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1.
Int J Mol Sci ; 24(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36614276

RESUMO

Auxin action largely depends on the establishment of auxin concentration gradient within plant organs, where PIN-formed (PIN) auxin transporter-mediated directional auxin movement plays an important role. Accumulating studies have revealed the need of polar plasma membrane (PM) localization of PIN proteins as well as regulation of PIN polarity in response to developmental cues and environmental stimuli, amongst which a typical example is regulation of PIN phosphorylation by AGCVIII protein kinases and type A regulatory subunits of PP2A phosphatases. Recent findings, however, highlight the importance of PIN degradation in reestablishing auxin gradient. Although the underlying mechanism is poorly understood, these findings provide a novel aspect to broaden the current knowledge on regulation of polar auxin transport. In this review, we summarize the current understanding on controlling PIN degradation by endosome-mediated vacuolar targeting, autophagy, ubiquitin modification and the related E3 ubiquitin ligases, cytoskeletons, plant hormones, environmental stimuli, and other regulators, and discuss the possible mechanisms according to recent studies.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteólise , Transporte Biológico , Ácidos Indolacéticos/metabolismo , Ubiquitinas/metabolismo , Raízes de Plantas/metabolismo
2.
Mol Med Rep ; 27(2)2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36660934

RESUMO

Ubiquitin D (UBD), a member of the ubiquitin­like modifier family, has been reported to be highly expressed in various types of cancer and its overexpression is positively associated with tumor progression. However, the role and mechanism of UBD in rheumatoid arthritis (RA) remain elusive. In the present study, the gene expression profiles of GSE55457 were downloaded from the Gene Expression Omnibus database to assess differentially expressed genes and perform functional enrichment analyses. UBD was overexpressed by lentivirus transfection. The protein level of UBD, p­p38 and p38 in RA­fibroblast­like synoviocytes (FLSs) were examined by western blotting. Cell Counting Kit­8 and flow cytometry assays were used to detect the functional changes of RA­FLSs transfected with UBD and MAPK inhibitor SB202190. The concentrations of inflammatory factors (IL­2, IL­6, IL­10 and TNF­α) were evaluated using ELISA kits. The results revealed that UBD was overexpressed in RA tissues compared with in the healthy control tissues. Functionally, UBD significantly accelerated the viability and proliferation of RA­FLSs, whereas it inhibited their apoptosis. Furthermore, UBD significantly promoted the secretion of inflammatory factors (IL­2, IL­6, IL­10 and TNF­α). Mechanistically, elevated UBD activated phospohorylated­p38 in RA­FLSs. By contrast, UBD overexpression and treatment with the p38 MAPK inhibitor SB202190 not only partially relieved the UBD­dependent effects on cell viability and proliferation, but also reversed its inhibitory effects on cell apoptosis. Furthermore, SB202190 partially inhibited the effects of UBD overexpression on the enhanced secretion of inflammatory factors. The present study indicated that UBD may mediate the activation of p38 MAPK, thereby facilitating the proliferation of RA­FLSs and ultimately promoting the progression of RA. Therefore, UBD may be considered a potential therapeutic target and a promising prognostic biomarker for RA.


Assuntos
Artrite Reumatoide , Sinoviócitos , Humanos , Interleucina-10/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Interleucina-2/metabolismo , Proliferação de Células , Artrite Reumatoide/patologia , Sinoviócitos/metabolismo , Ubiquitinas/metabolismo , Fibroblastos/metabolismo , Células Cultivadas , Apoptose/genética
3.
Biol Res ; 56(1): 4, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36683111

