[HTML][HTML] A yeast model of FUS/TLS-dependent cytotoxicity

S Ju, DF Tardiff, H Han, K Divya, Q Zhong… - PLoS …, 2011 - journals.plos.org
S Ju, DF Tardiff, H Han, K Divya, Q Zhong, LE Maquat, DA Bosco, LJ Hayward, RH Brown Jr…
PLoS biology, 2011journals.plos.org
FUS/TLS is a nucleic acid binding protein that, when mutated, can cause a subset of familial
amyotrophic lateral sclerosis (fALS). Although FUS/TLS is normally located predominantly in
the nucleus, the pathogenic mutant forms of FUS/TLS traffic to, and form inclusions in, the
cytoplasm of affected spinal motor neurons or glia. Here we report a yeast model of human
FUS/TLS expression that recapitulates multiple salient features of the pathology of the
disease-causing mutant proteins, including nuclear to cytoplasmic translocation, inclusion …
FUS/TLS is a nucleic acid binding protein that, when mutated, can cause a subset of familial amyotrophic lateral sclerosis (fALS). Although FUS/TLS is normally located predominantly in the nucleus, the pathogenic mutant forms of FUS/TLS traffic to, and form inclusions in, the cytoplasm of affected spinal motor neurons or glia. Here we report a yeast model of human FUS/TLS expression that recapitulates multiple salient features of the pathology of the disease-causing mutant proteins, including nuclear to cytoplasmic translocation, inclusion formation, and cytotoxicity. Protein domain analysis indicates that the carboxyl-terminus of FUS/TLS, where most of the ALS-associated mutations are clustered, is required but not sufficient for the toxicity of the protein. A genome-wide genetic screen using a yeast over-expression library identified five yeast DNA/RNA binding proteins, encoded by the yeast genes ECM32, NAM8, SBP1, SKO1, and VHR1, that rescue the toxicity of human FUS/TLS without changing its expression level, cytoplasmic translocation, or inclusion formation. Furthermore, hUPF1, a human homologue of ECM32, also rescues the toxicity of FUS/TLS in this model, validating the yeast model and implicating a possible insufficiency in RNA processing or the RNA quality control machinery in the mechanism of FUS/TLS mediated toxicity. Examination of the effect of FUS/TLS expression on the decay of selected mRNAs in yeast indicates that the nonsense-mediated decay pathway is probably not the major determinant of either toxicity or suppression.
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