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1.
Article in English | WPRIM | ID: wpr-880485

ABSTRACT

Ubiquitination, an essential post-transcriptional modification (PTM), plays a vital role in nearly every biological process, including development and growth. Despite its functions in plant reproductive development, its targets in rice panicles remain unclear. In this study, we used proteome-wide profiling of lysine ubiquitination in rice (O. sativa ssp. indica) young panicles. We created the largest ubiquitinome dataset in rice to date, identifying 1638 lysine ubiquitination sites on 916 unique proteins. We detected three conserved ubiquitination motifs, noting that acidic glutamic acid (E) and aspartic acid (D) were most frequently present around ubiquitinated lysine. Enrichment analysis of Gene Ontology (GO) annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of these ubiquitinated proteins revealed that ubiquitination plays an important role in fundamental cellular processes in rice young panicles. Interestingly, enrichment analysis of protein domains indicated that ubiquitination was enriched on a variety of receptor-like kinases and cytoplasmic tyrosine and serine-threonine kinases. Furthermore, we analyzed the crosstalk between ubiquitination, acetylation, and succinylation, and constructed a potential protein interaction network within our rice ubiquitinome. Moreover, we identified ubiquitinated proteins related to pollen and grain development, indicating that ubiquitination may play a critical role in the physiological functions in young panicles. Taken together, we reported the most comprehensive lysine ubiquitinome in rice so far, and used it to reveal the functional role of lysine ubiquitination in rice young panicles.


Subject(s)
Acetylation , Lysine/metabolism , Oryza/metabolism , Plant Proteins/metabolism , Protein Interaction Maps , Protein Processing, Post-Translational , Proteome/metabolism , Ubiquitin/metabolism , Ubiquitination
2.
Protein & Cell ; (12): 894-914, 2020.
Article in English | WPRIM | ID: wpr-880885

ABSTRACT

Tripartite motif (TRIM) family proteins are important effectors of innate immunity against viral infections. Here we identified TRIM35 as a regulator of TRAF3 activation. Deficiency in or inhibition of TRIM35 suppressed the production of type I interferon (IFN) in response to viral infection. Trim35-deficient mice were more susceptible to influenza A virus (IAV) infection than were wild-type mice. TRIM35 promoted the RIG-I-mediated signaling by catalyzing Lys63-linked polyubiquitination of TRAF3 and the subsequent formation of a signaling complex with VISA and TBK1. IAV PB2 polymerase countered the innate antiviral immune response by impeding the Lys63-linked polyubiquitination and activation of TRAF3. TRIM35 mediated Lys48-linked polyubiquitination and proteasomal degradation of IAV PB2, thereby antagonizing its suppression of TRAF3 activation. Our in vitro and in vivo findings thus reveal novel roles of TRIM35, through catalyzing Lys63- or Lys48-linked polyubiquitination, in RIG-I antiviral immunity and mechanism of defense against IAV infection.


Subject(s)
A549 Cells , Animals , Apoptosis Regulatory Proteins/immunology , DEAD Box Protein 58/immunology , Dogs , HEK293 Cells , Humans , Influenza A Virus, H1N1 Subtype/immunology , Madin Darby Canine Kidney Cells , Mice , Mice, Knockout , Orthomyxoviridae Infections/pathology , Proteolysis , Signal Transduction/immunology , THP-1 Cells , TNF Receptor-Associated Factor 3/immunology , Ubiquitination/immunology , Viral Proteins/immunology
3.
Article in Chinese | WPRIM | ID: wpr-826373

ABSTRACT

Ubiquitin is a small molecule protein consisting of 76 amino acids,widely found in eukaryotic cells. The process by which ubiquitin binding to a specific protein is called ubiquitination. Deubiquitination is the reversed process of ubiquitination. Ubiquitination stimulates downstream signal,including complex assembly,protein conformation and activity changes,proteolysis,autophagy,guilt,chromatin remodeling,and DNA repair. More than 80% of eukaryotic protein degradation is mediated by the ubiquitination system,and ubiquitin-dependent proteolysis is an extremely complex process involving many biomolecular processes. By regulating protein homeostasis,ubiquitination can also regulate a variety of biological processes including cell cycle,cell proliferation,and apoptosis,which are closely related to tumorigenesis and progression. Many abnormalities of androgen receptor (AR) including AR gene amplification,mutation,shear mutation,and AR activity enhancement are closely related to prostate cancer progression. In particular,prostate cancer progression is regulated by the ubiquitination/deubiquitination processes. This article summarizes the recent research advances in the roles of ubiquitination/deubiquitination in AR abnormalities and prostate cancer.


