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Clinical and Translational Medicine Aug 2023CCN6 is a matricellular protein that critically regulates the tumourigenesis and progression of breast cancer. Although the tumour-suppressive function of CCN6 has been...
BACKGROUND
CCN6 is a matricellular protein that critically regulates the tumourigenesis and progression of breast cancer. Although the tumour-suppressive function of CCN6 has been extensively studied, molecular mechanisms regulating protein levels of CCN6 remain largely unclear. This study aims to investigate the regulation of CCN6 by ubiquitination and deubiquitinating enzymes (DUBs) in breast cancer.
METHODS
A screening assay was performed to identify OTUB1 as the DUB for CCN6. Various biochemical methods were applied to elucidate the molecular mechanism of OTUB1 in the regulation of CCN6. The role of OTUB1-CCN6 interaction in breast cancer was studied with cell experiments and the allograft model. The correlation of OTUB1 and CCN6 in human breast cancer was determined by immunohistochemistry and Western blot.
RESULTS
We found that CCN6 protein levels were controlled by the ubiquitin-proteasome system. The K48 ubiquitination and degradation of CCN6 was inhibited by OTUB1, which directly interacted with CCN6 through its linker domain. Furthermore, OTUB1 inhibited the ubiquitination of CCN6 in a non-canonical manner. Deletion of OTUB1, concomitant with reduced CCN6 abundance, increased the migration, proliferation and viability of breast cancer cells. Supplementation of CCN6 abolished the effect of OTUB1 deletion on breast cancer. Importantly, OTUB1 expression was downregulated in human breast cancer and positively correlated with CCN6 levels.
CONCLUSION
This study identified OTUB1 as a novel regulator of CCN6 in breast cancer.
Topics: Humans; Blotting, Western; Carcinogenesis; Cell Transformation, Neoplastic; Cytoplasm; Proteasome Endopeptidase Complex; Deubiquitinating Enzymes; CCN Intercellular Signaling Proteins
PubMed: 37608493
DOI: 10.1002/ctm2.1385 -
Molecules and Cells Mar 2020Post-translational modifications play major roles in the stability, function, and localization of target proteins involved in the nervous system. The... (Review)
Review
Post-translational modifications play major roles in the stability, function, and localization of target proteins involved in the nervous system. The ubiquitin-proteasome pathway uses small ubiquitin molecules to degrade neuronal proteins. Deubiquitinating enzymes (DUBs) reverse this degradation and thereby control neuronal cell fate, synaptic plasticity,axonal growth, and proper function of the nervous system.Moreover, mutations or downregulation of certain DUBshave been found in several neurodegenerative diseases, as well as gliomas and neuroblastomas. Based on emerging findings, DUBs represent an important target for therapeutic intervention in various neurological disorders. Here, we summarize advances in our understanding of the roles of DUBs related to neurobiology.
Topics: Deubiquitinating Enzymes; Humans; Nervous System; Neurodegenerative Diseases; Protein Processing, Post-Translational; Ubiquitin
PubMed: 32133826
DOI: 10.14348/molcells.2020.2289 -
Cells Apr 2023OTUD5 (OTU Deubiquitinase 5) is a functional cysteine protease with deubiquitinase activity and is a member of the ovarian tumor protease (OTU) family. OTUD5 is involved... (Review)
Review
OTUD5 (OTU Deubiquitinase 5) is a functional cysteine protease with deubiquitinase activity and is a member of the ovarian tumor protease (OTU) family. OTUD5 is involved in the deubiquitination of many key proteins in various cellular signaling pathways and plays an important role in maintaining normal human development and physiological functions. Its dysfunction can affect physiological processes, such as immunity and DNA damage repair, and it can even lead to tumors, inflammatory diseases and genetic disorders. Therefore, the regulation of OTUD5 activity and expression has become a hot topic of research. A comprehensive understanding of the regulatory mechanisms of OTUD5 and its use as a therapeutic target for diseases is of great value. Herein, we review the physiological processes and molecular mechanisms of OTUD5 regulation, outline the specific regulatory processes of OTUD5 activity and expression, and link OTUD5 to diseases from the perspective of studies on signaling pathways, molecular interactions, DNA damage repair and immune regulation, thus providing a theoretical basis for future studies.
Topics: Female; Humans; Ubiquitination; DNA Repair; Signal Transduction; Ovarian Neoplasms; Deubiquitinating Enzymes
PubMed: 37190070
DOI: 10.3390/cells12081161 -
International Journal of Biological... 2022Ferroptosis is a novel type of regulated cell death driven by the excessive accumulation of iron-dependent lipid peroxidation. Therapy-resistant tumor cells,... (Review)
Review
Ferroptosis is a novel type of regulated cell death driven by the excessive accumulation of iron-dependent lipid peroxidation. Therapy-resistant tumor cells, particularly those in the mesenchymal-like state and prone to metastasis, are highly susceptible to ferroptosis, suggesting that induction of ferroptosis in tumor cells is a promising strategy for cancer therapy. Although ferroptosis is regulated at various levels, ubiquitination is key to post-translational regulation of ferroptotic cell death. E3 ubiquitin ligases (E3s) and deubiquitinating enzymes (DUBs) are the most remarkable ubiquitin system enzymes, whose dysregulation accounts for the progression of multiple cancers. E3s are involved in the attachment of ubiquitin to substrates for their degradation, and this process is reversed by DUBs. Accumulating evidence has highlighted the important role of ubiquitin system enzymes in regulating the sensitivity of ferroptosis. Herein, we will portray the regulatory networks of ferroptosis mediated by E3s or DUBs and discuss opportunities and challenges for incorporating this regulation into cancer therapy.
