1
|
Patel PA, LaConte LEW, Liang C, Cecere T, Rajan D, Srivastava S, Mukherjee K. Genetic evidence for splicing-dependent structural and functional plasticity in CASK protein. J Med Genet 2024; 61:759-768. [PMID: 38670634 PMCID: PMC11290809 DOI: 10.1136/jmg-2023-109747] [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: 11/10/2023] [Accepted: 04/14/2024] [Indexed: 04/28/2024]
Abstract
BACKGROUND Pontocerebellar hypoplasia (PCH) may present with supratentorial phenotypes and is often accompanied by microcephaly. Damaging mutations in the X-linked gene CASK produce self-limiting microcephaly with PCH in females but are often lethal in males. CASK deficiency leads to early degeneration of cerebellar granule cells but its role in other regions of the brain remains uncertain. METHOD We generated a conditional Cask knockout mice and deleted Cask ubiquitously after birth at different times. We examined the clinical features in several subjects with damaging mutations clustered in the central part of the CASK protein. We have performed phylogenetic analysis and RT-PCR to assess the splicing pattern within the same protein region and performed in silico structural analysis to examine the effect of splicing on the CASK's structure. RESULT We demonstrate that deletion of murine Cask after adulthood does not affect survival but leads to cerebellar degeneration and ataxia over time. Intriguingly, damaging hemizygous CASK mutations in boys who display microcephaly and cerebral dysfunction but without PCH are known. These mutations are present in two vertebrate-specific CASK exons. These exons are subject to alternative splicing both in forebrain and hindbrain. Inclusion of these exons differentially affects the molecular structure and hence possibly the function/s of the CASK C-terminus. CONCLUSION Loss of CASK function disproportionately affects the cerebellum. Clinical data, however, suggest that CASK may have additional vertebrate-specific function/s that play a role in the mammalian forebrain. Thus, CASK has an ancient function shared between invertebrates and vertebrates as well as novel vertebrate-specific function/s.
Collapse
Affiliation(s)
- Paras A Patel
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | - Leslie E W LaConte
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
- Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
| | - Chen Liang
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
| | - Thomas Cecere
- Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
| | - Deepa Rajan
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarika Srivastava
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
- Department of Genetics, The University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, USA
| | - Konark Mukherjee
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, USA
- Department of Genetics, The University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, USA
| |
Collapse
|
2
|
Bhandari A, Seguin A, Rothenfluh A. Synaptic Mechanisms of Ethanol Tolerance and Neuroplasticity: Insights from Invertebrate Models. Int J Mol Sci 2024; 25:6838. [PMID: 38999947 PMCID: PMC11241699 DOI: 10.3390/ijms25136838] [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: 05/06/2024] [Revised: 06/09/2024] [Accepted: 06/10/2024] [Indexed: 07/14/2024] Open
Abstract
Alcohol tolerance is a neuroadaptive response that leads to a reduction in the effects of alcohol caused by previous exposure. Tolerance plays a critical role in the development of alcohol use disorder (AUD) because it leads to the escalation of drinking and dependence. Understanding the molecular mechanisms underlying alcohol tolerance is therefore important for the development of effective therapeutics and for understanding addiction in general. This review explores the molecular basis of alcohol tolerance in invertebrate models, Drosophila and C. elegans, focusing on synaptic transmission. Both organisms exhibit biphasic responses to ethanol and develop tolerance similar to that of mammals. Furthermore, the availability of several genetic tools makes them a great candidate to study the molecular basis of ethanol response. Studies in invertebrate models show that tolerance involves conserved changes in the neurotransmitter systems, ion channels, and synaptic proteins. These neuroadaptive changes lead to a change in neuronal excitability, most likely to compensate for the enhanced inhibition by ethanol.
Collapse
Affiliation(s)
- Aakriti Bhandari
- Department of Psychiatry, University of Utah, Salt Lake City, UT 84112, USA
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT 84112, USA
| | - Alexandra Seguin
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
| | - Adrian Rothenfluh
- Department of Psychiatry, University of Utah, Salt Lake City, UT 84112, USA
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT 84112, USA
- Department of Neurobiology, University of Utah, Salt Lake City, UT 84112, USA
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| |
Collapse
|
3
|
Tello JA, Jiang L, Zohar Y, Restifo LL. Drosophila CASK regulates brain size and neuronal morphogenesis, providing a genetic model of postnatal microcephaly suitable for drug discovery. Neural Dev 2023; 18:6. [PMID: 37805506 PMCID: PMC10559581 DOI: 10.1186/s13064-023-00174-y] [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: 08/20/2023] [Accepted: 09/08/2023] [Indexed: 10/09/2023] Open
Abstract
BACKGROUND CASK-related neurodevelopmental disorders are untreatable. Affected children show variable severity, with microcephaly, intellectual disability (ID), and short stature as common features. X-linked human CASK shows dosage sensitivity with haploinsufficiency in females. CASK protein has multiple domains, binding partners, and proposed functions at synapses and in the nucleus. Human and Drosophila CASK show high amino-acid-sequence similarity in all functional domains. Flies homozygous for a hypomorphic CASK mutation (∆18) have motor and cognitive deficits. A Drosophila genetic model of CASK-related disorders could have great scientific and translational value. METHODS We assessed the effects of CASK loss of function on morphological phenotypes in Drosophila using established genetic, histological, and primary neuronal culture approaches. NeuronMetrics software was used to quantify neurite-arbor morphology. Standard nonparametric statistics methods were supplemented by linear mixed effects modeling in some cases. Microfluidic devices of varied dimensions were fabricated and numerous fluid-flow parameters were used to induce oscillatory stress fields on CNS tissue. Dissociation into viable neurons and neurite outgrowth in vitro were assessed. RESULTS We demonstrated that ∆18 homozygous flies have small brains, small heads, and short bodies. When neurons from developing CASK-mutant CNS were cultured in vitro, they grew small neurite arbors with a distinctive, quantifiable "bushy" morphology that was significantly rescued by transgenic CASK+. As in humans, the bushy phenotype showed dosage-sensitive severity. To overcome the limitations of manual tissue trituration for neuronal culture, we optimized the design and operation of a microfluidic system for standardized, automated dissociation of CNS tissue into individual viable neurons. Neurons from CASK-mutant CNS dissociated in the microfluidic system recapitulate the bushy morphology. Moreover, for any given genotype, device-dissociated neurons grew larger arbors than did manually dissociated neurons. This automated dissociation method is also effective for rodent CNS. CONCLUSIONS These biological and engineering advances set the stage for drug discovery using the Drosophila model of CASK-related disorders. The bushy phenotype provides a cell-based assay for compound screening. Nearly a dozen genes encoding CASK-binding proteins or transcriptional targets also have brain-development mutant phenotypes, including ID. Hence, drugs that improve CASK phenotypes might also benefit children with disorders due to mutant CASK partners.
Collapse
Affiliation(s)
- Judith A Tello
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, 85721, USA
- Department of Neurology, University of Arizona Health Sciences, 1501 N. Campbell Ave, Tucson, AZ, 85724-5023, USA
- Present address: Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY, 10010, USA
| | - Linan Jiang
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ, 85721, USA
| | - Yitshak Zohar
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ, 85721, USA
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, 85721, USA
- BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, 85721, USA
| | - Linda L Restifo
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, 85721, USA.
- Department of Neurology, University of Arizona Health Sciences, 1501 N. Campbell Ave, Tucson, AZ, 85724-5023, USA.
- BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, 85721, USA.
- Department of Cellular & Molecular Medicine, University of Arizona Health Sciences, Tucson, AZ, 85724, USA.
| |
Collapse
|
4
|
Singh AK. Hsrω and Other lncRNAs in Neuronal Functions and Disorders in Drosophila. LIFE (BASEL, SWITZERLAND) 2022; 13:life13010017. [PMID: 36675966 PMCID: PMC9865238 DOI: 10.3390/life13010017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 11/27/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022]
Abstract
Long noncoding RNAs (lncRNAs) have a crucial role in epigenetic, transcriptional and posttranscriptional regulation of gene expression. Many of these regulatory lncRNAs, such as MALAT1, NEAT1, HOTAIR, etc., are associated with different neurodegenerative diseases in humans. The lncRNAs produced by the hsrω gene are known to modulate neurotoxicity in polyQ and amyotrophic lateral sclerosis disease models of Drosophila. Elevated expression of hsrω lncRNAs exaggerates, while their genetic depletion through hsrω-RNAi or in an hsrω-null mutant background suppresses, the disease pathogenicity. This review discusses the possible mechanistic details and implications of the functions of hsrω lncRNAs in the modulation of neurodegenerative diseases.
