scholarly journals Overview of Mitochondrial E3 Ubiquitin Ligase MITOL/MARCH5 from Molecular Mechanisms to Diseases

2020 ◽  
Vol 21 (11) ◽  
pp. 3781
Author(s):  
Isshin Shiiba ◽  
Keisuke Takeda ◽  
Shun Nagashima ◽  
Shigeru Yanagi
Keyword(s):  
Quality Control ◽  
Drug Discovery ◽  
Ubiquitin Ligase ◽  
Molecular Mechanisms ◽  
Mitochondrial Dynamics ◽  
E3 Ubiquitin Ligase ◽  
Mitochondrial Outer Membrane ◽  
Mitochondrial Quality Control ◽  
Important Regulator ◽  
Drug Discovery Target

The molecular pathology of diseases seen from the mitochondrial axis has become more complex with the progression of research. A variety of factors, including the failure of mitochondrial dynamics and quality control, have made it extremely difficult to narrow down drug discovery targets. We have identified MITOL (mitochondrial ubiquitin ligase: also known as MARCH5) localized on the mitochondrial outer membrane and previously reported that it is an important regulator of mitochondrial dynamics and mitochondrial quality control. In this review, we describe the pathological aspects of MITOL revealed through functional analysis and its potential as a drug discovery target.

scholarly journals Adipocyte-Mineralocorticoid Receptor Alters Mitochondrial Quality Control Leading to Mitochondrial Dysfunction and Senescence of Visceral Adipose Tissue

2021 ◽  
Vol 22 (6) ◽  
pp. 2881
Author(s):  
Clara Lefranc ◽  
Malou Friederich-Persson ◽  
Fabienne Foufelle ◽  
Aurélie Nguyen Dinh Cat ◽  
Frédéric Jaisser
Keyword(s):  
Quality Control ◽  
Adipose Tissue ◽  
Mitochondrial Dysfunction ◽  
Cellular Senescence ◽  
Mineralocorticoid Receptor ◽  
Molecular Mechanisms ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Quality Control ◽  
Mitochondrial Oxidative Stress ◽  
Specific Effects

Mineralocorticoid receptor (MR) expression is increased in the adipose tissue (AT) of obese patients and animals. We previously demonstrated that adipocyte-MR overexpression in mice (Adipo-MROE mice) is associated with metabolic alterations. Moreover, we showed that MR regulates mitochondrial dysfunction and cellular senescence in the visceral AT of obese db/db mice. Our hypothesis is that adipocyte-MR overactivation triggers mitochondrial dysfunction and cellular senescence, through increased mitochondrial oxidative stress (OS). Using the Adipo-MROE mice with conditional adipocyte-MR expression, we evaluated the specific effects of adipocyte-MR on global and mitochondrial OS, as well as on OS-induced damage. Mitochondrial function was assessed by high throughput respirometry. Molecular mechanisms were probed in AT focusing on mitochondrial quality control and senescence markers. Adipo-MROE mice exhibited increased mitochondrial OS and altered mitochondrial respiration, associated with reduced biogenesis and increased fission. This was associated with OS-induced DNA-damage and AT premature senescence. In conclusion, targeted adipocyte-MR overexpression leads to an imbalance in mitochondrial dynamics and regeneration, to mitochondrial dysfunction and to ageing in visceral AT. These data bring new insights into the MR-dependent AT dysfunction in obesity.

scholarly journals Mitochondrial quality control in intervertebral disc degeneration

2021 ◽  
Author(s):  
Yu Song ◽  
Saideng Lu ◽  
Wen Geng ◽  
Xiaobo Feng ◽  
Rongjin Luo ◽  
...  
Keyword(s):  
Quality Control ◽  
Intervertebral Disc ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
Molecular Mechanisms ◽  
Cell Function ◽  
Current Knowledge ◽  
Mitochondrial Dynamics ◽  
Intervertebral Discs ◽  
Mitochondrial Quality Control

