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1.
Chinese Journal of Biotechnology ; (12): 561-579, 2021.
Article in Chinese | WPRIM | ID: wpr-878582

ABSTRACT

Proteases are widely found in organisms participating in the decomposition of proteins to maintain the organisms' normal life activities. Protease inhibitors regulate the activities of target proteases by binding to their active sites, thereby affecting protein metabolism. The key amino acid mutations in proteases and protease inhibitors can affect their physiological functions, stability, catalytic activity, and inhibition specificity. More active, stable, specific, environmentally friendly and cheap proteases and protease inhibitors might be obtained by excavating various natural mutants of proteases and protease inhibitors, analyzing their key active sites by using protein engineering methods. Here, we review the studies on proteases' key active sites and protease inhibitors to deepen the understanding of the active mechanism of proteases and their inhibitors.


Subject(s)
Binding Sites , Catalytic Domain , Endopeptidases , Peptide Hydrolases/genetics , Protease Inhibitors , Proteins
2.
Article in English | WPRIM | ID: wpr-785397

ABSTRACT

BACKGROUND: Pathogenic variants of USH1C, encoding a PDZ-domain-containing protein called harmonin, have been known to cause autosomal recessive syndromic or nonsyndromic hearing loss (NSHL). We identified a causative gene in a large Korean family with NSHL showing a typical pattern of autosomal dominant (AD) inheritance.METHODS: Exome sequencing was performed for five affected and three unaffected individuals in this family. Following identification of a candidate gene variant, segregation analysis and functional studies, including circular dichroism and biolayer interferometry experiments, were performed.RESULTS: A novel USH1C heterozygous missense variant (c.667G>T;p.Gly223Cys) was shown to segregate with the NSHL phenotype in this family. This variant affects an amino acid residue located in the highly conserved carboxylate-binding loop of the harmonin PDZ2 domain and is predicted to disturb the interaction with cadherin-related 23 (cdh23). The affinity of the variant PDZ2 domain for a biotinylated synthetic peptide containing the PDZ-binding motif of cdh23 was approximately 16-fold lower than that of the wild-type PDZ2 domain and that this inaccessibility of the binding site was caused by a conformational change in the variant PDZ2 domain.CONCLUSIONS: A heterozygous variant of USH1C that interferes with the interaction between cdh23 and harmonin causes novel AD-NSHL.


Subject(s)
Binding Sites , Circular Dichroism , Exome , Hearing Loss , Hearing , Humans , Interferometry , Phenotype , Wills
3.
Protein & Cell ; (12): 723-739, 2020.
Article in English | WPRIM | ID: wpr-828747

ABSTRACT

Emerging and re-emerging RNA viruses occasionally cause epidemics and pandemics worldwide, such as the on-going outbreak of the novel coronavirus SARS-CoV-2. Herein, we identified two potent inhibitors of human DHODH, S312 and S416, with favorable drug-likeness and pharmacokinetic profiles, which all showed broad-spectrum antiviral effects against various RNA viruses, including influenza A virus, Zika virus, Ebola virus, and particularly against SARS-CoV-2. Notably, S416 is reported to be the most potent inhibitor so far with an EC of 17 nmol/L and an SI value of 10,505.88 in infected cells. Our results are the first to validate that DHODH is an attractive host target through high antiviral efficacy in vivo and low virus replication in DHODH knock-out cells. This work demonstrates that both S312/S416 and old drugs (Leflunomide/Teriflunomide) with dual actions of antiviral and immuno-regulation may have clinical potentials to cure SARS-CoV-2 or other RNA viruses circulating worldwide, no matter such viruses are mutated or not.


