim1/Tim (Tim), which is known to be involved in both circadian rhythm and cell cycle checkpoint regulation. The endogenous Tim and Tipin proteins in human cells, interacting through the N-terminal segment of each molecule, form a complex throughout the cell cycle. Tipin and Tim are expressed in the interphase nuclei mostly at constant levels during the cell cycle, and small fractions are recovered in the chromatin-enriched fractions during S phase. Depletion of endogenous Tipin results in reduced growth rate, and this may be due in part to inefficient progression of S phase and DNA synthesis. Knockdown of Tipin induces radioresistant DNA synthesis and inhibits phosphorylation of Chk1 kinase caused by replication stress, as was observed with that of Tim. Knockdown of Tipin or Tim results in reduced protein level and relocation to the cytoplasm of the respective binding partner, suggesting that the complex formation may be required for stabilization and nuclear accumulation of both proteins. Furthermore, both Tipin and Tim may facilitate the accumulation of Claspin in the nuclei under replication stress, whereas nuclear localization of Tipin and Tim is unaffected by Claspin. Our results indicate that mammalian Tipin is a checkpoint mediator that cooperates with Tim and may regulate the nuclear relocation of Claspin in response to replication checkpoint.
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Affiliation(s)
- Naoko Yoshizawa-Sugata
- Genome Dynamics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 113-8613, Japan
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25
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Chou DM, Elledge SJ. Tipin and Timeless form a mutually protective complex required for genotoxic stress resistance and checkpoint function. Proc Natl Acad Sci U S A 2006; 103:18143-7. [PMID: 17116885 PMCID: PMC1654129 DOI: 10.1073/pnas.0609251103] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Tipin is a mammalian protein that interacts with Timeless, which plays a role in DNA damage checkpoint responses. Here, we show that Tipin is a nuclear protein that associates with the replicative helicase and protects cells against genotoxic agents. Tipin is required for efficient cell cycle arrest in response to DNA damage, and depletion of Tipin renders cells sensitive to ionizing radiation as well as replication stress. Loss of Tipin results in spontaneous gamma-H2AX foci, a marker for DNA double-strand breaks. We find that Tipin and Timeless form a complex that maintains the level of both proteins in cells and that the loss of either one will lead to the loss of the interacting partner. This observation explains the similar checkpoint phenotypes observed in both Tipin- and Timeless-depleted cells.
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Affiliation(s)
- Danny M. Chou
- Department of Genetics, Howard Hughes Medical Institute, Center for Genetics and Genomics, Brigham and Women's Hospital, Harvard University Medical School, Boston, MA 02115
| | - Stephen J. Elledge
- Department of Genetics, Howard Hughes Medical Institute, Center for Genetics and Genomics, Brigham and Women's Hospital, Harvard University Medical School, Boston, MA 02115
- *To whom correspondence should be sent at: Department of Genetics,
Center for Genetics and Genomics, Howard Hughes Medical Institute, Room 158D, New Research Building, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115. E-mail:
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Abstract
Mammalian TIMELESS (TIM) was identified due to its sequence similarity to Drosophila TIM, an essential circadian clock protein in flies. Published literature is inconsistent regarding the rhythmic expression of mammalian Tim, the interaction of the TIM protein with other clock proteins and its role in regulating clock gene transcription. Comprehensive sequence analysis not only demonstrates that mammalian TIM is more similar to a second, TIM-like sequence in Drosophila (TIMEOUT), but is also a member of an evolutionarily conserved family of TIM orthologs that is distinct from the circadian-specific TIM proteins found in insects. The vital cellular function of these widely conserved TIM orthologs makes it difficult to determine the specific role of mammalian TIM in the circadian clock mechanism.
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Affiliation(s)
- Anthony L Gotter
- Division of Human Genetics and Molecular Biology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.
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Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that has been intensively studied with respect to the toxicity of xenobiotics. However, its function in response to light has never been summarized. Here, we provide an overview of AhR activation by light with a focus on the role of tryptophan in light-induced AhR activation. We discuss the involvement of the AhR in different biological rhythms and speculate on the possible role of the AhR in UV-induced responses in skin. Furthermore, this review points out future research needs in this field.
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Affiliation(s)
- Agneta Rannug
- Karolinska Institute, Institute of Environmental Medicine, P.O. Box 210, S-171 77 Stockholm, Sweden.