RESUMO

BACKGROUND: Spermatogonial stem cells (SSCs) are critical for sustaining spermatogenesis. Even though several regulators of SSC have been identified in rodents, the regulatory mechanism of SSC in humans has yet to be discovered. METHODS: To explore the regulatory mechanisms of human SSCs, we analyzed publicly available human testicular single-cell sequencing data and found that Ankyrin repeat and SOCS box protein 9 (ASB9) is highly expressed in SSCs. We examined the expression localization of ASB9 using immunohistochemistry and overexpressed ASB9 in human SSC lines to explore its role in SSC proliferation and apoptosis. Meanwhile, we used immunoprecipitation to find the target protein of ASB9 and verified its functions. In addition, we examined the changes in the distribution of ASB9 in non-obstructive azoospermia (NOA) patients using Western blot and immunofluorescence. RESULTS: The results of uniform manifold approximation and projection (UMAP) clustering and pseudotime analysis showed that ASB9 was highly expressed in SSCs, and its expression gradually increased during development. The immunohistochemical and dual-color immunofluorescence results displayed that ASB9 was mainly expressed in nonproliferating SSCs. Overexpression of ASB9 in the SSC line revealed significant inhibition of cell proliferation and increased apoptosis. We predicted the target proteins of ASB9 and verified that hypoxia-inducible factor 1-alpha inhibitor (HIF1AN), but not creatine kinase B-type (CKB), has a direct interaction with ASB9 in human SSC line using protein immunoprecipitation experiments. Subsequently, we re-expressed HIF1AN in ASB9 overexpressing cells and found that HIF1AN reversed the proliferative and apoptotic changes induced by ASB9 overexpression. In addition, we found that ABS9 was significantly downregulated in some NOA patients, implying a correlation between ASB9 dysregulation and impaired spermatogenesis. CONCLUSION: ASB9 is predominantly expressed in human SSCs, it affects the proliferation and apoptotic process of the SSC line through HIF1AN, and its abnormal expression may be associated with NOA.


Assuntos
Testículo , Ubiquitina-Proteína Ligases , Masculino , Humanos , Ubiquitina-Proteína Ligases/metabolismo , Testículo/metabolismo , Espermatogênese/fisiologia , Linhagem Celular , Proliferação de Células , Apoptose , Ubiquitinas/metabolismo , Oxigenases de Função Mista/metabolismo , Proteínas Repressoras/metabolismo , Proteínas Supressoras da Sinalização de Citocina/metabolismo
4.
Proc Natl Acad Sci U S A ; 120(5): e2217992120, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36689659

RESUMO

SWItch/sucrose non-fermenting (SWI/SNF) complexes are a family of chromatin remodelers that are conserved across eukaryotes. Mutations in subunits of SWI/SNF cause a multitude of different developmental disorders in humans, most of which have no current treatment options. Here, we identify an alanine-to-valine-causing mutation in the SWI/SNF subunit snfc-5 (SMARCB1 in humans) that prevents embryonic lethality in Caenorhabditis elegans nematodes harboring a loss-of-function mutation in the SWI/SNF subunit swsn-1 (SMARCC1/2 in humans). Furthermore, we found that the combination of this specific mutation in snfc-5 and a loss-of-function mutation in either of the E3 ubiquitin ligases ubr-5 (UBR5 in humans) or hecd-1 (HECTD1 in humans) can restore development to adulthood in swsn-1 loss-of-function mutants that otherwise die as embryos. Using these mutant models, we established a set of 335 genes that are dysregulated in SWI/SNF mutants that arrest their development embryonically but exhibit near wild-type levels of expression in the presence of suppressor mutations that prevent embryonic lethality, suggesting that SWI/SNF promotes development by regulating some subset of these 335 genes. In addition, we show that SWI/SNF protein levels are reduced in swsn-1; snfc-5 double mutants and partly restored to wild-type levels in swsn-1; snfc-5; ubr-5 triple mutants, consistent with a model in which UBR-5 regulates SWI/SNF levels by tagging the complex for proteasomal degradation. Our findings establish a link between two E3 ubiquitin ligases and SWI/SNF function and suggest that UBR5 and HECTD1 could be potential therapeutic targets for the many developmental disorders caused by missense mutations in SWI/SNF subunits.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Humanos , Caenorhabditis elegans/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Ubiquitinas/metabolismo
5.
Int J Mol Sci ; 24(2)2023 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-36674743

RESUMO

Ubiquitin-like proteins (Ubls) are involved in a variety of biological processes through the modification of proteins. Dysregulation of Ubl modifications is associated with various diseases, especially cancer. Ubiquitin-like protein 3 (UBL3), a type of Ubl, was revealed to be a key factor in the process of small extracellular vesicle (sEV) protein sorting and major histocompatibility complex class II ubiquitination. A variety of sEV proteins that affects cancer properties has been found to interact with UBL3. An increasing number of studies has implied that UBL3 expression affects cancer cell growth and cancer prognosis. In this review, we provide an overview of the relationship between various Ubls and cancers. We mainly introduce UBL3 and its functions and summarize the current findings of UBL3 and examine its potential as a therapeutic target in cancers.