Collapse
Affiliation(s)
- Anand Kumar Singh
- Interdisciplinary School of Life Sciences, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| |
Collapse
|
5
|
The Non-Linear Path from Gene Dysfunction to Genetic Disease: Lessons from the MICPCH Mouse Model. Cells 2022; 11:cells11071131. [PMID: 35406695 PMCID: PMC8997851 DOI: 10.3390/cells11071131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/09/2022] [Accepted: 03/24/2022] [Indexed: 11/17/2022] Open
Abstract
Most human disease manifests as a result of tissue pathology, due to an underlying disease process (pathogenesis), rather than the acute loss of specific molecular function(s). Successful therapeutic strategies thus may either target the correction of a specific molecular function or halt the disease process. For the vast majority of brain diseases, clear etiologic and pathogenic mechanisms are still elusive, impeding the discovery or design of effective disease-modifying drugs. The development of valid animal models and their proper characterization is thus critical for uncovering the molecular basis of the underlying pathobiological processes of brain disorders. MICPCH (microcephaly and pontocerebellar hypoplasia) is a monogenic condition that results from variants of an X-linked gene, CASK (calcium/calmodulin-dependent serine protein kinase). CASK variants are associated with a wide range of clinical presentations, from lethality and epileptic encephalopathies to intellectual disabilities, microcephaly, and autistic traits. We have examined CASK loss-of-function mutations in model organisms to simultaneously understand the pathogenesis of MICPCH and the molecular function/s of CASK. Our studies point to a highly complex relationship between the potential molecular function/s of CASK and the phenotypes observed in model organisms and humans. Here we discuss the implications of our observations from the pathogenesis of MICPCH as a cautionary narrative against oversimplifying molecular interpretations of data obtained from genetically modified animal models of human diseases.
Collapse
|
6
|
Salim S, Banu A, Alwa A, Gowda SBM, Mohammad F. The gut-microbiota-brain axis in autism: what Drosophila models can offer? J Neurodev Disord 2021; 13:37. [PMID: 34525941 PMCID: PMC8442445 DOI: 10.1186/s11689-021-09378-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/06/2021] [Indexed: 12/28/2022] Open
Abstract
The idea that alterations in gut-microbiome-brain axis (GUMBA)-mediated communication play a crucial role in human brain disorders like autism remains a topic of intensive research in various labs. Gastrointestinal issues are a common comorbidity in patients with autism spectrum disorder (ASD). Although gut microbiome and microbial metabolites have been implicated in the etiology of ASD, the underlying molecular mechanism remains largely unknown. In this review, we have summarized recent findings in human and animal models highlighting the role of the gut-brain axis in ASD. We have discussed genetic and neurobehavioral characteristics of Drosophila as an animal model to study the role of GUMBA in ASD. The utility of Drosophila fruit flies as an amenable genetic tool, combined with axenic and gnotobiotic approaches, and availability of transgenic flies may reveal mechanistic insight into gut-microbiota-brain interactions and the impact of its alteration on behaviors relevant to neurological disorders like ASD.
Collapse
Affiliation(s)
- Safa Salim
- Division of Biological and Biomedical Sciences (BBS), College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Doha, 34110, Qatar
| | - Ayesha Banu
- Division of Biological and Biomedical Sciences (BBS), College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Doha, 34110, Qatar
| | - Amira Alwa
- Division of Biological and Biomedical Sciences (BBS), College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Doha, 34110, Qatar
| | - Swetha B M Gowda
- Division of Biological and Biomedical Sciences (BBS), College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Doha, 34110, Qatar
| | - Farhan Mohammad
- Division of Biological and Biomedical Sciences (BBS), College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Doha, 34110, Qatar.
| |
Collapse
|
7
|
Zhang K, Wang T, Liu X, Yuan Q, Xiao T, Yuan X, Zhang Y, Yuan L, Wang Y. CASK, APBA1, and STXBP1 collaborate during insulin secretion. Mol Cell Endocrinol 2021; 520:111076. [PMID: 33159991 DOI: 10.1016/j.mce.2020.111076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 01/09/2023]
Abstract
Calcium/calmodulin-dependent serine protein kinase (CASK) knockdown reduces insulin vesicle docking to cell membranes. Here, we explored CASK interactions with other proteins during insulin secretion. Using co-immunoprecipitation, liquid chromatography-mass spectrometry and bioinformatic analysis, we identified that CASK, Adapter protein X11 alpha (APBA1), and Syntaxin binding protein 1 (STXBP1) formed tripartite complex during insulin secretion. CASK enhanced APBA1-STXBP1 interaction and mediated their traffic from cytoplasm to plasma membrane during insulin release. High fatty acid stimulation decreased insulin secretion along with CASK, APBA1, and STXBP1 expression; Cask overexpression enhanced CASK/APBA1/STXBP1 tripartite complex function, and may thereby rescue lipotoxicity-induced insulin-release defects. Collectively, our results illustrated the function of CASK in insulin granules exocytosis, which broadens the underlying mechanism of insulin secretion and highlights the clinical potential of CASK as a drug target of type 2 Diabetes Mellitus (T2DM).
Collapse
Affiliation(s)
- Kai Zhang
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China
| | - Tianyuan Wang
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China
| | - Xingjing Liu
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China
| | - Qingzhao Yuan
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China
| | - Tin Xiao
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China
| | - Xiangjiang Yuan
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 210009, China
| | - Yijian Zhang
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 210009, China
| | - Li Yuan
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 210009, China
| | - Yao Wang
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing, 210009, China.
| |
Collapse
|
8
|
Andrew DR, Moe ME, Chen D, Tello JA, Doser RL, Conner WE, Ghuman JK, Restifo LL. Spontaneous motor-behavior abnormalities in two Drosophila models of neurodevelopmental disorders. J Neurogenet 2020; 35:1-22. [PMID: 33164597 DOI: 10.1080/01677063.2020.1833005] [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: 10/23/2022]
Abstract
Mutations in hundreds of genes cause neurodevelopmental disorders with abnormal motor behavior alongside cognitive deficits. Boys with fragile X syndrome (FXS), a leading monogenic cause of intellectual disability, often display repetitive behaviors, a core feature of autism. By direct observation and manual analysis, we characterized spontaneous-motor-behavior phenotypes of Drosophila dfmr1 mutants, an established model for FXS. We recorded individual 1-day-old adult flies, with mature nervous systems and prior to the onset of aging, in small arenas. We scored behavior using open-source video-annotation software to generate continuous activity timelines, which were represented graphically and quantitatively. Young dfmr1 mutants spent excessive time grooming, with increased bout number and duration; both were rescued by transgenic wild-type dfmr1+. By two grooming-pattern measures, dfmr1-mutant flies showed elevated repetitions consistent with perseveration, which is common in FXS. In addition, the mutant flies display a preference for grooming posterior body structures, and an increased rate of grooming transitions from one site to another. We raise the possibility that courtship and circadian rhythm defects, previously reported for dfmr1 mutants, are complicated by excessive grooming. We also observed significantly increased grooming in CASK mutants, despite their dramatically decreased walking phenotype. The mutant flies, a model for human CASK-related neurodevelopmental disorders, displayed consistently elevated grooming indices throughout the assay, but transient locomotory activation immediately after placement in the arena. Based on published data identifying FMRP-target transcripts and functional analyses of mutations causing human genetic neurodevelopmental disorders, we propose the following proteins as candidate mediators of excessive repetitive behaviors in FXS: CaMKIIα, NMDA receptor subunits 2A and 2B, NLGN3, and SHANK3. Together, these fly-mutant phenotypes and mechanistic insights provide starting points for drug discovery to identify compounds that reduce dysfunctional repetitive behaviors.
