title: Interaction of RNA with a C-terminal fragment of the amyotrophic lateral sclerosis-associated TDP43 reduces cytotoxicity.
abstract: A hallmark of amyotrophic lateral sclerosis (ALS), a devastating neurodegenerative disease, is formation of inclusion bodies (IBs) from misfolded proteins in neuronal cells. TAR RNA/DNA-binding protein 43 kDa (TDP43) is an ALS-causative protein forming IBs in ALS patients. The relation between localization of the IBs and neurotoxicity remains largely unknown. We characterized aggregation of fluorescently tagged TDP43 and its carboxyl-terminal fragments (CTFs) by analytical fluorescence imaging techniques. Quantitative time-lapse analysis in individual live cells showed that fluorescent-protein-tagged TDP43 was cleaved and a 35 kDa TDP43 CTF (TDP35) formed ubiquitin (Ub)-negative cytoplasmic IBs. Although TDP35 formed mildly toxic Ub-negative IBs in the cytoplasm, TDP25, another type of a TDP43 CTF, efficiently formed sufficiently toxic Ub-positive IBs. One- or two-color fluorescence correlation spectroscopy (FCS/FCCS) revealed that coaggregation of TDP25 with TDP43 was initiated by depletion of the RNA that binds to TDP25. Moreover, nuclear localization tagging TDP25 reduced the rate of neuronal cell death. These observations point to the need to elucidate the novel sequestration mechanism and details of the toxicity of the misfolded and aggregation-prone TDP43 CTFs (as well as the RNA binding and nuclear retention) in order to identify possible preventive interventions against ALS.
authors.affiliation: Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kitamura
authors.affiliation: Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.|Graduate School of Life Science, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Nakayama
authors.affiliation: Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.|Graduate School of Life Science, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Shibasaki
authors.affiliation: Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.|Graduate School of Life Science, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Ayami
authors.initials: A
authors.lastname: Taki
authors.affiliation: Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.|Graduate School of Life Science, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Yuno
authors.affiliation: Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.|School of Science, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Kayo
authors.initials: K
authors.lastname: Takeda
authors.affiliation: Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.|Graduate School of Life Science, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Yahara
authors.affiliation: Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.|School of Science, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Tanabe
authors.affiliation: Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Kinjo
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D053148:Caspase 3 / Q000378:metabolism; D016923:Cell Death; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D002479:Inclusion Bodies / Q000378:metabolism; D051379:Mice; D010446:Peptide Fragments / Q000378:metabolism; D066329:Protein Aggregates; D066263:Protein Aggregation, Pathological; D011485:Protein Binding; D017510:Protein Folding; D054730:Protein Interaction Domains and Motifs; D021381:Protein Transport; D059748:Proteolysis; D012313:RNA / Q000235:genetics / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D010446:Peptide Fragments; D066329:Protein Aggregates; C000598624:TARDBP protein, human; C574535:TDP-25 protein, human; D012313:RNA; D053148:Caspase 3