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Malik DM, Rhoades SD, Kain P, Sengupta A, Sehgal A, Weljie AM. Altered Metabolism during the Dark Period in Drosophila Short Sleep Mutants. J Proteome Res 2024. [PMID: 38836855 DOI: 10.1021/acs.jproteome.4c00106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Sleep is regulated via circadian mechanisms, but effects of sleep disruption on physiological rhythms, in particular metabolic cycling, remain unclear. To examine this question, we probed diurnal metabolic alterations of two Drosophila short sleep mutants, fumin and sleepless. Samples were collected with high temporal sampling (every 2 h) over 24 h under a 12:12 light:dark cycle, and profiling was done using an ion-switching LCMS/MS method. Fewer metabolites with 24 h oscillations were noted with short sleep (50 and 46 in fumin and sleepless, BH. Q < 0.2 by RAIN analysis) compared to a wild-type control (iso31, 63 with BH. Q < 0.2), and peak phases of the sleep mutants were consolidated into two major phase peaks at mid-day and middle of night. Overall, altered nicotinate/nicotinamide, alanine/aspartate/glutamate, acetylcholine, glyoxylate/dicarboxylate, and TCA cycle metabolism were observed in the short sleep mutants, indicative of increased energetic demand and oxidative stress compared to wild type. Both changes in cycling and discriminant models suggest unique alterations in the dark period indicative of constrained metabolic networks. Thus, we conclude that sleep loss alters metabolic function uniquely throughout the day, and further examination of specific mechanisms is warranted.
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Affiliation(s)
- Dania M Malik
- Pharmacology Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Seth D Rhoades
- Pharmacology Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Fulgens Consulting, LLC, Cambridge, Massachusetts 02142, United States
| | - Pinky Kain
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Arjun Sengupta
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Amita Sehgal
- Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Howard Hughes Medical Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Aalim M Weljie
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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2
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Yuan Y, Chen Q, Brovkina M, Clowney EJ, Yadlapalli S. Clock-dependent chromatin accessibility rhythms regulate circadian transcription. PLoS Genet 2024; 20:e1011278. [PMID: 38805552 PMCID: PMC11161047 DOI: 10.1371/journal.pgen.1011278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 06/07/2024] [Accepted: 04/29/2024] [Indexed: 05/30/2024] Open
Abstract
Chromatin organization plays a crucial role in gene regulation by controlling the accessibility of DNA to transcription machinery. While significant progress has been made in understanding the regulatory role of clock proteins in circadian rhythms, how chromatin organization affects circadian rhythms remains poorly understood. Here, we employed ATAC-seq (Assay for Transposase-Accessible Chromatin with Sequencing) on FAC-sorted Drosophila clock neurons to assess genome-wide chromatin accessibility at dawn and dusk over the circadian cycle. We observed significant oscillations in chromatin accessibility at promoter and enhancer regions of hundreds of genes, with enhanced accessibility either at dusk or dawn, which correlated with their peak transcriptional activity. Notably, genes with enhanced accessibility at dusk were enriched with E-box motifs, while those more accessible at dawn were enriched with VRI/PDP1-box motifs, indicating that they are regulated by the core circadian feedback loops, PER/CLK and VRI/PDP1, respectively. Further, we observed a complete loss of chromatin accessibility rhythms in per01 null mutants, with chromatin consistently accessible at both dawn and dusk, underscoring the critical role of Period protein in driving chromatin compaction during the repression phase at dawn. Together, this study demonstrates the significant role of chromatin organization in circadian regulation, revealing how the interplay between clock proteins and chromatin structure orchestrates the precise timing of biological processes throughout the day. This work further implies that variations in chromatin accessibility might play a central role in the generation of diverse circadian gene expression patterns in clock neurons.
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Affiliation(s)
- Ye Yuan
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Qianqian Chen
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Margarita Brovkina
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, United States of America
| | - E Josephine Clowney
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
- Michigan Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Swathi Yadlapalli
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
- Michigan Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, United States of America
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3
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Akpoghiran O, Afonso DJS, Zhang Y, Koh K. TARANIS Interacts with VRILLE and PDP1 to Modulate the Circadian Transcriptional Feedback Mechanism in Drosophila. J Neurosci 2024; 44:e0922232023. [PMID: 38296648 PMCID: PMC10860567 DOI: 10.1523/jneurosci.0922-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 11/18/2023] [Accepted: 11/22/2023] [Indexed: 02/02/2024] Open
Abstract
The molecular clock that generates daily rhythms of behavior and physiology consists of interlocked transcription-translation feedback loops. In Drosophila, the primary feedback loop involving the CLOCK-CYCLE transcriptional activators and the PERIOD-TIMELESS transcriptional repressors is interlocked with a secondary loop involving VRILLE (VRI) and PAR DOMAIN PROTEIN 1 (PDP1), a repressor and activator of Clock transcription, respectively. Whereas extensive studies have found numerous transcriptional, translational, and posttranslational modulators of the primary loop, relatively little is known about the secondary loop. In this study, using male and female flies as well as cultured cells, we demonstrate that TARANIS (TARA), a Drosophila homolog of the TRIP-Br/SERTAD family of transcriptional coregulators, functions with VRI and PDP1 to modulate the circadian period and rhythm strength. Knocking down tara reduces rhythm amplitude and can shorten the period length, while overexpressing TARA lengthens the circadian period. Additionally, tara mutants exhibit reduced rhythmicity and lower expression of the PDF neuropeptide. We find that TARA can form a physical complex with VRI and PDP1, enhancing their repressor and activator functions, respectively. The conserved SERTA domain of TARA is required to regulate the transcriptional activity of VRI and PDP1, and its deletion leads to reduced locomotor rhythmicity. Consistent with TARA's role in enhancing VRI and PDP1 activity, overexpressing tara has a similar effect on the circadian period and rhythm strength as simultaneously overexpressing vri and Pdp1 Together, our results suggest that TARA modulates circadian behavior by enhancing the transcriptional activity of VRI and PDP1.
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Affiliation(s)
- Oghenerukevwe Akpoghiran
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia 19107, Pennsylvania
| | - Dinis J S Afonso
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia 19107, Pennsylvania
| | - Yanan Zhang
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia 19107, Pennsylvania
| | - Kyunghee Koh
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia 19107, Pennsylvania
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4
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Akpoghiran O, Afonso DJ, Zhang Y, Koh K. TARANIS interacts with VRILLE and PDP1 to modulate the circadian transcriptional feedback mechanism in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.19.541420. [PMID: 38076905 PMCID: PMC10705542 DOI: 10.1101/2023.05.19.541420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
The molecular clock that generates daily rhythms of behavior and physiology consists of interlocked transcription-translation feedback loops. In Drosophila, the primary feedback loop involving the CLOCK-CYCLE transcriptional activators and the PERIOD-TIMELESS transcriptional repressors is interlocked with a secondary loop involving VRILLE (VRI) and PAR DOMAIN PROTEIN 1 (PDP1), a repressor and activator of Clock transcription, respectively. Whereas extensive studies have found numerous transcriptional, translational, and post-translational modulators of the primary loop, relatively little is known about the secondary loop. In this study, using male and female flies as well as cultured cells, we demonstrate that TARANIS (TARA), a Drosophila homolog of the TRIP-Br/SERTAD family of transcriptional coregulators, functions with VRI and PDP1 to modulate the circadian period and rhythm strength. Knocking down tara reduces rhythm amplitude and can shorten the period length, while overexpressing TARA lengthens the circadian period. Additionally, tara mutants exhibit reduced rhythmicity and lower expression of the PDF neuropeptide. We find that TARA can form a physical complex with VRI and PDP1, enhancing their repressor and activator functions, respectively. The conserved SERTA domain of TARA is required to regulate the transcriptional activity of VRI and PDP1, and its deletion leads to reduced locomotor rhythmicity. Consistent with TARA's role in enhancing VRI and PDP1 activity, overexpressing tara has a similar effect on the circadian period and rhythm strength as simultaneously overexpressing vri and Pdp1. Together, our results suggest that TARA modulates circadian behavior by enhancing the transcriptional activity of VRI and PDP1.
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Affiliation(s)
- Oghenerukevwe Akpoghiran
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, USA. 19107
| | - Dinis J.S. Afonso
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, USA. 19107
| | - Yanan Zhang
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, USA. 19107
| | - Kyunghee Koh
- Department of Neuroscience, the Farber Institute for Neurosciences, and Synaptic Biology Center, Thomas Jefferson University, Philadelphia, USA. 19107
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5
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Malik DM, Sengupta A, Sehgal A, Weljie AM. Altered Metabolism During the Dark Period in Drosophila Short Sleep Mutants. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.30.564858. [PMID: 37961245 PMCID: PMC10634958 DOI: 10.1101/2023.10.30.564858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Sleep is an almost universally required state in biology. Disrupted sleep has been associated with adverse health risks including metabolic perturbations. Sleep is in part regulated via circadian mechanisms, however, metabolic dysfunction at different times of day arising from sleep disruption is unclear. We used targeted liquid chromatography-mass spectrometry to probe metabolic alterations using high-resolution temporal sampling of two Drosophila short sleep mutants, fumin and sleepless, across a circadian day. Discriminant analyses revealed overall distinct metabolic profiles for mutants when compared to a wild type dataset. Altered levels of metabolites involved in nicotinate/nicotinamide, alanine, aspartate, and glutamate, glyoxylate and dicarboxylate metabolism, and the TCA cycle were observed in mutants suggesting increased energetic demands. Furthermore, rhythmicity analyses revealed fewer 24 hr rhythmic metabolites in both mutants. Interestingly, mutants displayed two major peaks in phases while wild type displayed phases that were less concerted. In contrast to 24 hr rhythmic metabolites, an increase in the number of 12 hr rhythmic metabolites was observed in fumin while sleepless displayed a decrease. These results support that decreased sleep alters the overall metabolic profile with short sleep mutants displaying altered metabolite levels associated with a number of pathways in addition to altered neurotransmitter levels.