Collapse
Affiliation(s)
- David R Andrew
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Center for Insect Science, University of Arizona, Tucson, AZ, USA.,Department of Biological Sciences, Lycoming College, Williamsport, PA, USA
| | - Mariah E Moe
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Dailu Chen
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Judith A Tello
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, USA
| | - Rachel L Doser
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA
| | - William E Conner
- Department of Biology, Wake Forest University, Winston-Salem, NC, USA
| | - Jaswinder K Ghuman
- Department of Psychiatry, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Linda L Restifo
- Department of Neurology, University of Arizona Health Sciences, Tucson, AZ, USA.,Center for Insect Science, University of Arizona, Tucson, AZ, USA.,Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, USA.,BIO5 Interdisciplinary Research Institute, University of Arizona, Tucson, AZ, USA
| |
Collapse
|
9
|
Patel PA, Liang C, Arora A, Vijayan S, Ahuja S, Wagley PK, Settlage R, LaConte LEW, Goodkin HP, Lazar I, Srivastava S, Mukherjee K. Haploinsufficiency of X-linked intellectual disability gene CASK induces post-transcriptional changes in synaptic and cellular metabolic pathways. Exp Neurol 2020; 329:113319. [PMID: 32305418 DOI: 10.1016/j.expneurol.2020.113319] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 04/04/2020] [Accepted: 04/15/2020] [Indexed: 12/17/2022]
Abstract
Heterozygous mutations in the X-linked gene CASK are associated with intellectual disability, microcephaly, pontocerebellar hypoplasia, optic nerve hypoplasia and partially penetrant seizures in girls. The Cask+/- heterozygous knockout female mouse phenocopies the human disorder and exhibits postnatal microencephaly, cerebellar hypoplasia and optic nerve hypoplasia. It is not known if Cask+/- mice also display seizures, nor is known the molecular mechanism by which CASK haploinsufficiency produces the numerous documented phenotypes. 24-h video electroencephalography demonstrates that despite sporadic seizure activity, the overall electrographic patterns remain unaltered in Cask+/- mice. Additionally, seizure threshold to the commonly used kindling agent, pentylenetetrazol, remains unaltered in Cask+/- mice, indicating that even in mice the seizure phenotype is only partially penetrant and may have an indirect mechanism. RNA sequencing experiments on Cask+/- mouse brain uncovers a very limited number of changes, with most differences arising in the transcripts of extracellular matrix proteins and the transcripts of a group of nuclear proteins. In contrast to limited changes at the transcript level, quantitative whole-brain proteomics using iTRAQ quantitative mass-spectrometry reveals major changes in synaptic, metabolic/mitochondrial, cytoskeletal, and protein metabolic pathways. Unbiased protein-protein interaction mapping using affinity chromatography demonstrates that CASK may form complexes with proteins belonging to the same functional groups in which altered protein levels are observed. We discuss the mechanism of the observed changes in the context of known molecular function/s of CASK. Overall, our data indicate that the phenotypic spectrum of female Cask+/- mice includes sporadic seizures and thus closely parallels that of CASK haploinsufficient girls; the Cask+/- mouse is thus a face-validated model for CASK-related pathologies. We therefore surmise that CASK haploinsufficiency is likely to affect brain structure and function due to dysregulation of several cellular pathways including synaptic signaling and cellular metabolism.
Collapse
Affiliation(s)
- P A Patel
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States; Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA, United States
| | - C Liang
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - A Arora
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - S Vijayan
- School of Neuroscience, Virginia Tech, Blacksburg, VA, United States
| | - S Ahuja
- Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - P K Wagley
- Neurology, University of Virginia, Charlottesville, VA, USA
| | - R Settlage
- Advanced Research Computing, Virginia Tech, Blacksburg, VA, United States
| | - L E W LaConte
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - H P Goodkin
- Neurology, University of Virginia, Charlottesville, VA, USA
| | - I Lazar
- Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - S Srivastava
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States
| | - K Mukherjee
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States; Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, United States; Department of Psychiatry and Behavioral Medicine, Virginia Tech Carilion School of Medicine, Roanoke, VA, United States.
| |
Collapse
|
10
|
Abstract
Locomotion is an ancient and fundamental output of the nervous system required for animals to perform many other complex behaviors. Although the formation of motor circuits is known to be under developmental control of transcriptional mechanisms that define the fates and connectivity of the many neurons, glia and muscle constituents of these circuits, relatively little is known about the role of post-transcriptional regulation of locomotor behavior. MicroRNAs have emerged as a potentially rich source of modulators for neural development and function. In order to define the microRNAs required for normal locomotion in Drosophila melanogaster, we utilized a set of transgenic Gal4-dependent competitive inhibitors (microRNA sponges, or miR-SPs) to functionally assess ca. 140 high-confidence Drosophila microRNAs using automated quantitative movement tracking systems followed by multiparametric analysis. Using ubiquitous expression of miR-SP constructs, we identified a large number of microRNAs that modulate aspects of normal baseline adult locomotion. Addition of temperature-dependent Gal80 to identify microRNAs that act during adulthood revealed that the majority of these microRNAs play developmental roles. Comparison of ubiquitous and neural-specific miR-SP expression suggests that most of these microRNAs function within the nervous system. Parallel analyses of spontaneous locomotion in adults and in larvae also reveal that very few of the microRNAs required in the adult overlap with those that control the behavior of larval motor circuits. These screens suggest that a rich regulatory landscape underlies the formation and function of motor circuits and that many of these mechanisms are stage and/or parameter-specific.
Collapse
|
11
|
Grantham ME, Brisson JA. Extensive Differential Splicing Underlies Phenotypically Plastic Aphid Morphs. Mol Biol Evol 2018; 35:1934-1946. [PMID: 29722880 PMCID: PMC6063273 DOI: 10.1093/molbev/msy095] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Phenotypic plasticity results in a diversity of phenotypes from a single genotype in response to environmental cues. To understand the molecular basis of phenotypic plasticity, studies have focused on differential gene expression levels between environmentally determined phenotypes. The extent of alternative splicing differences among environmentally determined phenotypes has largely been understudied. Here, we study alternative splicing differences among plastically produced morphs of the pea aphid using RNA-sequence data. Pea aphids express two separate polyphenisms (plasticity with discrete phenotypes): a wing polyphenism consisting of winged and wingless females and a reproduction polyphenism consisting of asexual and sexual females. We find that pea aphids alternatively splice 34% of their genes, a high percentage for invertebrates. We also find that there is extensive use of differential spliced events between genetically identical, polyphenic females. These differentially spliced events are enriched for exon skipping and mutually exclusive exon events that maintain the open reading frame, suggesting that polyphenic morphs use alternative splicing to produce phenotype-biased proteins. Many genes that are differentially spliced between polyphenic morphs have putative functions associated with their respective phenotypes. We find that the majority of differentially spliced genes is not differentially expressed genes. Our results provide a rich candidate gene list for future functional studies that would not have been previously considered based solely on gene expression studies, such as ensconsin in the reproductive polyphenism, and CAKI in the wing polyphenism. Overall, this study suggests an important role for alternative splicing in the expression of environmentally determined phenotypes.
Collapse
Affiliation(s)
- Mary E Grantham
- Department of Biology, University of Rochester, Rochester, NY
| | | |
Collapse
|
12
|
Lo Piccolo L. Drosophila as a Model to Gain Insight into the Role of lncRNAs in Neurological Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1076:119-146. [PMID: 29951818 DOI: 10.1007/978-981-13-0529-0_8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
It is now clear that the majority of transcription in humans results in the production of long non-protein-coding RNAs (lncRNAs) with a variable length spanning from 200 bp up to several kilobases. To date, we have a limited understanding of the lncRNA function, but a huge number of evidences have suggested that lncRNAs represent an outstanding asset for cells. In particular, temporal and spatial expression of lncRNAs appears to be important for proper neurological functioning. Stunningly, abnormal lncRNA function has been found as being critical for the onset of neurological disorders. This chapter focus on the lncRNAs with a role in diseases affecting the central nervous system with particular regard for the lncRNAs causing those neurodegenerative diseases that exhibit dementia and/or motor dysfunctions. A specific section will be dedicated to the human neuronal lncRNAs that have been modelled in Drosophila. Finally, even if only few examples have been reported so far, an overview of the Drosophila lncRNAs with neurological functions will be also included in this chapter.
Collapse
Affiliation(s)
- Luca Lo Piccolo
- Department of Neurotherapeutics, Osaka University Graduate School of Medicine 2-2 Yamadaoka, Suita Osaka, 565-0871, Japan.
| |
Collapse
|
13
|
Liang C, Kerr A, Qiu Y, Cristofoli F, Van Esch H, Fox MA, Mukherjee K. Optic Nerve Hypoplasia Is a Pervasive Subcortical Pathology of Visual System in Neonates. Invest Ophthalmol Vis Sci 2017; 58:5485-5496. [PMID: 29067402 PMCID: PMC5656421 DOI: 10.1167/iovs.17-22399] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Purpose Optic nerve hypoplasia (ONH) is the most common cause of childhood congenital blindness in developed nations, yet the fundamental pathobiology of ONH remains unknown. The objective of this study was to employ a ‘face validated' murine model to determine the timing of onset and the pathologic characteristics of ONH. Methods Based on the robust linkage between X-linked CASK haploinsufficiency and clinically diagnosed ONH, we hypothesized that heterozygous deletion of CASK (CASK(+/−)) in rodents will produce an optic nerve pathology closely recapitulating ONH. We quantitatively analyzed the entire subcortical visual system in female CASK(+/−) mice using immunohistochemistry, anterograde axonal tracing, toluidine blue staining, transmission electron microscopy, and serial block-face scanning electron microscopy. Results CASK haploinsuffiency in mice phenocopies human ONH with complete penetrance, thus satisfying the ‘face validity'. We demonstrate that the optic nerve in CASK(+/−) mice is not only thin, but is comprised of atrophic retinal axons and displays reactive astrogliosis. Myelination of the optic nerve axons remains unchanged. Moreover, we demonstrate a significant decrease in retinal ganglion cell (RGC) numbers and perturbation in retinothalamic connectivity. Finally, we used this mouse model to define the onset and progression of ONH pathology, demonstrating for the first time that optic nerve defects arise at neonatally in CASK(+/−)mice. Conclusions Optic nerve hypoplasia is a complex neuropathology of the subcortical visual system involving RGC loss, axonopathy, and synaptopathy and originates at a developmental stage in mice that corresponds to the late third trimester development in humans.
