1
|
Lancaster CL, Yalamanchili PS, Goldy JN, Leung SW, Corbett AH, Moberg KH. The RNA-binding protein Nab2 regulates levels of the RhoGEF Trio to govern axon and dendrite morphology. Mol Biol Cell 2024; 35:ar109. [PMID: 38985523 DOI: 10.1091/mbc.e24-04-0150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2024] Open
Abstract
The Drosophila RNA-binding protein (RBP) Nab2 acts in neurons to regulate neurodevelopment and is orthologous to the human intellectual disability-linked RBP, ZC3H14. Nab2 governs axon projection in mushroom body neurons and limits dendritic arborization of class IV sensory neurons in part by regulating splicing events in ∼150 mRNAs. Analysis of the Sex-lethal (Sxl) mRNA revealed that Nab2 promotes an exon-skipping event and regulates m6A methylation on Sxl pre-mRNA by the Mettl3 methyltransferase. Mettl3 heterozygosity broadly rescues Nab2null phenotypes implying that Nab2 acts through similar mechanisms on other RNAs, including unidentified targets involved in neurodevelopment. Here, we show that Nab2 and Mettl3 regulate the removal of a 5'UTR (untranslated region) intron in the trio pre-mRNA. Trio utilizes two GEF domains to balance Rac and RhoGTPase activity. Intriguingly, an isoform of Trio containing only the RhoGEF domain, GEF2, is depleted in Nab2null nervous tissue. Expression of Trio-GEF2 rescues projection defects in Nab2null axons and dendrites, while the GEF1 Rac1-regulatory domain exacerbates these defects, suggesting Nab2-mediated regulation Trio-GEF activities. Collectively, these data indicate that Nab2-regulated processing of trio is critical for balancing Trio-GEF1 and -GEF2 activity and show that Nab2, Mettl3, and Trio function in a common pathway that shapes axon and dendrite morphology.
Collapse
Affiliation(s)
- Carly L Lancaster
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA 30322
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University, Atlanta, GA 30322
| | - Pranav S Yalamanchili
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA 30322
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
| | - Jordan N Goldy
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA 30322
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
- Graduate Program in Biochemistry, Cell and Developmental Biology, Emory University, Atlanta, GA 30322
| | - Sara W Leung
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA 30322
| | - Anita H Corbett
- Department of Biology, Emory College of Arts and Sciences, Atlanta, GA 30322
| | - Kenneth H Moberg
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
| |
Collapse
|
2
|
Katrancha SM, Shaw JE, Zhao AY, Myers SA, Cocco AR, Jeng AT, Zhu M, Pittenger C, Greer CA, Carr SA, Xiao X, Koleske AJ. Trio Haploinsufficiency Causes Neurodevelopmental Disease-Associated Deficits. Cell Rep 2020; 26:2805-2817.e9. [PMID: 30840899 PMCID: PMC6436967 DOI: 10.1016/j.celrep.2019.02.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 12/22/2018] [Accepted: 02/06/2019] [Indexed: 12/31/2022] Open
Abstract
Heterozygous coding mutations in TRIO are associated with neurodevelopmental disorders, including autism, schizophrenia, bipolar disorder, and epilepsy, and impair TRIO's biochemical activities. To model mutant alleles, we ablated one or both Trio alleles from excitatory neurons in the cortex and hippocampus of mice. Trio haploinsufficiency increases anxiety and impairs social preference and motor coordination. Trio loss reduces forebrain size and dendritic arborization but increases dendritic spine densities. Cortical synapses in Trio haploinsufficient mice are small, exhibit pre- and postsynaptic deficits, and cannot undergo long-term potentiation. Similar phenotypes are observed in Trio knockout mice. Overall, Trio haploinsufficiency causes severe disease-relevant deficits in behavior and neuronal structure and function. Interestingly, phosphodiesterase 4A5 (PDE4A5) levels are reduced and protein kinase A (PKA) signaling is increased when TRIO levels are reduced. Elevation of PDE4A5 and drug-based attenuation of PKA signaling rescue Trio haploinsufficiency-related dendritic spine defects, suggesting an avenue for therapeutic intervention for TRIO-related neurodevelopmental disorders.
