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1.
Chinese Journal of Biotechnology ; (12): 3915-3932, 2021.
Article in Chinese | WPRIM | ID: wpr-921476

ABSTRACT

Targeted protein degradation (TPD) technology facilitates specific and efficient degradation of disease-related proteins through hijacking the two major protein degradation systems in mammalian cells: ubiquitin-proteasome system and lysosome pathway. Compared with traditional small molecule-inhibitors, TPD-based drugs exhibit the characteristics of a broader target spectrum. Compared with techniques interfere with protein expression on the gene and mRNA level, TPD-based drugs are target-specific, efficaciously rapid, and not constrained by post-translational modification of proteins. In the past 20 years, various TPD-based technologies have been developed. Most excitingly, two TPD-based therapeutic drugs have been approved by FDA for phase Ⅰ clinical trials in 2019. Despite of the early stage characteristics and various obstructions of the TPD technology, it could serve as a powerful tool for the development of novel drugs. This review summarizes the advances of different degradation systems based on TPD technologies and their applications in disease therapy. Moreover, the advantages and challenges of various technologies were discussed systematically, with the aim to provide theoretical guidance for further application of TPD technologies in scientific research and drug development.


Subject(s)
Animals , Proteasome Endopeptidase Complex/metabolism , Protein Processing, Post-Translational , Proteins/metabolism , Proteolysis , Technology
2.
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
3.
Article in English | WPRIM | ID: wpr-826302

ABSTRACT

Methylmercury is an environmental pollutant that causes neurotoxicity. Recent studies have reported that the ubiquitin-proteasome system is involved in defense against methylmercury toxicity through the degradation of proteins synthesizing the pyruvate. Mitochondrial accumulation of pyruvate can enhance methylmercury toxicity. In addition, methylmercury exposure induces several immune-related chemokines, specifically in the brain, and may cause neurotoxicity. This summary highlights several molecular mechanisms of methylmercury-induced neurotoxicity.


Subject(s)
Animals , Chemokines , Metabolism , Humans , Methylmercury Compounds , Toxicity , Mice , Neurotoxins , Toxicity , Proteolysis , Rats , Saccharomyces cerevisiae
4.
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
5.
Laboratory Animal Research ; : 172-179, 2019.
Article in English | WPRIM | ID: wpr-786406

ABSTRACT

Glutamate leads to neuronal cell damage by generating neurotoxicity during brain development. The objective of this study is to identify proteins that differently expressed by glutamate treatment in neonatal cerebral cortex. Sprague-Dawley rat pups (post-natal day 7) were intraperitoneally injected with vehicle or glutamate (10 mg/kg). Brain tissues were isolated 4 h after drug treatment and fixed for morphological study. Moreover, cerebral cortices were collected for protein study. Two-dimensional gel electrophoresis and mass spectrometry were carried out to identify specific proteins. We observed severe histopathological changes in glutamate-exposed cerebral cortex. We identified various proteins that differentially expressed by glutamate exposure. Identified proteins were thioredoxin, peroxiredoxin 5, ubiquitin carboxy-terminal hydrolase L1, proteasome subunit alpha proteins, isocitrate dehydrogenase, and heat shock protein 60. Heat shock protein 60 was increased in glutamate exposed condition. However, other proteins were decreased in glutamate-treated animals. These proteins are related to anti-oxidant, protein degradation, metabolism, signal transduction, and anti-apoptotic function. Thus, our findings can suggest that glutamate leads to neonatal cerebral cortex damage by regulation of specific proteins that mediated with various functions.


Subject(s)
Animals , Brain , Cerebral Cortex , Chaperonin 60 , Electrophoresis, Gel, Two-Dimensional , Glutamic Acid , Humans , Infant, Newborn , Isocitrate Dehydrogenase , Mass Spectrometry , Metabolism , Neurons , Peroxiredoxins , Proteasome Endopeptidase Complex , Proteolysis , Proteomics , Rats , Rats, Sprague-Dawley , Signal Transduction , Thioredoxins , Ubiquitin Thiolesterase
6.
Article in English | WPRIM | ID: wpr-763681