Subject(s)
Animals , Antiviral Agents , Pharmacology , Therapeutic Uses , Betacoronavirus , Physiology , Binding Sites , Cell Line , Coronavirus Infections , Drug Therapy , Virology , Crotonates , Pharmacology , Cytokine Release Syndrome , Drug Therapy , Drug Evaluation, Preclinical , Gene Knockout Techniques , Humans , Influenza A virus , Leflunomide , Pharmacology , Mice , Mice, Inbred BALB C , Orthomyxoviridae Infections , Drug Therapy , Oseltamivir , Therapeutic Uses , Oxidoreductases , Metabolism , Pandemics , Pneumonia, Viral , Drug Therapy , Virology , Protein Binding , Pyrimidines , RNA Viruses , Physiology , Structure-Activity Relationship , Toluidines , Pharmacology , Ubiquinone , Metabolism , Virus Replication
4.
Protein & Cell ; (12): 723-739, 2020.
Article in English | WPRIM | ID: wpr-828583

ABSTRACT

Emerging and re-emerging RNA viruses occasionally cause epidemics and pandemics worldwide, such as the on-going outbreak of the novel coronavirus SARS-CoV-2. Herein, we identified two potent inhibitors of human DHODH, S312 and S416, with favorable drug-likeness and pharmacokinetic profiles, which all showed broad-spectrum antiviral effects against various RNA viruses, including influenza A virus, Zika virus, Ebola virus, and particularly against SARS-CoV-2. Notably, S416 is reported to be the most potent inhibitor so far with an EC of 17 nmol/L and an SI value of 10,505.88 in infected cells. Our results are the first to validate that DHODH is an attractive host target through high antiviral efficacy in vivo and low virus replication in DHODH knock-out cells. This work demonstrates that both S312/S416 and old drugs (Leflunomide/Teriflunomide) with dual actions of antiviral and immuno-regulation may have clinical potentials to cure SARS-CoV-2 or other RNA viruses circulating worldwide, no matter such viruses are mutated or not.


Subject(s)
Animals , Antiviral Agents , Pharmacology , Therapeutic Uses , Betacoronavirus , Physiology , Binding Sites , Cell Line , Coronavirus Infections , Drug Therapy , Virology , Crotonates , Pharmacology , Cytokine Release Syndrome , Drug Therapy , Drug Evaluation, Preclinical , Gene Knockout Techniques , Humans , Influenza A virus , Leflunomide , Pharmacology , Mice , Mice, Inbred BALB C , Orthomyxoviridae Infections , Drug Therapy , Oseltamivir , Therapeutic Uses , Oxidoreductases , Metabolism , Pandemics , Pneumonia, Viral , Drug Therapy , Virology , Protein Binding , Pyrimidines , RNA Viruses , Physiology , Structure-Activity Relationship , Toluidines , Pharmacology , Ubiquinone , Metabolism , Virus Replication
5.
Protein & Cell ; (12): 723-739, 2020.
Article in English | WPRIM | ID: wpr-827018

ABSTRACT

Emerging and re-emerging RNA viruses occasionally cause epidemics and pandemics worldwide, such as the on-going outbreak of the novel coronavirus SARS-CoV-2. Herein, we identified two potent inhibitors of human DHODH, S312 and S416, with favorable drug-likeness and pharmacokinetic profiles, which all showed broad-spectrum antiviral effects against various RNA viruses, including influenza A virus, Zika virus, Ebola virus, and particularly against SARS-CoV-2. Notably, S416 is reported to be the most potent inhibitor so far with an EC of 17 nmol/L and an SI value of 10,505.88 in infected cells. Our results are the first to validate that DHODH is an attractive host target through high antiviral efficacy in vivo and low virus replication in DHODH knock-out cells. This work demonstrates that both S312/S416 and old drugs (Leflunomide/Teriflunomide) with dual actions of antiviral and immuno-regulation may have clinical potentials to cure SARS-CoV-2 or other RNA viruses circulating worldwide, no matter such viruses are mutated or not.


Subject(s)
Animals , Antiviral Agents , Pharmacology , Therapeutic Uses , Betacoronavirus , Physiology , Binding Sites , Cell Line , Coronavirus Infections , Drug Therapy , Virology , Crotonates , Pharmacology , Cytokine Release Syndrome , Drug Therapy , Drug Evaluation, Preclinical , Gene Knockout Techniques , Humans , Influenza A virus , Leflunomide , Pharmacology , Mice , Mice, Inbred BALB C , Orthomyxoviridae Infections , Drug Therapy , Oseltamivir , Therapeutic Uses , Oxidoreductases , Metabolism , Pandemics , Pneumonia, Viral , Drug Therapy , Virology , Protein Binding , Pyrimidines , RNA Viruses , Physiology , Structure-Activity Relationship , Toluidines , Pharmacology , Ubiquinone , Metabolism , Virus Replication
6.
Article in English | WPRIM | ID: wpr-787134