Subject(s)
Cell Line, Tumor , Humans , Male , Prostatic Neoplasms , Metabolism , Pathology , Proteolysis , Receptors, Androgen , Metabolism , Ubiquitination
4.
Article in Chinese | WPRIM | ID: wpr-878682

ABSTRACT

Proteins exert their roles in life activities via post-translational modifications(PTMs),which include phosphorylation,acetylation,ubiquitination,glycosylation,and methylation.These modifications can change the functions of proteins and play key roles in a variety of diseases.Endometriosis is a common disease in women of childbearing age,although its molecular mechanisms remain unclear.Recent studies have shown that PTMs may be involved in the pathogenesis of endometriosis.Here we review the roles of PTMs in the occurrence and development of endometriosis and the potential medical treatments.


Subject(s)
Acetylation , Endometriosis/pathology , Female , Glycosylation , Humans , Phosphorylation , Protein Processing, Post-Translational , Ubiquitination
5.
Article in Chinese | WPRIM | ID: wpr-828529

ABSTRACT

Cullin-RING E3 ligases (CRLs) are the major components of ubiquitin-proteasome system, responsible for ubiquitylation and subsequent degradation of thousands of cellular proteins. CRLs play vital roles in the regulation of multiple cellular processes, including cell cycle, cell apoptosis, DNA replication, signalling transduction among the others, and are frequently dysregulated in many human cancers. The discovery of specific neddylation inhibitors, represented by MLN4924, has validated CRLs as promising targets for anti-cancer therapies with a growing market. Recent studies have focused on the discovery of the CRLs inhibitors by a variety of approaches, including high through-put screen, virtual screen or structure-based drug design. The field is, however, still facing the major challenging, since CRLs are a large multi-unit protein family without typical active pockets to facilitate the drug design, and enzymatic activity is mainly dependent on undruggable protein-protein interactions and dynamic conformation changes. Up to now, most reported CRLs inhibitors are aiming at targeting the F-box family proteins (e.g., SKP2, β-TrCP and FBXW7), the substrate recognition subunit of SCF E3 ligases. Other studies reported few small molecule inhibitors targeting the UBE2M-DCN1 interaction, which specifically inhibits CRL3/CRL1 by blocking the cullin neddylation. On the other hand, several CRL activators have been reported, such as plant auxin and immunomodulatory imide drugs, thalidomide. Finally, proteolysis-targeting chimeras (PROTACs) has emerged as a new technology in the field of drug discovery, specifically targeting the undruggable protein-protein interaction. The technique connects the small molecule that selectively binds to a target protein to a CRL E3 via a chemical linker to trigger the degradation of target protein. The PROTAC has become a hotspot in the field of E3-ligase-based anti-cancer drug discovery.


Subject(s)
Antineoplastic Agents , Pharmacology , Therapeutic Uses , Drug Design , Drug Discovery , Enzyme Inhibitors , Pharmacology , Therapeutic Uses , Humans , Neoplasms , Ubiquitin-Protein Ligases , Metabolism , Ubiquitination
6.
Mem. Inst. Oswaldo Cruz ; 115: e190242, 2020. tab, graf
Article in English | LILACS | ID: biblio-1091241

