scholarly journals Proteasome and p97 mediate mitophagy and degradation of mitofusins induced by Parkin

2010 ◽  
Vol 191 (7) ◽  
pp. 1367-1380 ◽  
Author(s):  
Atsushi Tanaka ◽  
Megan M. Cleland ◽  
Shan Xu ◽  
Derek P. Narendra ◽  
Der-Fen Suen ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Mitochondrial Fission ◽  
E3 Ubiquitin Ligase ◽  
Membrane Depolarization ◽  
Dependent Manner ◽  
Inner Mitochondrial Membrane ◽  
Aaa Atpase ◽  
Selective Autophagy ◽  
Selective Elimination ◽  
Large Gtpases

Damage to mitochondria can lead to the depolarization of the inner mitochondrial membrane, thereby sensitizing impaired mitochondria for selective elimination by autophagy. However, fusion of uncoupled mitochondria with polarized mitochondria can compensate for damage, reverse membrane depolarization, and obviate mitophagy. Parkin, an E3 ubiquitin ligase that is mutated in monogenic forms of Parkinson’s disease, was recently found to induce selective autophagy of damaged mitochondria. Here we show that ubiquitination of mitofusins Mfn1 and Mfn2, large GTPases that mediate mitochondrial fusion, is induced by Parkin upon membrane depolarization and leads to their degradation in a proteasome- and p97-dependent manner. p97, a AAA+ ATPase, accumulates on mitochondria upon uncoupling of Parkin-expressing cells, and both p97 and proteasome activity are required for Parkin-mediated mitophagy. After mitochondrial fission upon depolarization, Parkin prevents or delays refusion of mitochondria, likely by the elimination of mitofusins. Inhibition of Drp1-mediated mitochondrial fission, the proteasome, or p97 prevents Parkin-induced mitophagy.

scholarly journals The mitochondrial E3 ubiquitin ligase MARCH5 is required for Drp1 dependent mitochondrial division

2007 ◽  
Vol 178 (1) ◽  
pp. 71-84 ◽  
Author(s):  
Mariusz Karbowski ◽  
Albert Neutzner ◽  
Richard J. Youle
Keyword(s):  
Rna Interference ◽  
Ubiquitin Ligase ◽  
Molecular Interactions ◽  
Mitochondrial Fission ◽  
Ectopic Expression ◽  
E3 Ubiquitin Ligase ◽  
Dependent Manner ◽  
Wild Type ◽  
Subcellular Trafficking ◽  
Mitochondrial Division

We identify a mitochondrial E3 ubiquitin ligase, MARCH5, as a critical regulator of mitochondrial fission. MARCH5 RING mutants and MARCH5 RNA interference induce an abnormal elongation and interconnection of mitochondria indicative of an inhibition of mitochondrial division. The aberrant mitochondrial phenotypes in MARCH5 RING mutant–expressing cells are reversed by ectopic expression of Drp1, but not another mitochondrial fission protein Fis1. Moreover, as indicated by abnormal clustering and mitochondrial accumulation of Drp1, as well as decreased cellular mobility of YFP-Drp1 in cells expressing MARCH5 RING mutants, MARCH5 activity regulates the subcellular trafficking of Drp1, likely by impacting the correct assembly at scission sites or the disassembly step of fission complexes. Loss of this activity may account for the observed mitochondrial division defects. Finally, MARCH5 RING mutants and endogenous Drp1, but not wild-type MARCH5 or Fis1, co-assemble into abnormally enlarged clusters in a Drp1 GTPase-dependent manner, suggesting molecular interactions among these proteins. Collectively, our data suggest a model in which mitochondrial division is regulated by a MARCH5 ubiquitin-dependent switch.