Assuntos
Vesículas Extracelulares , Neoplasias , Humanos , Ubiquitinas/genética , Ubiquitinas/metabolismo , Ubiquitinação , Proteínas/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Vesículas Extracelulares/metabolismo , Processamento de Proteína Pós-Traducional
6.
Eur J Med Chem ; 247: 115072, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36603510

RESUMO

Targeting Glutathione peroxidase 4 (GPX4) has become a promising strategy for drug-resistant cancer therapy via ferroptosis induction. It was found that the GPX4 inhibitors such as RSL3 have GPX4 degradation ability via not only autophagy-lysosome pathway but also ubiquitin-proteasome system (UPS). Proteolysis targeting chimeras (PROTACs) using small molecule with both inhibition and degradation ability as the ligand of protein of interest (POI) have not been reported. To obtain better compounds with effective disturbance of GPX4 activity, and compare the difference between GPX4 inhibitors with degradation ability and their related PROTACs, we designed and synthesized a series of GPX4 degraders using PROTAC technology in terms of its excellent characteristics such as high efficiency and selectivity and the capacity of overcoming resistance. Hence, 8e was discovered as a potent and highly efficacious GPX4 degrader based upon the inhibitor RSL3. It was 2-3 times more potent than RSL3 in all the in vitro anti-tumor assays, indicating the importance of the PROTAC ternary complex of GPX4, 8e and E3 ligase ligand. 8e revealed better potency in resistant tumor cells than in wide type cells. Furthermore, we discovered for the first time that degrader 8e exhibit GPX4 degradation activity via ubiquitin-proteasome system (UPS) and autophagy-lysosome pathway with UPS plays the major role in the process. Our data also suggested that 8e and RSL3 could potently induce ferroptosis of HT1080 cells via GPX4 inhibition and degradation. In summary, our data revealed that the GPX4 degrader 8e achieves better degradation and anti-tumor effects compared to its related GPX4 inhibitor RSL3. Thus, an efficient strategy to induce GPX4 degradation and subsequent ferroptosis was established in this study for malignant cancer treatment in the future.


Assuntos
Ferroptose , Neoplasias , Humanos , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligantes , Ubiquitinas/metabolismo , Proteólise
7.
Int J Biol Sci ; 19(2): 377-392, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36632463

RESUMO

HER2 is a transmembrane receptor with intrinsic tyrosine kinase activity that is overexpressed in almost 25% of human breast cancers. Here, we report that the neddylation of HER2 is a new post-translational modification that controls its expression and oncogenic activity in human breast cancer. Two critical members in the neddylation pathway, NEDD8 and NEDD8-activating enzyme E1 subunit 1 (NAE1), are detected in human breast specimens. Overexpressed NEDD8 and NAE1 are positively correlated with HER2 expression in human breast cancer. Subsequent structure and function experiments show that HER2 directly interacts with NEDD8 and NAE1, whereas HER2 protein expression is decreased by neddylation depletion. Mechanistically, neddylation inhibition promotes the degradation of HER2 protein by improving its ubiquitination. HER2 overexpression abrogates neddylation depletion-triggered cell growth suppression. The inhibition of neddylation synergized with trastuzumab significantly suppresses growth of HER2 positive breast cancer. Collectively, this study demonstrates a previously undiscovered role of NEDD8-dependent HER2 neddylation promotes tumor growth in breast cancer.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Proteólise , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Ubiquitinas/genética , Ubiquitinas/metabolismo , Processamento de Proteína Pós-Traducional , Ubiquitinação
8.
Spine (Phila Pa 1976) ; 48(3): 213-222, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36607628

RESUMO

STUDY DESIGN: A functional, transcriptome, and long noncoding RNAs (lncRNAs) expression analysis in the spinal cord of mice after hyperbaric oxygen (HBO) treatment. OBJECTIVE: We aimed to explore the mechanism by which HBO treats spinal cord injury (SCI) at the level of lncRNAs. SUMMARY OF BACKGROUND DATA: Immense amounts of research have established that HBO treatment promotes the recovery of neurological function after SCI. The mechanism of action remains to be clarified. METHODS: High-throughput RNA sequencing, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes enrichment analysis were used to profile lncRNA expression and analyze biological function in the spinal cords of mice from sham-operated, SCI, and HBO-treated groups. The differential expression of lncRNA between the groups was assessed using real-time quantitative polymerase chain reaction. RESULTS: Differential expression across 577 lncRNAs was identified among the three groups. GO analysis showed that free ubiquitin chain polymerization, ubiquitin homeostasis, DNA replication, synthesis of RNA primer, single-stranded telomeric DNA binding, and alpha-amylase activity were significantly enriched. Kyoto Encyclopedia of Genes and Genomes enrichment analysis displayed that vitamin B6 metabolism, one carbon pool by folate, DNA replication, lysine degradation, beta-alanine metabolism, fanconi anemia pathway, and Notch signal pathway were the main pathways with enrichment significance. LncRNAs NONMMUT 092674.1, NONMMUT042986.2, and NONMMUT018850.2 showed significantly different expression between the SCI and the other two groups (P<0.05, <0.01). CONCLUSIONS: This study is the first to determine the expression profiles of lncRNAs in the injured spinal cord after HBO treatment. We identified several important dysregulated lncRNAs in this setting. These results help us better understand the mechanism by which HBO treats SCI and provide new potential therapeutic targets for SCI.


