Synergistic effect between proteasome and autophagosome in the clearance of polyubiquitinated TDP‐43

Urushitani, Makoto; Satō, Takashi; Bamba, Hitoshi; Hisa, Yasuo; Tooyama, Ikuo

doi:10.1002/jnr.22243

Cited by 99 publications

(103 citation statements)

References 30 publications

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“…S2A). Similar to the previous findings (Urushitani et al, 2010), the half-lives of the full-length Myc-hTDP-43 and the truncated MychTDP-35 and Myc-hTDP-25 were ,16-18 h, ,10 h and ,7.6 h, respectively ( Fig. 3B; supplementary material Fig.…”

Section: Cleavage Of the Full-length Tdp-43 Into Tdp-35 And Tdp-25 Frsupporting

confidence: 89%

“…To date, several studies have reported findings regarding the degradation of the TDP-43 protein. In particular, it has been found that overexpressed full-length TDP-43 protein and its truncated 25 kDa and 35 kDa fragments are degraded through both the ubiquitin proteasome system (UPS) (Kim et al, 2009;Urushitani et al, 2010;Wang et al, 2010) and macroautophagy pathways (Caccamo et al, 2009;Filimonenko et al, 2007;Ju et al, 2009;Wang et al, 2012). Most short-lived proteins are degraded by UPS through the 26S proteasome (DeMartino and Slaughter, 1999), whereas the autophagy-lysosomal pathway primarily catabolizes unnecessary organelles, long-lived proteins and misfolded and/or aggregated proteins (Ravikumar et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

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Metabolism and mis-metabolism of the neuropathological signature protein TDP-43

Huang

Bose

Majumder

et al. 2014

Journal of Cell Science

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BSTRACT TDP-43 (also known as TARDBP) is a pathological signature protein of neurodegenerative diseases, with TDP-43 proteinopathies including frontotemporal lobar degeneration (FTLD)-TDP and amyotrophic lateral sclerosis (ALS)-TDP. These TDP-43 proteinopathies are characterized by cytoplasmic insoluble TDP-43-positive aggregates in the diseased cells, the formation of which requires the seeding of TDP-25 fragment generated by caspase cleavage of TDP-43. We have investigated the metabolism and mis-metabolism of TDP-43 in cultured cells and found that endogenous and exogenously overexpressed TDP-43 is degraded not only by the ubiquitin proteasome system (UPS) and macroautophagy, but also by the chaperone-mediated autophagy (CMA) mediated through an interaction between Hsc70 (also known as HSPA8) and ubiquitylated TDP-43. Furthermore, proteolytic cleavage of TDP-43 by caspase(s) is a necessary intermediate step for degradation of the majority of the TDP-43 protein, with the TDP-25 and TDP-35 fragments being the main substrates. Finally, we have determined the threshold level of the TDP-25 fragment that is necessary for formation of the cytosolic TDP-43-positive aggregates in cells containing the full-length TDP-43 at an elevated level close to that found in patients with TDP-43 proteinopathies. A comprehensive model of the metabolism and mismetabolism of TDP-43 in relation to these findings is presented.

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Section: Cleavage Of the Full-length Tdp-43 Into Tdp-35 And Tdp-25 Frsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Metabolism and mis-metabolism of the neuropathological signature protein TDP-43

Huang

Bose

Majumder

et al. 2014

Journal of Cell Science

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“…First, we introduce a novel method by which we can distinguish how a given pathway or modifier affects protein accumulation. Different degradation pathways have been implicated in affecting the accumulation of aggregation-prone proteins, from proteasome-mediated degradation (Mishra et al, 2008;Iwata et al, 2009;Zhang et al, 2010;Urushitani et al, 2010;Ortega and Lucas, 2014;Schipper-Krom et al, 2014) to the lysosome-mediated pathway or macroautophagy as being the predominant pathway for aggregate clearance (Ravikumar et al, 2002;Iwata et al, 2005b;Yamamoto et al, 2006;Pankiv et al, 2007;Lamark et al, 2009;Fan et al, 2010;Lamark and Johansen, 2012;Odagiri et al, 2012;Castillo et al, 2014;Bae et al, 2014). Our ability to interrogate how each pathway might contribute to aggregate turnover has been limited by our inability to temporally characterize aggregate formation and clearance in cells.…”

Section: Discussionmentioning

confidence: 99%

Distinguishing aggregate formation and aggregate clearance using cell-based assays

Eenjes

Dragich

Kampinga

et al. 2016

Journal of Cell Science

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The accumulation of ubiquitylated proteinaceous inclusions represents a complex process, reflecting the disequilibrium between aggregate formation and aggregate clearance. Although decreasing aggregate formation or augmenting aggregate clearance will ultimately lead to a diminished aggregate burden, in terms of disease pathogenesis, the different approaches can have distinct outcomes. Using a novel cellbased assay that can distinguish newly formed versus preformed inclusions, we demonstrate that two proteins previously implicated in the autophagic clearance of expanded polyglutamine inclusions, HspB7 and Alfy (also known as WDFY3), actually affect very distinct cellular processes to affect aggregate burden. Using this cell-based assay, we also establish that constitutive expression of the aggregation-prone protein can measurably slow the elimination of protein aggregates, given that not all aggregates appear to be available for degradation. This new assay can therefore not only determine at what step a modifier might influence aggregate burden, but also can be used to provide new insights into how protein aggregates are targeted for degradation.

