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Citation
Coyne, A.N., Yamada, S.B., Siddegowda, B.B., Estes, P.S., Zaepfel, B.L., Johannesmeyer, J.S., Lockwood, D.B., Pham, L.T., Hart, M.P., Cassel, J.A., Freibaum, B., Boehringer, A.V., Taylor, J.P., Reitz, A.B., Gitler, A.D., Zarnescu, D.C. (2015). Fragile X protein mitigates TDP-43 toxicity by remodeling RNA granules and restoring translation.  Hum. Mol. Genet. 24(24): 6886--6898.
FlyBase ID
FBrf0230196
Publication Type
Research paper
Abstract

RNA dysregulation is a newly recognized disease mechanism in amyotrophic lateral sclerosis (ALS). Here we identify Drosophila fragile X mental retardation protein (dFMRP) as a robust genetic modifier of TDP-43-dependent toxicity in a Drosophila model of ALS. We find that dFMRP overexpression (dFMRP OE) mitigates TDP-43 dependent locomotor defects and reduced lifespan in Drosophila. TDP-43 and FMRP form a complex in flies and human cells. In motor neurons, TDP-43 expression increases the association of dFMRP with stress granules and colocalizes with polyA binding protein in a variant-dependent manner. Furthermore, dFMRP dosage modulates TDP-43 solubility and molecular mobility with overexpression of dFMRP resulting in a significant reduction of TDP-43 in the aggregate fraction. Polysome fractionation experiments indicate that dFMRP OE also relieves the translation inhibition of futsch mRNA, a TDP-43 target mRNA, which regulates neuromuscular synapse architecture. Restoration of futsch translation by dFMRP OE mitigates Futsch-dependent morphological phenotypes at the neuromuscular junction including synaptic size and presence of satellite boutons. Our data suggest a model whereby dFMRP is neuroprotective by remodeling TDP-43 containing RNA granules, reducing aggregation and restoring the translation of specific mRNAs in motor neurons.

PubMed ID
PubMed Central ID
PMC5007633 (PMC) (EuropePMC)
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Secondary IDs
    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    Hum. Mol. Genet.
    Title
    Human Molecular Genetics
    Publication Year
    1992-
    ISBN/ISSN
    0964-6906
    Data From Reference
    Alleles (10)
    Genes (5)
    Human Disease Models (1)
    Physical Interactions (1)
    Insertions (1)
    Transgenic Constructs (8)