AbstractIntervertebral disc degeneration (IDD) is a common and early-onset pathogenesis in the human lifespan that can increase the risk of low back pain. More clarification of the molecular mechanisms associated with the onset and progression of IDD is likely to help establish novel preventive and therapeutic strategies. Recently, mitochondria have been increasingly recognized as participants in regulating glycolytic metabolism, which has historically been regarded as the main metabolic pathway in intervertebral discs due to their avascular properties. Indeed, mitochondrial structural and functional disruption has been observed in degenerated nucleus pulposus (NP) cells and intervertebral discs. Multilevel and well-orchestrated strategies, namely, mitochondrial quality control (MQC), are involved in the maintenance of mitochondrial integrity, mitochondrial proteostasis, the mitochondrial antioxidant system, mitochondrial dynamics, mitophagy, and mitochondrial biogenesis. Here, we address the key evidence and current knowledge of the role of mitochondrial function in the IDD process and consider how MQC strategies contribute to the protective and detrimental properties of mitochondria in NP cell function. The relevant potential therapeutic treatments targeting MQC for IDD intervention are also summarized. Further clarification of the functional and synergistic mechanisms among MQC mechanisms may provide useful clues for use in developing novel IDD treatments.

scholarly journals The RING domain of mitochondrial E3 ubiquitin ligase 1 and its complex with Ube2D2: crystallization and X-ray diffraction

2020 ◽  
Vol 76 (1) ◽  
pp. 1-7
Author(s):  
Sang-Ok Lee ◽  
Chong-Kil Lee ◽  
Kyoung-Seok Ryu ◽  
Seung-Wook Chi
Keyword(s):  
Ubiquitin Ligase ◽  
Mitochondrial Dynamics ◽  
P53 Protein ◽  
Three Dimensional ◽  
E3 Ubiquitin Ligase ◽  
Ring Domain ◽  
Mitochondrial Outer Membrane ◽  
Transactivation Domain ◽  
X Ray Diffraction ◽  
Substrate Protein

Mitochondrial E3 ubiquitin ligase 1 (MUL1) is located in the mitochondrial outer membrane and regulates various biological processes, including apoptosis, cell growth, mitophagy and mitochondrial dynamics. The C-terminal region of MUL1 faces the cytoplasm and contains the RING domain (MUL1-RING) where the Ub~E2 thioester binds. Unlike most RING-type E3 enzymes, MUL1-RING alone does not have an additional region that recruits a substrate protein, yet is still able to ubiquitylate the substrate, the p53 protein. Nevertheless, the exact mechanism of the ubiquitylation of p53 by MUL1-RING has not yet been elucidated. In order to understand this novel ubiquitylation mechanism, it is necessary to determine the three-dimensional structures of MUL1-RING and of its complex with the cognate E2 enzyme. Here, Ube2D2 was validated as a functional E2 enzyme for the ubiquitylation of the p53 transactivation domain (p53-TAD) by MUL1-RING, and purification and crystallization processes for MUL1-RING and the MUL1-RING–Ube2D2 complex are reported.

scholarly journals Disruption of Mitochondrial Quality Control Genes Promotes Caspase-Resistant Cell Survival Following Apoptotic Stimuli

2021 ◽  
Author(s):  
Tomomi Kuwana ◽  
Yulia Kushnareva ◽  
Vivian Moraes ◽  
Bjoern Peters ◽  
Julian Suess ◽  
...  
Keyword(s):  
Quality Control ◽  
Mitochondrial Dynamics ◽  
Single Cells ◽  
Clonogenic Survival ◽  
Resistant Cell ◽  
Death Process ◽  
Mitochondrial Outer Membrane ◽  
Mitochondrial Quality Control ◽  
Mitochondrial Outer Membrane Permeabilization ◽  
Cell Death Process

In cells undergoing cell-intrinsic apoptosis, mitochondrial outer membrane permeabilization (MOMP) typically marks an irreversible step in the cell death process. However, in some cases a subpopulation of the treated cells can exhibit a sublethal response, termed minority MOMP. In this phenomenon, the affected cells survive, despite a low level of caspase activation and a subsequent limited activation of the endonuclease CAD (DFFB). Consequently, these cells can experience DNA damage, increasing the probability of oncogenesis. To discover genes affecting MOMP response in individual cells, we conducted an imaging-based phenotypic siRNA screen. We identified multiple candidate genes whose downregulation increased the heterogeneity of MOMP within single cells. Among these were genes related to mitochondrial dynamics and mitophagy, which participate in the mitochondrial quality control (MQC) system. To test the hypothesis that functional MQC is important for reducing the frequency of minority MOMP, we developed an assay to measure the clonogenic survival of caspase-engaged cells. We found that cells deficient in various MQC genes were indeed prone to aberrant post-MOMP survival. Our data highlight the important role of proteins involved in mitochondrial dynamics and mitophagy in preventing apoptotic dysregulation and oncogenesis.

scholarly journals Ubiquitination, Biotech Startups, and the Future of TRIM Family Proteins: A TRIM-Endous Opportunity