The F-box E3 ubiquitin ligase BAF1 mediates the degradation of the brassinosteroid-activated transcription factor BES1 through selective autophagy in Arabidopsis

2021 ◽  
Author(s):  
Ping Wang ◽  
Trevor M Nolan ◽  
Natalie M Clark ◽  
Hao Jiang ◽  
Christian Montes-Serey ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Ubiquitin Ligase ◽  
Stress Responses ◽  
E3 Ubiquitin Ligase ◽  
Dependent Manner ◽  
Selective Autophagy ◽  
Sucrose Starvation ◽  
Autophagic Degradation ◽  
Autophagy Pathway

Abstract Brassinosteroids (BRs) regulate plant growth, development, and stress responses by activating the core transcription factor BRI1-EMS-SUPPRESSOR1 (BES1), whose degradation occurs through the proteasome and autophagy pathways. The E3 ubiquitin ligase(s) that modify BES1 for autophagy-mediated degradation remain to be fully defined. Here, we identified an F-box family E3 ubiquitin ligase named BES1-ASSOCIATED F-BOX1 (BAF1) in Arabidopsis thaliana. BAF1 interacts with BES1 and mediates its ubiquitination and degradation. Our genetic data demonstrated that BAF1 inhibits BR signaling in a BES1-dependent manner. Moreover, BAF1 targets BES1 for autophagic degradation in a selective manner. BAF1-triggered selective autophagy of BES1 depends on the ubiquitin binding receptor DOMINANT SUPPRESSOR OF KAR2 (DSK2). Sucrose starvation-induced selective autophagy of BES1, but not bulk autophagy, was significantly compromised in baf1 mutant and BAF1-ΔF (BAF1 F-box decoy) overexpression plants, but clearly increased by BAF1 overexpression. The baf1 and BAF1-ΔF overexpression plants had increased BR-regulated growth but were sensitive to long-term sucrose starvation, while BAF1 overexpression plants had decreased BR-regulated growth but were highly tolerant of sucrose starvation. Our results not only established BAF1 as an E3 ubiquitin ligase that targets BES1 for degradation through selective autophagy pathway, but also revealed a mechanism for plants to reduce growth during sucrose starvation.

scholarly journals Hect E3 ubiquitin ligase Tom1 controls Dia2 degradation during the cell cycle

2012 ◽  
Vol 23 (21) ◽  
pp. 4203-4211 ◽  
Author(s):  
Dong-Hwan Kim ◽  
Deanna M. Koepp
Keyword(s):  
Cell Cycle ◽  
Protein Degradation ◽  
Ubiquitin Ligase ◽  
E3 Ubiquitin Ligase ◽  
S Phase ◽  
Temperature Sensitive ◽  
Dependent Manner ◽  
Charged Residues ◽  
Phase Progression ◽  
Positively Charged

The ubiquitin proteasome system plays a pivotal role in controlling the cell cycle. The budding yeast F-box protein Dia2 is required for genomic stability and is targeted for ubiquitin-dependent degradation in a cell cycle–dependent manner, but the identity of the ubiquitination pathway is unknown. We demonstrate that the Hect domain E3 ubiquitin ligase Tom1 is required for Dia2 protein degradation. Deletion of DIA2 partially suppresses the temperature-sensitive phenotype of tom1 mutants. Tom1 is required for Dia2 ubiquitination and degradation during G1 and G2/M phases of the cell cycle, whereas the Dia2 protein is stabilized during S phase. We find that Tom1 binding to Dia2 is enhanced in G1 and reduced in S phase, suggesting a mechanism for this proteolytic switch. Tom1 recognizes specific, positively charged residues in a Dia2 degradation/NLS domain. Loss of these residues blocks Tom1-mediated turnover of Dia2 and causes a delay in G1–to–S phase progression. Deletion of DIA2 rescues a delay in the G1–to–S phase transition in the tom1Δ mutant. Together our results suggest that Tom1 targets Dia2 for degradation during the cell cycle by recognizing positively charged residues in the Dia2 degradation/NLS domain and that Dia2 protein degradation contributes to G1–to–S phase progression.

scholarly journals Proteomic analysis identifies the E3 ubiquitin ligase Pdzrn3 as a regulatory target of Wnt5a-Ror signaling

