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Lo Piccolo L, Yeewa R, Pohsa S, Yamsri T, Calovi D, Phetcharaburanin J, Suksawat M, Kulthawatsiri T, Shotelersuk V, Jantrapirom S. FAME4-associating YEATS2 knockdown impairs dopaminergic synaptic integrity and leads to seizure-like behaviours in Drosophila melanogaster. Prog Neurobiol 2024; 233:102558. [PMID: 38128822 DOI: 10.1016/j.pneurobio.2023.102558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 10/25/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023]
Abstract
Familial adult myoclonus epilepsy (FAME) is a neurological disorder caused by a TTTTA/TTTCA intronic repeat expansion. FAME4 is one of the six types of FAME that results from the repeat expansion in the first intron of the gene YEATS2. Although the RNA toxicity is believed to be the primary mechanism underlying FAME, the role of genes where repeat expansions reside is still unclear, particularly in the case of YEATS2 in neurons. This study used Drosophila to explore the effects of reducing YEATS2 expression. Two pan-neuronally driven dsDNA were used for knockdown of Drosophila YEATS2 (dYEATS2), and the resulting molecular and behavioural outcomes were evaluated. Drosophila with reduced dYEATS2 expression exhibited decreased tolerance to acute stress, disturbed locomotion, abnormal social behaviour, and decreased motivated activity. Additionally, reducing dYEATS2 expression negatively affected tyrosine hydroxylase (TH) gene expression, resulting in decreased dopamine biosynthesis. Remarkably, seizure-like behaviours induced by knocking down dYEATS2 were rescued by the administration of L-DOPA. This study reveals a novel role of YEATS2 in neurons in regulating acute stress responses, locomotion, and complex behaviours, and suggests that haploinsufficiency of YEATS2 may play a role in FAME4.
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Affiliation(s)
- Luca Lo Piccolo
- Centre of Multidisciplinary Technology for Advanced Medicine (CMUTEAM), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Ranchana Yeewa
- Centre of Multidisciplinary Technology for Advanced Medicine (CMUTEAM), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Sureena Pohsa
- Centre of Multidisciplinary Technology for Advanced Medicine (CMUTEAM), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Titaree Yamsri
- Centre of Multidisciplinary Technology for Advanced Medicine (CMUTEAM), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Daniel Calovi
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany; Department of Collective Behaviour, Max Planck Institute of Animal Behaviour, Konstanz, Germany
| | - Jutarop Phetcharaburanin
- International Phenome Laboratory, Khon Kaen University, Khon Kaen, Thailand; Department of Systems Biosciences and Computational Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Manida Suksawat
- International Phenome Laboratory, Khon Kaen University, Khon Kaen, Thailand; Department of Systems Biosciences and Computational Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Thanaporn Kulthawatsiri
- International Phenome Laboratory, Khon Kaen University, Khon Kaen, Thailand; Department of Systems Biosciences and Computational Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Vorasuk Shotelersuk
- Centre of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Paediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Excellence Centre for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, Thailand.
| | - Salinee Jantrapirom
- Drosophila Centre for Human Diseases and Drug Discovery (DHD), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
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Jejina A, Ayala Y, Beuchle D, Höhener T, Dörig RE, Vazquez-Pianzola P, Hernández G, Suter B. Role of BicDR in bristle shaft construction and support of BicD functions. J Cell Sci 2024; 137:jcs261408. [PMID: 38264934 PMCID: PMC10917063 DOI: 10.1242/jcs.261408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 12/15/2023] [Indexed: 01/25/2024] Open
Abstract
Cell polarization requires asymmetric localization of numerous mRNAs, proteins and organelles. The movement of cargo towards the minus end of microtubules mostly depends on cytoplasmic dynein motors. In the dynein-dynactin-Bicaudal-D transport machinery, Bicaudal-D (BicD) links the cargo to the motor. Here, we focus on the role of Drosophila BicD-related (BicDR, CG32137) in the development of the long bristles. Together with BicD, it contributes to the organization and stability of the actin cytoskeleton in the not-yet-chitinized bristle shaft. BicD and BicDR also support the stable expression and distribution of Rab6 and Spn-F in the bristle shaft, including the distal tip localization of Spn-F, pointing to the role of microtubule-dependent vesicle trafficking for bristle construction. BicDR supports the function of BicD, and we discuss the hypothesis whereby BicDR might transport cargo more locally, with BicD transporting cargo over long distances, such as to the distal tip. We also identified embryonic proteins that interact with BicDR and appear to be BicDR cargo. For one of them, EF1γ (also known as eEF1γ), we show that the encoding gene EF1γ interacts with BicD and BicDR in the construction of the bristles.
