title: Mass spectrometric analysis of accumulated TDP-43 in amyotrophic lateral sclerosis brains.
abstract: TDP-43 is the major disease-associated protein involved in the pathogenesis and progression of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitin-positive inclusions linked to TDP-43 pathology (FTLD-TDP). Abnormal phosphorylation, truncation and cytoplasmic mis-localization are known to be the characteristics for the aggregated forms of TDP-43, and gain of toxic abnormal TDP-43 or loss of function of physiological TDP-43 have been suggested as the cause of neurodegeneration. However, most of the post-translational modifications or truncation sites in the abnormal TDP-43 in brains of patients remain to be identified by protein chemical analysis. In this study, we carried out a highly sensitive liquid chromatography-mass spectrometry analysis of Sarkosyl-insoluble pathological TDP-43 from brains of ALS patients and identified several novel phosphorylation sites, deamidation sites, and cleavage sites. Almost all modifications were localized in the Gly-rich C-terminal half. Most of the cleavage sites identified in this study are novel and are located in N-terminal half, suggesting that these sites may be more accessible to proteolytic enzymes. The data obtained in this study provide a foundation for the molecular mechanisms of TDP-43 aggregation and ALS pathogenesis.
authors.affiliation: Department of Dementia and Higher Brain Function, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan.
authors.forename: Fuyuki
authors.initials: F
authors.lastname: Kametani
authors.affiliation: National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Urushiyama 886, Aoi-ku, Shizuoka 420-8688, Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Obi
authors.affiliation: National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Urushiyama 886, Aoi-ku, Shizuoka 420-8688, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Shishido
authors.affiliation: Choju Medical Institute, Fukushimura Hospital, Noyorimachiazayamanaka, Toyohashi 441-8124, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Akatsu
authors.affiliation: Department of Neuropathology (Brain Bank for Aging Research), Tokyo Metropolitan Geriatric Hospital &Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Murayama
authors.affiliation: Department of Laboratory Medicine, National Center Hospital, NCNP, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Department of Neuropathology, Institute for Medical Science of Aging, Aichi Medical University, Nagakute, Aichi 480-1195, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Department of Dementia and Higher Brain Function, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Hasegawa
mesh_terms: D000368:Aged; D000595:Amino Acid Sequence; D000690:Amyotrophic Lateral Sclerosis / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000378:metabolism; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D053719:Tandem Mass Spectrometry
chemical_list: D004268:DNA-Binding Proteins; D010446:Peptide Fragments; C000598624:TARDBP protein, human