ABSTRACT

Transient receptor potential canonical 4 (TRPC4) channel is a nonselective calcium-permeable cation channels. In intestinal smooth muscle cells, TRPC4 currents contribute more than 80% to muscarinic cationic current (mIcat). With its inward-rectifying current-voltage relationship and high calcium permeability, TRPC4 channels permit calcium influx once the channel is opened by muscarinic receptor stimulation. Polyamines are known to inhibit nonselective cation channels that mediate the generation of mIcat. Moreover, it is reported that TRPC4 channels are blocked by the intracellular spermine through electrostatic interaction with glutamate residues (E728, E729). Here, we investigated the correlation between the magnitude of channel inactivation by spermine and the magnitude of channel conductance. We also found additional spermine binding sites in TRPC4. We evaluated channel activity with electrophysiological recordings and revalidated structural significance based on Cryo-EM structure, which was resolved recently. We found that there is no correlation between magnitude of inhibitory action of spermine and magnitude of maximum current of the channel. In intracellular region, TRPC4 attracts spermine at channel periphery by reducing access resistance, and acidic residues contribute to blocking action of intracellular spermine; channel periphery, E649; cytosolic space, D629, D649, and E687.


Subject(s)
Amino Acids , Binding Sites , Calcium , Cytosol , Glutamic Acid , Myocytes, Smooth Muscle , Permeability , Polyamines , Receptors, Muscarinic , Spermine , Transient Receptor Potential Channels
7.
Article in English | WPRIM | ID: wpr-763794

ABSTRACT

In previous studies, we demonstrated that some sites in the first intron likely regulate gene expression. In the present work, we sought to further confirm the functional relevance of first intron sites by estimating the quantity of rare alleles in the first intron. A basic hypothesis posited herein is that genomic regions carrying more functionally important sites will have a higher proportion of rare alleles. We estimated the proportions of rare single nucleotide polymorphisms with a minor allele frequency < 0.01 located in several histone marks in the first introns of various genes, and compared them with those in other introns and those in 2-kb upstream regions. As expected, rare alleles were found to be significantly enriched in most of the regulatory sites located in the first introns. Meanwhile, transcription factor binding sites were significantly more enriched in the 2-kb upstream regions (i.e., the regions of putative promoters of genes) than in the first introns. These results strongly support our proposal that the first intron sites of genes may have important regulatory functions in gene expression independent of promoters.


Subject(s)
Alleles , Binding Sites , Chromatin , Epigenomics , Gene Expression , Gene Frequency , Histone Code , Introns , Polymorphism, Single Nucleotide , Transcription Factors
8.
Article in Chinese | WPRIM | ID: wpr-773226

ABSTRACT

Small molecules with physiological or pharmacological activities need to interact with biological macromolecules in order to function in the body. As the protein with the highest proportion of plasma protein,serum albumin is the main protein binding to various endogenous or exogenous small molecules. Serum albumin interacts with small molecules in a reversible non-covalent manner and transports small molecules to target sites. Bovine serum albumin( BSA) is an ideal target protein for drug research because of its low cost and high homology with human serum albumin. The research on the interaction between drugs and BSA has become a hotspot in the fields of pharmacy,medicine,biology and chemistry. In this research,molecular docking method was used to study the interaction between three small ginsenosides with high pharmacological value( Rg_1,Rb_1,Ro) and bovine serum albumin( BSA),and the binding mode information of three ginsenosides interacting with BSA was obtained. The results of molecular docking showed that ginsenosides and amino acid residues in the active pocket of proteins could be combined by hydrophobic action,hydrogen bonding and electrostatic action. The interaction between small ginsenosides and bovine serum albumin is not the only form,and their interaction has many forms of force. The interaction between these molecules and various weak forces is the key factor for the stability of the complex. The results of this study can provide the structural information of computer simulation for the determination of the interaction patterns between active components and proteins of ginseng.