Collapse
Affiliation(s)
- Sara Marie Katrancha
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06510, USA; Department of Neuroscience, Yale University, New Haven, CT 06510, USA
| | - Juliana E Shaw
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Amy Y Zhao
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06510, USA; Department of Neuroscience, Yale University, New Haven, CT 06510, USA
| | - Samuel A Myers
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Amanda T Jeng
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06510, USA
| | - Minsheng Zhu
- Model Animal Research Center, Nanjing University, Nanjing 210061, China
| | - Christopher Pittenger
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06510, USA; Department of Psychiatry, Yale University, New Haven, CT 06510, USA; Child Study Center, Yale University, New Haven, CT 06510, USA
| | - Charles A Greer
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06510, USA; Department of Neuroscience, Yale University, New Haven, CT 06510, USA; Department of Neurosurgery, Yale University, New Haven, CT 06510, USA
| | - Steven A Carr
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Xiao Xiao
- Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai 200433, China; Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence (Fudan University), Ministry of Education, Shanghai 200433, China.
| | - Anthony J Koleske
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06510, USA; Department of Neuroscience, Yale University, New Haven, CT 06510, USA.
| |
Collapse
|
3
|
Niftullayev S, Lamarche-Vane N. Regulators of Rho GTPases in the Nervous System: Molecular Implication in Axon Guidance and Neurological Disorders. Int J Mol Sci 2019; 20:E1497. [PMID: 30934641 PMCID: PMC6471118 DOI: 10.3390/ijms20061497] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 03/18/2019] [Indexed: 12/11/2022] Open
Abstract
One of the fundamental steps during development of the nervous system is the formation of proper connections between neurons and their target cells-a process called neural wiring, failure of which causes neurological disorders ranging from autism to Down's syndrome. Axons navigate through the complex environment of a developing embryo toward their targets, which can be far away from their cell bodies. Successful implementation of neuronal wiring, which is crucial for fulfillment of all behavioral functions, is achieved through an intimate interplay between axon guidance and neural activity. In this review, our focus will be on axon pathfinding and the implication of some of its downstream molecular components in neurological disorders. More precisely, we will talk about axon guidance and the molecules implicated in this process. After, we will briefly review the Rho family of small GTPases, their regulators, and their involvement in downstream signaling pathways of the axon guidance cues/receptor complexes. We will then proceed to the final and main part of this review, where we will thoroughly comment on the implication of the regulators for Rho GTPases-GEFs (Guanine nucleotide Exchange Factors) and GAPs (GTPase-activating Proteins)-in neurological diseases and disorders.
Collapse
Affiliation(s)
- Sadig Niftullayev
- Cancer Research Program, Research Institute of the MUHC, Montreal, QC H4A 3J1, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 2B2, Canada.
| | - Nathalie Lamarche-Vane
- Cancer Research Program, Research Institute of the MUHC, Montreal, QC H4A 3J1, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 2B2, Canada.
| |
Collapse
|
4
|
Shao L, Lu B, Wen Z, Teng S, Wang L, Zhao Y, Wang L, Ishizuka K, Xu X, Sawa A, Song H, Ming G, Zhong Y. Disrupted-in-Schizophrenia-1 (DISC1) protein disturbs neural function in multiple disease-risk pathways. Hum Mol Genet 2018; 26:2634-2648. [PMID: 28472294 DOI: 10.1093/hmg/ddx147] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/13/2017] [Indexed: 12/20/2022] Open
Abstract
Although the genetic contribution is under debate, biological studies in multiple mouse models have suggested that the Disrupted-in-Schizophrenia-1 (DISC1) protein may contribute to susceptibility to psychiatric disorders. In the present study, we took the advantages of the Drosophila model to dissect the molecular pathways that can be affected by DISC1 in the context of pathology-related phenotypes. We found that three pathways that include the homologs of Drosophila Dys, Trio, and Shot were downregulated by introducing a C-terminal truncated mutant DISC1. Consistently, these three molecules were downregulated in the induced pluripotent stem cell-derived forebrain neurons from the subjects carrying a frameshift deletion in DISC1 C-terminus. Importantly, the three pathways were underscored in the pathophysiology of psychiatric disorders in bioinformatics analysis. Taken together, our findings are in line with the polygenic theory of psychiatric disorders.
