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Kim T, Park H, Tanaka-Yamamoto K, Yamamoto Y. Developmental timing-dependent organization of synaptic connections between mossy fibers and granule cells in the cerebellum. Commun Biol 2023; 6:446. [PMID: 37095324 PMCID: PMC10125988 DOI: 10.1038/s42003-023-04825-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 04/07/2023] [Indexed: 04/26/2023] Open
Abstract
The long-standing hypothesis that synapses between mossy fibers (MFs) and cerebellar granule cells (GCs) are organized according to the origins of MFs and locations of GC axons, parallel fibers (PFs), is supported by recent findings. However, the mechanisms of such organized synaptic connections remain unknown. Here, using our technique that enabled PF location-dependent labeling of GCs in mice, we confirmed that synaptic connections of GCs with specific MFs originating from the pontine nucleus (PN-MFs) and dorsal column nuclei (DCoN-MFs) were gently but differentially organized according to their PF locations. We then found that overall MF-GC synaptic connectivity was biased in a way that dendrites of GCs having nearby PFs tended to connect with the same MF terminals, implying that the MF origin- and PF location-dependent organization is associated with the overall biased MF-GC synaptic connectivity. Furthermore, the development of PN-MFs preceded that of DCoN-MFs, which matches the developmental sequence of GCs that preferentially connect with each type of these MFs. Thus, our results revealed that overall MF-GC synaptic connectivity is biased in terms of PF locations, and suggested that such connectivity is likely the result of synaptic formation between developmental timing-matched partners.
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Affiliation(s)
- Taegon Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Heeyoun Park
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Keiko Tanaka-Yamamoto
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
| | - Yukio Yamamoto
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
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2
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Sousa E, Flames N. Transcriptional regulation of neuronal identity. Eur J Neurosci 2021; 55:645-660. [PMID: 34862697 PMCID: PMC9306894 DOI: 10.1111/ejn.15551] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 11/29/2022]
Abstract
Neuronal diversity is an intrinsic feature of the nervous system. Transcription factors (TFs) are key regulators in the establishment of different neuronal identities; how are the actions of different TFs coordinated to orchestrate this diversity? Are there common features shared among the different neuron types of an organism or even among different animal groups? In this review, we provide a brief overview on common traits emerging on the transcriptional regulation of neuron type diversification with a special focus on the comparison between mouse and Caenorhabditis elegans model systems. In the first part, we describe general concepts on neuronal identity and transcriptional regulation of gene expression. In the second part of the review, TFs are classified in different categories according to their key roles at specific steps along the protracted process of neuronal specification and differentiation. The same TF categories can be identified both in mammals and nematodes. Importantly, TFs are very pleiotropic: Depending on the neuron type or the time in development, the same TF can fulfil functions belonging to different categories. Finally, we describe the key role of transcriptional repression at all steps controlling neuronal diversity and propose that acquisition of neuronal identities could be considered a metastable process.
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Affiliation(s)
- Erick Sousa
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia IBV-CSIC, Valencia, Spain
| | - Nuria Flames
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia IBV-CSIC, Valencia, Spain
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3
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Refinement of Cerebellar Network Organization by Extracellular Signaling During Development. Neuroscience 2020; 462:44-55. [PMID: 32502568 DOI: 10.1016/j.neuroscience.2020.05.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 12/21/2022]
Abstract
The cerebellum forms regular neural network structures consisting of a few major types of neurons, such as Purkinje cells, granule cells, and molecular layer interneurons, and receives two major inputs from climbing fibers and mossy fibers. Its regular structures consist of three well-defined layers, with each type of neuron designated to a specific location and forming specific synaptic connections. During the first few weeks of postnatal development in rodents, the cerebellum goes through dynamic changes via proliferation, migration, differentiation, synaptogenesis, and maturation, to create such a network structure. The development of this organized network structure presumably relies on the communication between developing elements in the network, including not only individual neurons, but also their dendrites, axons, and synapses. Therefore, it is reasonable that extracellular signaling via synaptic transmission, secreted molecules, and cell adhesion molecules, plays important roles in cerebellar network development. Although it is not yet clear as to how overall cerebellar development is orchestrated, there is indeed accumulating lines of evidence that extracellular signaling acts toward the development of individual elements in the cerebellar networks. In this article, we introduce what we have learned from many studies regarding the extracellular signaling required for cerebellar network development, including our recent study suggesting the importance of unbiased synaptic inputs from parallel fibers.
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Remesal L, Roger-Baynat I, Chirivella L, Maicas M, Brocal-Ruiz R, Pérez-Villalba A, Cucarella C, Casado M, Flames N. PBX1 acts as terminal selector for olfactory bulb dopaminergic neurons. Development 2020; 147:dev.186841. [PMID: 32156753 DOI: 10.1242/dev.186841] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/24/2020] [Indexed: 02/03/2023]
Abstract
Neuronal specification is a protracted process that begins with the commitment of progenitor cells and culminates with the generation of mature neurons. Many transcription factors are continuously expressed during this process but it is presently unclear how these factors modify their targets as cells transition through different stages of specification. In olfactory bulb adult neurogenesis, the transcription factor PBX1 controls neurogenesis in progenitor cells and the survival of migrating neuroblasts. Here, we show that, at later differentiation stages, PBX1 also acts as a terminal selector for the dopaminergic neuron fate. PBX1 is also required for the morphological maturation of dopaminergic neurons and to repress alternative interneuron fates, findings that expand the known repertoire of terminal-selector actions. Finally, we reveal that the temporal diversification of PBX1 functions in neuronal specification is achieved, at least in part, through the dynamic regulation of alternative splicing. In Caenorhabditis elegans, PBX/CEH-20 also acts as a dopaminergic neuron terminal selector, which suggests an ancient role for PBX factors in the regulation of terminal differentiation of dopaminergic neurons.