Assuntos
Oxigenoterapia Hiperbárica , RNA Longo não Codificante , Traumatismos da Medula Espinal , Ratos , Camundongos , Animais , Oxigenoterapia Hiperbárica/métodos , Oxigênio/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Ratos Sprague-Dawley , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/terapia , Traumatismos da Medula Espinal/metabolismo , Medula Espinal , Ubiquitinas/genética , Ubiquitinas/metabolismo , Perfilação da Expressão Gênica
9.
Biogerontology ; 24(1): 137-148, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36550376

RESUMO

Aging-affected cellular compositions of the spinal cord are diverse and region specific. Age leads to the accumulation of abnormal protein aggregates and dysregulation of proteostasis. Dysregulated proteostasis and protein aggregates result from dysfunction of the ubiquitin-proteasome system (UPS) and autophagy. Understanding the molecular mechanisms of spinal cord aging is essential and important for scientists to discover new therapies for rejuvenation. We found age-related increases in STAT3 and decreases in Tuj1 in aging mouse spinal cords, which was characterized by increased expression of P16. Coaggregation of lysine-48 and lysine-63 ubiquitin with STAT3 was revealed in aging mouse spinal cords. STAT3-ubiquitin aggregates formed via lysine-48 and lysine-63 linkages were increased significantly in the aging spinal cords but not in central canal ependymal cells or neural stem cells in the spinal cord. These results highlight the increase in STAT3 and its region-specific aggregation and ubiquitin-conjugation during spinal cord aging.


Assuntos
Envelhecimento , Células-Tronco Neurais , Fator de Transcrição STAT3 , Animais , Masculino , Camundongos , Envelhecimento/metabolismo , Lisina/metabolismo , Células-Tronco Neurais/metabolismo , Agregados Proteicos , Medula Espinal/metabolismo , Fator de Transcrição STAT3/metabolismo , Ubiquitinas/metabolismo
10.
Methods Mol Biol ; 2591: 151-169, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36350548

RESUMO

Archaea can be used as microbial platforms to discover new types of deubiquitinase-like (DUB-like) enzymes and to produce ubiquitin/ubiquitin-like (Ub/Ubl) protein conjugates as substrates for DUB/DUB-like activity assays. Here we outline how to use archaea to synthesize, purify, and assay the activity of DUB-like enzymes with unusual properties, including catalytic activity in hypersaline conditions, organic solvents, and high temperatures. We also outline the application of archaea in forming Ub/Ubl isopeptide linkages that include the covalent attachments of diverse archaeal and eukaryotic Ub/Ubls to target proteins. Archaea form these Ub/Ubl-linked protein conjugates in vivo, and the resulting products are found to serve as useful DUB substrates for in vitro assays.


Assuntos
Archaea , Ubiquitinas , Ubiquitinas/metabolismo , Archaea/metabolismo , Ubiquitina/metabolismo , Células Eucarióticas/metabolismo , Enzimas Desubiquitinantes
11.
Methods Mol Biol ; 2591: 171-188, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36350549

RESUMO

Both severe acute respiratory syndrome coronavirus 1 and 2 (SARS-CoV-1 and SARS-CoV-2) encode a papain-like protease (PLpro), which plays a vital role in viral propagation. PLpro accomplishes this function by processing the viral polyproteins essential for viral replication and removing the small proteins, ubiquitin and ISG15 from the host's key immune signaling proteins, thereby preventing the host's innate immune response. Although PLpro from both SARS-CoV-1 and SARS-CoV-2 are structurally highly similar (83% sequence identity), they exhibit functional variability. Hence, to further elucidate the mechanism and aid in drug discovery efforts, the biochemical and kinetic characterization of PLpro is needed. This chapter describes step-by-step experimental procedures for evaluating PLpro activity in vitro using activity-based probes (ABPs) along with fluorescence-based substrates. Herein we describe a step-by-step experimental procedure to assess the activity of PLpro in vitro using a suite of activity-based probes (ABPs) and fluorescent substrates and how they can be applied as fast and yet sensitive methods to calculate kinetic parameters.


