An ALS-linked mutation in TDP-43 disrupts normal protein interactions in the motor neuron response to oxidative stress

Feneberg, Emily; Gordon, David; Thompson, Alexander G.; Finelli, Mattéa J.; Dafinca, Ruxandra; Candalija, Ana; Charles, Philip D.; Mäger, Imre; Wood, Matthew J.; Fischer, Roman; Kessler, Benedikt M.; Gray, Elizabeth; Turner, Martin R.; Talbot, Kevin

Abstract

TDP-43 pathology is a key feature of amyotrophic lateral sclerosis (ALS), but the mechanisms linking TDP-43 to altered cellular function and neurodegeneration remain unclear. We have recently described a mouse model in which human wild-type or mutant TDP-43 are expressed at low levels and where altered stress granule formation is a robust phenotype of TDP-43M337V/− expressing cells. In the present study we use this model to investigate the functional connectivity of human TDP-43 in primary motor neurons under resting conditions and in response to oxidative stress. The interactome of human TDP-43WT or TDP-43M337V was compared by mass spectrometry, and gene ontology enrichment analysis identified pathways dysregulated by the M337V mutation. We found that under normal conditions the interactome of human TDP-43WT was enriched for proteins involved in transcription, translation and poly(A)-RNA binding. In response to oxidative stress, TDP-43WT recruits proteins of the endoplasmic reticulum and endosomal-extracellular transport pathways, interactions which are reduced in the presence of the M337V mutation. Specifically, TDP-43M337V impaired protein-protein interactions involved in stress granule formation including reduced binding to the translation initiation factors Poly(A)-binding protein and Eif4a1 and the endoplasmic reticulum chaperone Grp78. The M337V mutation also affected interactions involved in endosomal-extracellular transport and this this was associated with reduced extracellular vesicle secretion in primary motor neurons from TDP-43M337V/− mice and in human iPSCs-derived motor neurons. Taken together, our analysis highlights a TDP-43 interaction network in motor neurons and demonstrates that an ALS associated mutation may alter the interactome to drive aberrant pathways involved in the pathogenesis of ALS.

• Journal Article Type: Article
• Acceptance Date: Aug 8, 2020
• Online Publication Date: Aug 13, 2020
• Publication Date: 2020-10
• Deposit Date: Dec 17, 2020
• Publicly Available Date: Dec 17, 2020
• Journal: Neurobiology of Disease
• Print ISSN: 0969-9961
• Electronic ISSN: 1095-953X
• Peer Reviewed: Peer Reviewed
• Volume: 144
• Article Number: 105050
• DOI: https://doi.org/10.1016/j.nbd.2020.105050
• Keywords: Amyotrophic lateral sclerosis; TDP-43; Neurodegeneration; Oxidative stress; Interactome; Biomarker; Motor neuron
• Public URL: https://nottingham-repository.worktribe.com/output/4846641
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0969996120303259?via%3Dihub
• Additional Information: This article is maintained by: Elsevier; Article Title: An ALS-linked mutation in TDP-43 disrupts normal protein interactions in the motor neuron response to oxidative stress; Journal Title: Neurobiology of Disease; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.nbd.2020.105050; Content Type: article; Copyright: © 2020 Published by Elsevier Inc.