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Sarkar M, Das S, Bandyopadhaya A, Ray K, Chaudhuri K. Upregulation of human mitochondrial NADH dehydrogenase subunit 5 in intestinal epithelial cells is modulated byVibrio choleraepathogenesis. FEBS Lett 2005; 579:3449-60. [PMID: 15946665 DOI: 10.1016/j.febslet.2005.05.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2005] [Revised: 03/14/2005] [Accepted: 04/25/2005] [Indexed: 11/20/2022]
Abstract
Cholera still remains an important global predicament especially in India and other developing countries. Vibrio cholerae, the etiologic agent of cholera, colonizes the small intestine and produces an enterotoxin that is largely responsible for the watery diarrheal symptoms of the disease. Using RNA arbitrarily primed PCR, ND5 a mitochondria encoded subunit of complex I of the mitochondrial respiratory chain was found to be upregulated in the human intestinal epithelial cell line Int407 following exposure to V. cholerae. The upregulation of ND5 was not observed when Int407 was infected with Escherichia coli strains. Incubation with heat-killed V. cholerae or cholera toxin or culture supernatant also showed no such upregulation indicating the involvement of live bacteria in the process. Infection of the monolayer with aflagellate non-motile mutant of V. cholerae O395 showed a very significant (59-fold) downregulation of ND5. In contrast, a remarkable upregulation of ND5 expression (200-fold) was observed in a hyperadherent icmF insertion mutant with reduced motility. V. cholerae cheY4 null mutant defective in adherence and motility also resulted in significantly reduced levels of ND5 expression while mutant with the cheY4 gene duplicated showing increased adherence and motility resulted in increased expression of ND5. These results clearly indicate that both motility and adherence to intestinal epithelial cells are possible triggering factors contributing to ND5 mRNA expression by V. cholerae. Interestingly infection with insertion mutant in the gene coding for ToxR, the master regulator of virulence in V. cholerae resulted in significant downregulation of ND5 expression. However, infection with ctxA or toxT insertion mutants did not show any significant changes in ND5 expression compared to wild-type. Almost no expression of ND5 was observed in case of mutation in the gene coding for OmpU, a ToxR activated protein. Thus, infection of Int407 with virulence mutant strains of V. cholerae revealed that the ND5 expression is modulated by the virulence of V. cholerae in a ToxT independent manner. Although no difference in the mitochondrial copy number could be detected between infected and uninfected cells, the modulation of the expression of other mitochondrial genes were also observed. Incidentally, upon V. cholerae infection, complex I activity was found to increase about 3-folds after 6 h. This is the first report of alteration in mitochondrial gene expression upon infection of a non-invasive enteric bacterium like V. cholerae showing its modulation with adherence, motility and virulence of the organism.
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Affiliation(s)
- Madhubanti Sarkar
- Human Genetics & Genomics Group, Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Jadavpur, Kolkata-700 032, India
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29
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Unsal-Kaçmaz K, Mullen TE, Kaufmann WK, Sancar A. Coupling of human circadian and cell cycles by the timeless protein. Mol Cell Biol 2005; 25:3109-16. [PMID: 15798197 PMCID: PMC1069621 DOI: 10.1128/mcb.25.8.3109-3116.2005] [Citation(s) in RCA: 228] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Timeless protein is essential for circadian rhythm in Drosophila. The Timeless orthologue in mice is essential for viability and appears to be required for the maintenance of a robust circadian rhythm as well. We have found that the human Timeless protein interacts with both the circadian clock protein cryptochrome 2 and with the cell cycle checkpoint proteins Chk1 and the ATR-ATRIP complex and plays an important role in the DNA damage checkpoint response. Down-regulation of Timeless in human cells seriously compromises replication and intra-S checkpoints, indicating an intimate connection between the circadian cycle and the DNA damage checkpoints that is in part mediated by the Timeless protein.
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Affiliation(s)
- Keziban Unsal-Kaçmaz
- Department of Biochemistry and Biophysics, Mary Ellen Jones Building CB 7260, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
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30
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Abstract
The circadian oscillator is composed of transcriptional feedback loops in organisms ranging from cyanobacteria to humans. These transcriptional feedback loops are so named because transcriptional regulators accumulate to high levels and then feed back to control their own genes' transcription, thus generating a self-sustaining rhythm in gene expression. In insects and vertebrates, the genes that encode these feedback regulators are remarkably well conserved and function to control not 1 but 2 feedback loops. These feedback loops control rhythmic transcription in opposite phases of the circadian cycle, yet they are interlocked because they share a number of components. In this review, the author will compare transcriptional regulatory mechanisms within the Drosophila and mammalian feedback loops and outline remaining questions concerning transcriptional regulation within and downstream of these feedback loops.