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Affiliation(s)
- Dania M. Malik
- Pharmacology Graduate Group
- Department of Systems Pharmacology and Translational Therapeutics
- Institute for Translational Medicine and Therapeutics
| | - Arjun Sengupta
- Department of Systems Pharmacology and Translational Therapeutics
- Institute for Translational Medicine and Therapeutics
| | - Amita Sehgal
- Chronobiology and Sleep Institute
- Howard Hughes Medical Institute
| | - Aalim M. Weljie
- Department of Systems Pharmacology and Translational Therapeutics
- Institute for Translational Medicine and Therapeutics
- Chronobiology and Sleep Institute
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Zhou J, He L, Liu M, Guo X, Du G, Yan L, Zhang Z, Zhong Z, Chen H. Sleep loss impairs intestinal stem cell function and gut homeostasis through the modulation of the GABA signalling pathway in Drosophila. Cell Prolif 2023; 56:e13437. [PMID: 36869584 PMCID: PMC10472530 DOI: 10.1111/cpr.13437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 02/08/2023] [Accepted: 02/17/2023] [Indexed: 03/05/2023] Open
Abstract
Sleep is essential for maintaining health. Indeed, sleep loss is closely associated with multiple health problems, including gastrointestinal disorders. However, it is not yet clear whether sleep loss affects the function of intestinal stem cells (ISCs). Mechanical sleep deprivation and sss mutant flies were used to generate the sleep loss model. qRT-PCR was used to measure the relative mRNA expression. Gene knock-in flies were used to observe protein localization and expression patterns. Immunofluorescence staining was used to determine the intestinal phenotype. The shift in gut microbiota was observed using 16S rRNA sequencing and analysis. Sleep loss caused by mechanical sleep deprivation and sss mutants disturbs ISC proliferation and intestinal epithelial repair through the brain-gut axis. In addition, disruption of SSS causes gut microbiota dysbiosis in Drosophila. As regards the mechanism, gut microbiota and the GABA signalling pathway both partially played a role in the sss regulation of ISC proliferation and gut function. The research shows that sleep loss disturbed ISC proliferation, gut microbiota, and gut function. Therefore, our results offer a stem cell perspective on brain-gut communication, with details on the effect of the environment on ISCs.
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Affiliation(s)
- Juanyu Zhou
- Department of Neurology, National Clinical Research Center for Geriatrics, West China HospitalSichuan UniversityChengduSichuanChina
- Laboratory of Metabolism and Aging Research, National Clinical Research Center for Geriatrics, West China HospitalSichuan UniversityChengduSichuanChina
| | - Li He
- Department of Neurology, National Clinical Research Center for Geriatrics, West China HospitalSichuan UniversityChengduSichuanChina
| | - Mengyou Liu
- Laboratory of Metabolism and Aging Research, National Clinical Research Center for Geriatrics, West China HospitalSichuan UniversityChengduSichuanChina
| | - Xiaoxin Guo
- Laboratory of Metabolism and Aging Research, National Clinical Research Center for Geriatrics, West China HospitalSichuan UniversityChengduSichuanChina
| | - Gang Du
- Laboratory of Metabolism and Aging Research, National Clinical Research Center for Geriatrics, West China HospitalSichuan UniversityChengduSichuanChina
| | - La Yan
- Laboratory of Metabolism and Aging Research, National Clinical Research Center for Geriatrics, West China HospitalSichuan UniversityChengduSichuanChina
| | - Zehong Zhang
- Laboratory of Metabolism and Aging Research, National Clinical Research Center for Geriatrics, West China HospitalSichuan UniversityChengduSichuanChina
| | - Zhendong Zhong
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Haiyang Chen
- Department of Neurology, National Clinical Research Center for Geriatrics, West China HospitalSichuan UniversityChengduSichuanChina
- Laboratory of Metabolism and Aging Research, National Clinical Research Center for Geriatrics, West China HospitalSichuan UniversityChengduSichuanChina
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7
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Yuan Y, Chen Q, Brovkina M, Clowney EJ, Yadlapalli S. Clock-dependent chromatin accessibility rhythms regulate circadian transcription. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.15.553315. [PMID: 37645872 PMCID: PMC10462003 DOI: 10.1101/2023.08.15.553315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Chromatin organization plays a crucial role in gene regulation by controlling the accessibility of DNA to transcription machinery. While significant progress has been made in understanding the regulatory role of clock proteins in circadian rhythms, how chromatin organization affects circadian rhythms remains poorly understood. Here, we employed ATAC-seq (Assay for Transposase-Accessible Chromatin with Sequencing) on FAC-sorted Drosophila clock neurons to assess genome-wide chromatin accessibility over the circadian cycle. We observed significant circadian oscillations in chromatin accessibility at promoter and enhancer regions of hundreds of genes, with enhanced accessibility either at dusk or dawn, which correlated with their peak transcriptional activity. Notably, genes with enhanced accessibility at dusk were enriched with E-box motifs, while those more accessible at dawn were enriched with VRI/PDP1-box motifs, indicating that they are regulated by the core circadian feedback loops, PER/CLK and VRI/PDP1, respectively. Further, we observed a complete loss of chromatin accessibility rhythms in per01 null mutants, with chromatin consistently accessible throughout the circadian cycle, underscoring the critical role of Period protein in driving chromatin compaction during the repression phase. Together, this study demonstrates the significant role of chromatin organization in circadian regulation, revealing how the interplay between clock proteins and chromatin structure orchestrates the precise timing of biological processes throughout the day. This work further implies that variations in chromatin accessibility might play a central role in the generation of diverse circadian gene expression patterns in clock neurons.
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Affiliation(s)
- Ye Yuan
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Qianqian Chen
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Margarita Brovkina
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - E Josephine Clowney
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
- Michigan Neuroscience Institute Affiliate, University of Michigan, Ann Arbor, MI 48109, USA
| | - Swathi Yadlapalli
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
- Michigan Neuroscience Institute Affiliate, University of Michigan, Ann Arbor, MI 48109, USA
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Li K, Tsukasa Y, Kurio M, Maeta K, Tsumadori A, Baba S, Nishimura R, Murakami A, Onodera K, Morimoto T, Uemura T, Usui T. Belly roll, a GPI-anchored Ly6 protein, regulates Drosophila melanogaster escape behaviors by modulating the excitability of nociceptive peptidergic interneurons. eLife 2023; 12:83856. [PMID: 37309249 DOI: 10.7554/elife.83856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 05/13/2023] [Indexed: 06/14/2023] Open
Abstract
Appropriate modulation of escape behaviors in response to potentially damaging stimuli is essential for survival. Although nociceptive circuitry has been studied, it is poorly understood how genetic contexts affect relevant escape responses. Using an unbiased genome-wide association analysis, we identified an Ly6/α-neurotoxin family protein, Belly roll (Bero), which negatively regulates Drosophila nociceptive escape behavior. We show that Bero is expressed in abdominal leucokinin-producing neurons (ABLK neurons) and bero knockdown in ABLK neurons resulted in enhanced escape behavior. Furthermore, we demonstrated that ABLK neurons responded to activation of nociceptors and initiated the behavior. Notably, bero knockdown reduced persistent neuronal activity and increased evoked nociceptive responses in ABLK neurons. Our findings reveal that Bero modulates an escape response by regulating distinct neuronal activities in ABLK neurons.
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Affiliation(s)
- Kai Li
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Yuma Tsukasa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Misato Kurio
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Kaho Maeta
- Faculty of Agriculture, Kyoto University, Kyoto, Japan
| | | | - Shumpei Baba
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Risa Nishimura
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | | | - Koun Onodera
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Takako Morimoto
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Kyoto, Japan
| | - Tadashi Uemura
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Research Center for Dynamic Living Systems, Kyoto University, Kyoto, Japan
| | - Tadao Usui
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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9
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ACh Transfers: Homeostatic Plasticity of Cholinergic Synapses. Cell Mol Neurobiol 2023; 43:697-709. [PMID: 35643882 DOI: 10.1007/s10571-022-01227-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/25/2022] [Indexed: 11/03/2022]
Abstract
The field of homeostatic plasticity continues to advance rapidly, highlighting the importance of stabilizing neuronal activity within functional limits in the context of numerous fundamental processes such as development, learning, and memory. Most homeostatic plasticity studies have been focused on glutamatergic synapses, while the rules that govern homeostatic regulation of other synapse types are less understood. While cholinergic synapses have emerged as a critical component in the etiology of mammalian neurodegenerative disease mechanisms, relatively few studies have been conducted on the homeostatic plasticity of such synapses, particularly in the mammalian nervous system. An exploration of homeostatic mechanisms at the cholinergic synapse may illuminate potential therapeutic targets for disease management and treatment. We will review cholinergic homeostatic plasticity in the mammalian neuromuscular junction, the autonomic nervous system, central synapses, and in relation to pathological conditions including Alzheimer disease and DYT1 dystonia. This work provides a historical context for the field of cholinergic homeostatic regulation by examining common themes, unique features, and outstanding questions associated with these distinct cholinergic synapse types and aims to inform future research in the field.
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10
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Palermo J, Chesi A, Zimmerman A, Sonti S, Pahl MC, Lasconi C, Brown EB, Pippin JA, Wells AD, Doldur-Balli F, Mazzotti DR, Pack AI, Gehrman PR, Grant SF, Keene AC. Variant-to-gene mapping followed by cross-species genetic screening identifies GPI-anchor biosynthesis as a regulator of sleep. SCIENCE ADVANCES 2023; 9:eabq0844. [PMID: 36608130 PMCID: PMC9821868 DOI: 10.1126/sciadv.abq0844] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 12/05/2022] [Indexed: 05/13/2023]
Abstract
Genome-wide association studies (GWAS) in humans have identified loci robustly associated with several heritable diseases or traits, yet little is known about the functional roles of the underlying causal variants in regulating sleep duration or quality. We applied an ATAC-seq/promoter focused Capture C strategy in human iPSC-derived neural progenitors to carry out a "variant-to-gene" mapping campaign that identified 88 candidate sleep effector genes connected to relevant GWAS signals. To functionally validate the role of the implicated effector genes in sleep regulation, we performed a neuron-specific RNA interference screen in the fruit fly, Drosophila melanogaster, followed by validation in zebrafish. This approach identified a number of genes that regulate sleep including a critical role for glycosylphosphatidylinositol (GPI)-anchor biosynthesis. These results provide the first physical variant-to-gene mapping of human sleep genes followed by a model organism-based prioritization, revealing a conserved role for GPI-anchor biosynthesis in sleep regulation.
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Affiliation(s)
- Justin Palermo
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - Alessandra Chesi
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Amber Zimmerman
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA 19104, USA
| | - Shilpa Sonti
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Matthew C. Pahl
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Chiara Lasconi
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Elizabeth B. Brown
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - James A. Pippin
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Andrew D. Wells
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA 19104, USA
| | - Fusun Doldur-Balli
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA 19104, USA
| | - Diego R. Mazzotti
- Division of Medical Informatics, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66103, USA
- Division of Pulmonary Critical Care and Sleep Medicine, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66103, USA
| | - Allan I. Pack
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA 19104, USA
| | - Phillip R. Gehrman
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA 19104, USA
| | - Struan F.A. Grant
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Divisions of Human Genetics and Endocrinology and Diabetes, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alex C. Keene
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
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11
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GluR2Q and GluR2R AMPA Subunits are not Targets of lypd2 Interaction. PLoS One 2022; 17:e0278278. [PMID: 36441793 PMCID: PMC9704558 DOI: 10.1371/journal.pone.0278278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 11/12/2022] [Indexed: 11/30/2022] Open
Abstract
A large family of prototoxin-like molecules endogenous to mammals, Ly6 proteins have been implicated in the regulation of cell signaling processes across multiple species. Previous work has shown that certain members of the Ly6 family are expressed in the brain and target nicotinic acetylcholine receptor and potassium channel function. Structural similarities between Ly6 proteins and alpha-neurotoxins suggest the possibility of additional ionotropic receptor targets. Here, we investigated the possibility of lypd2 as a novel regulator of AMPA receptor (AMPAR) function. In particular, we focused on potential interactions with the Q/R isoforms of the GluR2 subunit, which have profound impacts on AMPAR permeability to calcium during neuronal stimulation. We find that although lypd2 and GluR2 share overlapping expression patterns in the mouse hippocampus, there was no interaction between lypd2 and either GluR2Q or GluR2R isoform. These results underscore the importance of continuing to investigate novel targets for Ly6 interaction and regulation.