ABSTRACT

BACKGROUND: Protein arginine methyltransferase 1 (PRMT1) is a major enzyme responsible for the formation of methylarginine in mammalian cells. Recent studies have revealed that PRMT1 plays important roles in the development of various tissues. However, its role in pancreas development has not yet been elucidated. METHODS: Pancreatic progenitor cell-specific Prmt1 knock-out (Prmt1 PKO) mice were generated and characterized for their metabolic and histological phenotypes and their levels of Neurog3 gene expression and neurogenin 3 (NGN3) protein expression. Protein degradation assays were performed in mPAC cells. RESULTS: Prmt1 PKO mice showed growth retardation and a severely diabetic phenotype. The pancreatic size and β-cell mass were significantly reduced in Prmt1 PKO mice. Proliferation of progenitor cells during the secondary transition was decreased and endocrine cell differentiation was impaired. These defects in pancreas development could be attributed to the sustained expression of NGN3 in progenitor cells. Protein degradation assays in mPAC cells revealed that PRMT1 was required for the rapid degradation of NGN3. CONCLUSION: PRMT1 critically contributes to pancreas development by destabilizing the NGN3 protein.


Subject(s)
Animals , Diabetes Mellitus , Endocrine Cells , Gene Expression , Islets of Langerhans , Mice , Pancreas , Phenotype , Protein Stability , Protein-Arginine N-Methyltransferases , Proteolysis , Stem Cells
7.
Arq. Inst. Biol ; 86: e1212018, 2019. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1024562

ABSTRACT

In this study, we investigated the contamination of refrigerated raw milk produced in the western region of Paraná, southern Brazil, with psychrotrophic microorganisms, aiming to assay the proteolytic activity of the isolates and to identify Pseudomonas fluorescens, the main proteolytic species associated with the spoilage of milk products. Raw milk samples from 50 dairy farms were submitted to the counting of psychrotrophic microorganisms, being the microbiota characterized by its mesophilic behavior and proteolytic capacity, besides molecular identification of P. fluorescens. Of the samples evaluated, 94% had psychrotrophic counts ranging from 3 to 7.1 log CFU mL-1, and 48.5% of these showed mesophilic behavior. Of the isolates, 48.0% had proteolytic activity in at least one evaluated temperature (21 and 30°C), and 39.3% had proteolytic activity in both temperatures. Among the 61 isolates submitted to molecular identification by polymerase chain reaction (PCR), 86.8% contained the expression of the 16S gene characteristic for P. fluorescens. In this study, we demonstrated that P. fluorescens is the most prevalent psychrotrophic bacteria species in raw refrigerated milk and their proteolytic ability poses high risks to the dairy industry.(AU)


No presente estudo, investigamos a contaminação do leite cru refrigerado produzido na região oeste do Paraná, sul do Brasil, com micro-organismos psicrotróficos, visando testar a atividade proteolítica dos isolados e identificar Pseudomonas fluorescens, a principal espécie proteolítica associada à deterioração de produtos lácteos. Amostras de leite cru de 50 fazendas leiteiras foram submetidas à contagem de micro-organismos psicrotróficos, caracterizando-se a microbiota por seu comportamento mesofílico e sua capacidade proteolítica, além de identificação molecular de P. fluorescens. Entre as amostras avaliadas, 94% apresentaram contagem psicrotrófica variando de 3 a 7,1 log UFC mL-1 e 48,5% destas apresentaram comportamento mesofílico. Entre os isolados, 48,0% apresentaram atividade proteolítica em pelo menos uma das temperaturas testadas (21 e 30°C) e 39,3% apresentaram atividade proteolítica em ambas as temperaturas. Entre os 61 isolados sub-metidos à identificação molecular por reação em cadeia da polimerase (PCR), 86,8% continham expressão do gene 16S característico de P. fluorescens. Neste estudo, demonstramos que P. fluorescens é a espécie de bactérias psicrotróficas mais prevalente em leite refrigerado cru e sua capacidade proteolítica promove elevados riscos de deterioração para a indústria de laticínios.(AU)


Subject(s)
Pseudomonas fluorescens , Milk , Proteolysis , Bacteria , Food Contamination , Polymerase Chain Reaction , Cooled Foods
8.
Article in English | WPRIM | ID: wpr-763401