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Affiliation(s)
- Laura Remesal
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia, IBV-CSIC, 46010 Valencia, Spain
| | - Isabel Roger-Baynat
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia, IBV-CSIC, 46010 Valencia, Spain
| | - Laura Chirivella
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia, IBV-CSIC, 46010 Valencia, Spain
| | - Miren Maicas
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia, IBV-CSIC, 46010 Valencia, Spain
| | - Rebeca Brocal-Ruiz
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia, IBV-CSIC, 46010 Valencia, Spain
| | - Ana Pérez-Villalba
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED), and Departamento de Biología Celular, Biología Funcional y Antropología Física, Universidad de Valencia, 46100 Burjassot, Spain
| | - Carme Cucarella
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III (ISCIII), Metabolic Experimental Pathology Unit, Instituto de Biomedicina de Valencia, IBV-CSIC, 46010 Valencia, Spain
| | - Marta Casado
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III (ISCIII), Metabolic Experimental Pathology Unit, Instituto de Biomedicina de Valencia, IBV-CSIC, 46010 Valencia, Spain
| | - Nuria Flames
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia, IBV-CSIC, 46010 Valencia, Spain
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5
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Markwalter KH, Yang Y, Holy TE, Bonni A. Sensorimotor Coding of Vermal Granule Neurons in the Developing Mammalian Cerebellum. J Neurosci 2019; 39:6626-6643. [PMID: 31235645 PMCID: PMC6703891 DOI: 10.1523/jneurosci.0086-19.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/18/2019] [Accepted: 06/18/2019] [Indexed: 01/17/2023] Open
Abstract
The vermal cerebellum is a hub of sensorimotor integration critical for postural control and locomotion, but the nature and developmental organization of afferent information to this region have remained poorly understood in vivo Here, we use in vivo two-photon calcium imaging of the vermal cerebellum in awake behaving male and female mice to record granule neuron responses to diverse sensorimotor cues targeting visual, auditory, somatosensory, and motor domains. Use of an activity-independent marker revealed that approximately half (54%) of vermal granule neurons were activated during these recordings. A multikernel linear model distinguished the relative influences of external stimuli and co-occurring movements on neural responses, indicating that, among the subset of activated granule neurons, locomotion (44%-56%) and facial air puffs (50%) were more commonly and reliably encoded than visual (31%-32%) and auditory (19%-28%) stimuli. Strikingly, we also uncover populations of granule neurons that respond differentially to voluntary and forced locomotion, whereas other granule neurons in the same region respond similarly to locomotion in both conditions. Finally, by combining two-photon calcium imaging with birth date labeling of granule neurons via in vivo electroporation, we find that early- and late-born granule neurons convey similarly diverse sensorimotor information to spatially distinct regions of the molecular layer. Collectively, our findings elucidate the nature and developmental organization of sensorimotor information in vermal granule neurons of the developing mammalian brain.SIGNIFICANCE STATEMENT Cerebellar granule neurons comprise over half the neurons in the brain, and their coding properties have been the subject of theoretical and experimental interest for over a half-century. In this study, we directly test long-held theories about encoding of sensorimotor stimuli in the cerebellum and compare the in vivo coding properties of early- and late-born granule neurons. Strikingly, we identify populations of granule neurons that differentially encode voluntary and forced locomotion and find that, although the birth order of granule neurons specifies the positioning of their parallel fiber axons, both early- and late-born granule neurons convey a functionally diverse sensorimotor code. These findings constitute important conceptual advances in understanding the principles underlying cerebellar circuit development and function.
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Affiliation(s)
- Kelly H Markwalter
- Department of Neuroscience, and
- MD-PhD Program, Washington University School of Medicine, St. Louis, Missouri 63110
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6
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Goodman JV, Bonni A. Regulation of neuronal connectivity in the mammalian brain by chromatin remodeling. Curr Opin Neurobiol 2019; 59:59-68. [PMID: 31146125 DOI: 10.1016/j.conb.2019.04.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/22/2019] [Indexed: 10/26/2022]
Abstract
Precise temporal and spatial control of gene expression is essential for brain development. Besides DNA sequence-specific transcription factors, epigenetic factors play an integral role in the control of gene expression in neurons. Among epigenetic mechanisms, chromatin remodeling enzymes have emerged as essential to the control of neural circuit assembly and function in the brain. Here, we review recent studies on the roles and mechanisms of the chromodomain-helicase-DNA-binding (Chd) family of chromatin remodeling enzymes in the regulation of neuronal morphogenesis and connectivity in the mammalian brain. We explore the field through the lens of Chd3, Chd4, and Chd5 proteins, which incorporate into the nucleosome remodeling and deacetylase (NuRD) complex, and the related proteins Chd7 and Chd8, implicated in the pathogenesis of intellectual disability and autism spectrum disorders. These studies have advanced our understanding of the mechanisms that regulate neuronal connectivity in brain development and neurodevelopmental disorders of cognition.
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Affiliation(s)
- Jared V Goodman
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA; Medical Scientist Training Program, Washington University School of Medicine, St. Louis, MO, USA
| | - Azad Bonni
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA.
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7
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The Transcriptional Regulator SnoN Promotes the Proliferation of Cerebellar Granule Neuron Precursors in the Postnatal Mouse Brain. J Neurosci 2018; 39:44-62. [PMID: 30425119 DOI: 10.1523/jneurosci.0688-18.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 10/16/2018] [Accepted: 10/22/2018] [Indexed: 02/08/2023] Open
Abstract
Control of neuronal precursor cell proliferation is essential for normal brain development, and deregulation of this fundamental developmental event contributes to brain diseases. Typically, neuronal precursor cell proliferation extends over long periods of time during brain development. However, how neuronal precursor proliferation is regulated in a temporally specific manner remains to be elucidated. Here, we report that conditional KO of the transcriptional regulator SnoN in cerebellar granule neuron precursors robustly inhibits the proliferation of these cells and promotes their cell cycle exit at later stages of cerebellar development in the postnatal male and female mouse brain. In laser capture microdissection followed by RNA-Seq, designed to profile gene expression specifically in the external granule layer of the cerebellum, we find that SnoN promotes the expression of cell proliferation genes and concomitantly represses differentiation genes in granule neuron precursors in vivo Remarkably, bioinformatics analyses reveal that SnoN-regulated genes contain binding sites for the transcription factors N-myc and Pax6, which promote the proliferation and differentiation of granule neuron precursors, respectively. Accordingly, we uncover novel physical interactions of SnoN with N-myc and Pax6 in cells. In behavior analyses, conditional KO of SnoN impairs cerebellar-dependent learning in a delayed eye-blink conditioning paradigm, suggesting that SnoN-regulation of granule neuron precursor proliferation bears functional consequences at the organismal level. Our findings define a novel function and mechanism for the major transcriptional regulator SnoN in the control of granule neuron precursor proliferation in the mammalian brain.SIGNIFICANCE STATEMENT This study reports the discovery that the transcriptional regulator SnoN plays a crucial role in the proliferation of cerebellar granule neuron precursors in the postnatal mouse brain. Conditional KO of SnoN in granule neuron precursors robustly inhibits the proliferation of these cells and promotes their cycle exit specifically at later stages of cerebellar development, with biological consequences of impaired cerebellar-dependent learning. Genomics and bioinformatics analyses reveal that SnoN promotes the expression of cell proliferation genes and concomitantly represses cell differentiation genes in vivo Although SnoN has been implicated in distinct aspects of the development of postmitotic neurons, this study identifies a novel function for SnoN in neuronal precursors in the mammalian brain.