Assuntos
COVID-19 , Ubiquitina , Humanos , Ubiquitina/metabolismo , SARS-CoV-2/genética , Proteases Semelhantes à Papaína de Coronavírus , Papaína , Peptídeo Hidrolases/metabolismo , Ubiquitinas/metabolismo , Citocinas/metabolismo
12.
Nat Commun ; 13(1): 7857, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36543799

RESUMO

Protein modification by ubiquitin-like proteins (UBLs) amplifies limited genome information and regulates diverse cellular processes, including translation, autophagy and antiviral pathways. Ubiquitin-fold modifier 1 (UFM1) is a UBL covalently conjugated with intracellular proteins through ufmylation, a reaction analogous to ubiquitylation. Ufmylation is involved in processes such as endoplasmic reticulum (ER)-associated protein degradation, ribosome-associated protein quality control at the ER and ER-phagy. However, it remains unclear how ufmylation regulates such distinct ER-related functions. Here we identify a UFM1 substrate, NADH-cytochrome b5 reductase 3 (CYB5R3), that localizes on the ER membrane. Ufmylation of CYB5R3 depends on the E3 components UFL1 and UFBP1 on the ER, and converts CYB5R3 into its inactive form. Ufmylated CYB5R3 is recognized by UFBP1 through the UFM1-interacting motif, which plays an important role in the further uyfmylation of CYB5R3. Ufmylated CYB5R3 is degraded in lysosomes, which depends on the autophagy-related protein Atg7- and the autophagy-adaptor protein CDK5RAP3. Mutations of CYB5R3 and genes involved in the UFM1 system cause hereditary developmental disorders, and ufmylation-defective Cyb5r3 knock-in mice exhibit microcephaly. Our results indicate that CYB5R3 ufmylation induces ER-phagy, which is indispensable for brain development.


Assuntos
Autofagia , Citocromo-B(5) Redutase , Retículo Endoplasmático , Ubiquitinas , Animais , Camundongos , Autofagia/fisiologia , Proteínas de Ciclo Celular/metabolismo , Retículo Endoplasmático/metabolismo , Processamento de Proteína Pós-Traducional , Ubiquitinação/fisiologia , Ubiquitinas/química , Ubiquitinas/metabolismo , Citocromo-B(5) Redutase/química , Citocromo-B(5) Redutase/metabolismo
13.
Exp Mol Med ; 54(11): 1779-1792, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36319753

RESUMO

ISG15, the product of interferon (IFN)-stimulated gene 15, is the first identified ubiquitin-like protein (UBL), which plays multifaceted roles not only as a free intracellular or extracellular molecule but also as a post-translational modifier in the process of ISG15 conjugation (ISGylation). ISG15 has only been identified in vertebrates, indicating that the functions of ISG15 and its conjugation are restricted to higher eukaryotes and have evolved with IFN signaling. Despite the highlighted complexity of ISG15 and ISGylation, it has been suggested that ISG15 and ISGylation profoundly impact a variety of cellular processes, including protein translation, autophagy, exosome secretion, cytokine secretion, cytoskeleton dynamics, DNA damage response, telomere shortening, and immune modulation, which emphasizes the necessity of reassessing ISG15 and ISGylation. However, the underlying mechanisms and molecular consequences of ISG15 and ISGylation remain poorly defined, largely due to a lack of knowledge on the ISG15 target repertoire. In this review, we provide a comprehensive overview of the mechanistic understanding and molecular consequences of ISG15 and ISGylation. We also highlight new insights into the roles of ISG15 and ISGylation not only in physiology but also in the pathogenesis of various human diseases, especially in cancer, which could contribute to therapeutic intervention in human diseases.