ABSTRACT

Sarcopenia (loss of muscle mass and/or strength) frequently complicates liver cirrhosis and adversely affects the quality of life; cirrhosis related liver decompensation and significantly decreases wait-list and post-liver transplantation survival. The main therapeutic strategies to improve or reverse sarcopenia include dietary interventions (supplemental calorie and protein intake), increased physical activity (supervised resistance and endurance exercises), hormonal therapy (testosterone), and ammonia lowering agents (L-ornithine L-aspartate, branch chain amino acids) as well as mechanistic approaches that target underlying molecular and metabolic abnormalities. Besides other factors, hyperammonemia has recently gained attention and increase sarcopenia by various mechanisms including increased expression of myostatin, increased phosphorylation of eukaryotic initiation factor 2a, cataplerosis of α ketoglutarate, mitochondrial dysfunction, increased reactive oxygen species that decrease protein synthesis and increased autophagy-mediated proteolysis. Sarcopenia contributes to frailty and increases the risk of minimal and overt hepatic encephalopathy.


Subject(s)
Ammonia , Aspartic Acid , Fibrosis , Hepatic Encephalopathy , Hyperammonemia , Liver , Liver Cirrhosis , Metabolism , Motor Activity , Myostatin , Peptide Initiation Factors , Phosphorylation , Proteolysis , Quality of Life , Reactive Oxygen Species , Sarcopenia , Testosterone
9.
Article in Chinese | WPRIM | ID: wpr-772087

ABSTRACT

OBJECTIVE@#To explore whether bortezomib and a Bcl-2 inhibitor exhibit synergistic anti-tumor effect in human acute T lymphoblastic leukemia cells.@*METHODS@#MTT assay was used to determine the cytotoxicity of bortezomib in the absence or presence of Bcl-2 inhibitors (obatoclax, AT-101 and ABT-199) in Jurkat cells. The effects of drug treatment on the expression of Bcl-2 family proteins, LC3B, p62, ubiquitin, BiP/Grp78, p-JNK, p-p38 and CHOP proteins were examined by Western blotting. Flow cytometry was used to determine the effects of bortezomib and Bcl-2 inhibitors (obatoclax, AT-101 and ABT-199) on cell apoptosis. Quantitative real-time PCR was used to measure the mRNA expression levels of the key regulatory factors of unfolded protein reaction (UPR). A zebrafish xenograft model was used to study the anti-tumor effect of bortezomib, obatoclax and their combination in vivo.@*RESULTS@#Bortezomib or Bcl-2 inhibitors alone inhibited the cell viability of Jurkat cells, but only obatoclax and bortezomib showed synergistic cytotoxicity and pro-apoptotic effect. Obatoclax, rather than AT-101 and ABT- 199, blocked autophagic flux in the cells evidenced by concomitant accumulation of LC3B-Ⅱ and p62. Both bortezomib and obatoclax alone caused accumulation of polyubiquinated proteins, and their combination showed a synergistic effect, which was consistent with their synergistic cytotoxicity. The dual blockade of proteasome and autophagy by the combination of bortezomib and obatoclax triggered unfolded protein response followed by cell apoptosis. Preventing UPS dysfunction by tauroursodeoxycholic acid (TUDCA) significantly attenuated the cytotoxicity and pro-apoptotic effect of bortezomib in combination with obatoclax. In zebrafish xenograft models, bortezomib combined with obatoclax significantly decreased tumor foci formation.@*CONCLUSIONS@#Bortezomib and obatoclax for dual blockade of protein degradation pathways show synergistic anti-tumor effect in human acute T lymphoblastic leukemia cells.