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8
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Cheng C, Deng PY, Ikeuchi Y, Yuede C, Li D, Rensing N, Huang J, Baldridge D, Maloney SE, Dougherty JD, Constantino J, Jahani-Asl A, Wong M, Wozniak DF, Wang T, Klyachko VA, Bonni A. Characterization of a Mouse Model of Börjeson-Forssman-Lehmann Syndrome. Cell Rep 2018; 25:1404-1414.e6. [PMID: 30403997 PMCID: PMC6261530 DOI: 10.1016/j.celrep.2018.10.043] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 09/18/2018] [Accepted: 10/11/2018] [Indexed: 01/10/2023] Open
Abstract
Mutations of the transcriptional regulator PHF6 cause the X-linked intellectual disability disorder Börjeson-Forssman-Lehmann syndrome (BFLS), but the pathogenesis of BFLS remains poorly understood. Here, we report a mouse model of BFLS, generated using a CRISPR-Cas9 approach, in which cysteine 99 within the PHD domain of PHF6 is replaced with phenylalanine (C99F). Mice harboring the patient-specific C99F mutation display deficits in cognitive functions, emotionality, and social behavior, as well as reduced threshold to seizures. Electrophysiological studies reveal that the intrinsic excitability of entorhinal cortical stellate neurons is increased in PHF6 C99F mice. Transcriptomic analysis of the cerebral cortex in C99F knockin mice and PHF6 knockout mice show that PHF6 promotes the expression of neurogenic genes and represses synaptic genes. PHF6-regulated genes are also overrepresented in gene signatures and modules that are deregulated in neurodevelopmental disorders of cognition. Our findings advance our understanding of the mechanisms underlying BFLS pathogenesis.
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Affiliation(s)
- Cheng Cheng
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Pan-Yue Deng
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63110, USA; Department of Cell Biology and Physiology, Washington University, St. Louis, MO 63110, USA
| | - Yoshiho Ikeuchi
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Carla Yuede
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Daofeng Li
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108, USA; Department of Genetics, Washington University School of Medicine, 4515 McKinley Ave., St. Louis, MO 63108, USA
| | - Nicholas Rensing
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ju Huang
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Dustin Baldridge
- Department of Pediatrics, Division of Newborn Medicine, Washington University School of Medicine, St. Louis, MO 63108, USA
| | - Susan E Maloney
- Department of Genetics, Washington University School of Medicine, 4515 McKinley Ave., St. Louis, MO 63108, USA; Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63108, USA
| | - Joseph D Dougherty
- Department of Genetics, Washington University School of Medicine, 4515 McKinley Ave., St. Louis, MO 63108, USA; Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63108, USA
| | - John Constantino
- Department of Psychiatry, Division of Child Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Arezu Jahani-Asl
- Department of Oncology, Faculty of Medicine, McGill University, Montreal, QC H3T 1E2, Canada; Lady Davis Research Institute, Jewish General Hospital, Montreal, QC H3T 1E2, Canada
| | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - David F Wozniak
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63108, USA
| | - Ting Wang
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108, USA; Department of Genetics, Washington University School of Medicine, 4515 McKinley Ave., St. Louis, MO 63108, USA
| | - Vitaly A Klyachko
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63110, USA; Department of Cell Biology and Physiology, Washington University, St. Louis, MO 63110, USA
| | - Azad Bonni
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
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9
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McLaughlin CN, Broihier HT. Keeping Neurons Young and Foxy: FoxOs Promote Neuronal Plasticity. Trends Genet 2018; 34:65-78. [PMID: 29102406 DOI: 10.1016/j.tig.2017.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 10/10/2017] [Accepted: 10/13/2017] [Indexed: 12/27/2022]
Abstract
Any adult who has tried to take up the piano or learn a new language is faced with the sobering realization that acquiring such skills is more challenging as an adult than as a child. Neuronal plasticity, or the malleability of brain circuits, declines with age. Young neurons tend to be more adaptable and can alter the size and strength of their connections more readily than can old neurons. Myriad circuit- and synapse-level mechanisms that shape plasticity have been identified. Yet, molecular mechanisms setting the overall competence of young neurons for distinct forms of plasticity remain largely obscure. Recent studies indicate evolutionarily conserved roles for FoxO proteins in establishing the capacity for cell-fate, morphological, and synaptic plasticity in neurons.
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Affiliation(s)
- Colleen N McLaughlin
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Heather T Broihier
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
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10
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Tecalco-Cruz AC, Ríos-López DG, Vázquez-Victorio G, Rosales-Alvarez RE, Macías-Silva M. Transcriptional cofactors Ski and SnoN are major regulators of the TGF-β/Smad signaling pathway in health and disease. Signal Transduct Target Ther 2018; 3:15. [PMID: 29892481 PMCID: PMC5992185 DOI: 10.1038/s41392-018-0015-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 02/16/2018] [Accepted: 03/15/2018] [Indexed: 12/19/2022] Open
Abstract
The transforming growth factor-β (TGF-β) family plays major pleiotropic roles by regulating many physiological processes in development and tissue homeostasis. The TGF-β signaling pathway outcome relies on the control of the spatial and temporal expression of >500 genes, which depend on the functions of the Smad protein along with those of diverse modulators of this signaling pathway, such as transcriptional factors and cofactors. Ski (Sloan-Kettering Institute) and SnoN (Ski novel) are Smad-interacting proteins that negatively regulate the TGF-β signaling pathway by disrupting the formation of R-Smad/Smad4 complexes, as well as by inhibiting Smad association with the p300/CBP coactivators. The Ski and SnoN transcriptional cofactors recruit diverse corepressors and histone deacetylases to repress gene transcription. The TGF-β/Smad pathway and coregulators Ski and SnoN clearly regulate each other through several positive and negative feedback mechanisms. Thus, these cross-regulatory processes finely modify the TGF-β signaling outcome as they control the magnitude and duration of the TGF-β signals. As a result, any alteration in these regulatory mechanisms may lead to disease development. Therefore, the design of targeted therapies to exert tight control of the levels of negative modulators of the TGF-β pathway, such as Ski and SnoN, is critical to restore cell homeostasis under the specific pathological conditions in which these cofactors are deregulated, such as fibrosis and cancer. Proteins that repress molecular signaling through the transforming growth factor-beta (TGF-β) pathway offer promising targets for treating cancer and fibrosis. Marina Macías-Silva and colleagues from the National Autonomous University of Mexico in Mexico City review the ways in which a pair of proteins, called Ski and SnoN, interact with downstream mediators of TGF-β to inhibit the effects of this master growth factor. Aberrant levels of Ski and SnoN have been linked to diverse range of diseases involving cell proliferation run amok, and therapies that regulate the expression of these proteins could help normalize TGF-β signaling to healthier physiological levels. For decades, drug companies have tried to target the TGF-β pathway, with limited success. Altering the activity of these repressors instead could provide a roundabout way of remedying pathogenic TGF-β activity in fibrosis and oncology.