ABSTRACT

BACKGROUND Ubiquitin (Ub) and Ub-like proteins (Ub-L) are critical regulators of complex cellular processes such as the cell cycle, DNA repair, transcription, chromatin remodeling, signal translation, and protein degradation. Giardia intestinalis possesses an experimentally proven Ub-conjugation system; however, a limited number of enzymes involved in this process were identified using basic local alignment search tool (BLAST). This is due to the limitations of BLAST's ability to identify homologous functional regions when similarity between the sequences dips to < 30%. In addition Ub-Ls and their conjugating enzymes have not been fully elucidated in Giardia. OBJETIVE To identify the enzymes involved in the Ub and Ub-Ls conjugation processes using intelligent systems based on the hidden Markov models (HMMs). METHODS We performed an HMM search of functional Pfam domains found in the key enzymes of these pathways in Giardia's proteome. Each open reading frame identified was analysed by sequence homology, domain architecture, and transcription levels. FINDINGS We identified 118 genes, 106 of which corresponded to the ubiquitination process (Ub, E1, E2, E3, and DUB enzymes). The E3 ligase group was the largest group with 82 members; 71 of which harbored a characteristic RING domain. Four Ub-Ls were identified and the conjugation enzymes for NEDD8 and URM1 were described for first time. The 3D model for Ub-Ls displayed the β-grasp fold typical. Furthermore, our sequence analysis for the corresponding activating enzymes detected the essential motifs required for conjugation. MAIN CONCLUSIONS Our findings highlight the complexity of Giardia's Ub-conjugation system, which is drastically different from that previously reported, and provides evidence for the presence of NEDDylation and URMylation enzymes in the genome and transcriptome of G. intestinalis.


Subject(s)
Ubiquitins/genetics , Giardia lamblia/metabolism , Ubiquitin/genetics , Ubiquitination , Ubiquitins/metabolism , Signal Transduction , Models, Molecular , Giardia lamblia/genetics , Ubiquitin/metabolism
7.
Article in Chinese | WPRIM | ID: wpr-774306

ABSTRACT

OBJECTIVE@#To explore the the effects of ubiquitin-proteasome system (UPS) on BCL6 protein level,proliferation and apoptosis of cell imatinib(IM)-resistant K562/G01 cells.@*METHODS@#Western blot was used to detect the expression of BCL6 in K562/G01 cells before and after treatment with protease inhibitor MG-132.The RT-PCR and Western blot respectively were used to detect the mRNA and protein expression levels of BCL6 and USP2 in K562/G01 cells treated with or without ML364 (a ubiquitin-specific protease USP2 inhibitor). The effects of IM alone or in combination with ML364 on proliferation and apoptosis of K562/G01 were analysed by CCK-8 method and flow cytometry.@*RESULTS@#After treatment with protease inhibitor MG132, the BCL6 protein level of K562/G01 significantly increased (P<0.05). The mRNA and protein expression level of ubiquitin-specific protease USP2 in K562/G01 cell line was higher than that in K562 cell line (P<0.05). After treatment of K562/G01 with USP2 protease inhibitor ML364, the expression levels of USP2 and BCL6 proteins were down-regulated simultaneously (P<0.05) . After combination of ML364 and IM, both the proliferation inhibitory rate and the apoptosis rate of K562/G01 cells significantly increased(P<0.05).@*CONCLUSION@#ML364 decreases the BCL6 protein stability in K562/G01 by inhibiting the USP2-mediated deubiquitination, and down-regulate the BCL6 protein experssion, thereby increases the sensitivity of drug-resistant cells to IM.


Subject(s)
Apoptosis , Cell Proliferation , Humans , Imatinib Mesylate , K562 Cells , Proto-Oncogene Proteins c-bcl-6 , Metabolism , Ubiquitination
8.
Article in Chinese | WPRIM | ID: wpr-813009

ABSTRACT

To investigate the effects of thanatos-associated protein 11 (THAP11) on the proliferation and apoptosis of esophageal cancer cell and the underlying mechanism.
 Methods: Expression of THAP11 in human esophageal epithelial cells (Het-1A) and esophageal cancer cells (Eca109, TE-1, Ec 9706) were detected by Western blotting. Esophageal cancer TE-1 cells were divided into 3 groups: a normal control (NC) group, a negative control (LV-NC) group and a THAP11 (LV-THAP11) group. Then the cell proliferation were detected by MTT assay, cell apoptosis were detected by flow cytometry, caspase-3 and caspase-9 levels were detected by caspases kits. Ubiquitination of p53 was determined in esophageal cancer TE-1 cells.
 Results: Expression of THAP11 was reduced in esophageal cancer cells compared with human esophageal epithelial cells (P<0.05). After transfection with LV-THAP11 in TE-1 cells, cell viability was reduced (P<0.05), while apoptosis rate and caspase-3 and caspase-9 levels were increased (P<0.05), indicating that THAP11 inhibited growth of esophageal cancer cells. In addition, the THAP11 increased the levels of p53 (P<0.05) and inhibited the ubiquitination of p53 regulated by MDM2. 
 Conclusion: THAP11 may inhibit the proliferation of esophageal cancer cells by inhibiting ubiquitination of p53.