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Affiliation(s)
- Aleksandra Jejina
- Institute of Cell Biology, University of Bern, CH-3012 Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, CH-3012 Bern, Switzerland
| | - Yeniffer Ayala
- Laboratory of Translation and Cancer, Unit of Biomedical Research on Cancer, Instituto Nacional de Cancerologıá (INCan), 14080 Tlalpan, Mexico City, Mexico
| | - Dirk Beuchle
- Institute of Cell Biology, University of Bern, CH-3012 Bern, Switzerland
| | - Thomas Höhener
- Institute of Cell Biology, University of Bern, CH-3012 Bern, Switzerland
| | - Ruth E. Dörig
- Institute of Cell Biology, University of Bern, CH-3012 Bern, Switzerland
| | | | - Greco Hernández
- Laboratory of Translation and Cancer, Unit of Biomedical Research on Cancer, Instituto Nacional de Cancerologıá (INCan), 14080 Tlalpan, Mexico City, Mexico
| | - Beat Suter
- Institute of Cell Biology, University of Bern, CH-3012 Bern, Switzerland
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Jejina A, Ayala Y, Hernández G, Suter B. Role of BicDR in bristle shaft construction, tracheal development, and support of BicD functions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.16.545245. [PMID: 37398393 PMCID: PMC10312712 DOI: 10.1101/2023.06.16.545245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Cell polarization requires asymmetric localization of numerous mRNAs, proteins, and organelles. The movement of cargo towards the minus end of microtubules mostly depends on cytoplasmic dynein motors, which function as multiprotein complexes. In the dynein/dynactin/Bicaudal-D (DDB) transport machinery, Bicaudal-D (BicD) links the cargo to the motor. Here we focus on the role of BicD-related (BicDR) and its contribution to microtubule-dependent transport processes. Drosophila BicDR is required for the normal development of bristles and dorsal trunk tracheae. Together with BicD, it contributes to the organization and stability of the actin cytoskeleton in the not-yet-chitinized bristle shaft and the localization of Spn-F and Rab6 at the distal tip. We show that BicDR supports the function of BicD in bristle development and our results suggest that BicDR transports cargo more locally whereas BicD is more responsible for delivering functional cargo over the long distance to the distal tip. We identified the proteins that interact with BicDR and appear to be BicDR cargo in embryonic tissues. For one of them, EF1γ, we showed that EF1γ genetically interacts with BicD and BicDR in the construction of the bristles.