Topics: Deubiquitinating Enzymes; Ferroptosis; Humans; Iron; Neoplasms; Ubiquitin; Ubiquitin-Protein Ligases; Ubiquitination
PubMed: 36147464
DOI: 10.7150/ijbs.73790 -
International Journal of Molecular... Aug 2020Deubiquitinating enzymes regulate various cellular processes, particularly protein degradation, localization, and protein-protein interactions. The dysregulation of... (Review)
Review
Deubiquitinating enzymes regulate various cellular processes, particularly protein degradation, localization, and protein-protein interactions. The dysregulation of deubiquitinating enzyme (DUB) activity has been linked to several diseases; however, the function of many DUBs has not been identified. Therefore, the development of methods to assess DUB activity is important to identify novel DUBs, characterize DUB selectivity, and profile dynamic DUB substrates. Here, we review various methods of evaluating DUB activity using cell lysates or purified DUBs, as well as the types of probes used in these methods. In addition, we introduce some techniques that can deliver DUB probes into the cells and cell-permeable activity-based probes to directly visualize and quantify DUB activity in live cells. This review could contribute to the development of DUB inhibitors by providing important information on the characteristics and applications of various probes used to evaluate and detect DUB activity in vitro and in vivo.
Topics: Animals; Deubiquitinating Enzymes; Enzyme Assays; Fluorescence Polarization; Humans; Molecular Probes; Ubiquitin; Ubiquitination
PubMed: 32781716
DOI: 10.3390/ijms21165638 -
Biomolecules Jul 2020The COP9 signalosome (CSN) is a signaling platform controlling the cellular ubiquitylation status. It determines the activity and remodeling of ~700 cullin-RING... (Review)
Review
The COP9 signalosome (CSN) is a signaling platform controlling the cellular ubiquitylation status. It determines the activity and remodeling of ~700 cullin-RING ubiquitin ligases (CRLs), which control more than 20% of all ubiquitylation events in cells and thereby influence virtually any cellular pathway. In addition, it is associated with deubiquitylating enzymes (DUBs) protecting CRLs from autoubiquitylation and rescuing ubiquitylated proteins from degradation. The coordination of ubiquitylation and deubiquitylation by the CSN is presumably important for fine-tuning the precise formation of defined ubiquitin chains. Considering its intrinsic DUB activity specific for deneddylation of CRLs and belonging to the JAMM family as well as its associated DUBs, the CSN represents a multi-DUB complex. Two CSN-associated DUBs, the ubiquitin-specific protease 15 (USP15) and USP48 are regulators in the NF-κB signaling pathway. USP15 protects CRL1 responsible for IκBα ubiquitylation, whereas USP48 stabilizes the nuclear pool of the NF-κB transcription factor RelA upon TNF stimulation by counteracting CRL2. Moreover, the CSN controls the neddylation status of cells by its intrinsic DUB activity and by destabilizing the associated deneddylation enzyme 1 (DEN1). Thus, the CSN is a master regulator at the intersection between ubiquitylation and neddylation.
Topics: Animals; COP9 Signalosome Complex; Cullin Proteins; Deubiquitinating Enzymes; Humans; Models, Molecular; NF-kappa B; Protein Interaction Maps; Ubiquitin-Specific Proteases; Ubiquitination
PubMed: 32708147
DOI: 10.3390/biom10071082 -
Protein Science : a Publication of the... Apr 2014Ubiquitination is a reversible post-translational modification that plays a dynamic role in regulating most eukaryotic processes. Deubiquitinating enzymes (DUBs), which... (Review)
Review
Ubiquitination is a reversible post-translational modification that plays a dynamic role in regulating most eukaryotic processes. Deubiquitinating enzymes (DUBs), which hydrolyze the isopeptide or peptide linkages joining ubiquitin to substrate lysines or N-termini, therefore play a key role in ubiquitin signaling. Cells employ multiple mechanisms to regulate DUB activity and thus ensure the appropriate biological response. Recent structural studies have shed light on several different mechanisms by which DUB activity and specificity is regulated.