Subject(s)
Animals , Binding Sites , Cattle , Computer Simulation , Ginsenosides , Chemistry , Molecular Docking Simulation , Protein Binding , Serum Albumin, Bovine , Chemistry , Spectrometry, Fluorescence , Thermodynamics
9.
Article in English | WPRIM | ID: wpr-761782

ABSTRACT

Polycystic kidney disease 2-like-1 (PKD2L1), polycystin-L or transient receptor potential polycystin 3 (TRPP3) is a TRP superfamily member. It is a calcium-permeable non-selective cation channel that regulates intracellular calcium concentration and thereby calcium signaling. Although the calmodulin (CaM) inhibitor, calmidazolium, is an activator of the PKD2L1 channel, the activating mechanism remains unclear. The purpose of this study is to clarify whether CaM takes part in the regulation of the PKD2L1 channel, and if so, how. With patch clamp techniques, we observed the current amplitudes of PKD2L1 significantly reduced when coexpressed with CaM and CaMΔN. This result suggests that the N-lobe of CaM carries a more crucial role in regulating PKD2L1 and guides us into our next question on the different functions of two lobes of CaM. We also identified the predicted CaM binding site, and generated deletion and truncation mutants. The mutants showed significant reduction in currents losing PKD2L1 current-voltage curve, suggesting that the C-terminal region from 590 to 600 is crucial for maintaining the functionality of the PKD2L1 channel. With PKD2L1608Stop mutant showing increased current amplitudes, we further examined the functional importance of EF-hand domain. Along with co-expression of CaM, ΔEF-hand mutant also showed significant changes in current amplitudes and potentiation time. Our findings suggest that there is a constitutive inhibition of EF-hand and binding of CaM C-lobe on the channel in low calcium concentration. At higher calcium concentration, calcium ions occupy the N-lobe as well as the EF-hand domain, allowing the two to compete to bind to the channel.


Subject(s)
Binding Sites , Calcium , Calcium Signaling , Calmodulin , Ion Channels , Ions , Patch-Clamp Techniques , Polycystic Kidney Diseases , Transient Receptor Potential Channels
10.
Yonsei Medical Journal ; : 381-388, 2019.
Article in English | WPRIM | ID: wpr-742544

ABSTRACT

PURPOSE: Osteoarthritis (OA) is a commonly occurring illness without a definitive cure, at present. Long non-coding RNAs (lncRNAs) have been widely confirmed to be involved in the modulation of OA progression. This study aimed to investigate the role and mechanism of lncRNA H19 in OA. MATERIALS AND METHODS: Abundances of H19 and microRNA-130a (miR-130a) in lipopolysaccharide (LPS)-treated C28/I2 cells were measured by reverse-transcription quantitative PCR (RT-qPCR). CCK-8 and flow cytometry analyses were carried out to assess cell viability and apoptosis. Starbase online software was used to predict the putative binding sites between H19 and miR-130a. Luciferase reporter, RNA pull down, and RT-qPCR were performed to analyze the true interaction between H19 and miR-130a. RESULTS: A notably dose-dependent elevation of H19 levels was observed in LPS-treated C28/I2 cells. Knockdown of H19 ameliorated the injury of LPS-induced C28/I2 cells, reflected by induced viability, decreased apoptosis, and reduced inflammatory factor secretions. Moreover, H19 negatively regulated the expression of miR-130a via acting as a molecular sponge for miR-130a. The stimulatory effects of H19 on cell damage were abolished following the restoration of miR-130a. CONCLUSION: LncRNA H19 aggravated the injury of LPS-induced C28/I2 cells by sponging miR-130a, hinting a novel regulatory mechanism and a potential therapeutic target for OA.