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Affiliation(s)
- Aleksandra Jejina
- Institute of Cell Biology, University of Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Switzerland
| | - Yeniffer Ayala
- Laboratory of Translation and Cancer, Unit of Biomedical Research on Cancer, Instituto Nacional de Cancerologıá (INCan), Mexico City, Mexico
| | - Greco Hernández
- Laboratory of Translation and Cancer, Unit of Biomedical Research on Cancer, Instituto Nacional de Cancerologıá (INCan), Mexico City, Mexico
| | - Beat Suter
- Institute of Cell Biology, University of Bern, Switzerland
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Banham GD, Lee CYC, Ferdinand JR, Matthews RJ, Jing C, Smithers N, Prinjha RK, Clatworthy MR. Bromodomain Inhibitors Modulate FcγR-Mediated Mononuclear Phagocyte Activation and Chemotaxis. Front Immunol 2022; 13:885101. [PMID: 35619690 PMCID: PMC9127238 DOI: 10.3389/fimmu.2022.885101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 04/14/2022] [Indexed: 11/18/2022] Open
Abstract
IgG antibodies form immune complexes (IC) that propagate inflammation and tissue damage in autoimmune diseases such as systemic lupus erythematosus. IgG IC engage Fcγ receptors (FcγR) on mononuclear phagocytes (MNP), leading to widespread changes in gene expression that mediate antibody effector function. Bromodomain and extra-terminal domain (BET) proteins are involved in governing gene transcription. We investigated the capacity of BET protein inhibitors (iBET) to alter IgG FcγR-mediated MNP activation. We found that iBET dampened IgG IC-induced pro-inflammatory gene expression and decreased activating FcγR expression on MNPs, reducing their ability to respond to IgG IC. Despite FcγR downregulation, iBET-treated macrophages demonstrated increased phagocytosis of protein antigen, IgG IC, and apoptotic cells. iBET also altered cell morphology, generating more amoeboid MNPs with reduced adhesion. iBET treatment impaired chemotaxis towards a CCL19 gradient in IC-stimulated dendritic cells (DC) in vitro, and inhibited IC-induced DC migration to draining lymph nodes in vivo, in a DC-intrinsic manner. Altogether, our data show that iBET modulates FcγR-mediated MNP activation and migration, revealing the therapeutic potential of BET protein inhibition in antibody-mediated diseases.
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Affiliation(s)
- Gemma D. Banham
- Molecular Immunity Unit, Department of Medicine, Medical Research Council Laboratory of Molecular Biology, University of Cambridge, Cambridge, United Kingdom
| | - Colin Y. C. Lee
- Molecular Immunity Unit, Department of Medicine, Medical Research Council Laboratory of Molecular Biology, University of Cambridge, Cambridge, United Kingdom
- Cellular Genetics, Wellcome Sanger Institute, Cambridge, United Kingdom
| | - John R. Ferdinand
- Molecular Immunity Unit, Department of Medicine, Medical Research Council Laboratory of Molecular Biology, University of Cambridge, Cambridge, United Kingdom
| | - Rebeccah J. Matthews
- Molecular Immunity Unit, Department of Medicine, Medical Research Council Laboratory of Molecular Biology, University of Cambridge, Cambridge, United Kingdom
| | - Chenzhi Jing
- Molecular Immunity Unit, Department of Medicine, Medical Research Council Laboratory of Molecular Biology, University of Cambridge, Cambridge, United Kingdom
| | - Nicholas Smithers
- Epinova DPU, Immuno-Inflammation Centre of Excellence for Drug Discovery, GlaxoSmithKline, Medicines Research Centre, Stevenage, United Kingdom
| | - Rab K. Prinjha
- Epinova DPU, Immuno-Inflammation Centre of Excellence for Drug Discovery, GlaxoSmithKline, Medicines Research Centre, Stevenage, United Kingdom
| | - Menna R. Clatworthy
- Molecular Immunity Unit, Department of Medicine, Medical Research Council Laboratory of Molecular Biology, University of Cambridge, Cambridge, United Kingdom
- Cellular Genetics, Wellcome Sanger Institute, Cambridge, United Kingdom
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5
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Branigan GL, Olsen KS, Burda I, Haemmerle MW, Ho J, Venuto A, D’Antonio ND, Briggs IE, DiBenedetto AJ. Zebrafish Paralogs brd2a and brd2b Are Needed for Proper Circulatory, Excretory and Central Nervous System Formation and Act as Genetic Antagonists during Development. J Dev Biol 2021; 9:jdb9040046. [PMID: 34842711 PMCID: PMC8629005 DOI: 10.3390/jdb9040046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 12/17/2022] Open
Abstract
Brd2 belongs to the BET family of epigenetic transcriptional co-regulators that act as adaptor-scaffolds for the assembly of chromatin-modifying complexes and other factors at target gene promoters. Brd2 is a protooncogene and candidate gene for juvenile myoclonic epilepsy in humans, a homeobox gene regulator in Drosophila, and a maternal-zygotic factor and cell death modulator that is necessary for normal development of the vertebrate central nervous system (CNS). As two copies of Brd2 exist in zebrafish, we use antisense morpholino knockdown to probe the role of paralog Brd2b, as a comparative study to Brd2a, the ortholog of human Brd2. A deficiency in either paralog results in excess cell death and dysmorphology of the CNS, whereas only Brd2b deficiency leads to loss of circulation and occlusion of the pronephric duct. Co-knockdown of both paralogs suppresses single morphant defects, while co-injection of morpholinos with paralogous RNA enhances them, suggesting novel genetic interaction with functional antagonism. Brd2 diversification includes paralog-specific RNA variants, a distinct localization of maternal factors, and shared and unique spatiotemporal expression, providing unique insight into the evolution and potential functions of this gene.