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Affiliation(s)
- Paul E Hardin
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5001, USA.
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31
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Lowrey PL, Takahashi JS. Mammalian circadian biology: elucidating genome-wide levels of temporal organization. Annu Rev Genomics Hum Genet 2004; 5:407-41. [PMID: 15485355 PMCID: PMC3770722 DOI: 10.1146/annurev.genom.5.061903.175925] [Citation(s) in RCA: 694] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
During the past decade, the molecular mechanisms underlying the mammalian circadian clock have been defined. A core set of circadian clock genes common to most cells throughout the body code for proteins that feed back to regulate not only their own expression, but also that of clock output genes and pathways throughout the genome. The circadian system represents a complex multioscillatory temporal network in which an ensemble of coupled neurons comprising the principal circadian pacemaker in the suprachiasmatic nucleus of the hypothalamus is entrained to the daily light/dark cycle and subsequently transmits synchronizing signals to local circadian oscillators in peripheral tissues. Only recently has the importance of this system to the regulation of such fundamental biological processes as the cell cycle and metabolism become apparent. A convergence of data from microarray studies, quantitative trait locus analysis, and mutagenesis screens demonstrates the pervasiveness of circadian regulation in biological systems. The importance of maintaining the internal temporal homeostasis conferred by the circadian system is revealed by animal models in which mutations in genes coding for core components of the clock result in disease, including cancer and disturbances to the sleep/wake cycle.
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32
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Barnes JW, Tischkau SA, Barnes JA, Mitchell JW, Burgoon PW, Hickok JR, Gillette MU. Requirement of mammalian Timeless for circadian rhythmicity. Science 2003; 302:439-42. [PMID: 14564007 DOI: 10.1126/science.1086593] [Citation(s) in RCA: 152] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Despite a central circadian role in Drosophila for the transcriptional regulator Timeless (dTim), the relevance of mammalian Timeless (mTim) remains equivocal. Conditional knockdown of mTim protein expression in the rat suprachiasmatic nucleus (SCN) disrupted SCN neuronal activity rhythms, and altered levels of known core clock elements. Full-length mTim protein (mTIM-fl) exhibited a 24-hour oscillation, where as a truncated isoform (mTIM-s) was constitutively expressed. mTIM-fl associated with the mammalian clock Period proteins (mPERs) in oscillating SCN cells. These data suggest that mTim is required for rhythmicity and is a functional homolog of dTim on the negative-feedback arm of the mammalian molecular clockwork.
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Affiliation(s)
- Jessica W Barnes
- Department of Cell and Structural Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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33
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Abstract
The Clock gene, timeless, regulates circadian rhythm in Drosophila, but its vertebrate homolog is critical to embryonic development. Timeless was shown to be involved in murine urethral bud branching morphogenesis. We generated a polyclonal antibody to mouse TIMELESS (mTIM) and studied its distribution and its potential role during lung development, which also requires branching morphogenesis. In the early mouse embryo, TIM was localized to all organs, especially the neural epithelium. In embryonic day (E) 9.5 embryos, TIM was present in both epithelial and mesenchymal cells at the onset of lung morphogenesis. In E15 embryos, TIM decreased in the mesenchyme but remained pronounced in the epithelium of both large and small airways. Later, TIM was localized to a specific subset of epithelial cells with alveolar type 2 phenotype. This finding was verified by immunostaining of isolated alveolar type 2 cells. In the proximal airways, TIM was colocalized with CCSP to nonciliated columnar epithelial cells. Antisense oligonucleotides to mTim specifically inhibited branching morphogenesis of embryonic lungs in explant culture without affecting SpC expression an alveolar type 2 cell marker. In cultured lung cells, expression of TIM is independent of cell cycle and proliferation. These studies indicate that the function of Timeless is highly conserved in organs whose formation requires branching morphogenesis.