Topics: Humans; Models, Molecular; Peptides; Signal Transduction; Ubiquitin; Ubiquitin-Specific Proteases; Ubiquitination
PubMed: 24403057
DOI: 10.1002/pro.2415 -
International Journal of Molecular... Nov 2019Mitosis is a complex and dynamic process that is tightly regulated by a large number of mitotic proteins. Dysregulation of these proteins can generate daughter cells... (Review)
Review
Mitosis is a complex and dynamic process that is tightly regulated by a large number of mitotic proteins. Dysregulation of these proteins can generate daughter cells that exhibit genomic instability and aneuploidy, and such cells can transform into tumorigenic cells. Thus, it is important for faithful mitotic progression to regulate mitotic proteins at specific locations in the cells at a given time in each phase of mitosis. Ubiquitin-dependent modifications play critical roles in this process by regulating the degradation, translocation, or signal transduction of mitotic proteins. Here, we review how ubiquitination and deubiquitination regulate the progression of mitosis. In addition, we summarize the substrates and roles of some deubiquitinating enzymes (DUBs) crucial for mitosis and describe how they contribute error correction during mitosis and control the transition between the mitotic phases.
Topics: Animals; Deubiquitinating Enzymes; Humans; Mitosis; Ubiquitin-Protein Ligases; Ubiquitination
PubMed: 31795161
DOI: 10.3390/ijms20235997 -
Cancer Metastasis Reviews Dec 2016Although growing numbers of oncoproteins and pro-metastatic proteins have been extensively characterized, many of these tumor-promoting proteins are not good drug... (Review)
Review
Although growing numbers of oncoproteins and pro-metastatic proteins have been extensively characterized, many of these tumor-promoting proteins are not good drug targets, which represent a major barrier to curing breast cancer and other cancers. There is a need, therefore, for alternative therapeutic approaches to destroying cancer-promoting proteins. The human genome encodes approximately 100 deubiquitinating enzymes (DUBs, also called deubiquitinases), which are amenable to pharmacologic inhibition by small molecules. By removing monoubiquitin or polyubiquitin chains from the target protein, DUBs can modulate the degradation, localization, activity, trafficking, and recycling of the substrate, thereby contributing substantially to the regulation of cancer proteins and pathways. Targeting certain DUBs may lead to destabilization or functional inactivation of some key oncoproteins or pro-metastatic proteins, including non-druggable ones, which will provide therapeutic benefits to cancer patients. In breast cancer, growing numbers of DUBs are found to be aberrantly expressed. Depending on their substrates, specific DUBs can either promote or suppress mammary tumors. In this article, we review the role and mechanisms of action of DUBs in breast cancer and discuss the potential of targeting DUBs for cancer treatment.
Topics: Animals; Breast Neoplasms; Deubiquitinating Enzymes; Female; Humans; Ubiquitination
PubMed: 27844253
DOI: 10.1007/s10555-016-9640-2 -
Cellular and Molecular Gastroenterology... 2022Severe acute pancreatitis can easily lead to systemic inflammatory response syndrome and death. Macrophages are known to be involved in the pathophysiology of acute...
BACKGROUND & AIMS
Severe acute pancreatitis can easily lead to systemic inflammatory response syndrome and death. Macrophages are known to be involved in the pathophysiology of acute pancreatitis (AP), and macrophage activation correlates with disease severity. In this study, we examined the role of ubiquitin-specific protease 25, a deubiquitinating enzyme and known regulator of macrophages, in the pathogenesis of AP.
METHODS
We used L-arginine, cerulein, and choline-deficient ethionine-supplemented diet-induced models of AP in Usp25 mice and wild-type mice. We also generated bone marrow Usp25 chimeric mice and initiated L-arginine-mediated AP. Primary acinar cells and bone marrow-derived macrophages were isolated from wild-type and Usp25 mice to dissect molecular mechanisms.
RESULTS
Our results show that Usp25 deficiency exacerbates pancreatic and lung injury, neutrophil and macrophage infiltration, and systemic inflammatory responses in L-arginine, cerulein, and choline-deficient ethionine-supplemented diet-induced models of AP. Bone marrow Usp25 chimeric mice challenged with L-arginine show that Usp25 deficiency in macrophages exaggerates AP by up-regulating the TANK-binding kinase 1 (TBK1)-nuclear factor-κB (NF-κB) signaling pathway. Similarly, in vitro data confirm that Usp25 deficiency enhances the TBK1-NF-κB pathway, leading to increased expression of inflammatory cytokines in bone marrow-derived macrophages.
CONCLUSIONS
Usp25 deficiency in macrophages enhances TBK1-NF-κB signaling, and the induction of inflammatory chemokines and type I interferon-related genes exacerbates pancreatic and lung injury in AP.
Topics: Animals; Mice; Acute Disease; Arginine; Ceruletide; Choline; Cytokines; Deubiquitinating Enzymes; Disease Models, Animal; Ethionine; Interferon Type I; Lung Injury; Macrophages; Mice, Inbred C57BL; NF-kappa B; Pancreatitis; Signal Transduction; Ubiquitin-Specific Proteases; Ubiquitin Thiolesterase
PubMed: 35934222
DOI: 10.1016/j.jcmgh.2022.07.013