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12
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Feng M, Swevers L, Sun J. Hemocyte Clusters Defined by scRNA-Seq in Bombyx mori: In Silico Analysis of Predicted Marker Genes and Implications for Potential Functional Roles. Front Immunol 2022; 13:852702. [PMID: 35281044 PMCID: PMC8914287 DOI: 10.3389/fimmu.2022.852702] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/07/2022] [Indexed: 12/16/2022] Open
Abstract
Within the hemolymph, insect hemocytes constitute a heterogeneous population of macrophage-like cells that play important roles in innate immunity, homeostasis and development. Classification of hemocytes in different subtypes by size, morphology and biochemical or immunological markers has been difficult and only in Drosophila extensive genetic analysis allowed the construction of a coherent picture of hemocyte differentiation from pro-hemocytes to granulocytes, crystal cells and plasmatocytes. However, the advent of high-throughput single cell technologies, such as single cell RNA sequencing (scRNA-seq), is bound to have a high impact on the study of hemocytes subtypes and their phenotypes in other insects for which a sophisticated genetic toolbox is not available. Instead of averaging gene expression across all cells as occurs in bulk-RNA-seq, scRNA-seq allows high-throughput and specific visualization of the differentiation status of individual cells. With scRNA-seq, interesting cell types can be identified in heterogeneous populations and direct analysis of rare cell types is possible. Next to its ability to profile the transcriptomes of individual cells in tissue samples, scRNA-seq can be used to propose marker genes that are characteristic of different hemocyte subtypes and predict their functions. In this perspective, the identities of the different marker genes that were identified by scRNA-seq analysis to define 13 distinct cell clusters of hemocytes in larvae of the silkworm, Bombyx mori, are discussed in detail. The analysis confirms the broad division of hemocytes in granulocytes, plasmatocytes, oenocytoids and perhaps spherulocytes but also reveals considerable complexity at the molecular level and highly specialized functions. In addition, predicted hemocyte marker genes in Bombyx generally show only limited convergence with the genes that are considered characteristic for hemocyte subtypes in Drosophila.
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Affiliation(s)
- Min Feng
- Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", Aghia Paraskevi, Athens, Greece
| | - Jingchen Sun
- Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
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13
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Vallejos MJ, Eadaim A, Hahm ET, Tsunoda S. Age-related changes in Kv4/Shal and Kv1/Shaker expression in Drosophila and a role for reactive oxygen species. PLoS One 2021; 16:e0261087. [PMID: 34932577 PMCID: PMC8691634 DOI: 10.1371/journal.pone.0261087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/23/2021] [Indexed: 11/19/2022] Open
Abstract
Age-related changes in ion channel expression are likely to affect neuronal signaling. Here, we examine how age affects Kv4/Shal and Kv1/Shaker K+ channel protein levels in Drosophila. We show that Kv4/Shal protein levels decline sharply from 3 days to 10 days, then more gradually from 10 to 40 days after eclosion. In contrast, Kv1/Shaker protein exhibits a transient increase at 10 days that then stabilizes and eventually declines at 40 days. We present data that begin to show a relationship between reactive oxygen species (ROS), Kv4/Shal, and locomotor performance. We show that Kv4/Shal levels are negatively affected by ROS, and that over-expression of Catalase or RNAi knock-down of the ROS-generating enzyme, Nicotinamide Adenine Dinucleotide Phosphate (NADPH) Oxidase (NOX), can attenuate the loss of Kv4/Shal protein. Finally, we compare levels of Kv4.2 and Kv4.3 in the hippocampus, olfactory bulb, cerebellum, and motor cortex of mice aged 6 weeks and 1 year. While there was no global decline in Kv4.2/4.3 that parallels what we report in Drosophila, we did find that Kv4.2/4.3 are differentially affected in various brain regions; this survey of changes may help inform mammalian studies that examine neuronal function with age.
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Affiliation(s)
- Maximiliano J. Vallejos
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Abdunaser Eadaim
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Eu-Teum Hahm
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Susan Tsunoda
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail:
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14
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Vaccaro A, Kaplan Dor Y, Nambara K, Pollina EA, Lin C, Greenberg ME, Rogulja D. Sleep Loss Can Cause Death through Accumulation of Reactive Oxygen Species in the Gut. Cell 2020; 181:1307-1328.e15. [PMID: 32502393 DOI: 10.1016/j.cell.2020.04.049] [Citation(s) in RCA: 219] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 01/15/2020] [Accepted: 04/24/2020] [Indexed: 02/06/2023]
Abstract
The view that sleep is essential for survival is supported by the ubiquity of this behavior, the apparent existence of sleep-like states in the earliest animals, and the fact that severe sleep loss can be lethal. The cause of this lethality is unknown. Here we show, using flies and mice, that sleep deprivation leads to accumulation of reactive oxygen species (ROS) and consequent oxidative stress, specifically in the gut. ROS are not just correlates of sleep deprivation but drivers of death: their neutralization prevents oxidative stress and allows flies to have a normal lifespan with little to no sleep. The rescue can be achieved with oral antioxidant compounds or with gut-targeted transgenic expression of antioxidant enzymes. We conclude that death upon severe sleep restriction can be caused by oxidative stress, that the gut is central in this process, and that survival without sleep is possible when ROS accumulation is prevented. VIDEO ABSTRACT.
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Affiliation(s)
- Alexandra Vaccaro
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Yosef Kaplan Dor
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Keishi Nambara
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Cindy Lin
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Dragana Rogulja
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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15
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Kim JH, Ki Y, Lee H, Hur MS, Baik B, Hur JH, Nam D, Lim C. The voltage-gated potassium channel Shaker promotes sleep via thermosensitive GABA transmission. Commun Biol 2020; 3:174. [PMID: 32296133 PMCID: PMC7160125 DOI: 10.1038/s42003-020-0902-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 03/20/2020] [Indexed: 02/07/2023] Open
Abstract
Genes and neural circuits coordinately regulate animal sleep. However, it remains elusive how these endogenous factors shape sleep upon environmental changes. Here, we demonstrate that Shaker (Sh)-expressing GABAergic neurons projecting onto dorsal fan-shaped body (dFSB) regulate temperature-adaptive sleep behaviors in Drosophila. Loss of Sh function suppressed sleep at low temperature whereas light and high temperature cooperatively gated Sh effects on sleep. Sh depletion in GABAergic neurons partially phenocopied Sh mutants. Furthermore, the ionotropic GABA receptor, Resistant to dieldrin (Rdl), in dFSB neurons acted downstream of Sh and antagonized its sleep-promoting effects. In fact, Rdl inhibited the intracellular cAMP signaling of constitutively active dopaminergic synapses onto dFSB at low temperature. High temperature silenced GABAergic synapses onto dFSB, thereby potentiating the wake-promoting dopamine transmission. We propose that temperature-dependent switching between these two synaptic transmission modalities may adaptively tune the neural property of dFSB neurons to temperature shifts and reorganize sleep architecture for animal fitness. Ji-hyung Kim and Yoonhee Ki et al. show that low temperatures suppress sleep in Drosophila by increasing GABA transmission in Shaker-expressing GABAergic neurons projecting onto the dorsal fan-shaped body, while high temperatures potentiate dopamine-induced arousal by reducing GABA transmission. This study highlights a role for Shaker in sleep modulation via a temperature-dependent switch in GABA signaling.
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Affiliation(s)
- Ji-Hyung Kim
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Yoonhee Ki
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Hoyeon Lee
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Moon Seong Hur
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Bukyung Baik
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Jin-Hoe Hur
- UNIST Optical Biomed Imaging Center, UNIST, Ulsan, 44919, Republic of Korea
| | - Dougu Nam
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Chunghun Lim
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
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16
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Abstract
Sleep is a ubiquitous and complex behavior in both its manifestation and regulation. Despite its essential role in maintaining optimal performance, health, and well-being, the genetic mechanisms underlying sleep remain poorly understood. Here, we review the forward genetic approaches undertaken in the last four years to elucidate the genes and gene pathways affecting sleep and its regulation. Despite an increasing number of studies and mining large databases, a coherent picture on “sleep” genes has yet to emerge. We highlight the results achieved by using unbiased genetic screens mainly in humans, mice, and fruit flies with an emphasis on normal sleep and make reference to lessons learned from the circadian field.
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Affiliation(s)
- Maxime Jan
- Centre for Integrative Genomics, University of Lausanne, Lausanne, 1015, Switzerland
| | - Bruce F O'Hara
- Department of Biology, University of Kentucky, Lexington, 40515, USA
| | - Paul Franken
- Centre for Integrative Genomics, University of Lausanne, Lausanne, 1015, Switzerland
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17
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Hill VM, O’Connor RM, Shirasu-Hiza M. Tired and stressed: Examining the need for sleep. Eur J Neurosci 2020; 51:494-508. [PMID: 30295966 PMCID: PMC6453762 DOI: 10.1111/ejn.14197] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 09/04/2018] [Accepted: 09/18/2018] [Indexed: 12/31/2022]
Abstract
A key feature of circadian rhythms is the sleep/wake cycle. Sleep causes reduced responsiveness to the environment, which puts animals in a particularly vulnerable state; yet sleep has been conserved throughout evolution, indicating that it fulfils a vital purpose. A core function of sleep across species has not been identified, but substantial advances in sleep research have been made in recent years using the genetically tractable model organism, Drosophila melanogaster. This review describes the universality of sleep, the regulation of sleep, and current theories on the function of sleep, highlighting a historical and often overlooked theory called the Free Radical Flux Theory of Sleep. Additionally, we summarize our recent work with short-sleeping Drosophila mutants and other genetic and pharmacological tools for manipulating sleep which supports an antioxidant theory of sleep and demonstrates a bi-directional relationship between sleep and oxidative stress.