Collapse
Affiliation(s)
- Chen Liang
- Developmental and Translational Neurobiology Center, Virginia Tech Carilion Research Institute, Roanoke, Virginia, United States.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States
| | - Alicia Kerr
- Developmental and Translational Neurobiology Center, Virginia Tech Carilion Research Institute, Roanoke, Virginia, United States.,Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, United States
| | - Yangfengzhong Qiu
- Developmental and Translational Neurobiology Center, Virginia Tech Carilion Research Institute, Roanoke, Virginia, United States
| | | | - Hilde Van Esch
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Michael A Fox
- Developmental and Translational Neurobiology Center, Virginia Tech Carilion Research Institute, Roanoke, Virginia, United States.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States
| | - Konark Mukherjee
- Developmental and Translational Neurobiology Center, Virginia Tech Carilion Research Institute, Roanoke, Virginia, United States.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States
| |
Collapse
|
14
|
Wang A, Wang J, Liu Y, Zhou Y. Mechanisms of Long Non-Coding RNAs in the Assembly and Plasticity of Neural Circuitry. Front Neural Circuits 2017; 11:76. [PMID: 29109677 PMCID: PMC5660110 DOI: 10.3389/fncir.2017.00076] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 09/28/2017] [Indexed: 12/31/2022] Open
Abstract
The mechanisms underlying development processes and functional dynamics of neural circuits are far from understood. Long non-coding RNAs (lncRNAs) have emerged as essential players in defining identities of neural cells, and in modulating neural activities. In this review, we summarized latest advances concerning roles and mechanisms of lncRNAs in assembly, maintenance and plasticity of neural circuitry, as well as lncRNAs' implications in neurological disorders. We also discussed technical advances and challenges in studying functions and mechanisms of lncRNAs in neural circuitry. Finally, we proposed that lncRNA studies would advance our understanding on how neural circuits develop and function in physiology and disease conditions.
Collapse
Affiliation(s)
- Andi Wang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Junbao Wang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Ying Liu
- Medical Research Institute, Wuhan University, Wuhan, China
| | - Yan Zhou
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China.,Medical Research Institute, Wuhan University, Wuhan, China
| |
Collapse
|
15
|
Rohde PD, Gaertner B, Ward K, Sørensen P, Mackay TFC. Genomic Analysis of Genotype-by-Social Environment Interaction for Drosophila melanogaster Aggressive Behavior. Genetics 2017; 206:1969-1984. [PMID: 28550016 PMCID: PMC5560801 DOI: 10.1534/genetics.117.200642] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/22/2017] [Indexed: 02/06/2023] Open
Abstract
Human psychiatric disorders such as schizophrenia, bipolar disorder, and attention-deficit/hyperactivity disorder often include adverse behaviors including increased aggressiveness. Individuals with psychiatric disorders often exhibit social withdrawal, which can further increase the probability of conducting a violent act. Here, we used the inbred, sequenced lines of the Drosophila Genetic Reference Panel (DGRP) to investigate the genetic basis of variation in male aggressive behavior for flies reared in a socialized and socially isolated environment. We identified genetic variation for aggressive behavior, as well as significant genotype-by-social environmental interaction (GSEI); i.e., variation among DGRP genotypes in the degree to which social isolation affected aggression. We performed genome-wide association (GWA) analyses to identify genetic variants associated with aggression within each environment. We used genomic prediction to partition genetic variants into gene ontology (GO) terms and constituent genes, and identified GO terms and genes with high prediction accuracies in both social environments and for GSEI. The top predictive GO terms significantly increased the proportion of variance explained, compared to prediction models based on all segregating variants. We performed genomic prediction across environments, and identified genes in common between the social environments that turned out to be enriched for genome-wide associated variants. A large proportion of the associated genes have previously been associated with aggressive behavior in Drosophila and mice. Further, many of these genes have human orthologs that have been associated with neurological disorders, indicating partially shared genetic mechanisms underlying aggression in animal models and human psychiatric disorders.
Collapse
Affiliation(s)
- Palle Duun Rohde
- Center for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University, 8830 Tjele, Denmark
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, 8000 Aarhus, Denmark
- ISEQ, Center for Integrative Sequencing, Aarhus University, 8000 Aarhus, Denmark
| | - Bryn Gaertner
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695
- Program in Genetics, North Carolina State University, Raleigh, North Carolina 27695
- W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina 27695
| | - Kirsty Ward
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695
- Program in Genetics, North Carolina State University, Raleigh, North Carolina 27695
- W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina 27695
| | - Peter Sørensen
- Center for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University, 8830 Tjele, Denmark
| | - Trudy F C Mackay
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695
- Program in Genetics, North Carolina State University, Raleigh, North Carolina 27695
- W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina 27695
| |
Collapse
|
16
|
X-linked intellectual disability gene CASK regulates postnatal brain growth in a non-cell autonomous manner. Acta Neuropathol Commun 2016; 4:30. [PMID: 27036546 PMCID: PMC4818453 DOI: 10.1186/s40478-016-0295-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 03/07/2016] [Indexed: 01/07/2023] Open
Abstract
The phenotypic spectrum among girls with heterozygous mutations in the X-linked intellectual disability (XLID) gene CASK (calcium/calmodulin-dependent serine protein kinase) includes postnatal microcephaly, ponto-cerebellar hypoplasia, seizures, optic nerve hypoplasia, growth retardation and hypotonia. Although CASK knockout mice were previously reported to exhibit perinatal lethality and a 3-fold increased apoptotic rate in the brain, CASK deletion was not found to affect neuronal physiology and their electrical properties. The pathogenesis of CASK associated disorders and the potential function of CASK therefore remains unknown. Here, using Cre-LoxP mediated gene excision experiments; we demonstrate that deleting CASK specifically from mouse cerebellar neurons does not alter the cerebellar architecture or function. We demonstrate that the neuron-specific deletion of CASK in mice does not cause perinatal lethality but induces severe recurrent epileptic seizures and growth retardation before the onset of adulthood. Furthermore, we demonstrate that although neuron-specific haploinsufficiency of CASK is inconsequential, the CASK mutation associated human phenotypes are replicated with high fidelity in CASK heterozygous knockout female mice (CASK(+/-)). These data suggest that CASK-related phenotypes are not purely neuronal in origin. Surprisingly, the observed microcephaly in CASK(+/-) animals is not associated with a specific loss of CASK null brain cells indicating that CASK regulates postnatal brain growth in a non-cell autonomous manner. Using biochemical assay, we also demonstrate that CASK can interact with metabolic proteins. CASK knockdown in human cell lines cause reduced cellular respiration and CASK(+/-) mice display abnormalities in muscle and brain oxidative metabolism, suggesting a novel function of CASK in metabolism. Our data implies that some phenotypic components of CASK heterozygous deletion mutation associated disorders represent systemic manifestation of metabolic stress and therefore amenable to therapeutic intervention.
Collapse
|
17
|
Tachibana SI, Touhara K, Ejima A. Modification of Male Courtship Motivation by Olfactory Habituation via the GABAA Receptor in Drosophila melanogaster. PLoS One 2015; 10:e0135186. [PMID: 26252206 PMCID: PMC4529276 DOI: 10.1371/journal.pone.0135186] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 07/18/2015] [Indexed: 11/29/2022] Open
Abstract
A male-specific component, 11-cis-vaccenyl acetate (cVA) works as an anti-aphrodisiac pheromone in Drosophila melanogaster. The presence of cVA on a male suppresses the courtship motivation of other males and contributes to suppression of male-male homosexual courtship, while the absence of cVA on a female stimulates the sexual motivation of nearby males and enhances the male-female interaction. However, little is known how a male distinguishes the presence or absence of cVA on a target fly from either self-produced cVA or secondhand cVA from other males in the vicinity. In this study, we demonstrate that male flies have keen sensitivity to cVA; therefore, the presence of another male in the area reduces courtship toward a female. This reduced level of sexual motivation, however, could be overcome by pretest odor exposure via olfactory habituation to cVA. Real-time imaging of cVA-responsive sensory neurons using the neural activity sensor revealed that prolonged exposure to cVA decreased the levels of cVA responses in the primary olfactory center. Pharmacological and genetic screening revealed that signal transduction via GABAA receptors contributed to this olfactory habituation. We also found that the habituation experience increased the copulation success of wild-type males in a group. In contrast, transgenic males, in which GABA input in a small subset of local neurons was blocked by RNAi, failed to acquire the sexual advantage conferred by habituation. Thus, we illustrate a novel phenomenon in which olfactory habituation positively affects sexual capability in a competitive environment.