Assuntos
Citocinas , Ubiquitinas , Animais , Humanos , Citocinas/metabolismo , Ubiquitinas/genética , Ubiquitinas/metabolismo , Interferons/genética , Interferons/metabolismo , Transdução de Sinais/fisiologia , Autofagia
14.
Biochem J ; 479(22): 2379-2394, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36383218

RESUMO

p21WAF1/Cip1 acts as a key negative regulator of cell cycle progression, which can form complexes with cyclin-dependent kinases together with specific cyclins to induce cell cycle arrest at specific stages. p21 protein levels have been shown to be regulated primarily through phosphorylation and ubiquitination during various stages of the cell cycle. Although phosphorylation and ubiquitin-dependent proteasomal degradation of p21 have been well established, other post-translational modifications that contribute to regulation of p21 stability and function remain to be further elucidated. Here, we show that p21 degradation and its function are controlled by tankyrases, which are members of the poly(ADP-ribose) polymerase (PARP) protein family. p21 interacts with tankyrases via newly defined tankyrase-binding motifs and is PARylated by tankyrases in vitro and in vivo, suggesting that PARylation is a new post-translational modification of p21. Up-regulation of tankyrases induces ubiquitin-dependent proteasomal degradation of p21 through an E3 ligase RNF146, thus promoting cell cycle progression in the G1/S phase transition. On the contrary, inhibition of tankyrases by knockdown or inhibitor treatment stabilizes p21 protein and leads to cell cycle arrest in the G1 phase. Together, our data demonstrate that tankyrase may function as a new molecular regulator that controls the protein levels of p21 through PARylation-dependent proteasomal degradation. Hence, a novel function of the tankyrase-p21 axis may represent a new avenue for regulating cell cycle progression.


Assuntos
Tanquirases , Tanquirases/química , Tanquirases/metabolismo , Poli ADP Ribosilação , Ubiquitinação , Ciclo Celular , Ubiquitinas/metabolismo
15.
Nat Commun ; 13(1): 6840, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36369429

RESUMO

The human transcriptome contains thousands of small open reading frames (sORFs) that encode microproteins whose functions remain largely unexplored. Here, we show that TINCR lncRNA encodes pTINCR, an evolutionary conserved ubiquitin-like protein (UBL) expressed in many epithelia and upregulated upon differentiation and under cellular stress. By gain- and loss-of-function studies, we demonstrate that pTINCR is a key inducer of epithelial differentiation in vitro and in vivo. Interestingly, low expression of TINCR associates with worse prognosis in several epithelial cancers, and pTINCR overexpression reduces malignancy in patient-derived xenografts. At the molecular level, pTINCR binds to SUMO through its SUMO interacting motif (SIM) and to CDC42, a Rho-GTPase critical for actin cytoskeleton remodeling and epithelial differentiation. Moreover, pTINCR increases CDC42 SUMOylation and promotes its activation, triggering a pro-differentiation cascade. Our findings suggest that the microproteome is a source of new regulators of cell identity relevant for cancer.


Assuntos
Neoplasias , RNA Longo não Codificante , Sumoilação , Humanos , Neoplasias/genética , Proteínas rho de Ligação ao GTP/metabolismo , Ubiquitinas/metabolismo , RNA Longo não Codificante/genética
16.
Semin Cancer Biol ; 87: 84-97, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36371028

RESUMO

Evidence has revealed that transcription factors play essential roles in regulation of multiple cellular processes, including cell proliferation, metastasis, EMT, cancer stem cells and chemoresistance. Dysregulated expression levels of transcription factors contribute to tumorigenesis and malignant progression. The expression of transcription factors is tightly governed by several signaling pathways, noncoding RNAs and E3 ubiquitin ligases. Cancer stem cells (CSCs) have been validated in regulation of tumor metastasis, reoccurrence and chemoresistance in human cancer. Transcription factors have been verified to participate in regulation of CSC formation, including Oct4, SOX2, KLF4, c-Myc, Nanog, GATA, SALL4, Bmi-1, OLIG2, POU3F2 and FOX proteins. In this review article, we will describe the critical role of CSC-related transcription factors. We will further discuss which E3 ligases regulate the degradation of these CSC-related transcription factors and their underlying mechanisms. We also mentioned the functions and mechanisms of EMT-associated transcription factors such as ZEB1, ZEB2, Snail, Slug, Twist1 and Twist2. Furthermore, we highlight the therapeutic potential via targeting E3 ubiquitin ligases for modulation of these transcription factors.