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Affiliation(s)
- Jing Xiao
- School of Medicine, University of Southern California, Los Angeles, California 90033, USA
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34
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Gotter AL. Tipin, a novel timeless-interacting protein, is developmentally co-expressed with timeless and disrupts its self-association. J Mol Biol 2003; 331:167-76. [PMID: 12875843 DOI: 10.1016/s0022-2836(03)00633-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The mouse Timeless gene (mTim) was identified originally on the basis of its similarity to a Drosophila circadian gene, but has no substantiated role in the circadian clock mechanism. The importance of mTim in cellular processes involved in development, however, is undeniable, since targeted mutagenesis of this gene arrests embryonic development. To connect mTim to known pathways controlling cellular processes important for early development, a yeast two-hybrid approach was used to identify embryonic mTIM-interacting proteins. One positive interactor, a previously uncharacterized protein that is here termed TIPIN (TIMELESS interacting protein), was shown to interact with mTIM in vitro and in cultured cells. mTim and Tipin transcripts are co-expressed in similar tissues during embryonic development and in the adult brain. In transiently transfected cultures, mTIM promotes the nuclear localization of TIPIN. Immunoprecipitation experiments suggest that TIPIN is capable of regulating mTIM activity by disrupting the ability of mTIM to form homo-multimeric complexes. Together, these results indicate that mTIM forms a functional complex with TIPIN, and provide a starting point from which to link mTim to biochemical pathways controlling vital cellular functions.
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Affiliation(s)
- Anthony L Gotter
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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35
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Hendricks JC. Invited review: Sleeping flies don't lie: the use of Drosophila melanogaster to study sleep and circadian rhythms. J Appl Physiol (1985) 2003; 94:1660-72; discussion 1673. [PMID: 12626480 DOI: 10.1152/japplphysiol.00904.2002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During the past century, flies thoroughly proved their value as an animal model for the study of the genetics of development and basic cell processes. During the past three decades, they have also been extensively used to study the genetics of behavior. For both circadian rhythms and for sleep, flies are helping us to understand the genetic mechanisms that underlie these complex behaviors. Since 1971, discoveries in the fly have led the way to a number of significant discoveries, establishing a mechanistic framework that is now known to be conserved in the mammalian clock. The highlights of this history are described. For sleep, the use of the fly as a model is relatively new, that is, only within the past 2 yr. Nonetheless, studies have already established that two transcription factors alter rest and rest homeostasis. The implications of these advances for the future of sleep research are summarized.
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Affiliation(s)
- Joan C Hendricks
- Center for Sleep and Respiratory Neurobiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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36
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Turek FW, Kolker DE. The discovery of circadian clock genes and the use of similar strategies to discover unknown genes underlying complex behaviors and brain disorders. Eur Neuropsychopharmacol 2001; 11:475-82. [PMID: 11704424 DOI: 10.1016/s0924-977x(01)00124-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Over just the past few years, tremendous progress has been made in unraveling the molecular basis of the circadian clock in mammals. This success has been primarily due to an approach whereby mutations are induced randomly in the germ line and the offspring of the mutagenized animals are tested for abnormal circadian phenotype. Circadian clock genes have been discovered this way in both fruit flies and mice and it is now clear that most, if not all clock genes show homology between flies and mammals, including humans. This 'forward genetics' approach is a powerful tool for uncovering genes which underline complex behaviors and brain disorders. Even when a complex neural function involves many, many genes, mutating just one of these genes can have pronounced effects on the expressed behavior and can lead to the discovery of other genes, and their protein products, that interact directly or indirectly with the mutated gene.
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Affiliation(s)
- F W Turek
- Center for Sleep and Circadian Biology, Northwestern University, 2153 N. Campus Drive, Evanston, IL 60208-3520, USA.
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37
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Desautels A, Turecki G, Montplaisir J, Sequeira A, Verner A, Rouleau GA. Identification of a major susceptibility locus for restless legs syndrome on chromosome 12q. Am J Hum Genet 2001; 69:1266-70. [PMID: 11704926 PMCID: PMC1235538 DOI: 10.1086/324649] [Citation(s) in RCA: 207] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2001] [Accepted: 09/27/2001] [Indexed: 11/04/2022] Open
Abstract
Restless legs syndrome (RLS) is a neurological disorder characterized by leg paresthesia associated with an irresistible urge to move that often interferes with nocturnal sleep, leading to chronic sleep deprivation. To map genes that may play a role in the vulnerability to RLS, a genomewide scan was conducted in a large French-Canadian family. Significant linkage was established on chromosome 12q, for a series of adjacent microsatellite markers with a maximum two-point LOD score of 3.42 (recombination fraction.05; P=6x10(-4); autosomal recessive mode of inheritance), whereas multipoint linkage calculations yielded a LOD score of 3.59. Haplotype analysis refined the genetic interval, positioning the RLS-predisposing gene in a 14.71-cM region between D12S1044 and D12S78. These findings represent the first mapping of a locus conferring susceptibility to RLS.