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Affiliation(s)
- Vanessa M. Hill
- Department of Genetics and Development; Columbia University Medical Center; NY, NY, 10032; USA
| | - Reed M. O’Connor
- Department of Genetics and Development; Columbia University Medical Center; NY, NY, 10032; USA
| | - Mimi Shirasu-Hiza
- Department of Genetics and Development; Columbia University Medical Center; NY, NY, 10032; USA
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18
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FUNATO H. Forward genetic approach for behavioral neuroscience using animal models. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2020; 96:10-31. [PMID: 31932526 PMCID: PMC6974404 DOI: 10.2183/pjab.96.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
Forward genetics is a powerful approach to understand the molecular basis of animal behaviors. Fruit flies were the first animal to which this genetic approach was applied systematically and have provided major discoveries on behaviors including sexual, learning, circadian, and sleep-like behaviors. The development of different classes of model organism such as nematodes, zebrafish, and mice has enabled genetic research to be conducted using more-suitable organisms. The unprecedented success of forward genetic approaches was the identification of the transcription-translation negative feedback loop composed of clock genes as a fundamental and conserved mechanism of circadian rhythm. This approach has now expanded to sleep/wakefulness in mice. A conventional strategy such as dominant and recessive screenings can be modified with advances in DNA sequencing and genome editing technologies.
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Affiliation(s)
- Hiromasa FUNATO
- Department of Anatomy, Faculty of Medicine, Toho University, Tokyo, Japan
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Ibaraki, Japan
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19
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Toda H, Williams JA, Gulledge M, Sehgal A. A sleep-inducing gene, nemuri, links sleep and immune function in Drosophila. Science 2019; 363:509-515. [PMID: 30705188 PMCID: PMC6505470 DOI: 10.1126/science.aat1650] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 06/29/2018] [Accepted: 11/26/2018] [Indexed: 12/19/2022]
Abstract
Sleep remains a major mystery of biology. In particular, little is known about the mechanisms that account for the drive to sleep. In an unbiased screen of more than 12,000 Drosophila lines, we identified a single gene, nemuri, that induces sleep. The NEMURI protein is an antimicrobial peptide that can be secreted ectopically to drive prolonged sleep (with resistance to arousal) and to promote survival after infection. Loss of nemuri increased arousability during daily sleep and attenuated the acute increase in sleep induced by sleep deprivation or bacterial infection. Conditions that increase sleep drive induced expression of nemuri in a small number of fly brain neurons and targeted it to the sleep-promoting, dorsal fan-shaped body. We propose that NEMURI is a bona fide sleep homeostasis factor that is particularly important under conditions of high sleep need; because these conditions include sickness, our findings provide a link between sleep and immune function.
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Affiliation(s)
| | | | - Michael Gulledge
- Howard Hughes Medical Institute, Chronobiology Program, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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20
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Leth JM, Leth-Espensen KZ, Kristensen KK, Kumari A, Lund Winther AM, Young SG, Ploug M. Evolution and Medical Significance of LU Domain-Containing Proteins. Int J Mol Sci 2019; 20:ijms20112760. [PMID: 31195646 PMCID: PMC6600238 DOI: 10.3390/ijms20112760] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/31/2019] [Accepted: 06/04/2019] [Indexed: 12/13/2022] Open
Abstract
Proteins containing Ly6/uPAR (LU) domains exhibit very diverse biological functions and have broad taxonomic distributions in eukaryotes. In general, they adopt a characteristic three-fingered folding topology with three long loops projecting from a disulfide-rich globular core. The majority of the members of this protein domain family contain only a single LU domain, which can be secreted, glycolipid anchored, or constitute the extracellular ligand binding domain of type-I membrane proteins. Nonetheless, a few proteins contain multiple LU domains, for example, the urokinase receptor uPAR, C4.4A, and Haldisin. In the current review, we will discuss evolutionary aspects of this protein domain family with special emphasis on variations in their consensus disulfide bond patterns. Furthermore, we will present selected cases where missense mutations in LU domain-containing proteins leads to dysfunctional proteins that are causally linked to genesis of human disease.
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Affiliation(s)
- Julie Maja Leth
- Finsen Laboratory, Ole Maaloes Vej 5, Righospitalet, DK-2200 Copenhagen, Denmark.
- Biotechnology Research Innovation Centre (BRIC), Ole Maaloes Vej 5, University of Copenhagen, DK-2200 Copenhagen, Denmark.
| | - Katrine Zinck Leth-Espensen
- Finsen Laboratory, Ole Maaloes Vej 5, Righospitalet, DK-2200 Copenhagen, Denmark.
- Biotechnology Research Innovation Centre (BRIC), Ole Maaloes Vej 5, University of Copenhagen, DK-2200 Copenhagen, Denmark.
| | - Kristian Kølby Kristensen
- Finsen Laboratory, Ole Maaloes Vej 5, Righospitalet, DK-2200 Copenhagen, Denmark.
- Biotechnology Research Innovation Centre (BRIC), Ole Maaloes Vej 5, University of Copenhagen, DK-2200 Copenhagen, Denmark.
| | - Anni Kumari
- Finsen Laboratory, Ole Maaloes Vej 5, Righospitalet, DK-2200 Copenhagen, Denmark.
- Biotechnology Research Innovation Centre (BRIC), Ole Maaloes Vej 5, University of Copenhagen, DK-2200 Copenhagen, Denmark.
| | - Anne-Marie Lund Winther
- Finsen Laboratory, Ole Maaloes Vej 5, Righospitalet, DK-2200 Copenhagen, Denmark.
- Biotechnology Research Innovation Centre (BRIC), Ole Maaloes Vej 5, University of Copenhagen, DK-2200 Copenhagen, Denmark.
| | - Stephen G Young
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
- Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Michael Ploug
- Finsen Laboratory, Ole Maaloes Vej 5, Righospitalet, DK-2200 Copenhagen, Denmark.
- Biotechnology Research Innovation Centre (BRIC), Ole Maaloes Vej 5, University of Copenhagen, DK-2200 Copenhagen, Denmark.
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21
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Toda H, Shi M, Williams JA, Sehgal A. Genetic Mechanisms Underlying Sleep. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2019; 83:57-61. [PMID: 30936393 DOI: 10.1101/sqb.2018.83.037705] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sleep is important for cognitive ability, and perturbations of sleep are associated with a myriad of brain disorders. However, how sleep promotes health and function during wake is poorly understood. To address the cellular and molecular mechanisms underlying sleep, we use the fruit fly Drosophila melanogaster as a genetic model. Forward genetic approaches in flies were critical for deciphering molecular mechanisms of the circadian clock. Using similar approaches, we and others are gaining insights into the pathways that control sleep amount.
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Affiliation(s)
- Hirofumi Toda
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Mi Shi
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Julie A Williams
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Amita Sehgal
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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22
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Bringmann H. Genetic sleep deprivation: using sleep mutants to study sleep functions. EMBO Rep 2019; 20:embr.201846807. [PMID: 30804011 PMCID: PMC6399599 DOI: 10.15252/embr.201846807] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 11/14/2018] [Accepted: 11/23/2018] [Indexed: 01/08/2023] Open
Abstract
Sleep is a fundamental conserved physiological state in animals and humans. It may serve multiple functions, ranging from energy conservation to higher brain operation. Understanding sleep functions and the underlying mechanisms requires the study of sleeplessness and its consequences. The traditional approach to remove sleep is sleep deprivation (SD) by sensory stimulation. However, stimulation-induced SD can be stressful and can cause non-specific side effects. An emerging alternative method is "genetic SD", which removes sleep using genetics or optogenetics. Sleep requires sleep-active neurons and their regulators. Thus, genetic impairment of sleep circuits might lead to more specific and comprehensive sleep loss. Here, I discuss the advantages and limits of genetic SD in key genetic sleep model animals: rodents, zebrafish, fruit flies and roundworms, and how the study of genetic SD alters our view of sleep functions. Genetic SD typically causes less severe phenotypes compared with stimulation-induced SD, suggesting that sensory stimulation-induced SD may have overestimated the role of sleep, calling for a re-investigation of sleep functions.
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Affiliation(s)
- Henrik Bringmann
- Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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23
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Abstract
The functions of sleep remain a mystery. Yet they must be important since sleep is highly conserved, and its chronic disruption is associated with various metabolic, psychiatric, and neurodegenerative disorders. This review will cover our evolving understanding of the mechanisms by which sleep is controlled and the complex relationship between sleep and disease states.
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Affiliation(s)
- William J Joiner
- Department of Pharmacology, Biomedical Sciences Graduate Program, Neurosciences Graduate Program, and Center for Circadian Biology, University of California San Diego , La Jolla, California
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24
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Baudouin-Gonzalez L, Santos MA, Tempesta C, Sucena É, Roch F, Tanaka K. Diverse Cis-Regulatory Mechanisms Contribute to Expression Evolution of Tandem Gene Duplicates. Mol Biol Evol 2018; 34:3132-3147. [PMID: 28961967 PMCID: PMC5850857 DOI: 10.1093/molbev/msx237] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Pairs of duplicated genes generally display a combination of conserved expression patterns inherited from their unduplicated ancestor and newly acquired domains. However, how the cis-regulatory architecture of duplicated loci evolves to produce these expression patterns is poorly understood. We have directly examined the gene-regulatory evolution of two tandem duplicates, the Drosophila Ly6 genes CG9336 and CG9338, which arose at the base of the drosophilids between 40 and 60 Ma. Comparing the expression patterns of the two paralogs in four Drosophila species with that of the unduplicated ortholog in the tephritid Ceratitis capitata, we show that they diverged from each other as well as from the unduplicated ortholog. Moreover, the expression divergence appears to have occurred close to the duplication event and also more recently in a lineage-specific manner. The comparison of the tissue-specific cis-regulatory modules (CRMs) controlling the paralog expression in the four Drosophila species indicates that diverse cis-regulatory mechanisms, including the novel tissue-specific enhancers, differential inactivation, and enhancer sharing, contributed to the expression evolution. Our analysis also reveals a surprisingly variable cis-regulatory architecture, in which the CRMs driving conserved expression domains change in number, location, and specificity. Altogether, this study provides a detailed historical account that uncovers a highly dynamic picture of how the paralog expression patterns and their underlying cis-regulatory landscape evolve. We argue that our findings will encourage studying cis-regulatory evolution at the whole-locus level to understand how interactions between enhancers and other regulatory levels shape the evolution of gene expression.