Collapse
Affiliation(s)
- Lisha Shao
- Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, P.R. China.,Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Binyan Lu
- Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, P.R. China.,State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, P.R. China
| | - Zhexing Wen
- Departments of Psychiatry and Behavioral Sciences, Cell Biology, and Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Shaolei Teng
- Department of Biology, Howard University, Washington, DC 20059, USA
| | - Lingling Wang
- Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, P.R. China
| | - Yi Zhao
- Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, P.R. China
| | - Liyuan Wang
- Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, P.R. China
| | - Koko Ishizuka
- Molecular Psychiatry Program, Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Xiufeng Xu
- Department of Psychiatry, First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - Akira Sawa
- Molecular Psychiatry Program, Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Hongjun Song
- Departments of Psychiatry and Behavioral Sciences, Cell Biology, and Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Guoli Ming
- Departments of Psychiatry and Behavioral Sciences, Cell Biology, and Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Yi Zhong
- Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, P.R. China.,Cold Spring Harbor Lab, Cold Spring Harbor, NY 11724, USA
| |
Collapse
|
5
|
Katrancha SM, Wu Y, Zhu M, Eipper BA, Koleske AJ, Mains RE. Neurodevelopmental disease-associated de novo mutations and rare sequence variants affect TRIO GDP/GTP exchange factor activity. Hum Mol Genet 2017; 26:4728-4740. [PMID: 28973398 PMCID: PMC5886096 DOI: 10.1093/hmg/ddx355] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 08/07/2017] [Accepted: 08/22/2017] [Indexed: 12/19/2022] Open
Abstract
Bipolar disorder, schizophrenia, autism and intellectual disability are complex neurodevelopmental disorders, debilitating millions of people. Therapeutic progress is limited by poor understanding of underlying molecular pathways. Using a targeted search, we identified an enrichment of de novo mutations in the gene encoding the 330-kDa triple functional domain (TRIO) protein associated with neurodevelopmental disorders. By generating multiple TRIO antibodies, we show that the smaller TRIO9 isoform is the major brain protein product, and its levels decrease after birth. TRIO9 contains two guanine nucleotide exchange factor (GEF) domains with distinct specificities: GEF1 activates both Rac1 and RhoG; GEF2 activates RhoA. To understand the impact of disease-associated de novo mutations and other rare sequence variants on TRIO function, we utilized two FRET-based biosensors: a Rac1 biosensor to study mutations in TRIO (T)GEF1, and a RhoA biosensor to study mutations in TGEF2. We discovered that one autism-associated de novo mutation in TGEF1 (K1431M), at the TGEF1/Rac1 interface, markedly decreased its overall activity toward Rac1. A schizophrenia-associated rare sequence variant in TGEF1 (F1538Intron) was substantially less active, normalized to protein level and expressed poorly. Overall, mutations in TGEF1 decreased GEF1 activity toward Rac1. One bipolar disorder-associated rare variant (M2145T) in TGEF2 impaired inhibition by the TGEF2 pleckstrin-homology domain, resulting in dramatically increased TGEF2 activity. Overall, genetic damage to both TGEF domains altered TRIO catalytic activity, decreasing TGEF1 activity and increasing TGEF2 activity. Importantly, both GEF changes are expected to decrease neurite outgrowth, perhaps consistent with their association with neurodevelopmental disorders.
