The Functional Role of RBM45 in Gene Expression and Neurodegeneration


Principal Investigator: Mahlon Collins
Abstract: DESCRIPTION (provided by applicant): Amyotrophic lateral sclerosis (ALS) is a progressive, inevitably fatal neurodegenerative disorder. Pathologically, ALS is characterized by the death of motor neurons of the corticospinal tract, resulting in a numerous debilitating symptoms culminating with paralysis and death. Research into the molecular mechanisms of ALS neurodegeneration has implicated impaired RNA processing and intracytoplasmic aggregation of RNA binding proteins in cell death. We recently performed a cerebrospinal fluid (CSF)-based proteomics study of ALS patients and identified the novel RNA binding protein RBM45 as a putative disease biomarker. Further investigation of RBM45 via immunohistochemistry of ALS patient spinal cord tissue revealed RBM45-positive intracytoplasmic inclusions in motor neurons similar in appearance to those containing the other ALS-associated RNA binding proteins TDP-43 and FUS. We now seek to extend these preliminary observations by studying the normal function of RBM45 as well as its contribution(s) to neurodegenerative disease pathology. To do so, we will first assess how overexpression and knockdown of RBM45 influences the morphology, formation of inclusions, and viability of two cell lines. We will also overexpress a naturally-occurring isoform of the protein lacking a putative nuclear localization signal to determine the propensity of this variant to aggregate in vitro. The next goal of this proposal is t understand what role (if any) RBM45 has in the cellular response to stress. Cells will be stressed via treatment with arsenite and the morphology, number of RBM45-containing inclusions, and cell viability will again be measured. We will also examine the cells for changes in RBM45 post-translational modifications, colocalization with other RNA binding proteins, and incorporation into stress granules to address the function of RBM45 during stress. In the second phase of this proposal, RBM45 gene targets will be defined via UV cross-linking and immunoprecipitation in conjunction with RNA-Seq. We will next assess the contribution of RBM45 to the regulation of gene expression and alternative splicing. For these experiments, RBM45 will be depleted from cells via shRNA and the changes in gene expression and exon splicing will be determined using exon junction- sensitive microarrays. In the last phase of this proposal, we will attempt to link findings obtained in aims 1 and 2 to human neurodegenerative disease using human post-mortem tissue for immunohistochemistry and confocal microscopy. Tissues will be evaluated for brain region-specific and cell type-specific expression of RBM45, inclusions, and colocalization with other ALS- and stress response-associated proteins. Collectively, these experiments will provide new information about the role of RBM45 in normal cell function and disease.
Funding Period: 2012-05-23 - 2015-05-22
more information: NIH RePORT

Top Publications

  1. pmc The RNA-binding motif 45 (RBM45) protein accumulates in inclusion bodies in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP) patients
    Mahlon Collins
    Departments of Neurobiology and Pathology, University of Pittsburgh, PA, USA
    Acta Neuropathol 124:717-32. 2012

Detail Information


  1. pmc The RNA-binding motif 45 (RBM45) protein accumulates in inclusion bodies in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP) patients
    Mahlon Collins
    Departments of Neurobiology and Pathology, University of Pittsburgh, PA, USA
    Acta Neuropathol 124:717-32. 2012
    ..We identified RBM45 using a proteomic screen of CSF from ALS and control subjects for candidate biomarkers, and link this RNA-binding protein to inclusion pathology in ALS, FTLD-TDP and AD...