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Affiliation(s)
- Angeles C Tecalco-Cruz
- 1Instituto de Investigaciones Biomédicas at Universidad Nacional Autónoma de México, Mexico city, 04510 Mexico
| | - Diana G Ríos-López
- 2Instituto de Fisiología Celular at Universidad Nacional Autónoma de México, Mexico city, 04510 Mexico
| | | | - Reyna E Rosales-Alvarez
- 2Instituto de Fisiología Celular at Universidad Nacional Autónoma de México, Mexico city, 04510 Mexico
| | - Marina Macías-Silva
- 2Instituto de Fisiología Celular at Universidad Nacional Autónoma de México, Mexico city, 04510 Mexico
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11
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Laumonnerie C, Solecki DJ. Regulation of Polarity Protein Levels in the Developing Central Nervous System. J Mol Biol 2018; 430:3472-3480. [PMID: 29864442 DOI: 10.1016/j.jmb.2018.05.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/28/2018] [Accepted: 05/29/2018] [Indexed: 12/21/2022]
Abstract
In the course of their development from neuroepithelial cells to mature neurons, neuronal progenitors proliferate, delaminate, differentiate, migrate, and extend processes to form a complex neuronal network. In addition to supporting the morphology of the neuroepithelium and radial glia, polarity proteins contribute to the remodeling of processes and support the architectural reorganizations that result in axon extension and dendrite formation. While a good amount of evidence highlights a rheostat-like regulation by signaling events leading to local activation and/or redistribution of polarity proteins, recent studies demonstrate a new paradigm involving a switch-like regulation directly controlling the availability of polarity protein at specific stage by transcriptional regulation and/or targeted ubiquitin proteasome degradation. During the process of differentiation, most neurons will adopt a morphology with reduced polarity which suggests that polarity complex proteins are strongly repressed during key step of development. Here we review the different mechanisms that directly impact the levels of polarity complex proteins in neurons in relation to the polarization context and discuss why this transient loss of polarity is essential to understand neural development and how this knowledge could be relevant for some neuropathy.
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Affiliation(s)
- Christophe Laumonnerie
- Department of Developmental Neurobiology, St Jude Children's Research Hospital, 262 Danny Thomas Blvd, Memphis, TN 38105, USA
| | - David J Solecki
- Department of Developmental Neurobiology, St Jude Children's Research Hospital, 262 Danny Thomas Blvd, Memphis, TN 38105, USA.
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12
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Neuron-specific alternative splicing of transcriptional machineries: Implications for neurodevelopmental disorders. Mol Cell Neurosci 2017; 87:35-45. [PMID: 29254826 DOI: 10.1016/j.mcn.2017.10.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 10/18/2017] [Accepted: 10/24/2017] [Indexed: 02/07/2023] Open
Abstract
The brain has long been known to display the most complex pattern of alternative splicing, thereby producing diverse protein isoforms compared to other tissues. Recent evidence indicates that many alternative exons are neuron-specific, evolutionarily conserved, and found in regulators of transcription including DNA-binding protein and histone modifying enzymes. This raises a possibility that neurons adopt unique mechanisms of transcription. Given that transcriptional machineries are frequently mutated in neurodevelopmental disorders with cognitive dysfunction, it is important to understand how neuron-specific alternative splicing contributes to proper transcriptional regulation in the brain. In this review, we summarize current knowledge regarding how neuron-specific splicing events alter the function of transcriptional regulators and shape unique gene expression patterns in the brain and the implications of neuronal splicing to the pathophysiology of neurodevelopmental disorders.
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13
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Chandhoke AS, Chanda A, Karve K, Deng L, Bonni S. The PIAS3-Smurf2 sumoylation pathway suppresses breast cancer organoid invasiveness. Oncotarget 2017; 8:21001-21014. [PMID: 28423498 PMCID: PMC5400561 DOI: 10.18632/oncotarget.15471] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 02/07/2017] [Indexed: 12/26/2022] Open
Abstract
Tumor metastasis profoundly reduces the survival of breast cancer patients, but the mechanisms underlying breast cancer invasiveness and metastasis are incompletely understood. Here, we report that the E3 ubiquitin ligase Smurf2 acts in a sumoylation-dependent manner to suppress the invasive behavior of MDA-MB-231 human breast cancer cell-derived organoids. We also find that the SUMO E3 ligase PIAS3 inhibits the invasive growth of breast cancer cell-derived organoids. In mechanistic studies, PIAS3 maintains breast cancer organoids in a non-invasive state via sumoylation of Smurf2. Importantly, the E3 ubiquitin ligase activity is required for sumoylated Smurf2 to suppress the invasive growth of breast cancer-cell derived organoids. Collectively, our findings define a novel role for the PIAS3-Smurf2 sumoylation pathway in the suppression of breast cancer cell invasiveness. These findings lay the foundation for the development of novel biomarkers and targeted therapeutic approaches in breast cancer.