2021 ◽  
Vol 118 (25) ◽  
pp. e2104944118
Author(s):  
Sara E. Konopelski Snavely ◽  
Michael W. Susman ◽  
Ryan C. Kunz ◽  
Jia Tan ◽  
Srisathya Srinivasan ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Large Scale ◽  
Glycogen Synthase ◽  
E3 Ubiquitin Ligase ◽  
Ubiquitin Proteasome System ◽  
Dependent Manner ◽  
Casein Kinase 1 ◽  
Downstream Signaling ◽  
Proteomic Screen ◽  
Responsive Element

Wnt5a-Ror signaling is a conserved pathway that regulates morphogenetic processes during vertebrate development [R. T. Moon et al., Development 119, 97–111 (1993); I. Oishi et al., Genes Cells 8, 645–654 (2003)], but its downstream signaling events remain poorly understood. Through a large-scale proteomic screen in mouse embryonic fibroblasts, we identified the E3 ubiquitin ligase Pdzrn3 as a regulatory target of the Wnt5a-Ror pathway. Upon pathway activation, Pdzrn3 is degraded in a β-catenin–independent, ubiquitin-proteasome system–dependent manner. We developed a flow cytometry-based reporter to monitor Pdzrn3 abundance and delineated a signaling cascade involving Frizzled, Dishevelled, Casein kinase 1, and Glycogen synthase kinase 3 that regulates Pdzrn3 stability. Epistatically, Pdzrn3 is regulated independently of Kif26b, another Wnt5a-Ror effector. Wnt5a-dependent degradation of Pdzrn3 requires phosphorylation of three conserved amino acids within its C-terminal LNX3H domain [M. Flynn, O. Saha, P. Young, BMC Evol. Biol. 11, 235 (2011)], which acts as a bona fide Wnt5a-responsive element. Importantly, this phospho-dependent degradation is essential for Wnt5a-Ror modulation of cell migration. Collectively, this work establishes a Wnt5a-Ror cell morphogenetic cascade involving Pdzrn3 phosphorylation and degradation.

scholarly journals TRIP13 promotes the cell proliferation, migration and invasion of glioblastoma through the FBXW7/c-MYC axis

2019 ◽  
Vol 121 (12) ◽  
pp. 1069-1078 ◽  
Author(s):  
Guanghui Zhang ◽  
Qingzong Zhu ◽  
Gang Fu ◽  
Jianbing Hou ◽  
Xiaosong Hu ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Therapeutic Target ◽  
Biological Effect ◽  
Thyroid Hormone Receptor ◽  
E3 Ubiquitin Ligase ◽  
Mitotic Checkpoint ◽  
Migration And Invasion ◽  
Cell Models ◽  
Aaa Atpase

Abstract Background Thyroid hormone receptor interactor 13 (TRIP13) is an AAA + ATPase that plays an important role in the mitotic checkpoint. TRIP13 is highly expressed in various human tumours and promotes tumorigenesis. However, the biological effect of TRIP13 in GBM cells remains unclear. Methods We generated GBM cell models with overexpressed or silenced TRIP13 via lentivirus-mediated overexpression and RNAi methods. The biological role of TRIP13 in the proliferation, migration and invasion of GBM cells has been further explored. Results Our research indicated that TRIP13 was highly expressed in GBM tissues and cells. We found that the proliferation, migration and invasion abilities were inhibited in TRIP13-knockdown GBM cells. These results indicated that TRIP13 plays an important role in the tumorigenesis of GBM. Moreover, we found that TRIP13 first stabilised c-MYC by inhibiting the transcription of FBXW7, which is an E3 ubiquitin ligase of c-MYC, by directly binding to the promoter region of FBXW7. Therefore, our study indicated that the TRIP13/FBXW7/c-MYC pathway might provide a prospective therapeutic target in the treatment of GBM. Conclusions These results indicated that TRIP13 plays an oncogenic role in GBM. The TRIP13/FBXW7/c-MYC pathway might act as a prospective therapeutic target for GBM patients.

scholarly journals Sequential ubiquitination of NLRP3 by RNF125 and Cbl-b limits inflammasome activation and endotoxemia

