Using tetracysteine-tagged TDP-43 with a biarsenical dye to monitor real-time trafficking in a cell model of Amyotrophic Lateral Sclerosis

TAR DNA-binding protein 43 (TDP-43) has been identified as the major constituent of the proteinaceous inclusions that are characteristic of most forms of amyotrophic lateral sclerosis (ALS) and ubiquitin positive frontotemporal lobar degeneration (FTLD). Wild type (WT) TDP-43 inclusions are a pathological hallmark of >95% of patients with sporadic ALS and of the majority of familial ALS cases, and they are also found in a significant proportion of FTLD cases. ALS is the most common form of motor neurone disease, characterised by progressive weakness and muscular wasting, and typically leads to death within a few years of diagnosis. To determine how the translocation and misfolding of TDP-43 contributes to ALS pathogenicity, it is crucial to define the dynamic behaviour of this protein within the cellular environment. It is therefore necessary to develop cell models that allow the location of the protein to be defined. We report the use of TDP-43 with a tetracysteine tag for visualisation using fluorogenic...