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Affiliation(s)
- Alex Desautels
- Centre d'étude du sommeil, Hôpital du Sacré-Cœur de Montréal and Centre de recherche en sciences neurologiques, Université de Montréal, Research Center, Douglas Hospital, and Montreal Genome Centre and Centre for Research in Neurosciences, The Montreal General Hospital, McGill University, Montréal
| | - Gustavo Turecki
- Centre d'étude du sommeil, Hôpital du Sacré-Cœur de Montréal and Centre de recherche en sciences neurologiques, Université de Montréal, Research Center, Douglas Hospital, and Montreal Genome Centre and Centre for Research in Neurosciences, The Montreal General Hospital, McGill University, Montréal
| | - Jacques Montplaisir
- Centre d'étude du sommeil, Hôpital du Sacré-Cœur de Montréal and Centre de recherche en sciences neurologiques, Université de Montréal, Research Center, Douglas Hospital, and Montreal Genome Centre and Centre for Research in Neurosciences, The Montreal General Hospital, McGill University, Montréal
| | - Adolfo Sequeira
- Centre d'étude du sommeil, Hôpital du Sacré-Cœur de Montréal and Centre de recherche en sciences neurologiques, Université de Montréal, Research Center, Douglas Hospital, and Montreal Genome Centre and Centre for Research in Neurosciences, The Montreal General Hospital, McGill University, Montréal
| | - Andrei Verner
- Centre d'étude du sommeil, Hôpital du Sacré-Cœur de Montréal and Centre de recherche en sciences neurologiques, Université de Montréal, Research Center, Douglas Hospital, and Montreal Genome Centre and Centre for Research in Neurosciences, The Montreal General Hospital, McGill University, Montréal
| | - Guy A. Rouleau
- Centre d'étude du sommeil, Hôpital du Sacré-Cœur de Montréal and Centre de recherche en sciences neurologiques, Université de Montréal, Research Center, Douglas Hospital, and Montreal Genome Centre and Centre for Research in Neurosciences, The Montreal General Hospital, McGill University, Montréal
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38
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Allada R, Emery P, Takahashi JS, Rosbash M. Stopping time: the genetics of fly and mouse circadian clocks. Annu Rev Neurosci 2001; 24:1091-119. [PMID: 11520929 DOI: 10.1146/annurev.neuro.24.1.1091] [Citation(s) in RCA: 254] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Forward genetic analyses in flies and mice have uncovered conserved transcriptional feedback loops at the heart of circadian pacemakers. Conserved mechanisms of posttranslational regulation, most notably phosphorylation, appear to be important for timing feedback. Transcript analyses have indicated that circadian clocks are not restricted to neurons but are found in several tissues. Comparisons between flies and mice highlight important differences in molecular circuitry and circadian organization. Future studies of pacemaker mechanisms and their control of physiology and behavior will likely continue to rely on forward genetics.
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Affiliation(s)
- R Allada
- Department of Neurobiology, Evanston, IL 60208, USA.
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39
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Abstract
The circadian clock is a widespread cellular mechanism that underlies diverse rhythmic functions in organisms from bacteria and fungi, to plants and animals. Intense genetic analysis during recent years has uncovered many of the components and molecular mechanisms comprising these clocks. Although autoregulatory genetic networks are a consistent feature in the design of all clocks, the weight of evidence favours their independent evolutionary origins in different kingdoms.
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Affiliation(s)
- M W Young
- Laboratory of Genetics, The Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.
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40
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Abstract
In mammals, a master circadian "clock" resides in the suprachiasmatic nuclei (SCN) of the anterior hypothalamus. The SCN clock is composed of multiple, single-cell circadian oscillators, which, when synchronized, generate coordinated circadian outputs that regulate overt rhythms. Eight clock genes have been cloned that are involved in interacting transcriptional-/translational-feedback loops that compose the molecular clockwork. The daily light-dark cycle ultimately impinges on the control of two clock genes that reset the core clock mechanism in the SCN. Clock-controlled genes are also generated by the central clock mechanism, but their protein products transduce downstream effects. Peripheral oscillators are controlled by the SCN and provide local control of overt rhythm expression. Greater understanding of the cellular and molecular mechanisms of the SCN clockwork provides opportunities for pharmacological manipulation of circadian timing.
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Affiliation(s)
- S M Reppert
- Laboratory of Developmental Chronobiology, Mass General Hospital for Children, and Harvard Medical School, Boston, Massachusetts 02114, USA.