Subject(s)
Apoptosis , Binding Sites , Cell Survival , Flow Cytometry , Luciferases , Osteoarthritis , Polymerase Chain Reaction , Porifera , RNA , RNA, Long Noncoding , Sincalide
11.
Article in Korean | WPRIM | ID: wpr-719667

ABSTRACT

BACKGROUND: Since free light chain (FLC) is metabolized in the kidney, serum FLC concentration and kappa/lambda ratio are increased in patients with decreased renal function, even in the absence of monoclonal protein. In this study, we measured serum FLC levels to investigate the change in kappa/lambda ratios in relation to the severity of renal dysfunction. METHODS: Serum FLC concentrations were measured in 92 archived serum samples from patients diagnosed with chronic kidney disease using the Freelite assay (The Binding Site Group Ltd., UK), and kappa/lambda ratios were calculated. Serum creatinine levels were assayed to calculate estimated glomerular filtration rate (eGFR), and patients were divided into subgroups according to Kidney Disease Improving Global Outcomes (KDIGO) guidelines. We analyzed the difference in serum FLC levels and kappa/lambda ratios between subgroups. RESULTS: Serum FLC levels and kappa/lambda ratios increased depending on the severity of renal dysfunction. When patients were classified by setting cut-off value of eGFR as 60 mL/min/1.73 m2 (group A: eGFR ≥60 mL/min/1.73 m2, group B: < 60 mL/min/1.73 m2), the kappa/lambda ratio of group B was significantly higher than that of group A (group B: 1.60±0.46 vs. group A: 1.35±0.27, P=0.018). Serum FLC kappa/lambda ratios were within the previously determined renal reference interval (0.37–3.1). CONCLUSIONS: When interpreting results of serum FLC kappa/lambda ratio, renal function status should be considered in addition to hematological findings. If renal function deteriorates, a wider renal reference interval is preferred instead of the usual reference interval.


Subject(s)
Binding Sites , Creatinine , Glomerular Filtration Rate , Humans , Kidney , Kidney Diseases , Renal Insufficiency, Chronic
12.
Article in English | WPRIM | ID: wpr-764546

ABSTRACT

OBJECTIVES: Pseudolaric acid B (PAB) has been shown to inhibit the growth of various tumor cells, but the molecular details of its function are still unknown. This study investigated the molecular mechanisms by which PAB induces apoptosis in HeLa cells. METHODS: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed to investigate the effect of PAB treatment in various cervical cancer cell lines. Annexin V/propidium iodide staining combined with flow cytometry and Hoechst 33258 staining were used to assess PAB-induced apoptosis. Additionally, we performed bioinformatics analyses and identified a paired box 2 (PAX2) binding site on the BAX promoter. We then validated the binding using luciferase and chromatin immunoprecipitation assays. Finally, western blotting assays were used to investigate PAB effect on the Wnt signaling and the involved signaling molecules. RESULTS: PAB promotes apoptosis and downregulates PAX2 expression in HeLa cells in a time- and concentration-dependent manner. PAX2 binds to the promoter of BAX and inhibits its expression; therefore, PAX2 inhibition is associated with increased levels of BAX, which induces apoptosis of HeLa cells via the mitochondrial pathway. Additionally, PAB inhibits classical Wnt signaling. CONCLUSION: PAB effectively inhibits Wnt signaling and PAX2 expression, and increases BAX levels, which induce apoptosis in HeLa cells. Therefore, PAB is a promising natural molecule for the treatment of cervical cancer.


Subject(s)
Apoptosis , Binding Sites , Bisbenzimidazole , Blotting, Western , Cell Line , Chromatin Immunoprecipitation , Computational Biology , Flow Cytometry , HeLa Cells , Humans , Luciferases , Mitochondria , Uterine Cervical Neoplasms , Wnt Signaling Pathway
13.
Article in English | WPRIM | ID: wpr-763042

ABSTRACT

Luteolin, a widespread flavonoid, has been known to have neuroprotective activity against various neurologic diseases such as epilepsy, and Alzheimer’s disease. However, little information is available regarding the hypnotic effect of luteolin. In this study, we evaluated the hypnotic effect of luteolin and its underlying mechanism. In pentobarbital-induced sleeping mice model, luteolin (1, and 3 mg/kg, p.o.) decreased sleep latency and increased the total sleep time. Through electroencephalogram (EEG) and electromyogram (EMG) recording, we demonstrated that luteolin increased non-rapid eye movement (NREM) sleep time and decreased wake time. To evaluate the underlying mechanism, we examined the effects of various pharmacological antagonists on the hypnotic effect of luteolin. The hypnotic effect of 3 mg/kg of luteolin was not affected by flumazenil, a GABAA receptor-benzodiazepine (GABAAR-BDZ) binding site antagonist, and bicuculine, a GABAAR-GABA binding site antagonist. On the other hand, the hypnotic effect of 3 mg/kg of luteolin was almost completely blocked by caffeine, an antagonist for both adenosine A1 and A2A receptor (A1R and A2AR), 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX), an A1R antagonist, and SCH-58261, an A2AR antagonist. From the binding affinity assay, we have found that luteolin significantly binds to not only A1R but also A2AR with IC₅₀ of 1.19, 0.84 μg/kg, respectively. However, luteolin did not bind to either BDZ-receptor or GABAAR. From these results, it has been suggested that luteolin has hypnotic efficacy through A1R and A2AR binding.


