FUS and amyotrophic lateral sclerosis: cDNAs for human wild type (hereafter referred as FUSWT) and either of two ALS-linked mutants of FUS, R514G (arginine to glycine substitution at amino acid 514, hereafter referred as FUSR514G) and R521C (arginine to cysteine substitution at amino acid 521, hereafter referred as FUSR521C) were fused to a N-terminal hemagglutinin (HA) tag and placed under the control of the murine prion promoter (Figure 1A).