Subject(s)
Apoptosis , Cell Line, Tumor , Cell Proliferation , Esophageal Neoplasms , Humans , Repressor Proteins , Metabolism , Tumor Suppressor Protein p53 , Ubiquitination
9.
Immune Network ; : e32-2019.
Article in English | WPRIM | ID: wpr-764028

ABSTRACT

Pellino-1 is a ubiquitin (Ub) E3 ligase that plays a role in M1, but not M2a polarization of macrophages. However, it is unknown whether Pellino-1 regulates IL-10-mediated M2c polarization of macrophages. Here, we found that Pellino-1 attenuated tumor growth by inhibiting M2c polarization of macrophages. Upon IL-10 stimulation, Pellino-1-deificient bone marrow-derived macrophages (BMDMs) showed higher expression of M2c markers, but not M2a, and M2b markers than wild-type (WT) BMDMs, indicating that Pellino-1 inhibits M2c polarization of macrophages. Pellino-1-deficient BMDMs exhibited a defect in mitochondria respiration, but enhancement of glycolysis during M2c polarization. During M2c polarization of macrophages, Pellino-1 increased STAT1 phosphorylation via K63-linked ubiquitination of IL-1 receptor associated kinase 1 (IRAK1). Furthermore, Lysm-CrePellino-1(fl/fl) mice showed enhancement of tumor growth via regulating M2c polarization of tumor-associated macrophages. These results demonstrate that Pellino-1 inhibits IL-10-induced M2c macrophage polarization via K63-linked ubiquitination of IRAK1 and activation of STAT1, thereby inhibiting tumor growth in vivo.


Subject(s)
Animals , Glycolysis , Interleukin-1 , Interleukin-10 , Macrophages , Mice , Mitochondria , Phosphorylation , Phosphotransferases , Respiration , Ubiquitin , Ubiquitin-Protein Ligases , Ubiquitination
10.
Immune Network ; : e16-2019.
Article in English | WPRIM | ID: wpr-764015

ABSTRACT

Sequestosome 1 (SQSTM1, p62), a ubiquitin binding protein, plays a role in cell signaling, oxidative stress, and autophagy. However, its functional role in inflammatory signaling is controversial. Recent studies have shown that p62 is negatively implicated in inflammatory responses. But, the precise molecular mechanisms by which p62 regulates inflammatory responses remain unclear. In this study, we report on a new regulatory role for p62 in TLR4-mediated signaling. p62 overexpression led to the suppression of NF-κB activation and the production of pro-inflammatory cytokines, TNF-α, IL-6, and IL-1β in response to TLR4 stimulation. In contrast, p62(−/−) mouse embryonic fibroblast (MEF) cells exhibited marked enhancement of NF-κB activation and production of pro-inflammatory cytokines by TLR4 stimulation, compared to p62(+/+) MEF cells. Additionally, the TLR4-induced activation of signal transduction was significantly augmented in p62(−/−) MEF cells, indicating that p62 was negatively implicated in TLR4-mediated signaling. Biochemical studies revealed that p62 interacted with the internal domain of evolutionarily conserved signaling intermediate in Toll pathways (ECSIT), which is critical for associating with the TNF receptor associated factor 6 (TRAF6)-ECSIT complex to activate NF-κB in TLR4 signaling. Interestingly, p62-ECSIT interaction inhibited the interaction between TRAF6 and ECSIT and attenuated the ubiquitination of ECSIT. Furthermore, upon LPS challenge, the mortality of p62(−/−) (p62-knockout) mice was markedly enhanced compared to p62(+/+) (p62 wild-type) mice. Taken together, our data demonstrate that p62 negatively regulated TLR4 signaling via functional regulation of the TRAF6-ECSIT complex.