Collapse
Affiliation(s)
- Sara M Katrancha
- Interdepartmental Neuroscience Program
- Department of Neuroscience
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Yi Wu
- Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT, USA
| | - Minsheng Zhu
- Model Animal Research Center, Nanjing University, Nanjing 210061, China
| | - Betty A Eipper
- Department of Neuroscience
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, USA
| | - Anthony J Koleske
- Interdepartmental Neuroscience Program
- Department of Neuroscience
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | | |
Collapse
|
6
|
The function of Drosophila larval class IV dendritic arborization sensory neurons in the larval-pupal transition is separable from their function in mechanical nociception responses. PLoS One 2017; 12:e0184950. [PMID: 28910410 PMCID: PMC5599056 DOI: 10.1371/journal.pone.0184950] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 09/05/2017] [Indexed: 11/19/2022] Open
Abstract
The sensory and physiological inputs which govern the larval-pupal transition in Drosophila, and the neuronal circuity that integrates them, are complex. Previous work from our laboratory identified a dosage-sensitive genetic interaction between the genes encoding the Rho-GEF Trio and the zinc-finger transcription factor Sequoia that interfered with the larval-pupal transition. Specifically, we reported heterozygous mutations in sequoia (seq) dominantly exacerbated the trio mutant phenotype, and this seq-enhanced trio mutant genotype blocked the transition of third instar larvae from foragers to wanderers, a requisite behavioral transition prior to pupation. In this work, we use the GAL4-UAS system to rescue this phenotype by tissue-specific trio expression. We find that expressing trio in the class IV dendritic arborization (da) sensory neurons rescues the larval-pupal transition, demonstrating the reliance of the larval-pupal transition on the integrity of these sensory neurons. As nociceptive responses also rely on the functionality of the class IV da neurons, we test mechanical nociceptive responses in our mutant and rescued larvae and find that mechanical nociception is separable from the ability to undergo the larval-pupal transition. This demonstrates for the first time that the roles of the class IV da neurons in governing two critical larval behaviors, the larval-pupal transition and mechanical nociception, are functionally separable from each other.
Collapse
|
7
|
Kannan R, Song JK, Karpova T, Clarke A, Shivalkar M, Wang B, Kotlyanskaya L, Kuzina I, Gu Q, Giniger E. The Abl pathway bifurcates to balance Enabled and Rac signaling in axon patterning in Drosophila. Development 2017; 144:487-498. [PMID: 28087633 DOI: 10.1242/dev.143776] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 12/15/2016] [Indexed: 01/31/2023]
Abstract
The Abl tyrosine kinase signaling network controls cell migration, epithelial organization, axon patterning and other aspects of development. Although individual components are known, the relationships among them remain unresolved. We now use FRET measurements of pathway activity, analysis of protein localization and genetic epistasis to dissect the structure of this network in Drosophila We find that the adaptor protein Disabled stimulates Abl kinase activity. Abl suppresses the actin-regulatory factor Enabled, and we find that Abl also acts through the GEF Trio to stimulate the signaling activity of Rac GTPase: Abl gates the activity of the spectrin repeats of Trio, allowing them to relieve intramolecular repression of Trio GEF activity by the Trio N-terminal domain. Finally, we show that a key target of Abl signaling in axons is the WAVE complex that promotes the formation of branched actin networks. Thus, we show that Abl constitutes a bifurcating network, suppressing Ena activity in parallel with stimulation of WAVE. We suggest that the balancing of linear and branched actin networks by Abl is likely to be central to its regulation of axon patterning.
Collapse
Affiliation(s)
- Ramakrishnan Kannan
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jeong-Kuen Song
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tatiana Karpova
- National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Akanni Clarke
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Madhuri Shivalkar
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Benjamin Wang
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lyudmila Kotlyanskaya
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Irina Kuzina
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Qun Gu
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Edward Giniger
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
8
|
Long-Term Memory in Drosophila Is Influenced by Histone Deacetylase HDAC4 Interacting with SUMO-Conjugating Enzyme Ubc9. Genetics 2016; 203:1249-64. [PMID: 27182943 DOI: 10.1534/genetics.115.183194] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 04/29/2016] [Indexed: 12/28/2022] Open
Abstract
HDAC4 is a potent memory repressor with overexpression of wild type or a nuclear-restricted mutant resulting in memory deficits. Interestingly, reduction of HDAC4 also impairs memory via an as yet unknown mechanism. Although histone deacetylase family members are important mediators of epigenetic mechanisms in neurons, HDAC4 is predominantly cytoplasmic in the brain and there is increasing evidence for interactions with nonhistone proteins, suggesting HDAC4 has roles beyond transcriptional regulation. To that end, we performed a genetic interaction screen in Drosophila and identified 26 genes that interacted with HDAC4, including Ubc9, the sole SUMO E2-conjugating enzyme. RNA interference-induced reduction of Ubc9 in the adult brain impaired long-term memory in the courtship suppression assay, a Drosophila model of associative memory. We also demonstrate that HDAC4 and Ubc9 interact genetically during memory formation, opening new avenues for investigating the mechanisms through which HDAC4 regulates memory formation and other neurological processes.
