Drosophila lines with mutant and wild type human TDP-43 replacing the endogenous gene reveals phosphorylation and ubiquitination in mutant lines in the absence of viability or lifespan defects

Jer Cherng Chang, David Morton

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6 Scopus citations

Abstract

Mutations in TDP-43 are associated with proteinaceous inclusions in neurons and are believed to be causative in neurodegenerative diseases such as frontotemporal dementia or amyotrophic lateral sclerosis. Here we describe a Drosophila system where we have engineered the genome to replace the endogenous TDP-43 orthologue with wild type or mutant human TDP-43(hTDP-43). In contrast to other models, these flies express both mutant and wild type hTDP-43 at similar levels to those of the endogenous gene and importantly, no age-related TDP-43 accumulation observed among all the transgenic fly lines. Immunopre-cipitation of TDP-43 showed that flies with hTDP-43 mutations had increased levels of ubiquitination and phosphorylation of the hTDP-43 protein. Furthermore, histologically, flies expressing hTDP-43 M337V showed global, robust neuronal staining for phospho-TDP. All three lines: wild type hTDP-43, -G294A and -M337V were homozygous viable, with no defects in development, life span or behaviors observed. The primary behavioral defect was that flies expressing either hTDP-43 G294A or M337V showed a faster decline with age in negative geotaxis. Together, these observations implied that neurons could handle these TDP-43 mutations by phosphorylation- and ubiquitin-dependent proteasome systems, even in a background without the wild type TDP-43. Our findings suggest that these two specific TDP-43 mutations are not inherently toxic, but may require additional environmental or genetic factors to affect longevity or survival.

Original languageEnglish (US)
Article numbere0180828
JournalPLoS One
Volume12
Issue number7
DOIs
StatePublished - Jul 1 2017

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ASJC Scopus subject areas

  • Medicine(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

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