A functional interaction between TDP-43 and USP10 reveals USP10 dysfunction in TDP-43 proteinopathies
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are fatal neurodegenerative disorders characterised by the progressive degeneration of specific neurons, that are defined by the appearance of TDP-43 pathology leading to TDP-43 cytoplasmic aggregation coupled with its nuclear loss. Although the causes of TDP-43 pathology in TDP-43 proteinopathies remain unclear, stress response may play a significant role, with some TDP-43 co-localizing with stress granules (SG). The ubiquitin-specific protease 10 (USP10) is a critical inhibitor of SG assembly. Here, we identify a new functional interaction between TDP-43 and USP10, with both proteins modulating different key aspects of the biology of the other. Adding to their functional connection, we assign a new function to USP10 as a modulator of alternative splicing, sharing a subset of splicing targets with TDP-43. Critically, we found that USP10 levels can increase in postmortem tissue from ALS and FTD patients and that USP10 can ameliorate TDP-43 mediated toxicity in vivo in an animal model, overall suggesting a new role for USP10 in TDP-43 proteinopathies.