Subject(s)
Animals , Autophagy , Carrier Proteins , Cytokines , Fibroblasts , Interleukin-6 , Mice , Mortality , Oxidative Stress , Signal Transduction , TNF Receptor-Associated Factor 6 , Toll-Like Receptor 4 , Ubiquitin , Ubiquitination
11.
Braz. j. med. biol. res ; 52(5): e8412, 2019. graf
Article in English | LILACS | ID: biblio-1001528

ABSTRACT

Multiple myeloma (MM) is a malignant neoplasm of plasma, and exhibits several harmful effects including osteolytic injuries, hypercalcemia, and immune dysfunction. Many patients with MM succumb to the underlying malignancy. An S-phase kinase-related protein 2 (Skp2) inhibitor, designated SKPin C1, has been developed and confirmed to have an inhibitory effect on metastatic melanoma cells. This study aimed to determine the effect of SKPin C1 on MM. Normal B lymphocytes, THP-1 cells, and MM U266 and RPMI 8226 cells were exposed to various dosages of SKPin C1 for 48 h. Cell proliferation was determined by MTT, EdU staining, and cell cycle assays. Western blot assays were performed to assess intracellular protein levels of Skp2, p27, and cleaved caspase-3. The amount of ubiquitin attached to p27 was determined using an immunoprecipitation assay. The viability of U266 and RPMI 8226 cells was significantly inhibited by 10 μM SKPin C1 and the inhibitory effect was enhanced with increasing doses of SKPin C1. In contrast, 50 μM SKPin C1 only marginally decreased viability of normal B lymphocytes in 12 h. Skp2 and p27 expression in U266 and RPMI 8226 cells was higher and lower, respectively, than that in the normal B lymphocytes. Treatment with SKPin C1 or Skp2 knockdown increased p27 protein levels in U266 and RPMI 8226 cells by preventing p27 from being ubiquitinated, which slowed the cell cycle, inhibited cell proliferation, and triggered apoptosis. Therefore, this study suggested SKPin C1 as a potent inhibitor against aberrant proliferation and immortalization of MM.


Subject(s)
Humans , Apoptosis , S-Phase Kinase-Associated Proteins/metabolism , Cell Proliferation/physiology , Cyclin-Dependent Kinase Inhibitor p27/metabolism , Multiple Myeloma/metabolism , Cell Cycle , S-Phase Kinase-Associated Proteins/antagonists & inhibitors , Cell Proliferation/drug effects , Cyclin-Dependent Kinase Inhibitor p27/pharmacology , Ubiquitination/physiology , Ubiquitinated Proteins/metabolism , Multiple Myeloma/physiopathology
12.
Braz. j. med. biol. res ; 52(9): e8525, 2019. tab, graf
Article in English | LILACS | ID: biblio-1011614

ABSTRACT

Many compounds of ginsenosides show anti-inflammatory properties. However, their anti-inflammatory effects in intervertebral chondrocytes in the presence of inflammatory factors have never been shown. Increased levels of pro-inflammatory cytokines are generally associated with the degradation and death of chondrocytes; therefore, finding an effective and nontoxic substance that attenuates the inflammation is worthwhile. In this study, chondrocytes were isolated from the nucleus pulposus tissues, and the cells were treated with ginsenoside compounds and IL-1β, alone and in combination. Cell viability and death rate were assessed by CCK-8 and flow cytometry methods, respectively. PCR, western blot, and immunoprecipitation assays were performed to determine the mRNA and protein expression, and the interactions between proteins, respectively. Monomeric component of ginsenoside Rd had no toxicity at the tested range of concentrations. Furthermore, Rd suppressed the inflammatory response of chondrocytes to interleukin (IL)-1β by suppressing the increase in IL-1β, tumor necrosis factor (TNF)-α, IL-6, COX-2, and inducible nitric oxide synthase (iNOS) expression, and retarding IL-1β-induced degradation of chondrocytes by improving cell proliferation characteristics and expression of aggrecan and COL2A1. These protective effects of Rd were associated with ubiquitination of IL-1 receptor accessory protein (IL1RAP), blocking the stimulation of IL-1β to NF-κB. Bioinformatics analysis showed that NEDD4, CBL, CBLB, CBLC, and ITCH most likely target IL1RAP. Rd increased intracellular ITCH level and the amount of ITCH attaching to IL1RAP. Thus, IL1RAP ubiquitination promoted by Rd is likely to occur by up-regulation of ITCH. In summary, Rd inhibited IL-1β-induced inflammation and degradation of intervertebral disc chondrocytes by increasing IL1RAP ubiquitination.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Chondrocytes/drug effects , Ginsenosides/pharmacology , Interleukin-1beta/drug effects , Interleukin-1 Receptor Accessory Protein/metabolism , Intervertebral Disc Degeneration/metabolism , Dinoprostone/metabolism , Cell Survival/drug effects , Tumor Necrosis Factor-alpha/metabolism , Low Back Pain/metabolism , Nitric Oxide Synthase/metabolism , Chondrocytes/cytology , Chondrocytes/metabolism , Ginsenosides/metabolism , Cyclooxygenase 2/metabolism , Aggrecans/metabolism , Interleukin-1beta/metabolism , Ubiquitination , Nucleus Pulposus/cytology , Nucleus Pulposus/drug effects , Nucleus Pulposus/metabolism , Inflammation/metabolism
13.
Article in English | WPRIM | ID: wpr-740116