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Affiliation(s)
- Luís Baudouin-Gonzalez
- Instituto Gulbenkian de Ciência, Oeiras, Portugal.,Centre de Biologie du Développement, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | | | - Camille Tempesta
- Centre de Biologie du Développement, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - Élio Sucena
- Instituto Gulbenkian de Ciência, Oeiras, Portugal.,Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Fernando Roch
- Centre de Biologie du Développement, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
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25
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Ly S, Pack AI, Naidoo N. The neurobiological basis of sleep: Insights from Drosophila. Neurosci Biobehav Rev 2018; 87:67-86. [PMID: 29391183 PMCID: PMC5845852 DOI: 10.1016/j.neubiorev.2018.01.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/22/2018] [Accepted: 01/24/2018] [Indexed: 12/12/2022]
Abstract
Sleep is a biological enigma that has raised numerous questions about the inner workings of the brain. The fundamental question of why our nervous systems have evolved to require sleep remains a topic of ongoing scientific deliberation. This question is largely being addressed by research using animal models of sleep. Drosophila melanogaster, also known as the common fruit fly, exhibits a sleep state that shares common features with many other species. Drosophila sleep studies have unearthed an immense wealth of knowledge about the neuroscience of sleep. Given the breadth of findings published on Drosophila sleep, it is important to consider how all of this information might come together to generate a more holistic understanding of sleep. This review provides a comprehensive summary of the neurobiology of Drosophila sleep and explores the broader insights and implications of how sleep is regulated across species and why it is necessary for the brain.
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Affiliation(s)
- Sarah Ly
- Center for Sleep and Circadian Neurobiology, 125 South 31st St., Philadelphia, PA, 19104-3403, United States.
| | - Allan I Pack
- Center for Sleep and Circadian Neurobiology, 125 South 31st St., Philadelphia, PA, 19104-3403, United States; Division of Sleep Medicine/Department of Medicine, University of Pennsylvania Perelman School of Medicine, 125 South 31st St., Philadelphia, PA, 19104-3403, United States
| | - Nirinjini Naidoo
- Center for Sleep and Circadian Neurobiology, 125 South 31st St., Philadelphia, PA, 19104-3403, United States; Division of Sleep Medicine/Department of Medicine, University of Pennsylvania Perelman School of Medicine, 125 South 31st St., Philadelphia, PA, 19104-3403, United States.
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26
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Abstract
Sleep is essential for proper brain function in mammals and insects. During sleep, animals are disconnected from the external world; they show high arousal thresholds and changed brain activity. Sleep deprivation results in a sleep rebound. Research using the fruit fly, Drosophila melanogaster, has helped us understand the genetic and neuronal control of sleep. Genes involved in sleep control code for ion channels, factors influencing neurotransmission and neuromodulation, and proteins involved in the circadian clock. The neurotransmitters/neuromodulators involved in sleep control are GABA, dopamine, acetylcholine, serotonin, and several neuropeptides. Sleep is controlled by the interplay between sleep homeostasis and the circadian clock. Putative sleep-wake centers are located in higher-order brain centers that are indirectly connected to the circadian clock network. The primary function of sleep appears to be the downscaling of synapses that have been built up during wakefulness. Thus, brain homeostasis is maintained and learning and memory are assured.
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Affiliation(s)
- Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, 97074 Würzburg, Germany;
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27
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Abstract
Despite decades of intense study, the functions of sleep are still shrouded in mystery. The difficulty in understanding these functions can be at least partly attributed to the varied manifestations of sleep in different animals. Daily sleep duration can range from 4-20 hrs among mammals, and sleep can manifest throughout the brain, or it can alternate over time between cerebral hemispheres, depending on the species. Ecological factors are likely to have shaped these and other sleep behaviors during evolution by altering the properties of conserved arousal circuits in the brain. Nonetheless, core functions of sleep are likely to have arisen early and to have persisted to the present day in diverse organisms. This review will discuss the evolutionary forces that may be responsible for phylogenetic differences in sleep and the potential core functions that sleep fulfills.
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Affiliation(s)
- William J Joiner
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093-0636, USA; Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093-0636, USA; Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093-0636, USA; Center for Circadian Biology, University of California San Diego, La Jolla, CA 92093-0636, USA.
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28
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Shi S, Ueda HR. Ca 2+ -Dependent Hyperpolarization Pathways in Sleep Homeostasis and Mental Disorders. Bioessays 2017; 40. [PMID: 29205420 DOI: 10.1002/bies.201700105] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/19/2017] [Indexed: 12/23/2022]
Abstract
Although we are beginning to understand the neuronal and biochemical nature of sleep regulation, questions remain about how sleep is homeostatically regulated. Beyond its importance in basic physiology, understanding sleep may also shed light on psychiatric and neurodevelopmental disorders. Recent genetic studies in mammals revealed several non-secretory proteins that determine sleep duration. Interestingly, genes identified in these studies are closely related to psychiatric and neurodevelopmental disorders, suggesting that the sleep-wake cycle shares some common mechanisms with these disorders. Here we review recent sleep studies, including reverse and forward genetic studies, from the perspectives of sleep duration and homeostasis. We then introduce a recent hypothesis for mammalian sleep in which the fast and slow Ca2+ -dependent hyperpolarization pathways are pivotal in generating the SWS firing pattern and regulating sleep homeostasis, respectively. Finally, we propose that these intracellular pathways are potential therapeutic targets for achieving depolarization/hyperpolarization (D/H) balance in psychiatric and neurodevelopmental disorders.
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Affiliation(s)
- Shoi Shi
- Dr. S. Shi, Prof. H. R. Ueda, Department of Systems Pharmacology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Hiroki R Ueda
- Dr. S. Shi, Prof. H. R. Ueda, Department of Systems Pharmacology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.,Prof. H. R. Ueda, Laboratory for Synthetic Biology, RIKEN Quantitative Biology Center, 1-3 Yamadaoka, Suita, Osaka, 565-5241, Japan
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29
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Ji D, Wang S, Li M, Zhang S, Li H. Involvement of Lypge in the formation of eye and pineal gland in zebrafish. Gene 2017; 642:491-497. [PMID: 29196253 DOI: 10.1016/j.gene.2017.11.062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 11/20/2017] [Accepted: 11/27/2017] [Indexed: 11/19/2022]
Abstract
The proteins of Ly-6 (lymphocyte antigen-6) family are involved in the regulation of immunoreaction, cell migration and adhesion, and neuronal excitability. However, little is known about the function of Ly-6 proteins in embryogenesis. Herein, we identified a GPI anchored Ly-6 member named ly6 expressed in pineal gland and eye (lypge). Dynamic expression pattern of lypge was revealed by whole mount in situ hybridization. It was strikingly expressed in the pineal gland and cone photoreceptor, and its expression was regulated by orthodenticle homolog 5 (otx5) which has been shown to control the expression of many pineal genes. In addition, we demonstrated that lypge was rhythmically expressed in larvae from 4dpf on. Moreover, knockdown of lypge resulted in small head and small eye formed in zebrafish embryos. These suggest that Lypge is involved in the formation of the eye and pineal gland in early development of zebrafish.
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Affiliation(s)
- Dongrui Ji
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Evolution & Development, Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Su Wang
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Evolution & Development, Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Mingyue Li
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Evolution & Development, Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Shicui Zhang
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Evolution & Development, Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Hongyan Li
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Evolution & Development, Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
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30
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Ruan H, Ueda A, Xing X, Wan X, Strub B, Mukai S, Certel K, Green D, Belozerov K, Yao WD, Johnson W, Jung-Ching Lin J, Hilliker AJ, Wu CF. Generation and characterization of new alleles of quiver (qvr) that encodes an extracellular modulator of the Shaker potassium channel. J Neurogenet 2017; 31:325-336. [PMID: 29117754 DOI: 10.1080/01677063.2017.1393076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Our earlier genetic screen uncovered a paraquat-sensitive leg-shaking mutant quiver1 (qvr1), whose gene product interacts with the Shaker (Sh) K+ channel. We also mapped the qvr locus to EY04063 and noticed altered day-night activity patterns in these mutants. Such circadian behavioral defects were independently reported by another group, who employed the qvr1 allele we supplied them, and attributed the extreme restless phenotype of EY04063 to the qvr gene. However, their report adopted a new noncanonical gene name sleepless (sss) for qvr. In addition to qvr1 and qvrEY, our continuous effort since the early 2000s generated a number of novel recessive qvr alleles, including ethyl methanesulfonate (EMS)-induced mutations qvr2 and qvr3, and P-element excision lines qvrip6 (imprecise jumpout), qvrrv7, and qvrrv9 (revertants) derived from qvrEY. Distinct from the original intron-located qvr1 allele that generates abnormal-sized mRNAs, qvr2, and qvr3 had their lesion sites in exons 6 and 7, respectively, producing nearly normal-sized mRNA products. A set of RNA-editing sites are nearby the lesion sites of qvr3 and qvrEY on exon 7. Except for the revertants, all qvr alleles display a clear ether-induced leg-shaking phenotype just like Sh, and weakened climbing abilities to varying degrees. Unlike Sh, all shaking qvr alleles (except for qvrf01257) displayed a unique activity-dependent enhancement in excitatory junction potentials (EJPs) at larval neuromuscular junctions (NMJs) at very low stimulus frequencies, with qvrEY displaying the largest EJP and more significant NMJ overgrowth than other alleles. Our detailed characterization of a collection of qvr alleles helps to establish links between novel molecular lesions and different behavioral and physiological consequences, revealing how modifications of the qvr gene lead to a wide spectrum of phenotypes, including neuromuscular hyperexcitability, defective motor ability and activity-rest cycles.
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Affiliation(s)
- Hongyu Ruan
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Atsushi Ueda
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Xiaomin Xing
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Xuxuan Wan
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Benjamin Strub
- b Department of Biology , York University , Toronto , ON , Canada
| | - Spencer Mukai
- b Department of Biology , York University , Toronto , ON , Canada
| | - Kaan Certel
- c Department of Molecular Physiology and Biophysics , University of Iowa , Iowa City , IA , USA
| | - David Green
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Kyle Belozerov
- b Department of Biology , York University , Toronto , ON , Canada
| | - Wei-Dong Yao
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Wayne Johnson
- c Department of Molecular Physiology and Biophysics , University of Iowa , Iowa City , IA , USA
| | | | | | - Chun-Fang Wu
- a Department of Biology , University of Iowa , Iowa City , IA , USA
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31
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Allada R, Cirelli C, Sehgal A. Molecular Mechanisms of Sleep Homeostasis in Flies and Mammals. Cold Spring Harb Perspect Biol 2017; 9:a027730. [PMID: 28432135 PMCID: PMC5538413 DOI: 10.1101/cshperspect.a027730] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Sleep is homeostatically regulated with sleep pressure accumulating with the increasing duration of prior wakefulness. Yet, a clear understanding of the molecular components of the homeostat, as well as the molecular and cellular processes they sense and control to regulate sleep intensity and duration, remain a mystery. Here, we will discuss the cellular and molecular basis of sleep homeostasis, first focusing on the best homeostatic sleep marker in vertebrates, slow wave activity; second, moving to the molecular genetic analysis of sleep homeostasis in the fruit fly Drosophila; and, finally, discussing more systemic aspects of sleep homeostasis.