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1015
Author(s):  
Utsa Bhaduri ◽  
Giuseppe Merla
Keyword(s):  
Drug Discovery ◽  
Protein Degradation ◽  
Ubiquitin Ligase ◽  
Genetic Disorders ◽  
E3 Ubiquitin Ligase ◽  
Ubiquitin Ligases ◽  
E3 Ubiquitin Ligases ◽  
Post Translational Modification ◽  
Disease Biology ◽  
The Future

Ubiquitination is a post-translational modification that has pivotal roles in protein degradation and diversified cellular processes, and for more than two decades it has been a subject of interest in the biotech or biopharmaceutical industry. Tripartite motif (TRIM) family proteins are known to have proven E3 ubiquitin ligase activities and are involved in a multitude of cellular and physiological events and pathophysiological conditions ranging from cancers to rare genetic disorders. Although in recent years many kinds of E3 ubiquitin ligases have emerged as the preferred choices of big pharma and biotech startups in the context of protein degradation and disease biology, from a surface overview it appears that TRIM E3 ubiquitin ligases are not very well recognized yet in the realm of drug discovery. This article will review some of the blockbuster scientific discoveries and technological innovations from the world of ubiquitination and E3 ubiquitin ligases that have impacted the biopharma community, from biotech colossuses to startups, and will attempt to evaluate the future of TRIM family proteins in the province of E3 ubiquitin ligase-based drug discovery.

scholarly journals At the heart of mitochondrial quality control: many roads to the top

2021 ◽  
Author(s):  
Roberta A. Gottlieb ◽  
Honit Piplani ◽  
Jon Sin ◽  
Savannah Sawaged ◽  
Syed M. Hamid ◽  
...  
Keyword(s):  
Quality Control ◽  
Unfolded Protein Response ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Quality Control ◽  
Unfolded Protein ◽  
Selective Elimination ◽  
Protein Response ◽  
Mitochondrial Unfolded Protein Response

AbstractMitochondrial quality control depends upon selective elimination of damaged mitochondria, replacement by mitochondrial biogenesis, redistribution of mitochondrial components across the network by fusion, and segregation of damaged mitochondria by fission prior to mitophagy. In this review, we focus on mitochondrial dynamics (fusion/fission), mitophagy, and other mechanisms supporting mitochondrial quality control including maintenance of mtDNA and the mitochondrial unfolded protein response, particularly in the context of the heart.

scholarly journals Autographa californica Nucleopolyhedrovirus AC141 (Exon0), a Potential E3 Ubiquitin Ligase, Interacts with Viral Ubiquitin and AC66 To Facilitate Nucleocapsid Egress

2017 ◽  
Vol 92 (3) ◽  
Author(s):  
Siddhartha Biswas ◽  
Leslie G. Willis ◽  
Minggang Fang ◽  
Yingchao Nie ◽  
David A. Theilmann
Keyword(s):  
Ubiquitin Ligase ◽  
Nuclear Export ◽  
Molecular Mechanisms ◽  
Nuclear Periphery ◽  
E3 Ubiquitin Ligase ◽  
Autographa Californica ◽  
Nucleocapsid Proteins ◽  
Systemic Spread ◽  
Autographa Californica Nucleopolyhedrovirus ◽  
Budded Virus

ABSTRACTDuring the infection cycle of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), two forms of virions are produced, budded virus (BV) and occlusion-derived virus (ODV). Nucleocapsids that form BV have to egress from the nucleus, whereas nucleocapsids that form ODV remain inside the nucleus. The molecular mechanism that determines whether nucleocapsids remain inside or egress from the nucleus is unknown. AC141 (a predicted E3 ubiquitin ligase) and viral ubiquitin (vUbi) have both been shown to be required for efficient BV production. In this study, it was hypothesized that vUbi interacts with AC141, and in addition, that this interaction was required for BV production. Deletion of bothac141andvubirestricted viral infection to a single cell, and BV production was completely eliminated. AC141 was ubiquitinated by either vUbi or cellular Ubi, and this interaction was required for optimal BV production. Nucleocapsids in BV, but not ODV, were shown to be specifically ubiquitinated by vUbi, including a 100-kDa protein, as well as high-molecular-weight conjugates. The viral ubiquitinated 100-kDa BV-specific nucleocapsid protein was identified as AC66, which is known to be required for BV production and was shown by coimmunoprecipitation and mass spectrometry to interact with AC141. Confocal microscopy also showed that AC141, AC66, and vUbi interact at the nuclear periphery. These results suggest that ubiquitination of nucleocapsid proteins by vUbi functions as a signal to determine if a nucleocapsid will egress from the nucleus and form BV or remain in the nucleus to form ODV.IMPORTANCEBaculoviruses produce two types of virions called occlusion-derived virus (ODV) and budded virus (BV). ODVs are required for oral infection, whereas BV enables the systemic spread of virus to all host tissues, which is critical for killing insects. One of the important steps for BV production is the export of nucleocapsids out of the nucleus. This study investigated the molecular mechanisms that enable the selection of nucleocapsids for nuclear export instead of being retained within the nucleus, where they would become ODV. Our data show that ubiquitination, a universal cellular process, specifically tags nucleocapsids of BV, but not those found in ODV, using a virus-encoded ubiquitin (vUbi). Therefore, ubiquitination may be the molecular signal that determines if a nucleocapsid is destined to form a BV, thus ensuring lethal infection of the host.

