title: Intranuclear aggregation of mutant FUS/TLS as a molecular pathomechanism of amyotrophic lateral sclerosis.
abstract: Dominant mutations in FUS/TLS cause a familial form of amyotrophic lateral sclerosis (fALS), where abnormal accumulation of mutant FUS proteins in cytoplasm has been observed as a major pathological change. Many of pathogenic mutations have been shown to deteriorate the nuclear localization signal in FUS and thereby facilitate cytoplasmic mislocalization of mutant proteins. Several other mutations, however, exhibit no effects on the nuclear localization of FUS in cultured cells, and their roles in the pathomechanism of fALS remain obscure. Here, we show that a pathogenic mutation, G156E, significantly increases the propensities for aggregation of FUS in vitro and in vivo. Spontaneous in vitro formation of amyloid-like fibrillar aggregates was observed in mutant but not wild-type FUS, and notably, those fibrils functioned as efficient seeds to trigger the aggregation of wild-type protein. In addition, the G156E mutation did not disturb the nuclear localization of FUS but facilitated the formation of intranuclear inclusions in rat hippocampal neurons with significant cytotoxicity. We thus propose that intranuclear aggregation of FUS triggered by a subset of pathogenic mutations is an alternative pathomechanism of FUS-related fALS diseases.
authors.affiliation: From the Department of Chemistry, Laboratory for Mechanistic Chemistry of Biomolecules, Keio University, Yokohama, Kanagawa 223-8522.
authors.forename: Takao
authors.initials: T
authors.lastname: Nomura
authors.forename: Shoji
authors.initials: S
authors.lastname: Watanabe
authors.forename: Kumi
authors.initials: K
authors.lastname: Kaneko
authors.forename: Koji
authors.initials: K
authors.lastname: Yamanaka
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Nukina
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Furukawa
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000682:Amyloid / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D009154:Mutation; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D011489:Protein Denaturation; D034702:RNA-Binding Protein FUS / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D000682:Amyloid; D034702:RNA-Binding Protein FUS; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase
keywords: Amyloid; Amyotrophic Lateral Sclerosis (Lou Gehrig's Disease); Neurodegenerative Diseases; Prions; Protein Aggregation