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Affiliation(s)
- Amrita Singh Chandhoke
- Department of Biochemistry and Molecular Biology, and The Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada, T2N 4N1
| | - Ayan Chanda
- Department of Biochemistry and Molecular Biology, and The Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada, T2N 4N1
| | - Kunal Karve
- Department of Biochemistry and Molecular Biology, and The Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada, T2N 4N1
| | - Lili Deng
- Department of Biochemistry and Molecular Biology, and The Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada, T2N 4N1
| | - Shirin Bonni
- Department of Biochemistry and Molecular Biology, and The Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada, T2N 4N1
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14
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Yang Z, Li PF, Chen RC, Wang J, Wang S, Shen Y, Wu X, Fang B, Cheng X, Xiong ZQ. ADAM10-Initiated Release of Notch Intracellular Domain Regulates Microtubule Stability and Radial Migration of Cortical Neurons. Cereb Cortex 2017; 27:919-932. [PMID: 28158408 PMCID: PMC6093323 DOI: 10.1093/cercor/bhx006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Indexed: 11/24/2022] Open
Abstract
Proper neuronal migration is orchestrated by combined membrane signal paradigms, whereas the role and mechanism of regulated intramembrane proteolysis (RIP) remain to be illustrated. We show here that the disintegrin and metalloprotease-domain containing protein 10 (ADAM10) regulates cortical neurons migration by initiating the RIP of Notch. We found that Notch intracellular domain (NICD) significantly rescued the migration defect of ADAM10-deficient neurons. Moreover, ADAM10 deficiency led to reduced neuronal motility and disrupted microtubule (MT) structure, which were associated with downregulated expression of acetylated tubulin and MT-associated proteins. Specifically, the NICD/RBPJ complex bound directly to the promoter, and regulated the neuronal expression level of doublecortin (DCX), a modulator of the MT cytoskeleton. Functionally, DCX overexpression largely restored neuron motility and reversed migration defect caused by ADAM10 knockout. Taken together, these findings demonstrate the direct requirement of ADAM10 in cortical radial migration and reveal the underlying mechanism by linking ADAM10-initiated RIP of Notch to the regulation of MT cytoskeleton through transcriptional control of Dcx expression.
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Affiliation(s)
- Zhi Yang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,Shanghai Key Laboratory of Stomatology, Department of Oral and Cranio-Maxillofacial Science, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200011, China
| | - Peng-Fei Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ren-Chao Chen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jie Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shaoran Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ya Shen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiaohui Wu
- Institute of Developmental Biology and Molecular Medicine, School of Life Science, Fudan University, Shanghai 200433, China
| | - Bing Fang
- Shanghai Key Laboratory of Stomatology, Department of Oral and Cranio-Maxillofacial Science, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200011, China
| | - Xuewen Cheng
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhi-Qi Xiong
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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15
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Chandhoke AS, Karve K, Dadakhujaev S, Netherton S, Deng L, Bonni S. The ubiquitin ligase Smurf2 suppresses TGFβ-induced epithelial-mesenchymal transition in a sumoylation-regulated manner. Cell Death Differ 2015; 23:876-88. [PMID: 26679521 DOI: 10.1038/cdd.2015.152] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 10/09/2015] [Accepted: 10/19/2015] [Indexed: 12/18/2022] Open
Abstract
Epithelial-mesenchymal transition (EMT) is a fundamental cellular process in epithelial tissue development, and can be reactivated in cancer contributing to tumor invasiveness and metastasis. The cytokine transforming growth factor-β (TGFβ) is a key inducer of EMT, but the mechanisms that regulate TGFβ-induced EMT remain incompletely understood. Here, we report that knockdown of the ubiquitin ligase Smurf2 promotes the ability of TGFβ to induce EMT in a three-dimensional cell culture model of NMuMG mammary epithelial cells. In other studies, we identify Smurf2 as a target of the small ubiquitin like modifier (SUMO) pathway. We find that the SUMO-E2 conjugating enzyme Ubc9 and the SUMO E3 ligase PIAS3 associate with Smurf2 and promote its sumoylation at the distinct sites of Lysines 26 and 369. The sumoylation of Smurf2 enhances its ability to induce the degradation of the TGFβ receptor and thereby suppresses EMT in NMuMG cells. Collectively, our data reveal that Smurf2 acts in a sumoylation-regulated manner to suppress TGFβ-induced EMT. These findings have significant implications for our understanding of epithelial tissue development and cancer.
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Affiliation(s)
- A S Chandhoke
- Department of Biochemistry and Molecular Biology, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - K Karve
- Department of Biochemistry and Molecular Biology, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - S Dadakhujaev
- Department of Biochemistry and Molecular Biology, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - S Netherton
- Department of Biochemistry and Molecular Biology, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - L Deng
- Department of Biochemistry and Molecular Biology, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - S Bonni
- Department of Biochemistry and Molecular Biology, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
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16
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Anckar J, Bonni A. Regulation of neuronal morphogenesis and positioning by ubiquitin-specific proteases in the cerebellum. PLoS One 2015; 10:e0117076. [PMID: 25607801 PMCID: PMC4301861 DOI: 10.1371/journal.pone.0117076] [Citation(s) in RCA: 12] [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: 09/29/2014] [Accepted: 12/19/2014] [Indexed: 11/19/2022] Open
Abstract
Ubiquitin signaling mechanisms play fundamental roles in the cell-intrinsic control of neuronal morphogenesis and connectivity in the brain. However, whereas specific ubiquitin ligases have been implicated in key steps of neural circuit assembly, the roles of ubiquitin-specific proteases (USPs) in the establishment of neuronal connectivity have remained unexplored. Here, we report a comprehensive analysis of USP family members in granule neuron morphogenesis and positioning in the rodent cerebellum. We identify a set of 32 USPs that are expressed in granule neurons. We also characterize the subcellular localization of the 32 USPs in granule neurons using a library of expression plasmids encoding GFP-USPs. In RNAi screens of the 32 neuronally expressed USPs, we uncover novel functions for USP1, USP4, and USP20 in the morphogenesis of granule neuron dendrites and axons and we identify a requirement for USP30 and USP33 in granule neuron migration in the rodent cerebellar cortex in vivo. These studies reveal that specific USPs with distinct spatial localizations harbor key functions in the control of neuronal morphogenesis and positioning in the mammalian cerebellum, with important implications for our understanding of the cell-intrinsic mechanisms that govern neural circuit assembly in the brain.