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41
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Wang Y, Osterbur DL, Megaw PL, Tosini G, Fukuhara C, Green CB, Besharse JC. Rhythmic expression of Nocturnin mRNA in multiple tissues of the mouse. BMC DEVELOPMENTAL BIOLOGY 2001; 1:9. [PMID: 11394964 PMCID: PMC32249 DOI: 10.1186/1471-213x-1-9] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2001] [Accepted: 05/25/2001] [Indexed: 11/10/2022]
Abstract
BACKGROUND Nocturnin was originally identified by differential display as a circadian clock regulated gene with high expression at night in photoreceptors of the African clawed frog, Xenopus laevis. Although encoding a novel protein, the nocturnin cDNA had strong sequence similarity with a C-terminal domain of the yeast transcription factor CCR4, and with mouse and human ESTs. Since its original identification others have cloned mouse and human homologues of nocturnin/CCR4, and we have cloned a full-length cDNA from mouse retina, along with partial cDNAs from human, cow and chicken. The goal of this study was to determine the temporal pattern of nocturnin mRNA expression in multiple tissues of the mouse. RESULTS cDNA sequence analysis revealed a high degree of conservation among vertebrate nocturnin/CCR4 homologues along with a possible homologue in Drosophila. Northern analysis of mRNA in C3H/He and C57/Bl6 mice revealed that the mNoc gene is expressed in a broad range of tissues, with greatest abundance in liver, kidney and testis. mNoc is also expressed in multiple brain regions including suprachiasmatic nucleus and pineal gland. Furthermore, mNoc exhibits circadian rhythmicity of mRNA abundance with peak levels at the time of light offset in the retina, spleen, heart, kidney and liver. CONCLUSION The widespread expression and rhythmicity of mNoc mRNA parallels the widespread expression of other circadian clock genes in mammalian tissues, and suggests that nocturnin plays an important role in clock function or as a circadian clock effector.
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Affiliation(s)
- Yunxia Wang
- PEL-FREEZ Clinical Systems, LLC, 9099 North Deerbrook Trail, Brown Deer, WI, 53223, USA
| | - David L Osterbur
- Biological Laboratories Library, Harvard University, 16 Divinity Ave, Cambridge, MA 02138, USA
| | - Pamela L Megaw
- School of Human and Biomedical Sciences, Division of Science and Design, University of Canberra, ACT 2601, Australia
| | - Gianluca Tosini
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, USA
| | - Chiaki Fukuhara
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, USA
| | - Carla B Green
- Department of Biology and NSF Center for Biological Timing, University of Virginia, Charlottesville, USA
| | - Joseph C Besharse
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, USA
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42
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Leloup JC, Goldbeter A. A molecular explanation for the long-term suppression of circadian rhythms by a single light pulse. Am J Physiol Regul Integr Comp Physiol 2001; 280:R1206-12. [PMID: 11247846 DOI: 10.1152/ajpregu.2001.280.4.r1206] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
With the use of a molecular model for circadian rhythms in Drosophila based on transcriptional regulation, we show how a single, critical pulse of light can permanently suppress circadian rhythmicity, whereas a second light pulse can restore the abolished rhythm. The phenomena occur via the pulsatile induction of either protein degradation or gene expression in conditions in which a stable steady state coexists with stable circadian oscillations of the limit cycle type. The model indicates that suppression by a light pulse can only be accounted for by assuming that the biochemical effects of such a pulse much outlast its actual duration. We determine the characteristics of critical pulses suppressing the oscillations as a function of the phase at which the rhythm is perturbed. The model predicts how the amplitude and duration of the biochemical changes induced by critical pulses vary with this phase. The results provide a molecular, dynamic explanation for the long-term suppression of circadian rhythms observed in a variety of organisms in response to a single light pulse and for the subsequent restoration of the rhythms by a second light pulse.