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Affiliation(s)
- Gregory L. Branigan
- Medical Scientist Training Program, Center for Innovation in Brain Science, Department of Pharmacology, University of Arizona College of Medicine-Tucson, 1501 N Campbell Ave., Tucson, AZ 85724, USA;
| | - Kelly S. Olsen
- Biological and Biomedical Sciences Program, Department of Microbiology and Immunology, University of North Carolina School of Medicine-Chapel Hill, 321 S Columbia St., Chapel Hill, NC 27516, USA;
| | - Isabella Burda
- Department of Molecular Biology and Genetics, Weill Institute for Cell & Molecular Biology, Cornell University, 239 Weill Hall, Ithaca, NY 14853, USA;
| | - Matthew W. Haemmerle
- Institute for Diabetes, Obesity, and Metabolism, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania, Room 12-124, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA;
| | - Jason Ho
- Robert Wood Johnson Medical School, Rutgers University, Clinical Academic Building (CAB), 125 Paterson St., New Brunswick, NJ 08901, USA;
| | - Alexandra Venuto
- Department of Biology, East Carolina University, Greenville, NC 27858, USA;
| | - Nicholas D. D’Antonio
- Sidney Kimmel Medical College, Thomas Jefferson University Hospital, 1025 Walnut St. #100, Philadelphia, PA 19107, USA;
| | - Ian E. Briggs
- Department of Biology, Villanova University, 800 Lancaster Ave., Villanova, PA 19085, USA;
| | - Angela J. DiBenedetto
- Department of Biology, Villanova University, 800 Lancaster Ave., Villanova, PA 19085, USA;
- Correspondence:
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Du Y, Jiang S, Cheng L, Liu J. JAK/STAT and VEGF/PAK1 signaling as emerging targets for topical treatment of psoriasis: a pilot study. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2020; 13:3111-3119. [PMID: 33425111 PMCID: PMC7791387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 10/17/2020] [Indexed: 06/12/2023]
Abstract
Psoriasis is reportedly modulated by the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) or vascular endothelial growth factor/p21-activated kinase 1 (VEGF/PAK1) pathways. However, no research has evaluated the expression of JAK/STAT and VEGF/PAK1 signaling pathway molecules in human psoriasis skin tissue concurrently. We investigated the expression of autocrine STAT1, STAT3, VEGF, suppressor of cytokine signaling-1 (SOCS1), SOCS3, and PAK1 in psoriatic tissues. Skin biopsies were retrospectively collected from 55 patients with psoriasis from the tissue biobank. Skin biopsies from 40 healthy volunteers undergoing plastic surgery were used as controls. Immunohistochemical staining revealed that STAT1, STAT3, SOCS1, SOCS3, VEGF, and PAK1 were present at significantly higher levels in the psoriasis samples compared to the control group. Similarly, the mRNA expression of these signaling molecules was also significantly upregulated in psoriatic skin. Additionally, some of the molecules in these two signaling pathways exhibited significant positive correlations. In summary, we present pilot evidence that JAK/STAT and VEGF/PAK1 signaling molecules are expressed in psoriasis, which may provide topical treatment targets for this disease.