Subject(s)
Antineoplastic Agents , Apoptosis , Bortezomib , Cell Line, Tumor , Drug Synergism , Humans , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Proteolysis , Proto-Oncogene Proteins c-bcl-2 , Pyrroles
10.
Article in English | WPRIM | ID: wpr-771633

ABSTRACT

The clinical treatment of joint contracture due to immobilization remains difficult. The pathological changes of muscle tissue caused by immobilization-induced joint contracture include disuse skeletal muscle atrophy and skeletal muscle tissue fibrosis. The proteolytic pathways involved in disuse muscle atrophy include the ubiquitin-proteasome-dependent pathway, caspase system pathway, matrix metalloproteinase pathway, Ca-dependent pathway and autophagy-lysosomal pathway. The important biological processes involved in skeletal muscle fibrosis include intermuscular connective tissue thickening caused by transforming growth factor-β1 and an anaerobic environment within the skeletal muscle leading to the induction of hypoxia-inducible factor-1α. This article reviews the progress made in understanding the pathological processes involved in immobilization-induced muscle contracture and the currently available treatments. Understanding the mechanisms involved in immobilization-induced contracture of muscle tissue should facilitate the development of more effective treatment measures for the different mechanisms in the future.


Subject(s)
Atrophy , Autophagy , Calcium , Metabolism , Caspases , Metabolism , Connective Tissue , Metabolism , Pathology , Contracture , Metabolism , Pathology , Therapeutics , Fibrosis , Humans , Immobilization , Joints , Lysosomes , Metabolism , Matrix Metalloproteinases , Metabolism , Muscle, Skeletal , Metabolism , Pathology , Proteasome Endopeptidase Complex , Metabolism , Proteolysis , Signal Transduction , Physiology , Transforming Growth Factor beta1 , Metabolism , Ubiquitin , Metabolism
11.
Article in English | WPRIM | ID: wpr-786670

ABSTRACT

BACKGROUND: Trichloroacetic acid (TCA) is an agent widely applied in dermatology for skin regeneration. To test whether TCA can offer an advantage for the regeneration of oral soft tissue defects, the cellular events following TCA application were explored in vitro and its influence on the oral soft tissue wound healing was evaluated in a canine palate model.METHODS: The cytotoxicity and growth factor gene expression in human gingival fibroblasts were tested in vitro following the application of TCA at four concentrations (0.005%, 0.05%, 0.5% and 1%) with different time intervals (0, 3, 9 and 21 h). One concentration of TCA was selected to screen the genes differentially expressed using DNA microarray and the associated pathways were explored. TCA was injected in open wound defects of the palatal mucosa from beagle dogs (n = 3) to monitor their healing and regeneration up to day 16-post-administration.RESULTS: While the 0.5–1% concentration induced the cytoxicity, a significantly higher expression of growth factor genes was observed after 3 and 9 h following the 0.5% TCA application in comparison to other groups. DNA microarray analysis in 0.5% TCA group showed 417 genes with a significant 1.5-fold differential expression, involving pathways of cell cycle, FoxO signaling, p53 signaling, ubiquitin mediated proteolysis and cAMP signaling. In vivo results showed a faster reepithelialization of TCA-treated wounds as compared to spontaneous healingCONCLUSION: TCA promoted the healing and regeneration of oral soft tissue wound defects by up-regulating the cell cycle progression, cell growth, and cell viability, particularly at a concentration of 0.5%.


Subject(s)
Animals , Cell Cycle , Cell Survival , Dermatology , Dogs , Fibroblasts , Gene Expression , Humans , In Vitro Techniques , Mouth Mucosa , Mucous Membrane , Oligonucleotide Array Sequence Analysis , Palate , Proteolysis , Regeneration , Skin , Trichloroacetic Acid , Ubiquitin , Up-Regulation , Wound Healing , Wounds and Injuries
12.
Arq. bras. med. vet. zootec. (Online) ; 70(1): 247-253, Jan.-Feb. 2018. tab, graf
Article in Portuguese | LILACS, VETINDEX | ID: biblio-888089