Collapse
Affiliation(s)
- Shin-Ichiro Tachibana
- Career-Path Promotion Unit for Young Life Scientists, Kyoto University, Kyoto, 606–8501, Japan
- Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka, 558–8585, Japan
| | - Kazushige Touhara
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113–8657, Japan
- ERATO Touhara Chemosensory Signal Project, JST, The University of Tokyo, Tokyo, 113–8657, Japan
| | - Aki Ejima
- Career-Path Promotion Unit for Young Life Scientists, Kyoto University, Kyoto, 606–8501, Japan
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113–8657, Japan
- ERATO Touhara Chemosensory Signal Project, JST, The University of Tokyo, Tokyo, 113–8657, Japan
- * E-mail:
| |
Collapse
|
18
|
Wang Y, Lin H, Hao N, Zhu Z, Wang D, Li Y, Chen H, Zhu Y, Han X. Forkhead box O1 mediates defects in palmitate-induced insulin granule exocytosis by downregulation of calcium/calmodulin-dependent serine protein kinase expression in INS-1 cells. Diabetologia 2015; 58:1272-81. [PMID: 25796372 DOI: 10.1007/s00125-015-3561-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 02/24/2015] [Indexed: 01/15/2023]
Abstract
AIMS/HYPOTHESIS The transcription factor forkhead box O1 (FOXO1) induces pancreatic islet beta cell endoplasmic reticulum stress and is involved in fatty-acid-induced insulin-secretion defects. Cask is a downstream target gene of FOXO1. Using INS-1 cells with palmitate-induced insulin-release defects, we investigated the relationship between FOXO1 and Cask. METHODS The expression levels and location of calcium/calmodulin-dependent serine protein kinase (CASK) and FOXO1 were evaluated by real-time PCR, western blotting and immunofluorescence. The regulation of Cask by FOXO1 was examined using chromatin immunoprecipitation (ChIP) and luciferase assays. Potassium-stimulated insulin-secretion assays were used to verify the function of INS-1 cells and islets. Electron microscopy was used to establish the anchoring process of the insulin granules after CASK knockdown in islets. RESULTS Palmitic acid reduced CASK levels and increased FOXO1 levels. ChIP and luciferase assays demonstrated FOXO1 binding with the Cask promoter, which was enhanced by palmitate treatment. CASK knockdown reduced insulin release in INS-1 cells and primary islets, and Cask overexpression reversed the palmitate-induced insulin reduction. CASK knockdown attenuated forskolin-enhanced insulin release, but Cask overexpression did not change the insulin-secretion suppression induced by nifedipine. In pancreatic islet beta cells, CASK knockdown reduced the anchoring of insulin vesicles to cell membranes. CONCLUSIONS/INTERPRETATION The induction of beta cell insulin-secretion defects by fatty acids is mediated, at least in part, by FOXO1 via downregulation of Cask expression. It is characterised mainly as an obstruction of the anchoring of insulin granules to beta cell membranes.
Collapse
Affiliation(s)
- Yao Wang
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Southeast University, Nanjing, People's Republic of China
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Slawson JB, Kuklin EA, Mukherjee K, Pírez N, Donelson NC, Griffith LC. Regulation of dopamine release by CASK-β modulates locomotor initiation in Drosophila melanogaster. Front Behav Neurosci 2014; 8:394. [PMID: 25477794 PMCID: PMC4235261 DOI: 10.3389/fnbeh.2014.00394] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Accepted: 10/25/2014] [Indexed: 11/13/2022] Open
Abstract
CASK is an evolutionarily conserved scaffolding protein that has roles in many cell types. In Drosophila, loss of the entire CASK gene or just the CASK-β transcript causes a complex set of adult locomotor defects. In this study, we show that the motor initiation component of this phenotype is due to loss of CASK-β in dopaminergic neurons and can be specifically rescued by expression of CASK-β within this subset of neurons. Functional imaging demonstrates that mutation of CASK-β disrupts coupling of neuronal activity to vesicle fusion. Consistent with this, locomotor initiation can be rescued by artificially driving activity in dopaminergic neurons. The molecular mechanism underlying this role of CASK-β in dopaminergic neurons involves interaction with Hsc70-4, a molecular chaperone previously shown to regulate calcium-dependent vesicle fusion. These data suggest that there is a novel CASK-β-dependent regulatory complex in dopaminergic neurons that serves to link activity and neurotransmitter release.
Collapse
Affiliation(s)
- Justin B Slawson
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University Waltham, MA, USA
| | - Elena A Kuklin
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University Waltham, MA, USA
| | - Konark Mukherjee
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University Waltham, MA, USA
| | - Nicolás Pírez
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University Waltham, MA, USA
| | - Nathan C Donelson
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University Waltham, MA, USA
| | - Leslie C Griffith
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University Waltham, MA, USA
| |
Collapse
|
20
|
Neural functions of long noncoding RNAs in Drosophila. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2014; 201:921-6. [PMID: 25223318 DOI: 10.1007/s00359-014-0937-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Accepted: 08/22/2014] [Indexed: 12/23/2022]
Abstract
Long noncoding RNA (lncRNA) is an emerging category of transcript, and comprises the majority of the transcriptome of various complex organisms. The biological functions of only a handful of lncRNAs have been investigated in detail, showing involvement in a wide range of biological processes through different functional paradigms. However, most lncRNAs remain to be identified. Many lncRNAs are predicted to function, often preferentially, in the nervous system, potentially playing roles in mediating neural functions such as development, behavior, and cognition. To examine the biological significance and potential mechanisms of the remaining unknown neural lncRNAs, certain tractable model organisms, such as Drosophila, can provide advantages including the use of numerous genetic tools. Herein, we summarize recent progress on the in vivo or potential functions of Drosophila lncRNAs, in particular, behavior and development-related lncRNAs.
Collapse
|
21
|
Mukherjee K, Slawson JB, Christmann BL, Griffith LC. Neuron-specific protein interactions of Drosophila CASK-β are revealed by mass spectrometry. Front Mol Neurosci 2014; 7:58. [PMID: 25071438 PMCID: PMC4075472 DOI: 10.3389/fnmol.2014.00058] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 06/08/2014] [Indexed: 11/13/2022] Open
Abstract
Modular scaffolding proteins are designed to have multiple interactors. CASK, a member of the membrane-associated guanylate kinase (MAGUK) superfamily, has been shown to have roles in many tissues, including neurons and epithelia. It is likely that the set of proteins it interacts with is different in each of these diverse tissues. In this study we asked if within the Drosophila central nervous system, there were neuron-specific sets of CASK-interacting proteins. A YFP-tagged CASK-β transgene was expressed in genetically defined subsets of neurons in the Drosophila brain known to be important for CASK function, and proteins present in an anti-GFP immunoprecipitation were identified by mass spectrometry. Each subset of neurons had a distinct set of interacting proteins, suggesting that CASK participates in multiple protein networks and that these networks may be different in different neuronal circuits. One common set of proteins was associated with mitochondria, and we show here that endogenous CASK-β co-purifies with mitochondria. We also determined CASK-β posttranslational modifications for one cell type, supporting the idea that this technique can be used to assess cell- and circuit-specific protein modifications as well as protein interaction networks.
Collapse
Affiliation(s)
- Konark Mukherjee
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University Waltham, MA, USA
| | - Justin B Slawson
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University Waltham, MA, USA
| | - Bethany L Christmann
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University Waltham, MA, USA
| | - Leslie C Griffith
- Department of Biology, Volen Center for Complex Systems, National Center for Behavioral Genomics, Brandeis University Waltham, MA, USA
| |
Collapse
|
22
|
Malik BR, Hodge JJL. CASK and CaMKII function in Drosophila memory. Front Neurosci 2014; 8:178. [PMID: 25009461 PMCID: PMC4070058 DOI: 10.3389/fnins.2014.00178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 06/06/2014] [Indexed: 12/04/2022] Open
Abstract
Calcium (Ca2+) and Calmodulin (CaM)-dependent serine/threonine kinase II (CaMKII) plays a central role in synaptic plasticity and memory due to its ability to phosphorylate itself and regulate its own kinase activity. Autophosphorylation at threonine 287 (T287) switches CaMKII to a Ca2+ independent and constitutively active state replicated by overexpression of a phosphomimetic CaMKII-T287D transgene or blocked by expression of a T287A transgene. A second pair of sites, T306 T307 in the CaM binding region once autophosphorylated, prevents CaM binding and inactivates the kinase during synaptic plasticity and memory, and can be blocked by a TT306/7AA transgene. Recently the synaptic scaffolding molecule called CASK (Ca2+/CaM-associated serine kinase) has been shown to control both sets of CaMKII autophosphorylation events during neuronal growth, Ca2+ signaling and memory in Drosophila. Deletion of either full length CASK or just its CaMK-like and L27 domains removed middle-term memory (MTM) and long-term memory (LTM), with CASK function in the α′/ß′ mushroom body neurons being required for memory. In a similar manner directly changing the levels of CaMKII autophosphorylation (T287D, T287A, or TT306/7AA) in the α′/ß′ neurons also removed MTM and LTM. In the CASK null mutant expression of either the Drosophila or human CASK transgene in the α′/ß′ neurons was found to completely rescue memory, confirming that CASK signaling in α′/β′ neurons is necessary and sufficient for Drosophila memory formation and that the neuronal function of CASK is conserved between Drosophila and human. Expression of human CASK in Drosophila also rescued the effect of CASK deletion on the activity state of CaMKII, suggesting that human CASK may also regulate CaMKII autophosphorylation. Mutations in human CASK have recently been shown to result in intellectual disability and neurological defects suggesting a role in plasticity and learning possibly via regulation of CaMKII autophosphorylation.