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Affiliation(s)
- Julius Anckar
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Azad Bonni
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St Louis, Missouri, United States of America
- * E-mail:
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17
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Ikeuchi Y, Dadakhujaev S, Chandhoke AS, Huynh MA, Oldenborg A, Ikeuchi M, Deng L, Bennett EJ, Harper JW, Bonni A, Bonni S. TIF1γ protein regulates epithelial-mesenchymal transition by operating as a small ubiquitin-like modifier (SUMO) E3 ligase for the transcriptional regulator SnoN1. J Biol Chem 2014; 289:25067-78. [PMID: 25059663 DOI: 10.1074/jbc.m114.575878] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Epithelial-mesenchymal transition (EMT) is a fundamental cellular process that contributes to epithelial tissue morphogenesis during normal development and in tumor invasiveness and metastasis. The transcriptional regulator SnoN robustly influences EMT in response to the cytokine TGFβ, but the mechanisms that regulate the fundamental role of SnoN in TGFβ-induced EMT are not completely understood. Here we employ interaction proteomics to uncover the signaling protein TIF1γ as a specific interactor of SnoN1 but not the closely related isoform SnoN2. A 16-amino acid peptide within a unique region of SnoN1 mediates the interaction of SnoN1 with TIF1γ. Strikingly, although TIF1γ is thought to act as a ubiquitin E3 ligase, we find that TIF1γ operates as a small ubiquitin-like modifier (SUMO) E3 ligase that promotes the sumoylation of SnoN1 at distinct lysine residues. Importantly, TIF1γ-induced sumoylation is required for the ability of SnoN1 to suppress TGFβ-induced EMT, as assayed by the disruption of the morphogenesis of acini in a physiologically relevant three-dimensional model of normal murine mammary gland (NMuMG) epithelial cells. Collectively, our findings define a novel TIF1γ-SnoN1 sumoylation pathway that plays a critical role in EMT and has important implications for our understanding of TGFβ signaling and diverse biological processes in normal development and cancer biology.
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Affiliation(s)
- Yoshiho Ikeuchi
- From the Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110, the Departments of Neurobiology and
| | - Shorafidinkhuja Dadakhujaev
- the Southern Alberta Cancer Research Institute and Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Amrita S Chandhoke
- the Southern Alberta Cancer Research Institute and Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | | | - Anna Oldenborg
- From the Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | | | - Lili Deng
- the Southern Alberta Cancer Research Institute and Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Eric J Bennett
- Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, and
| | - J Wade Harper
- Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Azad Bonni
- From the Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110, the Departments of Neurobiology and
| | - Shirin Bonni
- the Southern Alberta Cancer Research Institute and Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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18
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Holubowska A, Mukherjee C, Vadhvani M, Stegmüller J. Genetic manipulation of cerebellar granule neurons in vitro and in vivo to study neuronal morphology and migration. J Vis Exp 2014. [PMID: 24686379 DOI: 10.3791/51070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Developmental events in the brain including neuronal morphogenesis and migration are highly orchestrated processes. In vitro and in vivo analyses allow for an in-depth characterization to identify pathways involved in these events. Cerebellar granule neurons (CGNs) that are derived from the developing cerebellum are an ideal model system that allows for morphological analyses. Here, we describe a method of how to genetically manipulate CGNs and how to study axono- and dendritogenesis of individual neurons. With this method the effects of RNA interference, overexpression or small molecules can be compared to control neurons. In addition, the rodent cerebellar cortex is an easily accessible in vivo system owing to its predominant postnatal development. We also present an in vivo electroporation technique to genetically manipulate the developing cerebella and describe subsequent cerebellar analyses to assess neuronal morphology and migration.
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Affiliation(s)
- Anna Holubowska
- Cellular and Molelcular Neurobiology, Max Planck Institute of Experimental Medicine; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)
| | - Chaitali Mukherjee
- Cellular and Molelcular Neurobiology, Max Planck Institute of Experimental Medicine; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)
| | - Mayur Vadhvani
- Cellular and Molelcular Neurobiology, Max Planck Institute of Experimental Medicine; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB)
| | - Judith Stegmüller
- Cellular and Molelcular Neurobiology, Max Planck Institute of Experimental Medicine; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB);
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19
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Jaarsma D, van den Berg R, Wulf PS, van Erp S, Keijzer N, Schlager MA, de Graaff E, De Zeeuw CI, Pasterkamp RJ, Akhmanova A, Hoogenraad CC. A role for Bicaudal-D2 in radial cerebellar granule cell migration. Nat Commun 2014; 5:3411. [PMID: 24614806 DOI: 10.1038/ncomms4411] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 02/07/2014] [Indexed: 01/20/2023] Open
Abstract
Bicaudal-D (BICD) belongs to an evolutionary conserved family of dynein adaptor proteins. It was first described in Drosophila as an essential factor in fly oogenesis and embryogenesis. Missense mutations in a human BICD homologue, BICD2, have been linked to a dominant mild early onset form of spinal muscular atrophy. Here we further examine the in vivo function of BICD2 in Bicd2 knockout mice. BICD2-deficient mice develop disrupted laminar organization of cerebral cortex and the cerebellum, pointing to impaired radial neuronal migration. Using astrocyte and granule cell specific inactivation of BICD2, we show that the cerebellar migration defect is entirely dependent upon BICD2 expression in Bergmann glia cells. Proteomics analysis reveals that Bicd2 mutant mice have an altered composition of extracellular matrix proteins produced by glia cells. These findings demonstrate an essential non-cell-autonomous role of BICD2 in neuronal cell migration, which might be connected to cargo trafficking pathways in glia cells.
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Affiliation(s)
- Dick Jaarsma
- 1] Erasmus Medical Center, Department of Neuroscience, 3015 GE Rotterdam, The Netherlands [2]
| | - Robert van den Berg
- 1] Erasmus Medical Center, Department of Neuroscience, 3015 GE Rotterdam, The Netherlands [2] Cell Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands [3]
| | - Phebe S Wulf
- 1] Erasmus Medical Center, Department of Neuroscience, 3015 GE Rotterdam, The Netherlands [2] Cell Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands [3]
| | - Susan van Erp
- Netherlands Institute for Neuroscience, Royal Dutch Academy of Arts & Sciences, 1105 BA Amsterdam, The Netherlands
| | - Nanda Keijzer
- Erasmus Medical Center, Department of Neuroscience, 3015 GE Rotterdam, The Netherlands
| | - Max A Schlager
- Erasmus Medical Center, Department of Neuroscience, 3015 GE Rotterdam, The Netherlands
| | - Esther de Graaff
- 1] Erasmus Medical Center, Department of Neuroscience, 3015 GE Rotterdam, The Netherlands [2] Cell Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Chris I De Zeeuw
- 1] Erasmus Medical Center, Department of Neuroscience, 3015 GE Rotterdam, The Netherlands [2] Netherlands Institute for Neuroscience, Royal Dutch Academy of Arts & Sciences, 1105 BA Amsterdam, The Netherlands
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Anna Akhmanova
- 1] Cell Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands [2] Department of Cell Biology, Erasmus Medical Center, 3015 GE Rotterdam, The Netherlands
| | - Casper C Hoogenraad
- 1] Erasmus Medical Center, Department of Neuroscience, 3015 GE Rotterdam, The Netherlands [2] Cell Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
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20
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Abstract
The proper formation and morphogenesis of dendrites is fundamental to the establishment of neural circuits in the brain. Following cell cycle exit and migration, neurons undergo organized stages of dendrite morphogenesis, which include dendritic arbor growth and elaboration followed by retraction and pruning. Although these developmental stages were characterized over a century ago, molecular regulators of dendrite morphogenesis have only recently been defined. In particular, studies in Drosophila and mammalian neurons have identified numerous cell-intrinsic drivers of dendrite morphogenesis that include transcriptional regulators, cytoskeletal and motor proteins, secretory and endocytic pathways, cell cycle-regulated ubiquitin ligases, and components of other signaling cascades. Here, we review cell-intrinsic drivers of dendrite patterning and discuss how the characterization of such crucial regulators advances our understanding of normal brain development and pathogenesis of diverse cognitive disorders.