Subject(s)
Adenosine , Animals , Binding Sites , Caffeine , Electroencephalography , Epilepsy , Eye Movements , Flumazenil , Hand , Hypnotics and Sedatives , Luteolin , Mice , Receptor, Adenosine A1 , Receptor, Adenosine A2A , Sleep Initiation and Maintenance Disorders
14.
Article in English | WPRIM | ID: wpr-763040

ABSTRACT

HSP90 is a molecular chaperone that increases the stability of client proteins. Cancer cells show higher HSP90 expression than normal cells because many client proteins play an important role in the growth and survival of cancer cells. HSP90 inhibitors mainly bind to the ATP binding site of HSP90 and inhibit HSP90 activity, and these inhibitors can be distinguished as ansamycin and non-ansamycin depending on the structure. In addition, the histone deacetylase inhibitors inhibit the activity of HSP90 through acetylation of HSP90. These HSP90 inhibitors have undergone or are undergoing clinical trials for the treatment of cancer. On the other hand, recent studies have reported that various reagents induce cleavage of HSP90, resulting in reduced HSP90 client proteins and growth suppression in cancer cells. Cleavage of HSP90 can be divided into enzymatic cleavage and non-enzymatic cleavage. Therefore, reagents inducing cleavage of HSP90 can be classified as another class of HSP90 inhibitors. We discuss that the cleavage of HSP90 can be another mechanism in the cancer treatment by HSP90 inhibition.


Subject(s)
Acetylation , Adenosine Triphosphate , Binding Sites , Drug Therapy , Hand , Heat-Shock Proteins , Histone Deacetylase Inhibitors , Hot Temperature , Indicators and Reagents , Molecular Chaperones , Rifabutin
15.
Yonsei Medical Journal ; : 842-853, 2019.
Article in English | WPRIM | ID: wpr-762122

ABSTRACT

PURPOSE: Long intergenic non-protein coding RNA 665 (LINC00665) plays a vital role in the development of cancer. Its function in hepatocellular carcinoma (HCC), however, remains largely unknown. MATERIALS AND METHODS: The expressions of LINC00665, miR-186-5p, and MAP4K3 were determined by qRT-PCR. Cell viability and apoptosis were evaluated by MTT and flow cytometry, respectively. Autophagic puncta formation was observed by fluorescence microscopy. Bioinformatics analysis, luciferase reporter assay, RNA immunoprecipitation, and RNA pulldown were performed to identify associations among LINC00665, miR-186-5p, and MAP4K3. Western blot was utilized to examine the expressions of MAP4K3, Beclin-1, and LC3. Tumor growth was evaluated in a xenograft model. RESULTS: Elevations in LINC00665 were observed in HCC tissues and cells. The overall survival of HCC patients with high levels of LINC00665 was shorter than those with low levels. In vitro, LINC00665 depletion inhibited viability and induced apoptosis and autophagy. miR-186-5p interacted with LINC00665 and was downregulated in HCC tissues and cells. Upregulation of miR-186-5p inhibited viability and induced apoptosis and autophagy, which were attenuated by upregulation of LINC00665. MAP4K3 was found to possess binding sites with miR-186-5p and was upregulated in HCC tissues and cells. MAP4K3 depletion inhibited viability and induced apoptosis and autophagy, which were attenuated by miR-186-5p inhibitor. In vivo, miR-186-5p expression was negatively correlated with LINC00665 or MAP4K3 in HCC tissues, while LINC00665 was positively correlated with MAP4K3. LINC00665 knockdown suppressed tumor growth. CONCLUSION: LINC00665 was involved in cell viability, apoptosis, and autophagy in HCC via miR-186-5p/MAP4K3 axis, which may provide a new approach for HCC treatment.