Collapse
|
9
|
Ba W, Yan Y, Reijnders MRF, Schuurs-Hoeijmakers JHM, Feenstra I, Bongers EMHF, Bosch DGM, De Leeuw N, Pfundt R, Gilissen C, De Vries PF, Veltman JA, Hoischen A, Mefford HC, Eichler EE, Vissers LELM, Nadif Kasri N, De Vries BBA. TRIO loss of function is associated with mild intellectual disability and affects dendritic branching and synapse function. Hum Mol Genet 2015; 25:892-902. [PMID: 26721934 DOI: 10.1093/hmg/ddv618] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 12/18/2015] [Indexed: 12/21/2022] Open
Abstract
Recently, we marked TRIO for the first time as a candidate gene for intellectual disability (ID). Across diverse vertebrate species, TRIO is a well-conserved Rho GTPase regulator that is highly expressed in the developing brain. However, little is known about the specific events regulated by TRIO during brain development and its clinical impact in humans when mutated. Routine clinical diagnostic testing identified an intragenic de novo deletion of TRIO in a boy with ID. Targeted sequencing of this gene in over 2300 individuals with ID, identified three additional truncating mutations. All index cases had mild to borderline ID combined with behavioral problems consisting of autistic, hyperactive and/or aggressive behavior. Studies in dissociated rat hippocampal neurons demonstrated the enhancement of dendritic formation by suppressing endogenous TRIO, and similarly decreasing endogenous TRIO in organotypic hippocampal brain slices significantly increased synaptic strength by increasing functional synapses. Together, our findings provide new mechanistic insight into how genetic deficits in TRIO can lead to early neuronal network formation by directly affecting both neurite outgrowth and synapse development.
Collapse
Affiliation(s)
- Wei Ba
- Department of Human Genetics, Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Yan Yan
- Department of Neuroscience, UCONN Health Center, Farmington, CT 06030, USA
| | | | | | | | | | - Daniëlle G M Bosch
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands, Bartiméus, Institute for the Visually Impaired, Zeist, The Netherlands and
| | | | | | | | | | - Joris A Veltman
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands, Department of Clinical Genetics, Maastricht University Medical Centre, Maastricht, The Netherlands
| | | | - Heather C Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Evan E Eichler
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA, Howard Hughes Medical Institute, Seattle, WA 98195, USA
| | | | - Nael Nadif Kasri
- Department of Human Genetics, Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands,
| | - Bert B A De Vries
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands,
| |
Collapse
|
10
|
Copf T. Importance of gene dosage in controlling dendritic arbor formation during development. Eur J Neurosci 2015; 42:2234-49. [PMID: 26108333 DOI: 10.1111/ejn.13002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 06/05/2015] [Accepted: 06/18/2015] [Indexed: 12/11/2022]
Abstract
Proper dendrite morphology is crucial for normal nervous system functioning. While a number of genes have been implicated in dendrite morphogenesis in both invertebrates and mammals, it remains unclear how developing dendrites respond to changes in gene dosage and what type of patterns their responses may follow. To understand this, I review here evidence from the recent literature, focusing on the genetic studies performed in the Drosophila larval dendritic arborization class IV neuron, an excellent cell type to understand dendrite morphogenesis. I summarize how class IV arbors change morphology in response to developmental fluctuations in the expression levels of 47 genes, studied by means of genetic manipulations such as loss-of-function and gain-of-function, and for which sufficient information is available. I find that arbors can respond to changing gene dosage in several distinct ways, each characterized by a singular dose-response curve. Interestingly, in 72% of cases arbors are sensitive, and thus adjust their morphology, in response to both decreases and increases in the expression of a given gene, indicating that dendrite morphogenesis is a process particularly sensitive to gene dosage. By summarizing the parallels between Drosophila and mammals, I show that many Drosophila dendrite morphogenesis genes have orthologs in mammals, and that some of these are associated with mammalian dendrite outgrowth and human neurodevelopmental disorders. One notable disease-related molecule is kinase Dyrk1A, thought to be a causative factor in Down syndrome. Both increases and decreases in Dyrk1A gene dosage lead to impaired dendrite morphogenesis, which may contribute to Down syndrome pathoetiology.