2020 ◽  
Vol 217 (4) ◽  
Author(s):  
Juan Tang ◽  
Sha Tu ◽  
Guoxin Lin ◽  
Hui Guo ◽  
Chengkai Yan ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Lethal Dose ◽  
E3 Ubiquitin Ligase ◽  
Inflammasome Activation ◽  
Dependent Manner ◽  
Leucine Rich Repeat ◽  
Nlrp3 Inflammasome Activation ◽  
Repeat Domain ◽  
Nlrp3 Inflammasomes ◽  
Lrr Domain

Aberrant NLRP3 inflammasome activation contributes to the development of endotoxemia. The importance of negative regulation of NLRP3 inflammasomes remains poorly understood. Here, we show that the E3 ubiquitin ligase Cbl-b is essential for preventing endotoxemia induced by a sub-lethal dose of LPS via a caspase-11/NLRP3–dependent manner. Further studies show that NLRP3 undergoes both K63- and K48-linked polyubiquitination. Cbl-b binds to the K63-ubiquitin chains attached to the NLRP3 leucine-rich repeat domain (LRR) via its ubiquitin-associated region (UBA) and then targets NLRP3 at K496 for K48-linked ubiquitination and proteasome-mediated degradation. We also identify RNF125 as an additional E3 ubiquitin ligase that initiates K63-linked ubiquitination of the NLRP3 LRR domain. Therefore, NLRP3 is sequentially ubiquitinated by K63- and K48-linked ubiquitination, thus keeping the NLRP3 inflammasomes in check and restraining endotoxemia.

scholarly journals E3 Ubiquitin Ligase CHIP and NBR1-Mediated Selective Autophagy Protect Additively against Proteotoxicity in Plant Stress Responses

PLoS Genetics ◽  
2014 ◽  
Vol 10 (1) ◽  
pp. e1004116 ◽  
Author(s):  
Jie Zhou ◽  
Yan Zhang ◽  
Jingxia Qi ◽  
Yingjin Chi ◽  
Baofang Fan ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Stress Responses ◽  
Plant Stress ◽  
E3 Ubiquitin Ligase ◽  
Selective Autophagy ◽  
Plant Stress Responses

scholarly journals PELI1 functions as a dual modulator of necroptosis and apoptosis by regulating ubiquitination of RIPK1 and mRNA levels of c-FLIP

2017 ◽  
Vol 114 (45) ◽  
pp. 11944-11949 ◽  
Author(s):  
Huibing Wang ◽  
Huyan Meng ◽  
Xingyan Li ◽  
Kezhou Zhu ◽  
Kangyun Dong ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Kinase Activity ◽  
E3 Ubiquitin Ligase ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Distinct Cell ◽  
Regulated Expression ◽  
Cell Death Mechanisms ◽  
Induced Apoptosis ◽  
Downstream Mediator

Apoptosis and necroptosis are two distinct cell death mechanisms that may be activated in cells on stimulation by TNFα. It is still unclear, however, how apoptosis and necroptosis may be differentially regulated. Here we screened for E3 ubiquitin ligases that could mediate necroptosis. We found that deficiency of Pellino 1 (PELI1), an E3 ubiquitin ligase, blocked necroptosis. We show that PELI1 mediates K63 ubiquitination on K115 of RIPK1 in a kinase-dependent manner during necroptosis. Ubiquitination of RIPK1 by PELI1 promotes the formation of necrosome and execution of necroptosis. Although PELI1 is not directly involved in mediating the activation of RIPK1, it is indispensable for promoting the binding of activated RIPK1 with its downstream mediator RIPK3 to promote the activation of RIPK3 and MLKL. Inhibition of RIPK1 kinase activity blocks PELI1-mediated ubiquitination of RIPK1 in necroptosis. However, we show that PELI1 deficiency sensitizes cells to both RIPK1-dependent and RIPK1-independent apoptosis as a result of down-regulated expression of c-FLIP, an inhibitor of caspase-8. Finally, we show thatPeli1−/−mice are sensitized to TNFα-induced apoptosis. Thus, PELI1 is a key modulator of RIPK1 that differentially controls the activation of necroptosis and apoptosis.

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