Subject(s)
Apoptosis , Autophagy , Binding Sites , Blotting, Western , Carcinoma, Hepatocellular , Cell Survival , Computational Biology , Flow Cytometry , Heterografts , Humans , Immunoprecipitation , In Vitro Techniques , Luciferases , Microscopy, Fluorescence , RNA , RNA, Long Noncoding , Up-Regulation
16.
Article in Chinese | WPRIM | ID: wpr-772107

ABSTRACT

OBJECTIVE@#To explore the role of miR-593 in regulating the proliferation of colon cancer cells and the molecular mechanism.@*METHODS@#Bioinformatics analysis identified PLK1 as the possible target gene of miR-593. Luciferase assay was employed to verify the binding between miR-593 and PLK1, and qRT-PCR and Western blotting were used to verify that PLK1 was the direct target gene of miR-593. CCK-8 assay was performed to test the hypothesis that miR-593 inhibited the proliferation of colon cancer cells by targeting PLK1.@*RESULTS@#Luciferase assay identified the specific site of miR-593 binding with PLK1. Western blotting showed a significantly decreased expression of PLK1 in the colon cancer cells transfected with miR-593 mimics and an increased PLK1 expression in the cells transfected with the miR-593 inhibitor as compared with the control cells ( < 0.05). The results of qRT-PCR showed no significant differences in the expression levels of PLK1 among the cells with different treatments ( > 0.05). The cell proliferation assay showed opposite effects of miR-593 and PLK1 on the proliferation of colon cancer cells, and the effect of co-transfection with miR-593 mimic and a PLK1-overexpressing plasmid on the cell proliferation was between those in PLK1 over-expressing group and miR-593 mimic group.@*CONCLUSIONS@#miR-593 inhibits the proliferation of colon cancer cells by down-regulating PLK1 and plays the role as a tumor suppressor in colon cancer.


Subject(s)
Binding Sites , Cell Cycle Proteins , Genetics , Metabolism , Cell Line, Tumor , Cell Proliferation , Colonic Neoplasms , Metabolism , Pathology , Down-Regulation , Gene Expression Regulation, Neoplastic , Genes, Tumor Suppressor , Humans , In Vitro Techniques , MicroRNAs , Genetics , Metabolism , Protein-Serine-Threonine Kinases , Genetics , Metabolism , Proto-Oncogene Proteins , Genetics , Metabolism , Reverse Transcriptase Polymerase Chain Reaction , Sincalide , Metabolism , Transfection
17.
Chinese Journal of Biotechnology ; (12): 1469-1477, 2019.
Article in Chinese | WPRIM | ID: wpr-771782

ABSTRACT

The aim of this study was to screen the active regions and transcription factor binding sites in the promoter of the CBD103 gene related to Arctic fox coat color, and to provide a basis for revealing the molecular genetic mechanism of CBD103 gene regulating the coat color formation. The 5'-flanking region fragment 2 123 bp of Arctic fox CBD103 gene was cloned, and 4 truncated promoter reporter vectors of different lengths were constructed. The promoter activity was detected by the dual-luciferase reporter assay system. Point mutations were performed on the 3 predicted specificity protein 1 (Sp1) transcription factor binding sites in the highest promoter active region, and 3 mutant vectors were constructed. The activity was then detected by the dual-luciferase reporter assay system. The results showed that the region 1 656 (-1 604/+51) had the highest activity in the 4 truncated promoters of different lengths, and the promoter activity of the three mutant vectors constructed in this region were significantly lower than that of the wild type (fragment 1 656). The region of -1 604 /+51 was the core promoter region of CBD103 gene in Arctic fox and -1 552/-1 564, -1 439/-1 454 and -329/-339 regions were positive regulatory regions. This study successfully obtained the core promoter region and positive regulation regions of the Arctic fox CBD103 gene, which laid a foundation for further study on the molecular genetic mechanism of this gene regulating Arctic fox coat color.