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Affiliation(s)
- Ravi Allada
- Department of Neurobiology, Northwestern University, Evanston, Ilinois 60208
| | - Chiara Cirelli
- Department of Psychiatry, University of Wisconsin-Madison, Madison, Wisconsin 53719
| | - Amita Sehgal
- Department of Neuroscience, Perelman School of Medicine at University of Pennsylvania, Philadelphia, Pennsylvania 19104-6058
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32
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Circadian Rhythms and Sleep in Drosophila melanogaster. Genetics 2017; 205:1373-1397. [PMID: 28360128 DOI: 10.1534/genetics.115.185157] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/17/2016] [Indexed: 02/07/2023] Open
Abstract
The advantages of the model organism Drosophila melanogaster, including low genetic redundancy, functional simplicity, and the ability to conduct large-scale genetic screens, have been essential for understanding the molecular nature of circadian (∼24 hr) rhythms, and continue to be valuable in discovering novel regulators of circadian rhythms and sleep. In this review, we discuss the current understanding of these interrelated biological processes in Drosophila and the wider implications of this research. Clock genes period and timeless were first discovered in large-scale Drosophila genetic screens developed in the 1970s. Feedback of period and timeless on their own transcription forms the core of the molecular clock, and accurately timed expression, localization, post-transcriptional modification, and function of these genes is thought to be critical for maintaining the circadian cycle. Regulators, including several phosphatases and kinases, act on different steps of this feedback loop to ensure strong and accurately timed rhythms. Approximately 150 neurons in the fly brain that contain the core components of the molecular clock act together to translate this intracellular cycling into rhythmic behavior. We discuss how different groups of clock neurons serve different functions in allowing clocks to entrain to environmental cues, driving behavioral outputs at different times of day, and allowing flexible behavioral responses in different environmental conditions. The neuropeptide PDF provides an important signal thought to synchronize clock neurons, although the details of how PDF accomplishes this function are still being explored. Secreted signals from clock neurons also influence rhythms in other tissues. SLEEP is, in part, regulated by the circadian clock, which ensures appropriate timing of sleep, but the amount and quality of sleep are also determined by other mechanisms that ensure a homeostatic balance between sleep and wake. Flies have been useful for identifying a large set of genes, molecules, and neuroanatomic loci important for regulating sleep amount. Conserved aspects of sleep regulation in flies and mammals include wake-promoting roles for catecholamine neurotransmitters and involvement of hypothalamus-like regions, although other neuroanatomic regions implicated in sleep in flies have less clear parallels. Sleep is also subject to regulation by factors such as food availability, stress, and social environment. We are beginning to understand how the identified molecules and neurons interact with each other, and with the environment, to regulate sleep. Drosophila researchers can also take advantage of increasing mechanistic understanding of other behaviors, such as learning and memory, courtship, and aggression, to understand how sleep loss impacts these behaviors. Flies thus remain a valuable tool for both discovery of novel molecules and deep mechanistic understanding of sleep and circadian rhythms.
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33
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Genes and neural circuits for sleep of the fruit fly. Neurosci Res 2017; 118:82-91. [DOI: 10.1016/j.neures.2017.04.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/29/2017] [Accepted: 03/29/2017] [Indexed: 02/07/2023]
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Quasimodo mediates daily and acute light effects on Drosophila clock neuron excitability. Proc Natl Acad Sci U S A 2016; 113:13486-13491. [PMID: 27821737 DOI: 10.1073/pnas.1606547113] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have characterized a light-input pathway regulating Drosophila clock neuron excitability. The molecular clock drives rhythmic electrical excitability of clock neurons, and we show that the recently discovered light-input factor Quasimodo (Qsm) regulates this variation, presumably via an Na+, K+, Cl- cotransporter (NKCC) and the Shaw K+ channel (dKV3.1). Because of light-dependent degradation of the clock protein Timeless (Tim), constant illumination (LL) leads to a breakdown of molecular and behavioral rhythms. Both overexpression (OX) and knockdown (RNAi) of qsm, NKCC, or Shaw led to robust LL rhythmicity. Whole-cell recordings of the large ventral lateral neurons (l-LNv) showed that altering Qsm levels reduced the daily variation in neuronal activity: qsmOX led to a constitutive less active, night-like state, and qsmRNAi led to a more active, day-like state. Qsm also affected daily changes in K+ currents and the GABA reversal potential, suggesting a role in modifying membrane currents and GABA responses in a daily fashion, potentially modulating light arousal and input to the clock. When directly challenged with blue light, wild-type l-LNvs responded with increased firing at night and no net response during the day, whereas altering Qsm, NKKC, or Shaw levels abolished these day/night differences. Finally, coexpression of ShawOX and NKCCRNAi in a qsm mutant background restored LL-induced behavioral arrhythmicity and wild-type neuronal activity patterns, suggesting that the three genes operate in the same pathway. We propose that Qsm affects both daily and acute light effects in l-LNvs probably acting on Shaw and NKCC.
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35
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Abstract
Electrophysiological recordings have enabled identification of physiologically distinct yet behaviorally similar states of mammalian sleep. In contrast, sleep in nonmammals has generally been identified behaviorally and therefore regarded as a physiologically uniform state characterized by quiescence of feeding and locomotion, reduced responsiveness, and rapid reversibility. The nematode Caenorhabditis elegans displays sleep-like quiescent behavior under two conditions: developmentally timed quiescence (DTQ) occurs during larval transitions, and stress-induced quiescence (SIQ) occurs in response to exposure to cellular stressors. Behaviorally, DTQ and SIQ appear identical. Here, we use optogenetic manipulations of neuronal and muscular activity, pharmacology, and genetic perturbations to uncover circuit and molecular mechanisms of DTQ and SIQ. We find that locomotion quiescence induced by DTQ- and SIQ-associated neuropeptides occurs via their action on the nervous system, although their neuronal target(s) and/or molecular mechanisms likely differ. Feeding quiescence during DTQ results from a loss of pharyngeal muscle excitability, whereas feeding quiescence during SIQ results from a loss of excitability in the nervous system. Together these results indicate that, as in mammals, quiescence is subserved by different mechanisms during distinct sleep-like states in C. elegans.
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36
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Wu M, Liu CZ, Joiner WJ. Structural Analysis and Deletion Mutagenesis Define Regions of QUIVER/SLEEPLESS that Are Responsible for Interactions with Shaker-Type Potassium Channels and Nicotinic Acetylcholine Receptors. PLoS One 2016; 11:e0148215. [PMID: 26828958 PMCID: PMC4735452 DOI: 10.1371/journal.pone.0148215] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/13/2016] [Indexed: 12/16/2022] Open
Abstract
Ly6 proteins are endogenous prototoxins found in most animals. They show striking structural and functional parallels to snake α-neurotoxins, including regulation of ion channels and cholinergic signaling. However, the structural contributions of Ly6 proteins to regulation of effector molecules is poorly understood. This question is particularly relevant to the Ly6 protein QUIVER/SLEEPLESS (QVR/SSS), which has previously been shown to suppress excitability and synaptic transmission by upregulating potassium (K) channels and downregulating nicotinic acetylcholine receptors (nAChRs) in wake-promoting neurons to facilitate sleep in Drosophila. Using deletion mutagenesis, co-immunoprecipitations, ion flux assays, surface labeling and confocal microscopy, we demonstrate that only loop 2 is required for many of the previously described properties of SSS in transfected cells, including interactions with K channels and nAChRs. Collectively our data suggest that QVR/SSS, and by extension perhaps other Ly6 proteins, target effector molecules using limited protein motifs. Mapping these motifs may be useful in rational design of drugs that mimic or suppress Ly6-effector interactions to modulate nervous system function.
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Affiliation(s)
- Meilin Wu
- Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America
| | - Clifford Z Liu
- UCSD undergraduate program, Marshall College, University of California San Diego, La Jolla, California, United States of America
| | - William J Joiner
- Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America.,Center for Circadian Biology, University of California San Diego, La Jolla, California, United States of America
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37
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Galat A. Multidimensional Drift of Sequence Attributes and Functional Profiles in the Superfamily of the Three-Finger Proteins and Their Structural Homologues. J Chem Inf Model 2015; 55:2026-41. [DOI: 10.1021/acs.jcim.5b00322] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Andrzej Galat
- Commissariat à
l’Energie
Atomique, Direction des Sciences du Vivant, Institut de Biologie et
de Technologies de Saclay, Service d’Ingénierie Moléculaire
des Protéines, F-91191 Gif sur Yvette, France
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38
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Ratliff EP, Mauntz RE, Kotzebue RW, Gonzalez A, Achal M, Barekat A, Finley KA, Sparhawk JM, Robinson JE, Herr DR, Harris GL, Joiner WJ, Finley KD. Aging and Autophagic Function Influences the Progressive Decline of Adult Drosophila Behaviors. PLoS One 2015; 10:e0132768. [PMID: 26182057 PMCID: PMC4504520 DOI: 10.1371/journal.pone.0132768] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 06/19/2015] [Indexed: 12/11/2022] Open
Abstract
Multiple neurological disorders are characterized by the abnormal accumulation of protein aggregates and the progressive impairment of complex behaviors. Our Drosophila studies demonstrate that middle-aged wild-type flies (WT, ~4-weeks) exhibit a marked accumulation of neural aggregates that is commensurate with the decline of the autophagy pathway. However, enhancing autophagy via neuronal over-expression of Atg8a (Atg8a-OE) reduces the age-dependent accumulation of aggregates. Here we assess basal locomotor activity profiles for single- and group-housed male and female WT flies and observed that only modest behavioral changes occurred by 4-weeks of age, with the noted exception of group-housed male flies. Male flies in same-sex social groups exhibit a progressive increase in nighttime activity. Infrared videos show aged group-housed males (4-weeks) are engaged in extensive bouts of courtship during periods of darkness, which is partly repressed during lighted conditions. Together, these nighttime courtship behaviors were nearly absent in young WT flies and aged Atg8a-OE flies. Previous studies have indicated a regulatory role for olfaction in male courtship partner choice. Coincidently, the mRNA expression profiles of several olfactory genes decline with age in WT flies; however, they are maintained in age-matched Atg8a-OE flies. Together, these results suggest that middle-aged male flies develop impairments in olfaction, which could contribute to the dysregulation of courtship behaviors during dark time periods. Combined, our results demonstrate that as Drosophila age, they develop early behavior defects that are coordinate with protein aggregate accumulation in the nervous system. In addition, the nighttime activity behavior is preserved when neuronal autophagy is maintained (Atg8a-OE flies). Thus, environmental or genetic factors that modify autophagic capacity could have a positive impact on neuronal aging and complex behaviors.