Collapse
Affiliation(s)
- Bilal R Malik
- School of Physiology and Pharmacology, University of Bristol Bristol, UK
| | - James J L Hodge
- School of Physiology and Pharmacology, University of Bristol Bristol, UK
| |
Collapse
|
23
|
Petrosyan A, Gonçalves ÓF, Hsieh IH, Saberi K. Improved functional abilities of the life-extended Drosophila mutant Methuselah are reversed at old age to below control levels. AGE (DORDRECHT, NETHERLANDS) 2014; 36:213-21. [PMID: 23913251 PMCID: PMC3889883 DOI: 10.1007/s11357-013-9568-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 07/12/2013] [Indexed: 06/02/2023]
Abstract
Methuselah (mth) is a chromosome 3 Drosophila mutant with an increased lifespan. A large number of studies have investigated the genetic, molecular, and biochemical mechanisms of the mth gene. Much less is known about the effects of mth on preservation of sensorimotor abilities throughout Drosophila's lifespan, particularly in late life. The current study investigated functional senescence in mth and its parental-control line (w1118) in two experiments that measured age-dependent changes in flight functions and locomotor activity. In experiment 1, a total of 158 flies (81 mth and 77 controls) with an age range from 10 to 70 days were individually tethered under an infrared laser-sensor system that allowed monitoring of flight duration during phototaxic flight. We found that mth has a statistically significant advantage in maintaining continuous flight over control flies at age 10 days, but not during middle and late life. At age 70 days, the trend reversed and parental control flies had a small but significant advantage, suggesting an interaction between age and genotype in the ability to sustain flight. In experiment 2, a total of 173 different flies (97 mth and 76 controls) with an age range from 50 to 76 days were individually placed in a large well-lit arena (60 × 45 cm) and their locomotor activity quantified as the distance walked in a 1-min period. Results showed that mth flies had lower levels of locomotor activity relative to controls at ages 50 and 60 days. These levels converged for the two genotypes at the oldest ages tested. Findings show markedly different patterns of functional decline for the mth line relative to those previously reported for other life-extended genotypes, suggesting that different life-extending genes have dissimilar effects on preservation of sensory and motor abilities throughout an organism's lifespan.
Collapse
Affiliation(s)
- Agavni Petrosyan
- />Department of Cognitive Sciences, University of California, Irvine, CA 92697-5100 USA
- />Neuropsychophysiology Lab, CIPsi, School of Psychology, University of Minho, Braga, Portugal
| | - Óscar F. Gonçalves
- />Neuropsychophysiology Lab, CIPsi, School of Psychology, University of Minho, Braga, Portugal
- />Department of Counseling & Applied Educational Psychology, Bouvé College of Health Sciences, Northeastern University, Boston, USA
| | - I-Hui Hsieh
- />Institute of Cognitive Neuroscience, National Central University, Jhongli City, Taiwan
| | - Kourosh Saberi
- />Department of Cognitive Sciences, University of California, Irvine, CA 92697-5100 USA
| |
Collapse
|
24
|
Zhu ZQ, Wang D, Xiang D, Yuan YX, Wang Y. Calcium/calmodulin-dependent serine protein kinase is involved in exendin-4-induced insulin secretion in INS-1 cells. Metabolism 2014; 63:120-6. [PMID: 24140090 DOI: 10.1016/j.metabol.2013.09.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 08/23/2013] [Accepted: 09/15/2013] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Exendin-4 (Ex-4) is an anti-diabetic drug that is a potent agonist of the glucagon-like peptide-1 (GLP-1) receptor. It has already been approved for the treatment of type 2 diabetes mellitus, but its underlying mechanisms of action are not fully understood. Calcium/calmodulin-dependent serine protein kinase (CASK), which plays a vital role in the transport and release of neurotransmitters in neurons, is expressed in pancreatic islet cells and β-cells. This study aimed to investigate whether CASK is involved in the insulin secretagogue action induced by Ex-4 in INS-1 cells. MATERIAL/METHODS A glucose-stimulated insulin secretion (GSIS) assay was performed with or without siRNA treatment against CASK. The expression level and location of CASK were evaluated by real-time PCR, western blotting and immunofluorescence. With the use of a protein kinase A (PKA) inhibitor or an exchange protein directly activated by cAMP-2 (Epac2) agonist, immunoblotting was performed to establish the signaling pathway through which Ex-4 alters CASK expression. RESULTS Knock-down of CASK significantly attenuated the Ex-4-enhanced insulin release, and we showed that Ex-4 could increase transcription of CASK mRNA and expression of CASK protein but did not change the cellular location of CASK. A PKA inhibitor reduced the ability of Ex-4 to stimulate CASK expression, but an Epac2 agonist had no effect suggesting that regulation was mediated by the cAMP/PKA pathway. CONCLUSION Our study suggests that the stimulation of β-cell insulin secretion by Ex-4 is mediated, at least in part, by CASK via a novel signaling mechanism.
Collapse
Affiliation(s)
- Zheng-Qiu Zhu
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Southeast University, Nanjing 210009, PR China
| | | | | | | | | |
Collapse
|
25
|
Gillespie JM, Hodge JJL. CASK regulates CaMKII autophosphorylation in neuronal growth, calcium signaling, and learning. Front Mol Neurosci 2013; 6:27. [PMID: 24062638 PMCID: PMC3769642 DOI: 10.3389/fnmol.2013.00027] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 08/24/2013] [Indexed: 11/27/2022] Open
Abstract
Calcium (Ca2+)/calmodulin (CaM)-dependent kinase II (CaMKII) activity plays a fundamental role in learning and memory. A key feature of CaMKII in memory formation is its ability to be regulated by autophosphorylation, which switches its activity on and off during synaptic plasticity. The synaptic scaffolding protein CASK (calcium (Ca2+)/calmodulin (CaM) associated serine kinase) is also important for learning and memory, as mutations in CASK result in intellectual disability and neurological defects in humans. We show that in Drosophila larvae, CASK interacts with CaMKII to control neuronal growth and calcium signaling. Furthermore, deletion of the CaMK-like and L27 domains of CASK (CASK β null) or expression of overactive CaMKII (T287D) produced similar effects on synaptic growth and Ca2+ signaling. CASK overexpression rescues the effects of CaMKII overactivity, consistent with the notion that CASK and CaMKII act in a common pathway that controls these neuronal processes. The reduction in Ca2+ signaling observed in the CASK β null mutant caused a decrease in vesicle trafficking at synapses. In addition, the decrease in Ca2+ signaling in CASK mutants was associated with an increase in Ether-à-go-go (EAG) potassium (K+) channel localization to synapses. Reducing EAG restored the decrease in Ca2+ signaling observed in CASK mutants to the level of wildtype, suggesting that CASK regulates Ca2+ signaling via EAG. CASK knockdown reduced both appetitive associative learning and odor evoked Ca2+ responses in Drosophila mushroom bodies, which are the learning centers of Drosophila. Expression of human CASK in Drosophila rescued the effect of CASK deletion on the activity state of CaMKII, suggesting that human CASK may also regulate CaMKII autophosphorylation.
Collapse
Affiliation(s)
- John M Gillespie
- School of Physiology and Pharmacology, University of Bristol Bristol, UK
| | | |
Collapse
|
26
|
Abstract
CASK (Ca2+/calmodulin-activated serine kinase) is a synaptic protein that interacts with the cytosolic tail of adhesion molecules such as neurexins, syncam and syndecans. It belongs to the MAGUK (membrane-associated guanylate kinase) family of scaffolding proteins which are known to decorate cell–cell junctions. CASK is an essential gene in mammals, critical for neurodevelopment. Mutations in the CASK gene in humans result in phenotypes that range from intellectual disability to lethality. Despite its importance, CASK has a single genetic isoform located in the short arm of the X chromosome near an evolutionary breakpoint. Surprisingly, CASK is a non-essential gene in invertebrates and displays functional divergence. In the present article, we describe the phylogenetic differences in existing CASK orthologues. The CASK gene has undergone a huge expansion in size (~55-fold). Almost all of this expansion is a direct result of an increase in the size of the introns. The coding region of CASK orthologues, and hence the protein, exhibit a high degree of evolutionary conservation. Within the protein, domain arrangement is completely conserved and substitution rates are higher in the connecting loop regions [L27 (Lin2, Lin7)] than within the domain. Our analyses of single residue substitutions and genotype–phenotype relationships suggest that, other than intronic expansion, the dramatic functional changes of CASK are driven by subtle (non-radical) primary structure changes within the CASK protein and concomitant changes in its protein interactors.