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Affiliation(s)
- Yang Du
- The 7th People’s Hospital of ShenyangShenyang, Liaoning Province, P. R. China
| | - Shukun Jiang
- Department of Forensic Clinical Medicine, School of Forensic Medicine, China Medical UniversityShenyang, Liaoning Province, P. R. China
| | - Longlong Cheng
- Department of Forensic Clinical Medicine, School of Forensic Medicine, China Medical UniversityShenyang, Liaoning Province, P. R. China
| | - Jihui Liu
- Department of Forensic Clinical Medicine, School of Forensic Medicine, China Medical UniversityShenyang, Liaoning Province, P. R. China
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Korb E, Herre M, Zucker-Scharff I, Gresack J, Allis CD, Darnell RB. Excess Translation of Epigenetic Regulators Contributes to Fragile X Syndrome and Is Alleviated by Brd4 Inhibition. Cell 2017; 170:1209-1223.e20. [PMID: 28823556 DOI: 10.1016/j.cell.2017.07.033] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 05/17/2017] [Accepted: 07/21/2017] [Indexed: 11/28/2022]
Abstract
Fragile X syndrome (FXS) is a leading genetic cause of intellectual disability and autism. FXS results from the loss of function of fragile X mental retardation protein (FMRP), which represses translation of target transcripts. Most of the well-characterized target transcripts of FMRP are synaptic proteins, yet targeting these proteins has not provided effective treatments. We examined a group of FMRP targets that encode transcriptional regulators, particularly chromatin-associated proteins. Loss of FMRP in mice results in widespread changes in chromatin regulation and aberrant gene expression. To determine if targeting epigenetic factors could reverse phenotypes associated with the disorder, we focused on Brd4, a BET protein and chromatin reader targeted by FMRP. Inhibition of Brd4 function alleviated many of the phenotypes associated with FXS. We conclude that loss of FMRP results in significant epigenetic misregulation and that targeting transcription via epigenetic regulators like Brd4 may provide new treatments for FXS.
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Affiliation(s)
- Erica Korb
- Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University, New York, NY 10065, USA
| | - Margaret Herre
- Laboratory of Molecular Neuro-oncology and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Ilana Zucker-Scharff
- Laboratory of Molecular Neuro-oncology and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Jodi Gresack
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY 10065, USA
| | - C David Allis
- Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University, New York, NY 10065, USA.
| | - Robert B Darnell
- Laboratory of Molecular Neuro-oncology and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
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8
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Corty MM, Tam J, Grueber WB. Dendritic diversification through transcription factor-mediated suppression of alternative morphologies. Development 2016; 143:1351-62. [PMID: 27095495 DOI: 10.1242/dev.130906] [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: 09/29/2015] [Accepted: 02/25/2016] [Indexed: 01/23/2023]
Abstract
Neurons display a striking degree of functional and morphological diversity, and the developmental mechanisms that underlie diversification are of significant interest for understanding neural circuit assembly and function. We find that the morphology of Drosophila sensory neurons is diversified through a series of suppressive transcriptional interactions involving the POU domain transcription factors Pdm1 (Nubbin) and Pdm2, the homeodomain transcription factor Cut, and the transcriptional regulators Scalloped and Vestigial. Pdm1 and Pdm2 are expressed in a subset of proprioceptive sensory neurons and function to inhibit dendrite growth and branching. A subset of touch receptors show a capacity to express Pdm1/2, but Cut represses this expression and promotes more complex dendritic arbors. Levels of Cut expression are diversified in distinct sensory neurons by selective expression of Scalloped and Vestigial. Different levels of Cut impact dendritic complexity and, consistent with this, we show that Scalloped and Vestigial suppress terminal dendritic branching. This transcriptional hierarchy therefore acts to suppress alternative morphologies to diversify three distinct types of somatosensory neurons.