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Affiliation(s)
- J C Leloup
- Unité de Chronobiologie théorique, Faculté des Sciences, Université Libre de Bruxelles, Campus Plaine, C.P. 231, B-1050 Brussels, Belgium
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43
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Lowrey PL, Takahashi JS. Genetics of the mammalian circadian system: Photic entrainment, circadian pacemaker mechanisms, and posttranslational regulation. Annu Rev Genet 2001; 34:533-562. [PMID: 11092838 DOI: 10.1146/annurev.genet.34.1.533] [Citation(s) in RCA: 214] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
During the past four years, significant progress has been made in identifying the molecular components of the mammalian circadian clock system. An autoregulatory transcriptional feedback loop similar to that described in Drosophila appears to form the core circadian rhythm generating mechanism in mammals. Two basic helix-loop-helix (bHLH) PAS (PER-ARNT-SIM) transcription factors, CLOCK and BMAL1, form the positive elements of the system and drive transcription of three Period and two Cryptochrome genes. The protein products of these genes are components of a negative feedback complex that inhibits CLOCK and BMAL1 to close the circadian loop. In this review, we focus on three aspects of the circadian story in mammals: the genetics of the photic entrainment pathway; the molecular components of the circadian pacemaker in the hypothalamic suprachiasmatic nucleus; and the role of posttranslational regulation of circadian elements. A molecular description of the mammalian circadian system has revealed that circadian oscillations may be a fundamental property of many cells in the body and that a circadian hierarchy underlies the temporal organization of animals.
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Affiliation(s)
- P L Lowrey
- Howard Hughes Medical Institute, Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois 60208, USA.
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44
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Sakamoto S, Miyazaki K, Fukui H, Oishi K, Hayasaka N, Okada M, Kamakura M, Taniguchi T, Nagai K, Ishida N. Molecular characterization and nuclear localization of rat timeless-like gene product. Biochem Biophys Res Commun 2000; 279:131-8. [PMID: 11112428 DOI: 10.1006/bbrc.2000.3927] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Among three period genes (per1, per2, per3) in mammals, only per2 gene was shown to be involved in the core clock mechanism. To elucidate the molecular function of rat PERIOD2 (rPER2), we searched for binding proteins to the PAS domain of rPER2. We isolated a binding protein to this domain and identified it as a TIMELESS-like protein (TLP) on the basis of mass analyses. Then, we isolated a rat TLP cDNA from the rat hypothalamus library. RNA blot analysis and in situ hybridization indicates that rTLP mRNA was expressed in all rat tissues from whole brain, the suprachiasmatic nucleus, eye, lung, heart, liver, kidney, placenta, and testis. When rTLP gene product was expressed in COS-1 cells, nuclear localization of rTLP was detected in 99.6% of transfected cells. These results suggest that the interaction of rPER2 with rTLP may influence the regulation of circadian clock components in nucleus after rPER2 is translocated into the nucleus.
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Affiliation(s)
- S Sakamoto
- Laboratory of Molecular Biology, Medical Research Center, Kochi Medical School, Okoh, Nankoku, Kochi 783-8505, Japan
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45
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Zhuang M, Wang Y, Steenhard BM, Besharse JC. Differential regulation of two period genes in the Xenopus eye. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2000; 82:52-64. [PMID: 11042357 DOI: 10.1016/s0169-328x(00)00177-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The recent identification and analysis of mammalian homologues of the well characterized Drosophila circadian clock gene, Period (Per), has led to the idea that key features of vertebrate circadian rhythmicity are conserved at the molecular level. The Xenopus laevis retina contains a circadian clock mechanism that can be studied in vitro. To study the rhythmic expression of Per in the Xenopus retina, we used a degenerate RT-PCR strategy to obtain cDNA clones covering the entire 1427 amino acid coding region of a Xenopus homologue of Per2 and a partial cDNA sequence for a Xenopus homologue of Per1. Northern blot analysis shows that xPer1 and xPer2 transcripts are expressed most abundantly in the eye and the brain. However, rhythmic expression of xPer2 transcripts in the retina and retinal pigment epithelium (RPE) is light dependent and occurs only under 12 h light/12 h dark (LD) conditions, not in constant dark (DD). In contrast, xPer1 mRNA accumulation is rhythmic under both LD and DD conditions. Light dependent regulation of xPer2 mRNA and circadian regulation of xPer1 mRNA in the Xenopus retina differs from that in Drosophila and mammals. Light dependence of xPer2 mRNA levels and the offset phase relationship of the xPer2 rhythm to that for xPer1 suggests a role for xPer2 in circadian entrainment.
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Affiliation(s)
- M Zhuang
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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46
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Affiliation(s)
- S M Reppert
- Laboratory of Developmental Chronobiology, Massachusetts General Hospital, and Harvard Medical School, Boston 02114 USA
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47
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Abstract
Recent gene discovery approaches have led to a new era in our understanding of the molecular basis of circadian oscillators in animals. A conserved set of genes in Drosophila and mammals (Clock, Bmal1, Period, and Timeless) provide a molecular framework for the circadian mechanism. These genes define a transcription-translation-based negative autoregulatory feedback loop that comprises the core elements generating circadian rhythmicity. This circadian core provides a focal point for understanding how circadian rhythms arise, how environmental inputs entrain the oscillatory system, and how the circadian system regulates its outputs. The addition of molecular genetic approaches to the existing physiological understanding of the mammalian circadian system provides new opportunities for understanding this basic life process.