Collapse
Affiliation(s)
- Tijana Copf
- Institute of Molecular Biology and Biotechnology, Nikolaou Plastira 100, PO Box 1385, Heraklion, GR-70013, Crete, Greece
| |
Collapse
|
11
|
Zong W, Liu S, Wang X, Zhang J, Zhang T, Liu Z, Wang D, Zhang A, Zhu M, Gao J. Trio gene is required for mouse learning ability. Brain Res 2015; 1608:82-90. [PMID: 25727174 DOI: 10.1016/j.brainres.2015.02.040] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 02/03/2015] [Accepted: 02/15/2015] [Indexed: 01/08/2023]
Abstract
Trio is a guanine nucleotide exchange factor with multiple guanine nucleotide exchange factor domains. Trio regulates cytoskeleton dynamics and actin remodeling and is involved in cell migration and axonal guidance in neuronal development. The null allele of the Trio gene led to embryonic lethality, and Trio null embryos displayed aberrant organization in several regions of the brain at E18.5, including hippocampus. Nestin-Trio-/- mice, in which the Trio gene was deleted specifically in the neuronal system by the Nestin-Cre system, displayed severe phenotypes, including low survival rate, ataxia and multiple developmental defects of the cerebellum. All Nestin-Trio-/- mice died before reaching adulthood, which hinders research on Trio gene function in adult mice. Thus, we generated EMX1-Trio-/- mice by crossing Trio-floxed mice with EMX1-Cre mice in which Cre is expressed in the brain cortex and hippocampus. EMX1-Trio-/- mice can survive to adulthood. Trio gene deletion results in smaller brains, an abnormal hippocampus and disordered granule cells in the dentate gyrus (DG) and cornu ammonis (CA). Behavior tests showed that Trio deletion interfered with the hippocampal-dependent spatial learning in the mice, suggesting that Trio plays critical roles in the learning ability of adult mice. We conclude that the Trio gene regulates the neuronal development of the hippocampus and that it affects the intelligence of adult mice.
Collapse
Affiliation(s)
- Wen Zong
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Shuoyang Liu
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Xiaotong Wang
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Jian Zhang
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Tingting Zhang
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Ziyi Liu
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Dongdong Wang
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, School of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Aizhen Zhang
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China
| | - Minsheng Zhu
- Model Animal Research Center, Key Laboratory of Model Animal for Disease Study of Ministry of Education, Nanjing University, Nanjing210061, China.
| | - Jiangang Gao
- Key Laboratory of the Ministry of Education for Experimental Teratology and School of Life Science, Shandong University, Jinan 250100, China.