ABSTRACT

Imbalance of protein homeostasis (proteostasis) is known to cause cellular malfunction, cell death, and diseases. Elaborate regulation of protein synthesis and degradation is one of the important processes in maintaining normal cellular functions. Protein degradation pathways in eukaryotes are largely divided into proteasome-mediated degradation and lysosome-mediated degradation. Proteasome is a multisubunit complex that selectively degrades 80% to 90% of cellular proteins. Proteasome-mediated degradation can be divided into 26S proteasome (20S proteasome + 19S regulatory particle) and free 20S proteasome degradation. In 1980, it was discovered that during ubiquitination process, wherein ubiquitin binds to a substrate protein in an ATP-dependent manner, ubiquitin acts as a degrading signal to degrade the substrate protein via proteasome. Conversely, 20S proteasome degrades the substrate protein without using ATP or ubiquitin because it recognizes the oxidized and structurally modified hydrophobic patch of the substrate protein. To date, most studies have focused on protein degradation via 26S proteasome. This review describes the 26S/20S proteasomal pathway of protein degradation and discusses the potential of proteasome as therapeutic targets for cancer treatment as well as against diseases caused by abnormalities in the proteolytic system.


Subject(s)
Adenosine Triphosphate , Cell Death , Eukaryota , Homeostasis , Oxidative Stress , Proteasome Endopeptidase Complex , Proteolysis , Ubiquitin , Ubiquitination
14.
Article in English | WPRIM | ID: wpr-740115

ABSTRACT

TGF-β signaling plays a tumor suppressive role in normal and premalignant cells but promotes tumor progression during the late stages of tumor development. The TGF-β signaling pathway is tightly regulated at various levels, including transcriptional and post-translational mechanisms. Ubiquitination of signaling components, such as receptors and Smad proteins is one of the key regulatory mechanisms of TGF-β signaling. Tripartite motif (TRIM) family of proteins is a highly conserved group of E3 ubiquitin ligase proteins that have been implicated in a variety of cellular functions, including cell growth, differentiation, immune response, and carcinogenesis. Recent emerging studies have shown that some TRIM family proteins function as important regulators in tumor initiation and progression. This review summarizes current knowledge of TRIM family proteins regulating the TGF-β signaling pathway with relevance to cancer.


Subject(s)
Carcinogenesis , Humans , Smad Proteins , Transforming Growth Factor beta , Ubiquitin , Ubiquitin-Protein Ligases , Ubiquitination
15.
Article in English | WPRIM | ID: wpr-740072