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Affiliation(s)
- Eric P. Ratliff
- Donald P. Shiley BioScience Center, San Diego State University, San Diego, California, United States of America
- Expression Drug Designs, LLC, San Diego, California, United States of America
- Department of Biology, San Diego State University, San Diego, California, United States of America
| | - Ruth E. Mauntz
- Donald P. Shiley BioScience Center, San Diego State University, San Diego, California, United States of America
- Expression Drug Designs, LLC, San Diego, California, United States of America
| | - Roxanne W. Kotzebue
- Donald P. Shiley BioScience Center, San Diego State University, San Diego, California, United States of America
- Expression Drug Designs, LLC, San Diego, California, United States of America
- Department of Biology, San Diego State University, San Diego, California, United States of America
| | - Arysa Gonzalez
- Donald P. Shiley BioScience Center, San Diego State University, San Diego, California, United States of America
- Expression Drug Designs, LLC, San Diego, California, United States of America
- Department of Biology, San Diego State University, San Diego, California, United States of America
| | - Madhulika Achal
- Donald P. Shiley BioScience Center, San Diego State University, San Diego, California, United States of America
- Department of Biology, San Diego State University, San Diego, California, United States of America
| | - Ayeh Barekat
- Donald P. Shiley BioScience Center, San Diego State University, San Diego, California, United States of America
- Department of Biology, San Diego State University, San Diego, California, United States of America
| | - Kaelyn A. Finley
- Donald P. Shiley BioScience Center, San Diego State University, San Diego, California, United States of America
- Expression Drug Designs, LLC, San Diego, California, United States of America
| | - Jonathan M. Sparhawk
- Donald P. Shiley BioScience Center, San Diego State University, San Diego, California, United States of America
- Department of Biology, San Diego State University, San Diego, California, United States of America
| | - James E. Robinson
- Departments of Neurosciences and Pharmacology, University of California San Diego, La Jolla, California, United States of America
| | - Deron R. Herr
- Expression Drug Designs, LLC, San Diego, California, United States of America
- Department of Biology, San Diego State University, San Diego, California, United States of America
- Department of Pharmacology, National University of Singapore, Singapore, Singapore
| | - Greg L. Harris
- Expression Drug Designs, LLC, San Diego, California, United States of America
- Department of Biology, San Diego State University, San Diego, California, United States of America
| | - William J. Joiner
- Departments of Neurosciences and Pharmacology, University of California San Diego, La Jolla, California, United States of America
| | - Kim D. Finley
- Donald P. Shiley BioScience Center, San Diego State University, San Diego, California, United States of America
- Expression Drug Designs, LLC, San Diego, California, United States of America
- Department of Biology, San Diego State University, San Diego, California, United States of America
- * E-mail:
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39
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Donelson NC, Sanyal S. Use of Drosophila in the investigation of sleep disorders. Exp Neurol 2015; 274:72-9. [PMID: 26160555 DOI: 10.1016/j.expneurol.2015.06.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 06/26/2015] [Accepted: 06/30/2015] [Indexed: 12/24/2022]
Abstract
Genetic underpinnings for sleep disorders in humans remain poorly identified, investigated and understood. This is due to the inherent complexity of sleep and a disruption of normal sleep parameters in a number of neurological disorders. On the other hand, there have been steady and remarkable developments in the investigation of sleep using model organisms such as Drosophila. These studies have illuminated conserved genetic pathways, neural circuits and intra-cellular signaling modules in the regulation of sleep. Additionally, work in model systems is beginning to clarify the role of the circadian clock and basal sleep need in this process. There have also been initial efforts to directly model sleep disorders in flies in a few instances where a genetic basis has been suspected. Here, we discuss the opportunities and limitations of studying sleep disorders in Drosophila and propose that a greater convergence of basic sleep research in model organisms and human genetics should catalyze better understanding of sleep disorders and generate viable therapeutic options.
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Affiliation(s)
- Nathan C Donelson
- Neurology Research, 115 Broadway, Bio 6 Building, Biogen, Cambridge, MA 02142, USA
| | - Subhabrata Sanyal
- Neurology Research, 115 Broadway, Bio 6 Building, Biogen, Cambridge, MA 02142, USA.
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40
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Ly6h regulates trafficking of alpha7 nicotinic acetylcholine receptors and nicotine-induced potentiation of glutamatergic signaling. J Neurosci 2015; 35:3420-30. [PMID: 25716842 DOI: 10.1523/jneurosci.3630-14.2015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
α7 nAChRs are expressed widely throughout the brain, where they are important for synaptic signaling, gene transcription, and plastic changes that regulate sensory processing, cognition, and neural responses to chronic nicotine exposure. However, the mechanisms by which α7 nAChRs are regulated are poorly understood. Here we show that trafficking of α7-subunits is controlled by endogenous membrane-associated prototoxins in the Ly6 family. In particular, we find that Ly6h reduces cell-surface expression and calcium signaling by α7 nAChRs. We detect Ly6h in several rat brain regions, including the hippocampus, where we find it is both necessary and sufficient to limit the magnitude of α7-mediated currents. Consistent with such a regulatory function, knockdown of Ly6h in rat hippocampal pyramidal neurons enhances nicotine-induced potentiation of glutamatergic mEPSC amplitude, which is known to be mediated by α7 signaling. Collectively our data suggest a novel cellular role for Ly6 proteins in regulating nAChRs, which may be relevant to plastic changes in the nervous system including rewiring of glutamatergic circuitry during nicotine addiction.
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41
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Afonso DJS, Liu D, Machado DR, Pan H, Jepson JEC, Rogulja D, Koh K. TARANIS Functions with Cyclin A and Cdk1 in a Novel Arousal Center to Control Sleep in Drosophila. Curr Biol 2015; 25:1717-26. [PMID: 26096977 DOI: 10.1016/j.cub.2015.05.037] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 04/20/2015] [Accepted: 05/19/2015] [Indexed: 12/22/2022]
Abstract
Sleep is an essential and conserved behavior whose regulation at the molecular and anatomical level remains to be elucidated. Here, we identify TARANIS (TARA), a Drosophila homolog of the Trip-Br (SERTAD) family of transcriptional coregulators, as a molecule that is required for normal sleep patterns. Through a forward-genetic screen, we isolated tara as a novel sleep gene associated with a marked reduction in sleep amount. Targeted knockdown of tara suggests that it functions in cholinergic neurons to promote sleep. tara encodes a conserved cell-cycle protein that contains a Cyclin A (CycA)-binding homology domain. TARA regulates CycA protein levels and genetically and physically interacts with CycA to promote sleep. Furthermore, decreased levels of Cyclin-dependent kinase 1 (Cdk1), a kinase partner of CycA, rescue the short-sleeping phenotype of tara and CycA mutants, while increased Cdk1 activity mimics the tara and CycA phenotypes, suggesting that Cdk1 mediates the role of TARA and CycA in sleep regulation. Finally, we describe a novel wake-promoting role for a cluster of ∼14 CycA-expressing neurons in the pars lateralis (PL), previously proposed to be analogous to the mammalian hypothalamus. We propose that TARANIS controls sleep amount by regulating CycA protein levels and inhibiting Cdk1 activity in a novel arousal center.
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Affiliation(s)
- Dinis J S Afonso
- Department of Neuroscience, Farber Institute for Neurosciences and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA; Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057 Braga, Portugal; ICVS/3B's, PT Government Associate Laboratory, 4710-057 Braga/Guimarães, Portugal
| | - Die Liu
- Department of Neuroscience, Farber Institute for Neurosciences and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Daniel R Machado
- Department of Neuroscience, Farber Institute for Neurosciences and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA; Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057 Braga, Portugal; ICVS/3B's, PT Government Associate Laboratory, 4710-057 Braga/Guimarães, Portugal
| | - Huihui Pan
- Department of Neuroscience, Farber Institute for Neurosciences and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - James E C Jepson
- Department of Neuroscience, Farber Institute for Neurosciences and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Dragana Rogulja
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Kyunghee Koh
- Department of Neuroscience, Farber Institute for Neurosciences and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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KChIP-like auxiliary subunits of Kv4 channels regulate excitability of muscle cells and control male turning behavior during mating in Caenorhabditis elegans. J Neurosci 2015; 35:1880-91. [PMID: 25653349 DOI: 10.1523/jneurosci.3429-14.2015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Voltage-gated Kv4 channels control the excitability of neurons and cardiac myocytes by conducting rapidly activating-inactivating currents. The function of Kv4 channels is profoundly modulated by K(+) channel interacting protein (KChIP) soluble auxiliary subunits. However, the in vivo mechanism of the modulation is not fully understood. Here, we identified three C. elegans KChIP-like (ceKChIP) proteins, NCS-4, NCS-5, and NCS-7. All three ceKChIPs alter electrical characteristics of SHL-1, a C. elegans Kv4 channel ortholog, currents by slowing down inactivation kinetics and shifting voltage dependence of activation to more hyperpolarizing potentials. Native SHL-1 current is completely abolished in cultured myocytes of Triple KO worms in which all three ceKChIP genes are deleted. Reexpression of NCS-4 partially restored expression of functional SHL-1 channels, whereas NCS-4(efm), a NCS-4 mutant with impaired Ca(2+)-binding ability, only enhanced expression of SHL-1 proteins, but failed to transport them from the Golgi apparatus to the cell membrane in body wall muscles of Triple KO worms. Moreover, translational reporter revealed that NCS-4 assembles with SHL-1 K(+) channels in male diagonal muscles. Deletion of either ncs-4 or shl-1 significantly impairs male turning, a behavior controlled by diagonal muscles during mating. The phenotype of the ncs-4 null mutant could be rescued by reexpression of NCS-4, but not NCS-4(efm), further emphasizing the importance of Ca(2+) binding to ceKChIPs in regulating native SHL-1 channel function. Together, these data reveal an evolutionarily conserved mechanism underlying the regulation of Kv4 channels by KChIPs and unravel critical roles of ceKChIPs in regulating muscle cell excitability and animal behavior in C. elegans.
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Tabuchi M, Lone SR, Liu S, Liu Q, Zhang J, Spira AP, Wu MN. Sleep interacts with aβ to modulate intrinsic neuronal excitability. Curr Biol 2015; 25:702-712. [PMID: 25754641 PMCID: PMC4366315 DOI: 10.1016/j.cub.2015.01.016] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 12/05/2014] [Accepted: 01/06/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND Emerging data suggest an important relationship between sleep and Alzheimer's disease (AD), but how poor sleep promotes the development of AD remains unclear. RESULTS Here, using a Drosophila model of AD, we provide evidence suggesting that changes in neuronal excitability underlie the effects of sleep loss on AD pathogenesis. β-amyloid (Aβ) accumulation leads to reduced and fragmented sleep, while chronic sleep deprivation increases Aβ burden. Moreover, enhancing sleep reduces Aβ deposition. Increasing neuronal excitability phenocopies the effects of reducing sleep on Aβ, and decreasing neuronal activity blocks the elevated Aβ accumulation induced by sleep deprivation. At the single neuron level, we find that chronic sleep deprivation, as well as Aβ expression, enhances intrinsic neuronal excitability. Importantly, these data reveal that sleep loss exacerbates Aβ-induced hyperexcitability and suggest that defects in specific K(+) currents underlie the hyperexcitability caused by sleep loss and Aβ expression. Finally, we show that feeding levetiracetam, an anti-epileptic medication, to Aβ-expressing flies suppresses neuronal excitability and significantly prolongs their lifespan. CONCLUSIONS Our findings directly link sleep loss to changes in neuronal excitability and Aβ accumulation and further suggest that neuronal hyperexcitability is an important mediator of Aβ toxicity. Taken together, these data provide a mechanistic framework for a positive feedback loop, whereby sleep loss and neuronal excitation accelerate the accumulation of Aβ, a key pathogenic step in the development of AD.