Research Grants30

  1. Expanding the National Health Accounts
    David M Cutler; Fiscal Year: 2013
    ..Establishment of a set of national health accounts will allow us as a society to understand which medical interventions improve the health of the U.S. population most efficiently. ..
    John V Fahy; Fiscal Year: 2013
    ..Including studies in human biospecimens in a PPG that promises to advance understanding of airway TH2 inflammation in ways that are highly relevant to patients with asthma. ..
  3. Cellular and Molecular Mechanisms of FUS-related Amyotrophic Lateral Sclerosis
    Udai B Pandey; Fiscal Year: 2013
    ..Our proposed studies are expected to provide novel insights into the molecular mechanism of FUS-related ALS that would help in developing a therapeutic interventions for ALS for which currently no cure available. ..
    Bruce L Miller; Fiscal Year: 2013
    ..abstract_text> ..
  5. The Virtual Physiological Rat Project
    Daniel A Beard; Fiscal Year: 2013
    ..This proposal targets the grand challenge of understanding complex multi-faceted disease phenotypes through experiments and simulations that capture the complex genotype-environment-phenotype relationship. ..
  6. Deciphering RNA based mechanisms of neurodegeneration
    Daniela C Zarnescu; Fiscal Year: 2013
  7. TDP-43 Proteinopathies in ALS-Dementia
    Virginia M Lee; Fiscal Year: 2013
    ..abstract_text> ..
  8. University of Maryland Greenebaum Cancer Center Support Grant
    Kevin J Cullen; Fiscal Year: 2013
    ..Reflecting our remarkable and continued growth, UMGCC seeks to renew its CCSG to enhance and expand its efforts in high-quality and clinically relevant cancer research. ..
    Oliver W Press; Fiscal Year: 2013
    ..We anticipate that the investigations described in this application will allow us to maximize the therapeutic efficacy and minimize the toxicity of myeloablative RIT for hematologic malignancies. ..
  10. Posttranscriptional regulation by mRNA-binding shuttling and transport proteins
    Thomas Tuschl; Fiscal Year: 2013
    ..The proposed work will thus establish the first theoretical and experimental models that relate global maps of protein-RNA interactions to RNA transport, setting the stage for future systems-wide studies of PTGR. ..
  11. TDP-43 acetylation as a pathogenic modification in ALS &related proteinopathies
    TODD JONATHAN COHEN; Fiscal Year: 2013
    ..These innovative studies will highlight TDP-43 acetylation as a critical modification linked to the progression of ALS and related TDP-43 proteinopathies. ..
  12. Intellectual and Development Disabilities Research Center
    Marc Yudkoff; Fiscal Year: 2013
    ..5 million from NICHD). The Center includes an excess of 70 Penn faculty at 15 departments at the Schools of Medicine, Veterinary Medicine, Nursing, the Wistar Institute, and the College of Arts and Sciences. ..
  13. Serotonin as a Regulator of Bone Mass Accrual: Basic and Clinical
    Gerard Karsenty; Fiscal Year: 2013
    ..Together our studies should provide important and novel insights in the genetic and molecular control of bone remodeling as well as in the pathogenesis and treatment of osteoporosis, a major disease of aging. ..
  14. Molecular Mechanisms linking Aging, Abeta Proteotoxicity and Neurodegeneration
    Jeffery W Kelly; Fiscal Year: 2013
    ..abstract_text> ..
  15. Investigating a Toxic Gain-of-Interaction Between FUS/TLS &Stress Granules
    DARYL ANGELA BOSCO; Fiscal Year: 2013
    ..These studies have the potential to reveal stress granules as biomarkers of ALS. ..
  16. Role of FUS in ALS
    Haining Zhu; Fiscal Year: 2013
    ..The findings are expected to provide critical insights into the mechanisms by which FUS mutations perturb the RNA processing pathways and ultimately lead to the disease. ..
  17. Alzheimer's Disease Research Center
    Douglas R Galasko; Fiscal Year: 2013
    ..It will provide an environment and core resources to enhance research, foster professional and community training, and coordinate interdisciplinary research. ..
  18. Emory Alzheimer's Disease Center
    Allan I Levey; Fiscal Year: 2013
    ..abstract_text> ..
  19. TBI-Induced Cerebral Metabolic Depression and Recovery
    David A Hovda; Fiscal Year: 2013
    ..This program project will be housed within the UCLA Brain Injury Research Center (Dr. David A. Hovda, Director) so as to assure appropriate imaging, administrative and laboratory support. ..
    NEIL ALAN SHNEIDER; Fiscal Year: 2013
  21. Misregulation of the TDP-43 RNA target, Sortilin, in neurodegeneration
    Leonard Petrucelli; Fiscal Year: 2013
  22. Alzheimer's Disease Research Center at Columbia University
    Scott A Small; Fiscal Year: 2013
    ..HIPAA compliant data organization and statistical consulting services are provided under the ADRC to the research community at Columbia and external to it. ..
    Kenneth H Cowan; Fiscal Year: 2013
  24. Center for Study of Opioid Receptors and Drugs of Abuse (CSORDA)
    Christopher J Evans; Fiscal Year: 2013
    ..Balleine, Bonci, Koob, Levitt, Nestler and Whybrow ex-officio, will provide programmatic oversight and coordinate training, outreach and a Pilot Program for the center. ..