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Affiliation(s)
- Sidharth V Puram
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
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21
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McLoughlin HS, Wan J, Spengler RM, Xing Y, Davidson BL. Human-specific microRNA regulation of FOXO1: implications for microRNA recognition element evolution. Hum Mol Genet 2013; 23:2593-603. [PMID: 24368418 DOI: 10.1093/hmg/ddt655] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
MicroRNAs (miRNAs) have been established as important negative post-transcriptional regulators for gene expression. Within the past decade, miRNAs targeting transcription factors (TFs) has emerged as an important mechanism for gene expression regulation. Here, we tested the hypothesis that in TF 3'UTRs, human-specific single nucleotide change(s) that create novel miRNA recognition elements (MREs) contribute to species-specific differences in TF expression. From several potential human-specific TF MREs, one candidate, a member of the Forkhead Box O (FOXO) subclass in the Forkhead family known as Forkhead Box O1 (FOXO1; FKHR; NM_002015) was tested further. Human FOXO1 contains two sites predicted to confer miR-183-mediated post-transcriptional regulation: one specific to humans and the other conserved. Utilizing dual luciferase expression reporters, we show that only the human FOXO1 3'UTR contains a functional miR-183 site, not found in chimpanzee or mouse 3'untranslated regions (UTRs). Site-directed mutagenesis supports functionality of the human-specific miR-183 site, but not the conserved miR-183 site. Via overexpression and target site protection assays, we show that human FOXO1 is regulated by miR-183, but mouse FOXO1 is not. Finally, FOXO1-regulated cellular phenotypes, including cell invasion and proliferation, are impacted by miR-183 targeting only in human cells. These results provide strong evidence for human-specific gain of TF MREs, a process that may underlie evolutionary differences between phylogenic groups.
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22
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Pot I, Patel S, Deng L, Chandhoke AS, Zhang C, Bonni A, Bonni S. Identification of a Novel Link between the Protein Kinase NDR1 and TGFβ Signaling in Epithelial Cells. PLoS One 2013; 8:e67178. [PMID: 23840619 PMCID: PMC3694053 DOI: 10.1371/journal.pone.0067178] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 05/14/2013] [Indexed: 11/19/2022] Open
Abstract
Transforming growth factor-beta (TGFβ) is a secreted polypeptide that plays essential roles in cellular development and homeostasis. Although mechanisms of TGFβ-induced responses have been characterized, our understanding of TGFβ signaling remains incomplete. Here, we uncover a novel function for the protein kinase NDR1 (nuclear Dbf2-related 1) in TGFβ responses. Using an immunopurification approach, we find that NDR1 associates with SnoN, a key component of TGFβ signaling. Knockdown of NDR1 by RNA interference promotes the ability of TGFβ to induce transcription and cell cycle arrest in NMuMG mammary epithelial cells. Conversely, expression of NDR1 represses TGFβ-induced transcription and inhibits the ability of TGFβ to induce cell cycle arrest in NMuMG cells. Mechanistically, we find that NDR1 acts in a kinase-dependent manner to suppress the ability of TGFβ to induce the phosphorylation and consequent nuclear accumulation of Smad2, which is critical for TGFβ-induced transcription and responses. Strikingly, we also find that TGFβ reciprocally regulates NDR1, whereby TGFβ triggers the degradation of NDR1 protein. Collectively, our findings define a novel and intimate link between the protein kinase NDR1 and TGFβ signaling. NDR1 suppresses TGFβ-induced transcription and cell cycle arrest, and counteracting NDR1's negative regulation, TGFβ signaling induces the downregulation of NDR1 protein. These findings advance our understanding of TGFβ signaling, with important implications in development and tumorigenesis.
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Affiliation(s)
- Isabelle Pot
- Southern Alberta Cancer Research Institute and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | - Shachi Patel
- Southern Alberta Cancer Research Institute and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | - Lili Deng
- Southern Alberta Cancer Research Institute and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | - Amrita Singh Chandhoke
- Southern Alberta Cancer Research Institute and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | - Chi Zhang
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Azad Bonni
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Shirin Bonni
- Southern Alberta Cancer Research Institute and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
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23
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Kannan M, Lee SJ, Schwedhelm-Domeyer N, Nakazawa T, Stegmüller J. p250GAP is a novel player in the Cdh1-APC/Smurf1 pathway of axon growth regulation. PLoS One 2012; 7:e50735. [PMID: 23226367 PMCID: PMC3511349 DOI: 10.1371/journal.pone.0050735] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 10/24/2012] [Indexed: 12/23/2022] Open
Abstract
Axon growth is an essential process during brain development. The E3 ubiquitin ligase Cdh1-APC has emerged as a critical regulator of intrinsic axon growth control. Here, we identified the RhoGAP p250GAP as a novel interactor of the E3 ubiquitin ligase Cdh1-APC and found that p250GAP promotes axon growth downstream of Cdh1-APC. We also report that p250GAP undergoes non-proteolytic ubiquitination and associates with the Cdh1 substrate Smurf1 to synergistically regulate axon growth. Finally, we found that in vivo knockdown of p250GAP in the developing cerebellar cortex results in impaired migration and axonal growth. Taken together, our data indicate that Cdh1-APC together with the RhoA regulators p250GAP and Smurf1 controls axon growth in the mammalian brain.