Collapse
|
27
|
Gnanasekaran A, Sundukova M, Hullugundi S, Birsa N, Bianchini G, Hsueh YP, Nistri A, Fabbretti E. Calcium/calmodulin-dependent serine protein kinase (CASK) is a new intracellular modulator of P2X3 receptors. J Neurochem 2013; 126:102-12. [PMID: 23600800 DOI: 10.1111/jnc.12272] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 04/02/2013] [Accepted: 04/03/2013] [Indexed: 12/20/2022]
Abstract
ATP-gated P2X3 receptors of sensory ganglion neurons are important transducers of painful stimuli and are modulated by extracellular algogenic substances, via changes in the receptor phosphorylation state. The present study investigated the role of calcium/calmodulin-dependent serine protein kinase (CASK) in interacting and controlling P2X3 receptor expression and function in mouse trigeminal ganglia. Most ganglion neurons in situ or in culture co-expressed P2X3 and CASK. CASK was immunoprecipitated with P2X3 receptors from trigeminal ganglia and from P2X3/CASK-cotransfected human embryonic kidney (HEK) cells. Recombinant P2X3/CASK expression in HEK cells increased serine phosphorylation of P2X3 receptors, typically associated with receptor upregulation. CASK deletion mutants also enhanced P2X3 subunit expression. After silencing CASK, cell surface P2X3 receptor expression was decreased, which is consistent with depressed P2X3 currents. The reduction in P2X3 expression levels was reversed by the proteasomal inhibitor MG-132. Moreover, neuronal CASK/P2X3 interaction was up-regulated by nerve growth factor (NGF) signaling and down-regulated by P2X3 agonist-induced desensitization. These data suggest a novel interaction between CASK and P2X3 receptors with positive outcome for receptor stability and function. As CASK-mediated control of P2X3 receptors was dependent on the receptor activation state, CASK represents an intracellular gateway to regulate purinergic nociceptive signaling.
Collapse
Affiliation(s)
- Aswini Gnanasekaran
- Neuroscience Department, International School for Advanced Studies-SISSA, Trieste, Italy
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Malik BR, Gillespie JM, Hodge JJL. CASK and CaMKII function in the mushroom body α'/β' neurons during Drosophila memory formation. Front Neural Circuits 2013; 7:52. [PMID: 23543616 PMCID: PMC3608901 DOI: 10.3389/fncir.2013.00052] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 03/09/2013] [Indexed: 11/13/2022] Open
Abstract
Ca(2+)/CaM serine/threonine kinase II (CaMKII) is a central molecule in mechanisms of synaptic plasticity and memory. A vital feature of CaMKII in plasticity is its ability to switch to a calcium (Ca(2+)) independent constitutively active state after autophosphorylation at threonine 287 (T287). A second pair of sites, T306 T307 in the calmodulin (CaM) binding region once autophosphorylated, prevent subsequent CaM binding and inactivates the kinase during synaptic plasticity and memory. Recently a synaptic molecule called Ca(2+)/CaM-dependent serine protein kinase (CASK) has been shown to control both sets of CaMKII autophosphorylation events and hence is well poised to be a key regulator of memory. We show deletion of full length CASK or just its CaMK-like and L27 domains disrupts middle-term memory (MTM) and long-term memory (LTM), with CASK function in the α'/β' subset of mushroom body neurons being required for memory. Likewise directly changing the levels of CaMKII autophosphorylation in these neurons removed MTM and LTM. The requirement of CASK and CaMKII autophosphorylation was not developmental as their manipulation just in the adult α'/β' neurons was sufficient to remove memory. Overexpression of CASK or CaMKII in the α'/β' neurons also occluded MTM and LTM. Overexpression of either Drosophila or human CASK in the α'/β' neurons of the CASK mutant completely rescued memory, confirming that CASK signaling in α'/β' neurons is necessary and sufficient for Drosophila memory formation and that the neuronal function of CASK is conserved between Drosophila and human. At the cellular level CaMKII overexpression in the α'/β' neurons increased activity dependent Ca(2+) responses while reduction of CaMKII decreased it. Likewise reducing CASK or directly expressing a phosphomimetic CaMKII T287D transgene in the α'/β' similarly decreased Ca(2+) signaling. Our results are consistent with CASK regulating CaMKII autophosphorylation in a pathway required for memory formation that involves activity dependent changes in Ca(2+) signaling in the α'/β' neurons.
Collapse
Affiliation(s)
- Bilal R Malik
- School of Physiology and Pharmacology, University of Bristol Bristol, UK
| | | | | |
Collapse
|
29
|
Maiya R, Lee S, Berger KH, Kong EC, Slawson JB, Griffith LC, Takamiya K, Huganir RL, Margolis B, Heberlein U. DlgS97/SAP97, a neuronal isoform of discs large, regulates ethanol tolerance. PLoS One 2012; 7:e48967. [PMID: 23145041 PMCID: PMC3492131 DOI: 10.1371/journal.pone.0048967] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 10/01/2012] [Indexed: 11/19/2022] Open
Abstract
From a genetic screen for Drosophila melanogaster mutants with altered ethanol tolerance, we identified intolerant (intol), a novel allele of discs large 1 (dlg1). Dlg1 encodes Discs Large 1, a MAGUK (Membrane Associated Guanylate Kinase) family member that is the highly conserved homolog of mammalian PSD-95 and SAP97. The intol mutation disrupted specifically the expression of DlgS97, a SAP97 homolog, and one of two major protein isoforms encoded by dlg1 via alternative splicing. Expression of the major isoform, DlgA, a PSD-95 homolog, appeared unaffected. Ethanol tolerance in the intol mutant could be partially restored by transgenic expression of DlgS97, but not DlgA, in specific neurons of the fly's brain. Based on co-immunoprecipitation, DlgS97 forms a complex with N-methyl-D-aspartate (NMDA) receptors, a known target of ethanol. Consistent with these observations, flies expressing reduced levels of the essential NMDA receptor subunit dNR1 also showed reduced ethanol tolerance, as did mutants in the gene calcium/calmodulin-dependent protein kinase (caki), encoding the fly homolog of mammalian CASK, a known binding partner of DlgS97. Lastly, mice in which SAP97, the mammalian homolog of DlgS97, was conditionally deleted in adults failed to develop rapid tolerance to ethanol's sedative/hypnotic effects. We propose that DlgS97/SAP97 plays an important and conserved role in the development of tolerance to ethanol via NMDA receptor-mediated synaptic plasticity.
Collapse
Affiliation(s)
- Rajani Maiya
- Ernest Gallo Clinic and Research Center, Emeryville, California, United States of America
| | - Seonok Lee
- Department of Anatomy, University of California San Francisco, San Francisco, California, United States of America
| | - Karen H. Berger
- Ernest Gallo Clinic and Research Center, Emeryville, California, United States of America
| | - Eric C. Kong
- Ernest Gallo Clinic and Research Center, Emeryville, California, United States of America
| | - Justin B. Slawson
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Leslie C. Griffith
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Kogo Takamiya
- Department of Neuroscience, Faculty of Medicine, Graduate School of Medicine, University of Miyazaki, Kiyotake, Miyazaki, Japan
| | - Richard L. Huganir
- Department of Neuroscience and the Howard Hughes Medical Institute, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Ben Margolis
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Ulrike Heberlein
- Ernest Gallo Clinic and Research Center, Emeryville, California, United States of America
- Department of Anatomy, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
| |
Collapse
|
30
|
Li M, Wen S, Guo X, Bai B, Gong Z, Liu X, Wang Y, Zhou Y, Chen X, Liu L, Chen R. The novel long non-coding RNA CRG regulates Drosophila locomotor behavior. Nucleic Acids Res 2012; 40:11714-27. [PMID: 23074190 PMCID: PMC3526303 DOI: 10.1093/nar/gks943] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Long non-coding RNAs (lncRNAs) that have no protein-coding capacity make up a large proportion of the transcriptome of various species. Many lncRNAs are expressed within the animal central nervous system in spatial- and temporal-specific patterns, indicating that lncRNAs play important roles in cellular processes, neural development, and even in cognitive and behavioral processes. However, relatively little is known about their in vivo functions and underlying molecular mechanisms in the nervous system. Here, we report a neural-specific Drosophila lncRNA, CASK regulatory gene (CRG), which participates in locomotor activity and climbing ability by positively regulating its neighboring gene CASK (Ca(2+)/calmodulin-dependent protein kinase). CRG deficiency led to reduced locomotor activity and a defective climbing ability-phenotypes that are often seen in CASK mutant. CRG mutant also showed reduced CASK expression level while CASK over-expression could rescue the CRG mutant phenotypes in reciprocal. At the molecular level, CRG was required for the recruitment of RNA polymerase II to the CASK promoter regions, which in turn enhanced CASK expression. Our work has revealed new functional roles of lncRNAs and has provided insights to explore the pathogenesis of neurological diseases associated with movement disorders.