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“…As mentioned previously, inhibition of the autophagy compromises the ubiquitin-proteasome pathway (36,37). Evidence has been presented before that clearance of TDP-43 and its caspase-generated 35-and 25-kDa fragments is processed through both the autophagy (48 -50) as well as the proteasome pathway (48,49). For instance, use of the autophagy inhibitors such as 3-MA (49) and autophagy activators such as rapamycin (50) increases and reduces, respectively, the accumulation of TDP-43.…”

Section: Discussionmentioning

confidence: 99%

“…Evidence has been presented before that clearance of TDP-43 and its caspase-generated 35-and 25-kDa fragments is processed through both the autophagy (48 -50) as well as the proteasome pathway (48,49). For instance, use of the autophagy inhibitors such as 3-MA (49) and autophagy activators such as rapamycin (50) increases and reduces, respectively, the accumulation of TDP-43. Also, TDP-43 interacts with ubiquilin, a polyubiquitin-binding protein that is involved in both autophagy and UPS (51,52).…”

Section: Discussionmentioning

confidence: 99%

Regulation of Autophagy by Neuropathological Protein TDP-43

Bose¹,

Huang²,

Shen

2011

Journal of Biological Chemistry

132

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TDP-43 (TAR DNA-binding protein) (1) is a highly conserved and abundantly expressed protein among the mammals and invertebrates (2, 3). The protein is located mainly in the nucleus as punctuated structures designated T-bodies (4), but it is also distributed in the cytoplasm as discrete RNA granules (5). Multiple cellular functions have been implicated to be regulated by TDP-43, which consist of but are not restricted to transcriptional repression, RNA processing including splicing, biogenesis of miRNAs, and even translation (reviewed in Refs. 6 -8). Some of these regulations have been shown to be mediated through the two RNA recognition motifs (RRM1 and RRM2) and the C-terminal glycine-rich, prion-like GQN domain (6, 7). Mutational studies have revealed that the RNA recognition motif 1 (RRM1) 3 domain contributes much of the nucleic acid binding activity, whereas the function of RRM2 is still unclear and appears to play a lesser role in RNA binding (7). Studies have also established that an intact GQN domain, which recruits additional heterogeneous ribonucleoprotein (hnRNPs), is also necessary for the splicing activity of TDP-43 (2, 9).More recently, TDP-43 has been identified as the major pathological signature protein of patients with the frontotemporal lobar degeneration with ubiquitin-positive inclusions and amyotrophic lateral sclerosis (10, 11). In particular, the metabolism of TDP-43 in the diseased cells of frontotemporal lobar degeneration with ubiquitin-positive inclusions and amyotrophic lateral sclerosis are misregulated, resulting in the generation of polyubiquitinated, phosphorylated, and caspase-3-cleaved species concentrated in the ubiquitinated inclusions (UBIs) in the cytoplasm and, to a much lesser extent, in the nucleus. Often accompanied with formation of the cytoplasmic UBIs is depletion of the nuclear TDP-43 (10, 11) (reviewed in Ref. 12). A causative role of TDP-43 in the pathogenesis of these diseases is substantiated genetically by the identification of Ͼ30 different mutations in its C-terminal GQN domain (reviewed in Ref. 13). The molecular basis of misregulation of the TDP-43 metabolism remains to be examined. Also unclear are the exact roles of TDP-43 in the pathogenesis of diseases with TDP-43(ϩ)UBIs. Both loss-of-function of TDP-43 and gain-of-cytotoxicity, e.g. as caused by the TDP-43(ϩ)UBIs, have been suggested to facilitate the disease initiation as well as propagation (reviewed in Refs. 6,7,12,14).Regarding the scenario of pathogenesis by loss-of-function of TDP-43, it is interesting to note that knock-out of TDP-43 expression in mice and/or Drosophila could result in defects of early embryonic developments, impairment of the motor function, and decrease of learning ability (15-19). These studies, among others, have evidenced the importance of TDP-43 in development and/or neuronal function, but they do not provide clues to the role of this protein in TDP-43 proteinopathies on the molecular level. With respect to the metabolism of TDP-43, it is interesting to note that the homeo...

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Synergistic effect between proteasome and autophagosome in the clearance of polyubiquitinated TDP‐43

Cited by 99 publications

References 30 publications

Metabolism and mis-metabolism of the neuropathological signature protein TDP-43

Metabolism and mis-metabolism of the neuropathological signature protein TDP-43

Distinguishing aggregate formation and aggregate clearance using cell-based assays

Regulation of Autophagy by Neuropathological Protein TDP-43

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