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Affiliation(s)
- Megan M Corty
- Department of Neuroscience, Columbia University Medical Center, 630 W. 168th St. P&S 12-403, New York, NY 10032, USA Department of Physiology and Cellular Biophysics, Columbia University Medical Center, 630 W. 168th St. P&S 12-403, New York, NY 10032, USA
| | - Justina Tam
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, 630 W. 168th St. P&S 12-403, New York, NY 10032, USA
| | - Wesley B Grueber
- Department of Neuroscience, Columbia University Medical Center, 630 W. 168th St. P&S 12-403, New York, NY 10032, USA Department of Physiology and Cellular Biophysics, Columbia University Medical Center, 630 W. 168th St. P&S 12-403, New York, NY 10032, USA
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9
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Keap1-Independent Regulation of Nrf2 Activity by Protein Acetylation and a BET Bromodomain Protein. PLoS Genet 2016; 12:e1006072. [PMID: 27233051 PMCID: PMC4883770 DOI: 10.1371/journal.pgen.1006072] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 04/30/2016] [Indexed: 12/30/2022] Open
Abstract
Mammalian BET proteins comprise a family of bromodomain-containing epigenetic regulators with complex functions in chromatin organization and gene regulation. We identified the sole member of the BET protein family in Drosophila, Fs(1)h, as an inhibitor of the stress responsive transcription factor CncC, the fly ortholog of Nrf2. Fs(1)h physically interacts with CncC in a manner that requires the function of its bromodomains and the acetylation of CncC. Treatment of cultured Drosophila cells or adult flies with fs(1)h RNAi or with the BET protein inhibitor JQ1 de-represses CncC transcriptional activity and engages protective gene expression programs. The mechanism by which Fs(1)h inhibits CncC function is distinct from the canonical mechanism that stimulates Nrf2 function by abrogating Keap1-dependent proteasomal degradation. Consistent with the independent modes of CncC regulation by Keap1 and Fs(1)h, combinations of drugs that can specifically target these pathways cause a strong synergistic and specific activation of protective CncC- dependent gene expression and boosts oxidative stress resistance. This synergism might be exploitable for the design of combinatorial therapies to target diseases associated with oxidative stress or inflammation. Nrf2-related transcription factors regulate gene expression programs that protect organisms against chemical or oxidative stress. Nrf2-activating drugs hold promise for the treatment of diseases that are connected to oxidative stress or inflammation. We identified Fs(1)h, a bromodomain-containing BET protein, as a negative regulator of Nrf2 function in Drosophila. BET proteins are involved in transcription regulation and chromatin organization and have been implicated in several diseases, including cancer. Fs(1)h interacts with acetylated lysines on CncC, the homolog of Nrf2 in Drosophila, and thereby prevents target gene activation. Nrf2 can be released from this inhibitory effect by small molecules that specifically interfere with the binding of BET proteins to acetylated targets. Fs(1)h regulates Nrf2 independently of Keap1, a well-studied Nrf2 regulator. Consequently, chemical inhibitors of Keap1 and of Fs(1)h can be combined to achieve synergistic activation of Nrf2 target genes and strongly boost oxidative stress tolerance in Drosophila. The Keap1-independent mechanism of Nrf2 regulation is conserved in mammals. We suggest that the synergistic effect of combinatorial Nrf2 targeting drugs may be effective for the treatment of different oxidative stress and inflammation-related diseases.
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Ori-McKenney KM, McKenney RJ, Huang HH, Li T, Meltzer S, Jan LY, Vale RD, Wiita AP, Jan YN. Phosphorylation of β-Tubulin by the Down Syndrome Kinase, Minibrain/DYRK1a, Regulates Microtubule Dynamics and Dendrite Morphogenesis. Neuron 2016; 90:551-63. [PMID: 27112495 DOI: 10.1016/j.neuron.2016.03.027] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 02/02/2016] [Accepted: 03/16/2016] [Indexed: 12/31/2022]
Abstract
Dendritic arborization patterns are consistent anatomical correlates of genetic disorders such as Down syndrome (DS) and autism spectrum disorders (ASDs). In a screen for abnormal dendrite development, we identified Minibrain (MNB)/DYRK1a, a kinase implicated in DS and ASDs, as a regulator of the microtubule cytoskeleton. We show that MNB is necessary to establish the length and cytoskeletal composition of terminal dendrites by controlling microtubule growth. Altering MNB levels disrupts dendrite morphology and perturbs neuronal electrophysiological activity, resulting in larval mechanosensation defects. Using in vivo and in vitro approaches, we uncover a molecular pathway whereby direct phosphorylation of β-tubulin by MNB inhibits tubulin polymerization, a function that is conserved for mammalian DYRK1a. Our results demonstrate that phosphoregulation of microtubule dynamics by MNB/DYRK1a is critical for dendritic patterning and neuronal function, revealing a previously unidentified mode of posttranslational microtubule regulation in neurons and uncovering a conserved pathway for a DS- and ASD-associated kinase.