scholarly journals Identification of a PGXPP degron motif in dishevelled and structural basis for its binding to the E3 ligase KLHL12

Open Biology ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 200041 ◽  
Author(s):  
Zhuoyao Chen ◽  
Gregory A. Wasney ◽  
Sarah Picaud ◽  
Panagis Filippakopoulos ◽  
Masoud Vedadi ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Molecular Mechanisms ◽  
Hydrophobic Interactions ◽  
E3 Ubiquitin Ligase ◽  
Structural Basis ◽  
E3 Ligases ◽  
Kelch Domain ◽  
Ring E3 Ligases ◽  
Ring E3 ◽  
New Protein

Wnt signalling is dependent on dishevelled proteins (DVL1-3), which assemble an intracellular Wnt signalosome at the plasma membrane. The levels of DVL1-3 are regulated by multiple Cullin-RING E3 ligases that mediate their ubiquitination and degradation. The BTB-Kelch protein KLHL12 was the first E3 ubiquitin ligase to be identified for DVL1-3, but the molecular mechanisms determining its substrate interactions have remained unknown. Here, we mapped the interaction of DVL1-3 to a ‘PGXPP' motif that is conserved in other known partners and substrates of KLHL12, including PLEKHA4, PEF1, SEC31 and DRD4. To determine the binding mechanism, we solved a 2.4 Å crystal structure of the Kelch domain of KLHL12 in complex with a DVL1 peptide that bound with low micromolar affinity. The DVL1 substrate adopted a U-shaped turn conformation that enabled hydrophobic interactions with all six blades of the Kelch domain β-propeller. In cells, the mutation or deletion of this motif reduced the binding and ubiquitination of DVL1 and increased its stability confirming this sequence as a degron motif for KLHL12 recruitment. These results define the molecular mechanisms determining DVL regulation by KLHL12 and establish the KLHL12 Kelch domain as a new protein interaction module for a novel proline-rich motif.

scholarly journals E3 ubiquitin ligase MARCHF5 controls BAK apoptotic activity independently of BH3-only proteins

2022 ◽  
Author(s):  
Grant Dewson ◽  
Alan Shuai Huang ◽  
Hui San Chin ◽  
Boris Reljic ◽  
Tirta M Djajawi ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Apoptotic Cell ◽  
E3 Ubiquitin Ligase ◽  
Ubiquitin Ligase Activity ◽  
A Genome ◽  
Library Screen ◽  
Important Regulator ◽  
Apoptotic Activity ◽  
Bh3 Mimetic ◽  
Survival Proteins

Intrinsic apoptosis is principally governed by the BCL-2 family of proteins, but some non-BCL-2 proteins are also critical to control this process. To identify novel apoptosis regulators, we performed a genome-wide CRISPR-Cas9 library screen, and identified the mitochondrial E3 ubiquitin ligase MARCHF5/MITOL/RNF153 as an important regulator of BAK apoptotic function. Deleting MARCHF5 in diverse cell lines dependent on BAK conferred profound resistance to BH3-mimetic drugs. The loss of MARCHF5 or its E3 ubiquitin ligase activity surprisingly drove BAK to adopt an activated conformation, with resistance to BH3-mimetics afforded by the formation of inhibitory complexes with pro-survival proteins MCL-1 and BCL-XL. Importantly, these changes to BAK conformation and pro-survival association occurred independently of BH3-only proteins and influence on pro-survival proteins. This study identifies a new mechanism by which MARCHF5 regulates apoptotic cell death and provides new insight into how cancer cells respond to BH3-mimetic drugs. These data also highlight the emerging role of ubiquitin signalling in apoptosis that may be exploited therapeutically.

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