ABSTRACT

Este trabalho se propôs a desenvolver um modelo preditivo para identificação de perda de estabilidade e de sedimentação em leite UAT por determinação da atividade enzimática de aminopeptidase no leite por espectrofotometria. Foram analisadas amostras de leite cru, pasteurizado e UAT após envase durante seis meses, na região Sul do Brasil. Acidez, crioscopia, gordura, extrato seco total, extrato seco desengordurado e densidade foram analisados nos leites cru e pasteurizado. Amostras de leite cru foram ainda submetidas à análise de contagem de psicrotróficos e à atividade de aminopeptidase, e amostras de leite UAT estocadas foram analisadas quanto ao grau de proteólise mediante análises sensoriais e atividade de aminopeptidase. Alterações sensoriais foram observadas em tempos de estocagem menores para amostras originadas de leite cru com contagem de psicrotróficos acima de 107 UFC mL-1. Não houve correlação entre a atividade de aminopeptidase e proteólise e também não foi observada correlação significativa entre os parâmetros físico-químicos e a ocorrência de proteólise no leite estocado. O modelo estudado não foi apto para predizer perda de estabilidade e ocorrência de proteólise no leite UAT.(AU)


The aim of this work was to develop a predictive model for identifying loss of stability and sedimentation in UHT milk by determining the enzymatic activity of aminopeptidasis in milk by spectrophotometry. Samples of raw milk, pasteurized and UHT after filling for 6 months in Southern Brazil were analyzed. Acidity, freezing point, fat, total solids, nonfat solids and density were analyzed in raw and pasteurized milk. Raw milk samples were also subjected to psychrotrophic count analysis and aminopeptidasis activity and UAT samples of stored milk were analyzed for degree of proteolysis through sensory analysis and aminopeptidasis activity. Sensory changes were observed in smaller storage time for samples of raw milk originated with psychrotrophic count above 107 CFU ml-1. There was no correlation between aminopeptidasis activity and proteolysis and there was also no significant correlation between physicochemical parameters and the occurrence of proteolysis in stored milk. The model was unable to predict loss of stability and occurrence of proteolysis in UHT milk.(AU)


Subject(s)
Animals , Female , Cattle , Milk/enzymology , Proteolysis , Aminopeptidases/analysis , Spectrophotometry , Cattle
13.
Journal of Experimental Hematology ; (6): 1240-1243, 2018.
Article in Chinese | WPRIM | ID: wpr-689498

ABSTRACT

Cereblon(CRBN) is a brain-associated protein with ionic protease activity, which interacts with DNA damage-binding protein-1 (DDB1), Cullin 4 (Cul4A or Cul4B), and regulator of Cullins 1 (RoC1) to form the functional E3 ubiquitin ligase complex(CRBN-CRL4) that performs proteolysis via the ubiquitin-proteasome pathway. And CRBN is a necessary target protein for the anti-myeloma effect of immunomodulators. The combination of lenalidomide and CRBN recruited a new substrate that binds to the CRBN-CRL4 complex, leading to increased ubiquitination and proteasome-dependent degradation, thus resulting in anti-myeloma activity. The substrates binding to this complex are IKZF1, IKZF3 proteins and GS, etc. The CRBN-dependent degradation of IKZF1 and IKZF3 after lenalidomide treatment is also the result of HO-mediated oxidative stress. In addition to ubiquitination, lenalidomide also mediates ubiquitin-independent pathways that prevent CRBN from binding to CD147-MCT1 in a competitive manner to regulate its antitumor activity. Lenalidomide can also play a role in multiple myeloma(MM) cells by modulating miRNA levels and CRBN binding to downstream protein AGO2 expression. Thus, there are many molecular mechanisms of lenalidomide anti-myeloma activity. This review summarizes the molecular mechanisms of CRBN in lenalidomide against myeloma activity in terms of ubiquitin-dependent and ubiquitin-independent pathways.


Subject(s)
Cullin Proteins , Humans , Hydrogen Peroxide , Multiple Myeloma , Peptide Hydrolases , Proteolysis , Thalidomide , Ubiquitination
14.
Protein & Cell ; (12): 879-889, 2018.
Article in English | WPRIM | ID: wpr-757990