Collapse
Affiliation(s)
- Meixia Li
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Donelson N, Kim EZ, Slawson JB, Vecsey CG, Huber R, Griffith LC. High-resolution positional tracking for long-term analysis of Drosophila sleep and locomotion using the "tracker" program. PLoS One 2012; 7:e37250. [PMID: 22615954 PMCID: PMC3352887 DOI: 10.1371/journal.pone.0037250] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 04/18/2012] [Indexed: 11/18/2022] Open
Abstract
Drosophila melanogaster has been used for decades in the study of circadian behavior, and more recently has become a popular model for the study of sleep. The classic method for monitoring fly activity involves counting the number of infrared beam crosses in individual small glass tubes. Incident recording methods such as this can measure gross locomotor activity, but they are unable to provide details about where the fly is located in space and do not detect small movements (i.e. anything less than half the enclosure size), which could lead to an overestimation of sleep and an inaccurate report of the behavior of the fly. This is especially problematic if the fly is awake, but is not moving distances that span the enclosure. Similarly, locomotor deficiencies could be incorrectly classified as sleep phenotypes. To address these issues, we have developed a locomotor tracking technique (the "Tracker" program) that records the exact location of a fly in real time. This allows for the detection of very small movements at any location within the tube. In addition to circadian locomotor activity, we are able to collect other information, such as distance, speed, food proximity, place preference, and multiple additional parameters that relate to sleep structure. Direct comparisons of incident recording and our motion tracking application using wild type and locomotor-deficient (CASK-β null) flies show that the increased temporal resolution in the data from the Tracker program can greatly affect the interpretation of the state of the fly. This is especially evident when a particular condition or genotype has strong effects on the behavior, and can provide a wealth of information previously unavailable to the investigator. The interaction of sleep with other behaviors can also be assessed directly in many cases with this method.
Collapse
Affiliation(s)
- Nathan Donelson
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts, United States of America
| | - Eugene Z. Kim
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts, United States of America
| | - Justin B. Slawson
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts, United States of America
| | - Christopher G. Vecsey
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts, United States of America
| | - Robert Huber
- Department of Biological Sciences, JP Scott Center for Neuroscience, Mind, & Behavior, Bowling Green State University, Bowling Green, Ohio, United States of America
| | - Leslie C. Griffith
- Department of Biology, National Center for Behavioral Genomics and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
32
|
dyschronic, a Drosophila homolog of a deaf-blindness gene, regulates circadian output and Slowpoke channels. PLoS Genet 2012; 8:e1002671. [PMID: 22532808 PMCID: PMC3330124 DOI: 10.1371/journal.pgen.1002671] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 03/09/2012] [Indexed: 01/10/2023] Open
Abstract
Many aspects of behavior and physiology are under circadian control. In Drosophila, the molecular clock that regulates rhythmic patterns of behavior has been extensively characterized. In contrast, genetic loci involved in linking the clock to alterations in motor activity have remained elusive. In a forward-genetic screen, we uncovered a new component of the circadian output pathway, which we have termed dyschronic (dysc). dysc mutants exhibit arrhythmic locomotor behavior, yet their eclosion rhythms are normal and clock protein cycling remains intact. Intriguingly, dysc is the closest Drosophila homolog of whirlin, a gene linked to type II Usher syndrome, the leading cause of deaf-blindness in humans. Whirlin and other Usher proteins are expressed in the mammalian central nervous system, yet their function in the CNS has not been investigated. We show that DYSC is expressed in major neuronal tracts and regulates expression of the calcium-activated potassium channel SLOWPOKE (SLO), an ion channel also required in the circadian output pathway. SLO and DYSC are co-localized in the brain and control each other's expression post-transcriptionally. Co-immunoprecipitation experiments demonstrate they form a complex, suggesting they regulate each other through protein–protein interaction. Furthermore, electrophysiological recordings of neurons in the adult brain show that SLO-dependent currents are greatly reduced in dysc mutants. Our work identifies a Drosophila homolog of a deaf-blindness gene as a new component of the circadian output pathway and an important regulator of ion channel expression, and suggests novel roles for Usher proteins in the mammalian nervous system. In most organisms, endogenous circadian clocks help to restrict adaptive activities such as foraging and mating to ecologically appropriate periods of the day–night cycle. The fruit fly Drosophila melanogaster has been a crucial genetic model system for understanding the molecular underpinnings of the clock. Here, using a forward-genetic screen for mutant flies that lack circadian patterns of locomotion, we identify a novel gene critical to circadian behavior, which we have termed dyschronic (dysc). Interestingly, DYSC is not part of the molecular clock itself, but acts in an intermediate circuit between clock cells and motor neurons to regulate temporal alterations in locomotion. DYSC contains several protein-binding domains, suggesting a role as a scaffolding protein. Indeed, we show that DYSC forms a mutually dependent complex with the SLOWPOKE Ca2+–activated potassium channel, an ion channel required for circadian output. DYSC regulates SLOWPOKE expression and SLOWPOKE-dependent currents in the fly brain. Furthermore, dysc is the closest Drosophila homolog of whirlin, a locus mutated in the human deaf-blindness disease Type II Usher syndrome. Our results identify a novel ion channel regulator that impacts neuronal physiology and complex behavior, and suggest new roles for Whirlin in the human nervous system.
Collapse
|
33
|
Chorna T, Hasan G. The genetics of calcium signaling in Drosophila melanogaster. Biochim Biophys Acta Gen Subj 2011; 1820:1269-82. [PMID: 22100727 DOI: 10.1016/j.bbagen.2011.11.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 10/31/2011] [Accepted: 11/02/2011] [Indexed: 01/13/2023]
Abstract
BACKGROUND Genetic screens for behavioral and physiological defects in Drosophila melanogaster, helped identify several components of calcium signaling of which some, like the Trps, were novel. For genes initially identified in vertebrates, reverse genetic methods have allowed functional studies at the cellular and systemic levels. SCOPE OF REVIEW The aim of this review is to explain how various genetic methods available in Drosophila have been used to place different arms of Ca2+ signaling in the context of organismal development, physiology and behavior. MAJOR CONCLUSION Mutants generated in genes encoding a range of Ca2+ transport systems, binding proteins and enzymes affect multiple aspects of neuronal and muscle physiology. Some also affect the maintenance of ionic balance and excretion from malpighian tubules and innate immune responses in macrophages. Aspects of neuronal physiology affected include synaptic growth and plasticity, sensory transduction, flight circuit development and function. Genetic interaction screens have shown that mechanisms of maintaining Ca2+ homeostasis in Drosophila are cell specific and require a synergistic interplay between different intracellular and plasma membrane Ca2+ signaling molecules. GENERAL SIGNIFICANCE Insights gained through genetic studies of conserved Ca2+ signaling pathways have helped understand multiple aspects of fly physiology. The similarities between mutant phenotypes of Ca2+ signaling genes in Drosophila with certain human disease conditions, especially where homologous genes are causative factors, are likely to aid in the discovery of underlying disease mechanisms and help develop novel therapeutic strategies. This article is part of a Special Issue entitled Biochemical, biophysical and genetic approaches to intracellular calcium signalling.
Collapse
Affiliation(s)
- Tetyana Chorna
- National Center for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | | |
Collapse
|
34
|
Pre and postsynaptic roles for Drosophila CASK. Mol Cell Neurosci 2011; 48:171-82. [PMID: 21820054 DOI: 10.1016/j.mcn.2011.07.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 07/19/2011] [Accepted: 07/21/2011] [Indexed: 12/24/2022] Open
Abstract
CASK ('calcium/calmodulin-dependent serine protein kinase'), also known in Drosophila as 'Caki' or 'Camguk/CMG', and in C. elegans as 'Lin-2', is thought to play an important role in cell-cell junction formation and at synapses in particular. To understand the role of CASK in synapse formation and function, we functionally and morphologically analyzed Drosophila embryonic and larval glutamatergic neuromuscular junctions (NMJs) after pan-cellular and tissue-specific manipulation of CASK expression. Our results show that Drosophila CASK is associated with both pre and postsynaptic membranes. Loss of presynaptic CASK led to less evoked synaptic transmission, fewer spontaneous synaptic events, and reduced synaptic vesicle cycling. These changes were accompanied by a reduction in the number of synapses but no change in overall NMJ size. Loss of postsynaptic CASK, on the other hand, caused reduced spontaneous synaptic current amplitudes and smaller glutamate-gated currents. These changes were accompanied by loss of postsynaptic glutamate receptors, but the receptor loss was subtype-specific: Only receptors containing GluRIIA subunits were lost in CASK mutants. Receptors containing GluRIIB were unaffected.
Collapse
|