Assuntos
Neoplasias , Fatores de Transcrição , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Transição Epitelial-Mesenquimal/genética , Células-Tronco Neoplásicas/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Ubiquitinas/metabolismo , Linhagem Celular Tumoral
17.
Biochem Biophys Res Commun ; 633: 61-63, 2022 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-36344165

RESUMO

Ubiquitin-fold modifier 1 (UFM1) is a newly identified ubiquitin-like protein. Like ubiquitin, UFM1 is conjugated to its target proteins through a three-step enzyme system: UBA5 (E1), UFC1 (E2), and UFL1 (E3), but with an additional essential component, UFBP1. This protein modification by UFM1 (ufmylation) can be reversed by UFM1-specific proteases (UFSPs). So far only a handful of target proteins for ufmylation have been identified, and they are mostly associated with either promotion or suppression of tumorigenesis. Here, we summarize the recent progress in the knowledge of tumor-suppressive and tumorigenic functions of ufmylation as well as in the development of therapeutic drugs against ufmylation-associated cancer.


Assuntos
Neoplasias , Processamento de Proteína Pós-Traducional , Humanos , Enzimas Ativadoras de Ubiquitina/genética , Proteínas/metabolismo , Neoplasias/metabolismo , Ubiquitinas/metabolismo
18.
Nutrients ; 14(19)2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36235593

RESUMO

Oxidative stress induces DNA damage which can be repaired by DNA repair proteins, such as Ku70/80. Excess reactive oxygen species (ROS) stimulate the activation of caspase-3, which degrades Ku 70/80. Cells with decreased Ku protein levels undergo apoptosis. Astaxanthin exerts antioxidant activity by inducing the expression of catalase, an antioxidant enzyme, in gastric epithelial cells. Therefore, astaxanthin may inhibit oxidative stress-induced DNA damage by preventing Ku protein degradation and thereby suppressing apoptosis. Ku proteins can be degraded via ubiquitination and neddylation which adds ubiquitin-like protein to substrate proteins. We aimed to determine whether oxidative stress decreases Ku70/80 expression through the ubiquitin-proteasome pathway to induce apoptosis and whether astaxanthin inhibits oxidative stress-induced changes in gastric epithelial AGS cells. We induced oxidative stress caused by the treatment of ß-D-glucose (G) and glucose oxidase (GO) in the cells. As a result, the G/GO treatment increased ROS levels, decreased nuclear Ku protein levels and Ku-DNA-binding activity, and induced the ubiquitination of Ku80. G/GO increased the DNA damage marker levels (γ-H2AX; DNA fragmentation) and apoptosis marker annexin V-positive cells and cell death. Astaxanthin inhibited G/GO-induced alterations, including Ku degradation in AGS cells. MLN4924, a neddylation inhibitor, and MG132, a proteasome inhibitor, suppressed G/GO-mediated DNA fragmentation and decreased cell viability. These results indicated that G/GO-induced oxidative stress causes Ku protein loss through the ubiquitin-proteasome pathway, resulting in DNA fragmentation and apoptotic cell death. Astaxanthin inhibited oxidative stress-mediated apoptosis via the reduction of ROS levels and inhibition of Ku protein degradation. In conclusion, dietary astaxanthin supplementation or astaxanthin-rich food consumption may be effective for preventing or delaying oxidative stress-mediated cell damage by suppressing Ku protein loss and apoptosis in gastric epithelial cells.


Assuntos
Antioxidantes , Complexo de Endopeptidases do Proteassoma , Anexina A5/metabolismo , Anexina A5/farmacologia , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Apoptose , Caspase 3/metabolismo , Catalase/metabolismo , DNA/metabolismo , Proteínas de Ligação a DNA/genética , Células Epiteliais/metabolismo , Glucose/metabolismo , Glucose Oxidase/metabolismo , Glucose Oxidase/farmacologia , Autoantígeno Ku/metabolismo , Estresse Oxidativo , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma/farmacologia , Proteólise , Espécies Reativas de Oxigênio/metabolismo , Ubiquitinas/metabolismo , Ubiquitinas/farmacologia , Xantofilas
19.
Int J Mol Sci ; 23(19)2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36232617