ABSTRACT

We previously demonstrated that epidermal growth factor (EGF) enhances cell migration and invasion of breast cancer cells in a SMAD ubiquitination regulatory factor 1 (SMURF1)-dependent manner and that SMURF1 induces degradation of β-catenin in C2C12 cells. However, the relationship between EGF-induced SMURF1 and β-catenin expression in breast cancer cells remains unclear. So, we investigated if EGF and SMURF1 regulate β-catenin expression in MDAMB231 human breast cancer cells. When MDAMB231 cells were incubated with EGF for 24, 48, and 72 hours, EGF significantly increased expression levels of SMURF1 mRNA and protein while suppressing expression levels of β-catenin mRNA and protein. Overexpression of SMURF1 downregulated β-catenin mRNA and protein, whereas knockdown of SMURF1 increased β-catenin expression and blocked EGF-induced β-catenin downregulation. Knockdown of β-catenin enhanced cell migration and invasion of MDAMB231 cells, while β-catenin overexpression suppressed EGF-induced cell migration and invasion. Furthermore, knockdown of β-catenin enhanced vimentin expression and decreased cytokeratin expression, whereas β-catenin overexpression decreased vimentin expression and increased cytokeratin expression. These results suggest that EGF downregulates β-catenin in a SMURF1-dependent manner and that β-catenin downregulation contributes to EGF-induced cell migration and invasion in MDAMB breast cancer cells.


Subject(s)
beta Catenin , Breast Neoplasms , Cell Movement , Down-Regulation , Epidermal Growth Factor , Humans , Keratins , RNA, Messenger , Ubiquitin , Ubiquitination , Vimentin
16.
Article in English | WPRIM | ID: wpr-739922

ABSTRACT

Ubiquitination of proteins plays an essential role in various cellular processes, including protein degradation, DNA repair, and cell signaling pathways. Previous studies have shown that protein ubiquitination is implicated in regulating pluripotency as well as fate determination of stem cells. To identify how protein ubiquitination affects differentiation of embryonic stem cells, we analyzed microarray data, which are available in the public domain, of E3 ligases and deubiquitinases whose levels changed during stem cell differentiation. Expression of pja2, a member of the RING-type E3 ligase family, was up-regulated during differentiation of stem cells. Wnt/β-catenin signaling is one of the most important signaling pathways for regulation of the self-renewal and differentiation of embryonic stem cells. Pja2 was shown to bind to TCF/LEF1, which are transcriptional factors for Wnt/β-catenin signaling, and regulate protein levels by ubiquitination, leading to down-regulation of Wnt signaling activity. Based on these results, we suggest that E3 ligase Pja2 regulates stem cell differentiation by controlling the level of TCF/LEF1 by ubiquitination.


Subject(s)
DNA Repair , Down-Regulation , Embryonic Stem Cells , Humans , Ligases , Proteolysis , Public Sector , Stem Cells , Ubiquitin , Ubiquitin-Protein Ligases , Ubiquitin-Specific Proteases , Ubiquitination
17.
Article in English | WPRIM | ID: wpr-739645

ABSTRACT

Nuclear factor E2-related factor 2 (NRF2) plays an important role in redox metabolism and antioxidant defense. Under normal conditions, NRF2 proteins are maintained at very low levels because of their ubiquitination and proteasomal degradation via binding to the kelch-like ECH associated protein 1 (KEAP1)-E3 ubiquitin ligase complex. However, oxidative and/or electrophilic stresses disrupt the KEAP1-NRF2 interaction, which leads to the accumulation and transactivation of NRF2. During recent decades, a growing body of evidence suggests that NRF2 is frequently activated in many types of cancer by multiple mechanisms, including the genetic mutations in the KEAP1-NRF2 pathway. This suggested that NRF2 inhibition is a promising strategy for cancer therapy. Recently, several NRF2 inhibitors have been reported with anti-tumor efficacy. Here, we review the mechanisms whereby NRF2 is dysregulated in cancer and its contribution to the tumor development and radiochemoresistance. In addition, among the NRF2 inhibitors reported so far, we summarize and discuss repurposed NRF2 inhibitors with their potential mechanisms and provide new insights to develop selective NRF2 inhibitors.