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Affiliation(s)
- Madhuvanthi Kannan
- Cellullar and Molecular Neurobiology, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
| | - Shih-Ju Lee
- Cellullar and Molecular Neurobiology, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
| | - Nicola Schwedhelm-Domeyer
- Cellullar and Molecular Neurobiology, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
| | - Takanobu Nakazawa
- Department of Neurophysiology, School of Medicine, University of Tokyo, Tokyo, Japan
| | - Judith Stegmüller
- Cellullar and Molecular Neurobiology, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
- * E-mail:
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24
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Kannan M, Lee SJ, Schwedhelm-Domeyer N, Stegmüller J. The E3 ligase Cdh1-anaphase promoting complex operates upstream of the E3 ligase Smurf1 in the control of axon growth. Development 2012; 139:3600-12. [PMID: 22949615 DOI: 10.1242/dev.081786] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Axon growth is an essential event during brain development and is extremely limited due to extrinsic and intrinsic inhibition in the adult brain. The E3 ubiquitin ligase Cdh1-anaphase promoting complex (APC) has emerged as an important intrinsic suppressor of axon growth. In this study, we identify in rodents the E3 ligase Smurf1 as a novel substrate of Cdh1-APC and that Cdh1 targets Smurf1 for degradation in a destruction box-dependent manner. We find that Smurf1 acts downstream of Cdh1-APC in axon growth and that the turnover of RhoA by Smurf1 is important in this process. In addition, we demonstrate that acute knockdown of Smurf1 in vivo in the developing cerebellar cortex results in impaired axonal growth and migration. Finally, we show that a stabilized form of Smurf1 overrides the inhibition of axon growth by myelin. Taken together, we uncovered a Cdh1-APC/Smurf1/RhoA pathway that mediates axonal growth suppression in the developing mammalian brain.
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Affiliation(s)
- Madhuvanthi Kannan
- MPI of Experimental Medicine, Hermann Rein Strasse 3, 37075 Göttingen, Germany
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25
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Nechipurenko IV, Broihier HT. FoxO limits microtubule stability and is itself negatively regulated by microtubule disruption. ACTA ACUST UNITED AC 2012; 196:345-62. [PMID: 22312004 PMCID: PMC3275378 DOI: 10.1083/jcb.201105154] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
FoxO inhibits microtubule stability in the central nervous system, making its degradation an essential component of a cell’s protective response to cytoskeletal insult. Transcription factors are essential for regulating neuronal microtubules (MTs) during development and after axon damage. In this paper, we identify a novel neuronal function for Drosophila melanogaster FoxO in limiting MT stability at the neuromuscular junction (NMJ). foxO loss-of-function NMJs displayed augmented MT stability. In contrast, motor neuronal overexpression of wild-type FoxO moderately destabilized MTs, whereas overexpression of constitutively nuclear FoxO severely destabilized MTs. Thus, FoxO negatively regulates synaptic MT stability. FoxO family members are well-established components of stress-activated feedback loops. We hypothesized that FoxO might also be regulated by cytoskeletal stress because it was well situated to shape neuronal MT organization after cytoskeletal damage. Indeed, levels of neuronal FoxO were strongly reduced after acute pharmacological MT disruption as well as sustained genetic disruption of the neuronal cytoskeleton. This decrease was independent of the dual leucine zipper kinase–Wallenda pathway and required function of Akt kinase. We present a model wherein FoxO degradation is a component of a stabilizing, protective response to cytoskeletal insult.
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Affiliation(s)
- Inna V Nechipurenko
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
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26
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Zhu Q, Luo K. SnoN in regulation of embryonic development and tissue morphogenesis. FEBS Lett 2012; 586:1971-6. [PMID: 22710172 DOI: 10.1016/j.febslet.2012.03.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 03/03/2012] [Accepted: 03/05/2012] [Indexed: 01/15/2023]
Abstract
SnoN (Ski-novel protein) plays an important role in embryonic development, tumorigenesis and aging. Past studies largely focused on its roles in tumorigenesis. Recent studies of its expression patterns and functions in mouse models and mammalian cells have revealed that SnoN interacts with multiple signaling molecules at different cellular levels to modulate the activities of several signaling pathways in a tissue context and developmental stage dependent manner. These studies suggest that SnoN may have broad functions in the embryonic development and tissue morphogenesis.
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Affiliation(s)
- Qingwei Zhu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
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Bonni S, Bonni A. SnoN signaling in proliferating cells and postmitotic neurons. FEBS Lett 2012; 586:1977-83. [PMID: 22710173 DOI: 10.1016/j.febslet.2012.02.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 02/27/2012] [Accepted: 02/28/2012] [Indexed: 01/28/2023]
Abstract
The transcriptional regulator SnoN plays a fundamental role as a modulator of transforming growth factor beta (TGFβ)-induced signal transduction and biological responses. In recent years, novel functions of SnoN have been discovered in both TGFβ-dependent and TGFβ-independent settings in proliferating cells and postmitotic neurons. Accumulating evidence suggests that SnoN plays a dual role as a corepressor or coactivator of TGFβ-induced transcription. Accordingly, SnoN exerts oncogenic or tumor-suppressive effects in epithelial tissues. At the cellular level, SnoN antagonizes or mediates the ability of TGFβ to induce cell cycle arrest in a cell-type specific manner. SnoN also exerts key effects on epithelial-mesenchymal transition (EMT), with implications in cancer biology. Recent studies have expanded SnoN functions to postmitotic neurons, where SnoN orchestrates key aspects of neuronal development in the mammalian brain, from axon growth and branching to neuronal migration and positioning. In this review, we will highlight our understanding of SnoN biology at the crossroads of cancer biology and neurobiology.
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Affiliation(s)
- Shirin Bonni
- Department of Biochemistry and Molecular Biology, Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, Canada T2N 4N1.
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de la Torre-Ubieta L, Bonni A. Transcriptional regulation of neuronal polarity and morphogenesis in the mammalian brain. Neuron 2011; 72:22-40. [PMID: 21982366 DOI: 10.1016/j.neuron.2011.09.018] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2011] [Indexed: 11/17/2022]
Abstract
The highly specialized morphology of a neuron, typically consisting of a long axon and multiple branching dendrites, lies at the core of the principle of dynamic polarization, whereby information flows from dendrites toward the soma and to the axon. For more than a century, neuroscientists have been fascinated by how shape is important for neuronal function and how neurons acquire their characteristic morphology. During the past decade, substantial progress has been made in our understanding of the molecular underpinnings of neuronal polarity and morphogenesis. In these studies, transcription factors have emerged as key players governing multiple aspects of neuronal morphogenesis from neuronal polarization and migration to axon growth and pathfinding to dendrite growth and branching to synaptogenesis. In this review, we will highlight the role of transcription factors in shaping neuronal morphology with emphasis on recent literature in mammalian systems.
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Affiliation(s)
- Luis de la Torre-Ubieta
- Department of Neurobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
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