| |
Collapse
|
12
|
Kannan R, Kuzina I, Wincovitch S, Nowotarski SH, Giniger E. The Abl/enabled signaling pathway regulates Golgi architecture in Drosophila photoreceptor neurons. Mol Biol Cell 2014; 25:2993-3005. [PMID: 25103244 PMCID: PMC4230588 DOI: 10.1091/mbc.e14-02-0729] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 06/04/2014] [Accepted: 07/29/2014] [Indexed: 11/24/2022] Open
Abstract
The Golgi apparatus is optimized separately in different tissues for efficient protein trafficking, but we know little of how cell signaling shapes this organelle. We now find that the Abl tyrosine kinase signaling pathway controls the architecture of the Golgi complex in Drosophila photoreceptor (PR) neurons. The Abl effector, Enabled (Ena), selectively labels the cis-Golgi in developing PRs. Overexpression or loss of function of Ena increases the number of cis- and trans-Golgi cisternae per cell, and Ena overexpression also redistributes Golgi to the most basal portion of the cell soma. Loss of Abl or its upstream regulator, the adaptor protein Disabled, lead to the same alterations of Golgi as does overexpression of Ena. The increase in Golgi number in Abl mutants arises in part from increased frequency of Golgi fission events and a decrease in fusions, as revealed by live imaging. Finally, we demonstrate that the effects of Abl signaling on Golgi are mediated via regulation of the actin cytoskeleton. Together, these data reveal a direct link between cell signaling and Golgi architecture. Moreover, they raise the possibility that some of the effects of Abl signaling may arise, in part, from alterations of protein trafficking and secretion.
Collapse
Affiliation(s)
- Ramakrishnan Kannan
- Axon Guidance and Neural Connectivity Unit, Basic Neuroscience Program, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Irina Kuzina
- Axon Guidance and Neural Connectivity Unit, Basic Neuroscience Program, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Stephen Wincovitch
- Cytogenetics and Microscopy Core, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892
| | - Stephanie H Nowotarski
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Edward Giniger
- Axon Guidance and Neural Connectivity Unit, Basic Neuroscience Program, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| |
Collapse
|
13
|
Schmidt S, Debant A. Function and regulation of the Rho guanine nucleotide exchange factor Trio. Small GTPases 2014; 5:e29769. [PMID: 24987837 DOI: 10.4161/sgtp.29769] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Rho GTPases oscillate between an inactive GDP-bound state and an active GTP-bound state. They are activated by Rho Guanine nucleotide Exchange Factors (GEF), which accelerate the GDP to GTP exchange. RhoGEFs fall into two different classes: the Dbl family and the DOCK family of proteins. In this review, we focus on the function and regulation of the Dbl family RhoGEF Trio. Trio and its paralog Kalirin are unique within this family in that they display two GEF domains of distinct specificity. Trio is a major regulator of neuronal development, and its function is conserved through evolution. Moreover, Trio plays an important role in cell adhesion and in signaling pathways elicited by Gαq protein-coupled receptors. Combined, these observations suggest that Trio has a major role in cellular physiology. Of note, Trio is an essential gene for mouse development, with a prominent role in the development of the nervous system. Finally, Trio expression is significantly increased in different types of tumors and it has been proposed that it could participate in oncogenesis.
Collapse
Affiliation(s)
- Susanne Schmidt
- Centre de Recherche en Biochimie Macromoléculaire; CNRS - UMR 5237; Université de Montpellier; Montpellier, France
| | - Anne Debant
- Centre de Recherche en Biochimie Macromoléculaire; CNRS - UMR 5237; Université de Montpellier; Montpellier, France
| |
Collapse
|
14
|
Gates J. Drosophila egg chamber elongation: insights into how tissues and organs are shaped. Fly (Austin) 2012; 6:213-27. [PMID: 22940759 PMCID: PMC3519655 DOI: 10.4161/fly.21969] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
As tissues and organs are formed, they acquire a specific shape that plays an integral role in their ability to function properly. A relatively simple system that has been used to examine how tissues and organs are shaped is the formation of an elongated Drosophila egg. While it has been known for some time that Drosophila egg elongation requires interactions between a polarized intracellular basal actin network and a polarized extracellular network of basal lamina proteins, how these interactions contribute to egg elongation remained unclear. Recent studies using live imaging have revealed two novel processes, global tissue rotation and oscillating basal actomyosin contractions, which have provided significant insight into how the two polarized protein networks cooperate to produce an elongated egg. This review summarizes the proteins involved in Drosophila egg elongation and how this recent work has contributed to our current understanding of how egg elongation is achieved.
Collapse
Affiliation(s)
- Julie Gates
- Department of Biology, Bucknell University,Lewisburg, PA, USA.
| |
Collapse
|