RESUMO

Heart failure (HF) carries the highest mortality in the western world and ß-blockers [ß-adrenergic receptor (AR) antagonists] are part of the cornerstone pharmacotherapy for post-myocardial infarction (MI) chronic HF. Cardiac ß1AR-activated ßarrestin2, a G protein-coupled receptor (GPCR) adapter protein, promotes Sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2a SUMO (small ubiquitin-like modifier)-ylation and activity, thereby directly increasing cardiac contractility. Given that certain ß-blockers, such as carvedilol and metoprolol, can activate ßarrestins and/or SERCA2a in the heart, we investigated the effects of these two agents on cardiac ßarrestin2-dependent SERCA2a SUMOylation and activity. We found that carvedilol, but not metoprolol, acutely induces ßarrestin2 interaction with SERCA2a in H9c2 cardiomyocytes and in neonatal rat ventricular myocytes (NRVMs), resulting in enhanced SERCA2a SUMOylation. However, this translates into enhanced SERCA2a activity only in the presence of the ß2AR-selective inverse agonist ICI 118,551 (ICI), indicating an opposing effect of carvedilol-occupied ß2AR subtype on carvedilol-occupied ß1AR-stimulated, ßarrestin2-dependent SERCA2a activation. In addition, the amplitude of fractional shortening of NRVMs, transfected to overexpress ßarrestin2, is acutely enhanced by carvedilol, again in the presence of ICI only. In contrast, metoprolol was without effect on NRVMs' shortening amplitude irrespective of ICI co-treatment. Importantly, the pro-contractile effect of carvedilol was also observed in human induced pluripotent stem cell (hIPSC)-derived cardiac myocytes (CMs) overexpressing ßarrestin2, and, in fact, it was present even without concomitant ICI treatment of human CMs. Metoprolol with or without concomitant ICI did not affect contractility of human CMs, either. In conclusion, carvedilol, but not metoprolol, stimulates ßarrestin2-mediated SERCA2a SUMOylation and activity through the ß1AR in cardiac myocytes, translating into direct positive inotropy. However, this unique ßarrestin2-dependent pro-contractile effect of carvedilol may be opposed or masked by carvedilol-bound ß2AR subtype signaling.


Assuntos
Insuficiência Cardíaca , Células-Tronco Pluripotentes Induzidas , Adenosina Trifosfatases/metabolismo , Antagonistas Adrenérgicos beta/farmacologia , Animais , Carvedilol/farmacologia , Insuficiência Cardíaca/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Metoprolol/metabolismo , Metoprolol/farmacologia , Metoprolol/uso terapêutico , Miócitos Cardíacos/metabolismo , Ratos , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Ubiquitinas/metabolismo , beta-Arrestina 2/metabolismo
20.
J Neuroinflammation ; 19(1): 243, 2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36195875

RESUMO

BACKGROUND: Moderate physical exercise is conducive to the brains of healthy humans and AD patients. Previous reports have suggested that treadmill exercise plays an anti-AD role and improves cognitive ability by promoting amyloid clearance, inhibiting neuronal apoptosis, reducing oxidative stress level, alleviating brain inflammation, and promoting autophagy-lysosome pathway in AD mice. However, few studies have explored the relationships between the ubiquitin-proteasome system and proper exercise in AD. The current study was intended to investigate the mechanism by which the exercise-regulated E3 ubiquitin ligase improves AD. METHODS: Both wild type and APP/PS1 transgenic mice were divided into sedentary (WTC and ADC) and exercise (WTE and ADE) groups (n = 12 for each group). WTE and ADE mice were subjected to treadmill exercise of 12 weeks in order to assess the effect of treadmill running on learning and memory ability, Aß plaque burden, hyperphosphorylated Tau protein and E3 ubiquitin ligase. RESULTS: The results indicated that exercise restored learning and memory ability, reduced Aß plaque areas, inhibited the hyperphosphorylation of Tau protein activated PI3K/Akt/Hsp70 signaling pathway, and improved the function of the ubiquitin-proteasome system (increased UCHL-1 and CHIP levels, decreased BACE1 levels) in APP/PS1 transgenic mice. CONCLUSIONS: These findings suggest that exercise may promote the E3 ubiquitin ligase to clear ß-amyloid and hyperphosphorylated Tau by activating the PI3K/Akt signaling pathway in the hippocampus of AD mice, which is efficient in ameliorating pathological phenotypes and improving learning and memory ability.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/terapia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases , Cognição , Modelos Animais de Doenças , Hipocampo/metabolismo , Camundongos , Camundongos Transgênicos , Fosfatidilinositol 3-Quinases/metabolismo , Presenilina-1/genética , Presenilina-1/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinas/metabolismo , Ubiquitinas/farmacologia , Proteínas tau/genética , Proteínas tau/metabolismo
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