title: CUL2-mediated clearance of misfolded TDP-43 is paradoxically affected by VHL in oligodendrocytes in ALS.
abstract: The molecular machinery responsible for cytosolic accumulation of misfolded TDP-43 in amyotrophic lateral sclerosis (ALS) remains elusive. Here we identified a cullin-2 (CUL2) RING complex as a novel ubiquitin ligase for fragmented forms of TDP-43. The von Hippel Lindau protein (VHL), a substrate binding component of the complex, preferentially recognized misfolded TDP-43 at Glu246 in RNA-recognition motif 2. Recombinant full-length TDP-43 was structurally fragile and readily cleaved, suggesting that misfolded TDP-43 is cleared by VHL/CUL2 in a step-wise manner via fragmentation. Surprisingly, excess VHL stabilized and led to inclusion formation of TDP-43, as well as mutant SOD1, at the juxtanuclear protein quality control center. Moreover, TDP-43 knockdown elevated VHL expression in cultured cells, implying an aberrant interaction between VHL and mislocalized TDP-43 in ALS. Finally, cytoplasmic inclusions especially in oligodendrocytes in ALS spinal cords were immunoreactive to both phosphorylated TDP-43 and VHL. Thus, our results suggest that an imbalance in VHL and CUL2 may underlie oligodendrocyte dysfunction in ALS, and highlight CUL2 E3 ligase emerges as a novel therapeutic potential for ALS.
authors.affiliation: Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Uchida
authors.affiliation: Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tamaki
authors.affiliation: Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ayaki
authors.affiliation: Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 Japan.
authors.forename: Akemi
authors.initials: A
authors.lastname: Shodai
authors.affiliation: Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Kaji
authors.affiliation: Molecular Neuroscience Research Center, Shiga University of Medical Science, Seta-Tsukinowa-cho, Otsu, Shiga 520-2192, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Morimura
authors.affiliation: Molecular Neuroscience Research Center, Shiga University of Medical Science, Seta-Tsukinowa-cho, Otsu, Shiga 520-2192, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Banno
authors.affiliation: Department of Molecular Pathology, Tokushima University, 2-24 Shinkuracho, Tokushima, Tokushima Prefecture 770-0855, Japan.
authors.forename: Kazuchika
authors.initials: K
authors.lastname: Nishitsuji
authors.affiliation: Department of Molecular Pathology, Tokushima University, 2-24 Shinkuracho, Tokushima, Tokushima Prefecture 770-0855, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Sakashita
authors.affiliation: Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 Japan.
authors.forename: Takakuni
authors.initials: T
authors.lastname: Maki
authors.affiliation: Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yamashita
authors.affiliation: Department of Neurology, Wakayama Medical University, 811-1 Kimiidera, Wakayama, Wakayama Prefecture 641-8509, Japan.
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Ito
authors.affiliation: Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Takahashi
authors.affiliation: Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Urushitani
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D044842:Cullin Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D000939:Epitopes / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D007150:Immunohistochemistry; D002479:Inclusion Bodies / Q000378:metabolism; D008822:Mice, Transgenic; D008954:Models, Biological; D050505:Mutant Proteins / Q000378:metabolism; D009836:Oligodendroglia / Q000378:metabolism*; D010766:Phosphorylation; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D066329:Protein Aggregates; D011485:Protein Binding; D000072417:Protein Domains; D017510:Protein Folding; D055550:Protein Stability; D059748:Proteolysis; D051381:Rats; D013482:Superoxide Dismutase / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism; D054875:Ubiquitination; D051794:Von Hippel-Lindau Tumor Suppressor Protein / Q000378:metabolism*
chemical_list: C105153:CUL2 protein, human; D044842:Cullin Proteins; D004268:DNA-Binding Proteins; D000939:Epitopes; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D050505:Mutant Proteins; D066329:Protein Aggregates; C000598624:TARDBP protein, human; D025801:Ubiquitin; D013482:Superoxide Dismutase; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D046988:Proteasome Endopeptidase Complex; C497446:VHL protein, human