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Affiliation(s)
- Kassandra M Ori-McKenney
- Department of Physiology and Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Richard J McKenney
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Hector H Huang
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Tun Li
- Department of Physiology and Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Shan Meltzer
- Department of Physiology and Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Lily Yeh Jan
- Department of Physiology and Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ronald D Vale
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Arun P Wiita
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yuh Nung Jan
- Department of Physiology and Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
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11
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Nikolova LS, Metzstein MM. Intracellular lumen formation in Drosophila proceeds via a novel subcellular compartment. Development 2015; 142:3964-73. [PMID: 26428009 DOI: 10.1242/dev.127902] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/17/2015] [Indexed: 12/28/2022]
Abstract
Cellular tubes have diverse morphologies, including multicellular, unicellular and subcellular architectures. Subcellular tubes are found prominently within the vertebrate vasculature, the insect breathing system and the nematode excretory apparatus, but how such tubes form is poorly understood. To characterize the cellular mechanisms of subcellular tube formation, we have refined methods of high pressure freezing/freeze substitution to prepare Drosophila larvae for transmission electron microscopic (TEM) analysis. Using our methods, we have found that subcellular tube formation may proceed through a previously undescribed multimembrane intermediate composed of vesicles bound within a novel subcellular compartment. We have also developed correlative light/TEM procedures to identify labeled cells in TEM-fixed larval samples. Using this technique, we have found that Vacuolar ATPase (V-ATPase) and the V-ATPase regulator Rabconnectin-3 are required for subcellular tube formation, probably in a step resolving the intermediate compartment into a mature lumen. In general, our ultrastructural analysis methods could be useful for a wide range of cellular investigations in Drosophila larvae.
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Affiliation(s)
- Linda S Nikolova
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Mark M Metzstein
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
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Jeng MY, Ali I, Ott M. Manipulation of the host protein acetylation network by human immunodeficiency virus type 1. Crit Rev Biochem Mol Biol 2015; 50:314-25. [PMID: 26329395 DOI: 10.3109/10409238.2015.1061973] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Over the past 15 years, protein acetylation has emerged as a globally important post-translational modification that fine-tunes major cellular processes in many life forms. This dynamic regulatory system is critical both for complex eukaryotic cells and for the viruses that infect them. HIV-1 accesses the host acetylation network by interacting with several key enzymes, thereby promoting infection at multiple steps during the viral life cycle. Inhibitors of host histone deacetylases and bromodomain-containing proteins are now being pursued as therapeutic strategies to enhance current antiretroviral treatment. As more acetylation-targeting compounds are reaching clinical trials, it is time to review the role of reversible protein acetylation in HIV-infected CD4(+) T cells.
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Affiliation(s)
- Mark Y Jeng
- a Gladstone Institute of Virology and Immunology , San Francisco , CA , USA and.,b Department of Medicine , University of California , San Francisco , CA , USA
| | - Ibraheem Ali
- a Gladstone Institute of Virology and Immunology , San Francisco , CA , USA and.,b Department of Medicine , University of California , San Francisco , CA , USA
| | - Melanie Ott
- a Gladstone Institute of Virology and Immunology , San Francisco , CA , USA and.,b Department of Medicine , University of California , San Francisco , CA , USA
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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.
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Affiliation(s)
- Tijana Copf
- Institute of Molecular Biology and Biotechnology, Nikolaou Plastira 100, PO Box 1385, Heraklion, GR-70013, Crete, Greece
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