ABSTRACT

Wnt signaling has emerged as a major regulator of tissue development by governing the self-renewal and maintenance of stem cells in most tissue types. As a key upstream regulator of the Wnt pathway, the transmembrane E3 ligase ZNRF3 has recently been established to play a role in negative regulation of Wnt signaling by targeting Frizzled (FZD) receptor for ubiquitination and degradation. However, the upstream regulation of ZNRF3, in particular the turnover of ZNRF3, is still unclear. Here we report that ZNRF3 is accumulated in the presence of proteasome inhibitor treatment independent of its E3-ubiquitin ligase activity. Furthermore, the Cullin 1-specific SCF complex containing β-TRCP has been identified to directly interact with and ubiquitinate ZNRF3 thereby regulating its protein stability. Similar with the degradation of β-catenin by β-TRCP, ZNRF3 is ubiquitinated by β-TRCP in both CKI-phosphorylation- and degron-dependent manners. Thus, our findings not only identify a novel substrate for β-TRCP oncogenic regulation, but also highlight the dual regulation of Wnt signaling by β-TRCP in a context-dependent manner where β-TRCP negatively regulates Wnt signaling by targeting β-catenin, and positively regulates Wnt signaling by targeting ZNRF3.


Subject(s)
Cells, Cultured , Humans , Proteolysis , Ubiquitin-Protein Ligases , Metabolism , Ubiquitination , beta-Transducin Repeat-Containing Proteins , Metabolism
15.
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
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.
Electron. j. biotechnol ; 29: 7-12, sept. 2017. ilus, graf, tab
Article in English | LILACS | ID: biblio-1016095

ABSTRACT

Background: DegP is a serine protease that specifically cleaves and refolds unfolding proteins in the periplasmic space of the cells. To date, there is no information regarding DegP from halophilic bacteria. Chromohalobacter salexigens BKL5 is a moderately halophilic bacterium that has the ability to grow in a media containing more than 15% salt. Therefore, the objectives of this work were to clone and overexpress DegP-encoding gene from C. salexigens BKL5 and characterize its biochemical properties. Results: DegP-encoding gene was overexpressed in Escherichia coli BL21(DE3) CodonPlus in an active form. SDS-PAGE analysis showed that the molecular weight of the recombinant DegP was 45 kDa. Size-exclusion chromatography analysis suggested that recombinant DegP was present in two multimeric states, hexameric and dodecameric, with molecular weights of 297.9 and 579.12 kDa, respectively. Both conformations were enzymatically active when casein was used as substrate for enzymatic assay. Circular dichroism analysis showed that recombinant DegP was composed of 0.21­0.29 helical content, which was comparable to the helical content in the crystal structure of E. coli DegP. The basic/acidic residue ratio of recombinant DegP was 0.56, which was slightly higher than that of DegP from extreme halophiles (average, 0.45) but significantly lower than that of DegP from nonhalophiles (average, 0.94). Conclusions: Recombinant DegP from C. salexigens BKL5 showed proteolytic activity when ß-casein was used as a substrate. In silico analysis indicated that recombinant DegP had characteristics similar to those of halophilic proteins depending on its amino acid composition.


Subject(s)
Serine Endopeptidases/genetics , Periplasmic Proteins/genetics , Chromohalobacter/enzymology , Proteolysis , Heat-Shock Proteins/genetics , Recombinant Proteins , Serine Endopeptidases/metabolism , Caseins , Chromatography, Gel , Circular Dichroism , Cloning, Molecular , Periplasmic Proteins/metabolism , Electrophoresis, Polyacrylamide Gel , Escherichia coli , Salinity , Chromohalobacter/genetics , Heat-Shock Proteins/metabolism , Molecular Weight
18.
Braz. j. microbiol ; 48(1): 13-24, Jan.-Mar. 2017. tab, graf
Article in English | LILACS | ID: biblio-839339

ABSTRACT

Abstract Specific proteases capable of degrading native triple helical or denatured collagen have been required for many years and have a large spectrum of applications. There are few complete reports that fully uncover production, characterization and purification of fungi collagenases. In this review, authors searched through four scientific on line data bases using the following keywords (collagenolytic OR collagenase) AND (fungi OR fungus OR fungal) AND (production OR synthesis OR synthesize) AND (characterization). Scientific criteria were adopted in this review to classify found articles by score (from 0 to 10). After exclusion criteria, 21 articles were selected. None obtained the maximum of 10 points defined by the methodology, which indicates a deficiency in studies dealing simultaneously with production, characterization and purification of collagenase by fungi. Among microorganisms studied the non-pathogenic fungi Penicillium aurantiogriseum and Rhizoctonia solani stood out in volumetric and specific collagenase activity. The only article found that made sequencing of a true collagenase showed 100% homology with several metalloproteinases fungi. A clear gap in literature about collagenase production by fungi was verified, which prevents further development in the area and increases the need for further studies, particularly full characterization of fungal collagenases with high specificity to collagen.