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Affiliation(s)
- D P King
- Howard Hughes Medical Institute, Northwestern University, Evanston, Illinois 60208, USA.
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Li Z, Stuart RO, Qiao J, Pavlova A, Bush KT, Pohl M, Sakurai H, Nigam SK. A role for Timeless in epithelial morphogenesis during kidney development. Proc Natl Acad Sci U S A 2000; 97:10038-43. [PMID: 10963667 PMCID: PMC27664 DOI: 10.1073/pnas.97.18.10038] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2000] [Accepted: 06/26/2000] [Indexed: 12/22/2022] Open
Abstract
Central to the process of epithelial organogenesis is branching morphogenesis into tubules and ducts. In the kidney, this can be modeled by a very simple system consisting of isolated ureteric bud (UB) cells, which undergo branching morphogenesis in response to soluble factors present in the conditioned medium of a metanephric mesenchyme cell line. By employing a targeted screen to identify transcription factors involved early in the morphogenetic program leading to UB branching, we identified the mammalian ortholog of Timeless (mTim) as a potential immediate early gene (IEG) important in this process. In the embryo, mTim was found to be expressed in patterns very suggestive of a role in epithelial organogenesis with high levels of expression in the developing lung, liver, and kidney, as well as neuroepithelium. In the embryonic kidney, the expression of mTim was maximal in regions of active UB branching, and a shift from the large isoform of mTim to a smaller isoform occurred as the kidney developed. Selective down-regulation of mTim resulted in profound inhibition of embryonic kidney growth and UB morphogenesis in organ culture. A direct effect on the branching UB was supported by the observation that down-regulation of mTim in the isolated UB (cultured in the absence of mesenchyme) resulted in marked inhibition of morphogenesis, suggesting a key role for Tim in the epithelial cell morphogenetic pathway leading to the formation of branching tubules.
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Affiliation(s)
- Z Li
- Departments of Pediatrics and Medicine, Division of Nephrology and Hypertension, University of California at San Diego, La Jolla, CA 92093-0693, USA
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Abstract
Living organisms on this planet have adapted to the daily rotation of the earth on its axis. By means of endogenous circadian clocks that can be synchronized to the daily and seasonal changes in external time cues, most notably light and temperature, life forms anticipate environmental transitions, perform activities at biologically advantageous times during the day, and undergo characteristic seasonal responses. The effects of transmeridian flight and shift work are stark reminders that although modern technologies can create "cities that never sleep" we cannot escape the recalcitrance of endogenous clocks that regulate much of our physiology and behavior. Moreover, malfunctions in the human circadian timing system are implicated in several disorders, including chronic sleep disorders in the elderly, manic-depression, and seasonal affective disorders (SAD or winter depression). Recent progress in understanding the molecular mechanisms underlying circadian rhythms has been remarkable. In its most basic form, circadian clocks are comprised of a set of proteins that, by virtue of the design principles involved, generate a self-sustaining transcriptional-translational feedback loop with a free-running period of about 24 h. One or more of the clock components is acutely sensitive to light, resulting in an oscillator that can be synchronized to local time. This review provides an overview of the roles circadian clocks play in nature, how they might have arisen, human health concerns related to clock dysfunction, and mainly focuses on the clockworks found in Drosophila and mice, the two best studied animal model systems for understanding the biochemical and cellular bases of circadian rhythms.
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Affiliation(s)
- I Edery
- Department of Molecular Biology and Biochemistry, Rutgers University, Center for Advanced Biotechnology and Medicine, Piscataway, New Jersey 08854, USA.
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50
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Gotter AL, Manganaro T, Weaver DR, Kolakowski LF, Possidente B, Sriram S, MacLaughlin DT, Reppert SM. A time-less function for mouse timeless. Nat Neurosci 2000; 3:755-6. [PMID: 10903565 DOI: 10.1038/77653] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The timeless (tim) gene is essential for circadian clock function in Drosophila melanogaster. A putative mouse homolog, mTimeless (mTim), has been difficult to place in the circadian clock of mammals. Here we show that mTim is essential for embryonic development, but does not have substantiated circadian function.
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Affiliation(s)
- A L Gotter
- Laboratory of Developmental Chronobiology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
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