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Affiliation(s)
- Masashi Tabuchi
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Shahnaz R Lone
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Sha Liu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Qili Liu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Julia Zhang
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Adam P Spira
- Department of Mental Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Mark N Wu
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA.
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Tanaka K, Diekmann Y, Hazbun A, Hijazi A, Vreede B, Roch F, Sucena É. Multispecies Analysis of Expression Pattern Diversification in the Recently Expanded Insect Ly6 Gene Family. Mol Biol Evol 2015; 32:1730-47. [PMID: 25743545 PMCID: PMC4476152 DOI: 10.1093/molbev/msv052] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Gene families often consist of members with diverse expression domains reflecting their functions in a wide variety of tissues. However, how the expression of individual members, and thus their tissue-specific functions, diversified during the course of gene family expansion is not well understood. In this study, we approached this question through the analysis of the duplication history and transcriptional evolution of a rapidly expanding subfamily of insect Ly6 genes. We analyzed different insect genomes and identified seven Ly6 genes that have originated from a single ancestor through sequential duplication within the higher Diptera. We then determined how the original embryonic expression pattern of the founding gene diversified by characterizing its tissue-specific expression in the beetle Tribolium castaneum, the butterfly Bicyclus anynana, and the mosquito Anopheles stephensi and those of its duplicates in three higher dipteran species, representing various stages of the duplication history (Megaselia abdita, Ceratitis capitata, and Drosophila melanogaster). Our results revealed that frequent neofunctionalization episodes contributed to the increased expression breadth of this subfamily and that these events occurred after duplication and speciation events at comparable frequencies. In addition, at each duplication node, we consistently found asymmetric expression divergence. One paralog inherited most of the tissue-specificities of the founder gene, whereas the other paralog evolved drastically reduced expression domains. Our approach attests to the power of combining a well-established duplication history with a comprehensive coverage of representative species in acquiring unequivocal information about the dynamics of gene expression evolution in gene families.
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Affiliation(s)
| | | | | | - Assia Hijazi
- Centre de Biologie du Développement, CNRS UMR 5547, Université de Toulouse UPS, Toulouse, France
| | | | - Fernando Roch
- Centre de Biologie du Développement, CNRS UMR 5547, Université de Toulouse UPS, Toulouse, France
| | - Élio Sucena
- Instituto Gulbenkian de Ciência, Oeiras, Portugal Departamento de Biologia Animal, Faculdade de Ciências, Edifício C2, Universidade de Lisboa, Lisboa, Portugal
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A neuron-glia interaction involving GABA transaminase contributes to sleep loss in sleepless mutants. Mol Psychiatry 2015; 20:240-51. [PMID: 24637426 PMCID: PMC4168011 DOI: 10.1038/mp.2014.11] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 01/08/2014] [Accepted: 01/09/2014] [Indexed: 11/25/2022]
Abstract
Sleep is an essential process and yet mechanisms underlying it are not well understood. Loss of the Drosophila quiver/sleepless (qvr/sss) gene increases neuronal excitability and diminishes daily sleep, providing an excellent model for exploring the underpinnings of sleep regulation. Here, we used a proteomic approach to identify proteins altered in sss brains. We report that loss of sleepless post-transcriptionally elevates the CG7433 protein, a mitochondrial γ-aminobutyric acid transaminase (GABAT), and reduces GABA in fly brains. Loss of GABAT increases daily sleep and improves sleep consolidation, indicating that GABAT promotes wakefulness. Importantly, disruption of the GABAT gene completely suppresses the sleep phenotype of sss mutants, demonstrating that GABAT is required for loss of sleep in sss mutants. While SSS acts in distinct populations of neurons, GABAT acts in glia to reduce sleep in sss flies. Our results identify a novel mechanism of interaction between neurons and glia that is important for the regulation of sleep.
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Identification of a Ly-6 superfamily gene expressed in lateral line neuromasts in zebrafish. Dev Genes Evol 2015; 225:47-53. [DOI: 10.1007/s00427-015-0487-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Accepted: 01/05/2015] [Indexed: 02/02/2023]
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SLEEPLESS is a bifunctional regulator of excitability and cholinergic synaptic transmission. Curr Biol 2014; 24:621-9. [PMID: 24613312 DOI: 10.1016/j.cub.2014.02.026] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 01/15/2014] [Accepted: 02/11/2014] [Indexed: 01/01/2023]
Abstract
BACKGROUND Although sleep is conserved throughout evolution, the molecular basis of its control is still largely a mystery. We previously showed that the quiver/sleepless (qvr/sss) gene encodes a membrane-tethered protein that is required for normal sleep in Drosophila. SLEEPLESS (SSS) protein functions, at least in part, by upregulating the levels and open probability of Shaker (Sh) potassium channels to suppress neuronal excitability and enable sleep. Consistent with this proposed mechanism, loss-of-function mutations in Sh phenocopy qvr/sss-null mutants. However, sleep is more genetically modifiable in Sh than in qvr/sss mutants, suggesting that SSS may regulate additional molecules to influence sleep. RESULTS Here we show that SSS also antagonizes nicotinic acetylcholine receptors (nAChRs) to reduce synaptic transmission and promote sleep. Mimicking this antagonism with the nAChR inhibitor mecamylamine or by RNAi knockdown of specific nAChR subunits is sufficient to restore sleep to qvr/sss mutants. Regulation of nAChR activity by SSS occurs posttranscriptionally, since the levels of nAChR mRNAs are unchanged in qvr/sss mutants. Regulation of nAChR activity by SSS may in fact be direct, since SSS forms a stable complex with and antagonizes nAChR function in transfected cells. Intriguingly, lynx1, a mammalian homolog of SSS, can partially restore normal sleep to qvr/sss mutants, and lynx1 can form stable complexes with Shaker-type channels and nAChRs. CONCLUSIONS Together, our data point to an evolutionarily conserved, bifunctional role for SSS and its homologs in controlling excitability and synaptic transmission in fundamental processes of the nervous system such as sleep.
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Day-night cycles and the sleep-promoting factor, Sleepless, affect stem cell activity in the Drosophila testis. Proc Natl Acad Sci U S A 2014; 111:3026-31. [PMID: 24516136 DOI: 10.1073/pnas.1316552111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Adult stem cells maintain tissue integrity and function by renewing cellular content of the organism through regulated mitotic divisions. Previous studies showed that stem cell activity is affected by local, systemic, and environmental cues. Here, we explore a role of environmental day-night cycles in modulating cell cycle progression in populations of adult stem cells. Using a classic stem cell system, the Drosophila spermatogonial stem cell niche, we reveal daily rhythms in division frequencies of germ-line and somatic stem cells that act cooperatively to produce male gametes. We also examine whether behavioral sleep-wake cycles, which are driven by the environmental day-night cycles, regulate stem cell function. We find that flies lacking the sleep-promoting factor Sleepless, which maintains normal sleep in Drosophila, have increased germ-line stem cell (GSC) division rates, and this effect is mediated, in part, through a GABAergic signaling pathway. We suggest that alterations in sleep can influence the daily dynamics of GSC divisions.
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Shi M, Yue Z, Kuryatov A, Lindstrom JM, Sehgal A. Identification of Redeye, a new sleep-regulating protein whose expression is modulated by sleep amount. eLife 2014; 3:e01473. [PMID: 24497543 PMCID: PMC3912633 DOI: 10.7554/elife.01473] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this study, we report a new protein involved in the homeostatic regulation of sleep in Drosophila. We conducted a forward genetic screen of chemically mutagenized flies to identify short-sleeping mutants and found one, redeye (rye) that shows a severe reduction of sleep length. Cloning of rye reveals that it encodes a nicotinic acetylcholine receptor α subunit required for Drosophila sleep. Levels of RYE oscillate in light-dark cycles and peak at times of daily sleep. Cycling of RYE is independent of a functional circadian clock, but rather depends upon the sleep homeostat, as protein levels are up-regulated in short-sleeping mutants and also in wild type animals following sleep deprivation. We propose that the homeostatic drive to sleep increases levels of RYE, which responds to this drive by promoting sleep. DOI: http://dx.doi.org/10.7554/eLife.01473.001.
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Affiliation(s)
- Mi Shi
- Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, United States
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Cell-specific fine-tuning of neuronal excitability by differential expression of modulator protein isoforms. J Neurosci 2013; 33:16767-77. [PMID: 24133277 DOI: 10.1523/jneurosci.1001-13.2013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
SLOB (SLOWPOKE-binding protein) modulates the Drosophila SLOWPOKE calcium-activated potassium channel. We have shown previously that SLOB deletion or RNAi knockdown decreases excitability of neurosecretory pars intercerebralis (PI) neurons in the adult Drosophila brain. In contrast, we found that SLOB deletion/knockdown enhances neurotransmitter release from motor neurons at the fly larval neuromuscular junction, suggesting an increase in excitability. Because two prominent SLOB isoforms, SLOB57 and SLOB71, modulate SLOWPOKE channels in opposite directions in vitro, we investigated whether divergent expression patterns of these two isoforms might underlie the differential modulation of excitability in PI and motor neurons. By performing detailed in vitro and in vivo analysis, we found strikingly different modes of regulatory control by the slob57 and slob71 promoters. The slob71, but not slob57, promoter contains binding sites for the Hunchback and Mirror transcriptional repressors. Furthermore, several core promoter elements that are absent in the slob57 promoter coordinately drive robust expression of a luciferase vector by the slob71 promoter in vitro. In addition, we visualized the expression patterns of the slob57 and slob71 promoters in vivo and found clear spatiotemporal differences in promoter activity. SLOB57 is expressed prominently in adult PI neurons, whereas larval motor neurons exclusively express SLOB71. In contrast, at the larval neuromuscular junction, SLOB57 expression appears to be restricted mainly to a subset of glial cells. Our results illustrate how the use of alternative transcriptional start sites within an ion channel modulator locus coupled with functionally relevant alternative splicing can be used to fine-tune neuronal excitability in a cell-specific manner.
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