Subject(s)
Collagen/metabolism , Collagenases/metabolism , Fungi/metabolism , Substrate Specificity , Collagen/chemistry , Collagenases/isolation & purification , Collagenases/biosynthesis , Collagenases/chemistry , Culture Media , Enzyme Activation , Proteolysis , Fungi/classification
19.
Braz. j. med. biol. res ; 50(12): e6733, 2017. graf
Article in English | LILACS | ID: biblio-888967

ABSTRACT

Myostatin is a novel negative regulator of skeletal muscle mass. Myostatin expression is also found in heart in a much less extent, but it can be upregulated in pathological conditions, such as heart failure. Myostatin may be involved in inhibiting protein synthesis and/or increasing protein degradation in skeletal and cardiac muscles. Herein, we used cell cultures and isolated muscles from rats to determine protein degradation and synthesis. Muscles incubated with myostatin exhibited an increase in proteolysis with an increase of Atrogin-1, MuRF1 and LC3 genes. Extensor digitorum longus muscles and C2C12 myotubes exhibited a reduction in protein turnover. Cardiomyocytes showed an increase in proteolysis by activating autophagy and the ubiquitin proteasome system, and a decrease in protein synthesis by decreasing P70S6K. The effect of myostatin on protein metabolism is related to fiber type composition, which may be associated to the extent of atrophy mediated effect of myostatin on muscle.


Subject(s)
Animals , Male , Muscle Fibers, Skeletal/drug effects , Muscle Fibers, Skeletal/metabolism , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Myostatin/pharmacology , Muscle Proteins/drug effects , Muscle Proteins/metabolism , Phosphorylation/drug effects , Phosphorylation/physiology , Time Factors , Tyrosine/drug effects , Tyrosine/metabolism , Gene Expression , Cells, Cultured , Blotting, Western , Reproducibility of Results , Rats, Wistar , Real-Time Polymerase Chain Reaction , Proteolysis/drug effects
20.
Article in English | WPRIM | ID: wpr-111254

ABSTRACT

BACKGROUND: The ubiquitin-proteasome system (UPS) is an important pathway of proteolysis in pathologic hypertrophic cardiomyocytes. We hypothesize that MG132, a proteasome inhibitor, might prevent hypertrophic cardiomyopathy (CMP) by blocking the UPS. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and androgen receptor (AR) have been reported to be mediators of CMP and heart failure. This study drew upon pathophysiologic studies and the analysis of NF-κB and AR to assess the cardioprotective effects of MG132 in a left ventricular hypertrophy (LVH) rat model. METHODS: We constructed a transverse aortic constriction (TAC)-induced LVH rat model with 3 groups: sham (TAC-sham, n=10), control (TAC-cont, n=10), and MG132 administration (TAC-MG132, n=10). MG-132 (0.1 mg/kg) was injected for 4 weeks in the TAC-MG132 group. Pathophysiologic evaluations were performed and the expression of AR and NF-κB was measured in the left ventricle. RESULTS: Fibrosis was prevalent in the pathologic examination of the TAC-cont model, and it was reduced in the TAC-MG132 group, although not significantly. Less expression of AR, but not NF-κB, was found in the TAC-MG132 group than in the TAC-cont group (p<0.05). CONCLUSION: MG-132 was found to suppress AR in the TAC-CMP model by blocking the UPS, which reduced fibrosis. However, NF-κB expression levels were not related to UPS function.


Subject(s)
Animals , Animals , B-Lymphocytes , Cardiomyopathy, Hypertrophic , Constriction , Fibrosis , Heart Failure , Heart Ventricles , Hypertrophy , Hypertrophy, Left Ventricular , Models, Animal , Myocytes, Cardiac , NF-kappa B , Proteasome Endopeptidase Complex , Proteasome Inhibitors , Proteolysis , Rats , Receptors, Androgen , Ubiquitins
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