Subject(s)
Metabolism , NF-E2-Related Factor 2 , Oxidation-Reduction , Transcriptional Activation , Ubiquitin , Ubiquitination
18.
Article in English | WPRIM | ID: wpr-739491

ABSTRACT

An interaction between ribosomal protein S3 (rpS3) and nuclear factor kappa B or macrophage migration inhibitory factor in non-small-cell lung cancer is responsible for radioresistance. However, the role of rpS3 in glioblastoma (GBM) has not been investigated to date. Here we found that in irradiated GBM cells, rpS3 translocated into the nucleus and was subsequently ubiquitinated by ring finger protein 138 (RNF138). Ubiquitin-dependent degradation of rpS3 consequently led to radioresistance in GBM cells. To elucidate the apoptotic role of rpS3, we analyzed the interactome of rpS3 in ΔRNF138 GBM cells. Nuclear rpS3 interacted with DNA damage inducible transcript 3 (DDIT3), leading to DDIT3-induced apoptosis in irradiated ΔRNF138 GBM cells. These results were confirmed using in vivo orthotopic xenograft models and GBM patient tissues. This study aims to clarify the role of RNF138 in GBM cells and demonstrate that rpS3 may be a promising substrate of RNF138 for the induction of GBM radioresistance, indicating RNF138 as a potential target for GBM therapy.


Subject(s)
Apoptosis , DNA Damage , Fingers , Glioblastoma , Heterografts , Humans , Lung Neoplasms , Macrophages , NF-kappa B , Ribosomal Proteins , Ubiquitin , Ubiquitination
19.
Article in English | WPRIM | ID: wpr-772974

ABSTRACT

DNA damage response (DDR) is essential for maintaining genome stability and protecting cells from tumorigenesis. Ubiquitin and ubiquitin-like modifications play an important role in DDR, from signaling DNA damage to mediating DNA repair. In this report, we found that the E3 ligase ring finger protein 126 (RNF126) was recruited to UV laser micro-irradiation-induced stripes in a RNF8-dependent manner. RNF126 directly interacted with and ubiquitinated another E3 ligase, RNF168. Overexpression of wild type RNF126, but not catalytically-inactive mutant RNF126 (CC229/232AA), diminished ubiquitination of H2A histone family member X (H2AX), and subsequent bleomycin-induced focus formation of total ubiquitin FK2, TP53-binding protein 1 (53BP1), and receptor-associated protein 80 (RAP80). Interestingly, both RNF126 overexpression and RNF126 downregulation compromised homologous recombination (HR)-mediated repair of DNA double-strand breaks (DSBs). Taken together, our findings demonstrate that RNF126 negatively regulates RNF168 function in DDR and its appropriate cellular expression levels are essential for HR-mediated DSB repair.


Subject(s)
Carrier Proteins , Metabolism , Cell Line, Tumor , DNA Breaks, Double-Stranded , DNA Repair , Genetics , DNA-Binding Proteins , Metabolism , Genomic Instability , HeLa Cells , Histones , Metabolism , Humans , Nuclear Proteins , Metabolism , RNA Interference , RNA, Small Interfering , Genetics , Signal Transduction , Tumor Suppressor p53-Binding Protein 1 , Metabolism , Ubiquitin , Ubiquitin-Protein Ligases , Genetics , Metabolism , Ubiquitination
20.
Article in Chinese | WPRIM | ID: wpr-772594

ABSTRACT

Inflammatory bowel disease refers to chronic inflammatory disorders that affect the gastrointestinal tract. Ubiquitination is an important protein post-translational modification. In recent years, the research of ubiquitination-deubiquitination system in the development of inflammatory bowel disease has become a hot spot. Up to now, the E3 ubiquitin ligases such as ring finger protein 183 (RNF183), RNF20, Itch and A20 were well studied in inflammatory bowel disease. RNF183 promotes the activation of the NF-κB pathway by increasing the ubiquitination and degradation of IκBα; RNF20 drives histone H2B monoubiquitylation, downregulates a panel of inflammation-associated genes; Itch inhibits IL-17-mediated colon inflammation by retinoid acid related orphan receptor γt ubiquitination; A20 has ubiquitinating-deubiquitinating activity to regulates colon inflammation. This article reviews the role and regulatory mechanism of RNF183, RNF20, Itch and A20 in the pathogenesis of inflammatory bowel disease.


Subject(s)
Histones , Metabolism , Humans , Inflammatory Bowel Diseases , NF-kappa B , Metabolism , Ubiquitin-Protein Ligases , Metabolism , Ubiquitination
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