Subject(s)
Animals , Binding Sites , Foxes , Luciferases , Promoter Regions, Genetic , Sp1 Transcription Factor , beta-Defensins
18.
Journal of Gastric Cancer ; : 460-472, 2019.
Article in English | WPRIM | ID: wpr-785956

ABSTRACT

PURPOSE: Long noncoding RNA 00703 (LINC00703) was found originating from a region downstream of Kruppel-like factor 6 (KLF6) gene, having 2 binding sites for miR-181a. Since KLF6 has been reported as a target of miR-181a in gastric cancer (GC), this study aims to investigate whether LINC00703 regulates the miR-181a/KLF6 axis and plays a functional role in GC pathogenesis.MATERIALS AND METHODS: GC tissues, cell lines, and nude mice were included in this study. RNA binding protein immunoprecipitation (RIP) and pull-down assays were used to evaluate interaction between LINC00703 and miR-181a. Quantitative real-time polymerase chain reaction and western blot were applied for analysis of gene expression at the transcriptional and protein levels. A nude xenograft mouse model was used to determine LINC00703 function in vivo.RESULTS: We revealed that LINC00703 competitively interacts with miR-181a to regulate KLF6. Overexpression of LINC00703 inhibited cell proliferation, migration/invasion, but promoted apoptosis in vitro, and arrested tumor growth in vivo. LINC00703 expression was found to be decreased in GC tissues, which was positively correlated with KLF6, but negatively with the miR-181a levels.CONCLUSIONS: LINC00703 may have an anti-cancer function via modulation of the miR-181a/KLF6 axis. This study also provides a new potential diagnostic marker and therapeutic target for GC treatment.


Subject(s)
Animals , Apoptosis , Binding Sites , Blotting, Western , Cell Line , Cell Proliferation , Gene Expression , Heterografts , Immunoprecipitation , In Vitro Techniques , Mice , Mice, Nude , Real-Time Polymerase Chain Reaction , RNA, Long Noncoding , RNA-Binding Proteins , Stomach Neoplasms
19.
Int. j. high dilution res ; 18(3/4): 19-34, 2019.
Article in English | LILACS | ID: biblio-1050037

ABSTRACT

Background: Mercuric chloride is known to inhibit the activity of enzymes. It is used in homeopathy at ultra low concentration (ULC) and is known as Mercurius corrosivus (Merc cor). ULCs of Merc cor are reported to promote enzyme activity. Objective: To see whether the mother tincture (θ) of Merc cor and its ULCs interact with an enzyme invertase at its binding sites and influence enzyme's action on its substrate sucrose. Methods: Merc cor θ (0.15 M HgCl2) was diluted with deionized and distilled (DD) water 1:100 and succussed 10 times to prepare Merc cor 1 cH or 1st potency. This potency was further diluted and succussed in 200 and 1000 steps to prepare 200cH and 1000cH potencies, respectively. Merc cor 200 cH and 1000cH were prepared in 90% ethanol. The two potencies and blank 90% EtOH were diluted with DD water 1:1000 to minimize ethanol content to a negligible amount 0.09%. The control was DD water (0.99g/M). The drugs, EtOH and water control were mixed separately with 0.037 mM invertase in DD water. Using an isothermal calorimetry (ITC) instrument the substrate sucrose (65mM) was injected at 2 µl every 2 min into 300 µl invertase solution 20 times at 25 0C. Molecular modeling study was done to predict possible binding sites and nature of binding between the enzyme and HgCl2, and between the enzyme and water. Potencies after dilution are virtually water. Fluorescence spectra of invertase (4µM) mixed with drug/control solutions were also obtained to see the effect of drugs on protein folding. Results: Thermodynamic parameters like binding constant (K), change in enthalpy(ΔH), entropy(ΔS) and Gibbs free energy(ΔG) showed marked variation in treatment effects on the enzyme. Molecular modeling study also shows variation in binding between invertase and HgCl2, and between invertase and water. Fluorescence spectra show variation in quenching related to different treatments. Conclusion: Merc cor mother tincture and its potencies interact at different binding sites of invertase and modify the enzyme's action on sucrose. So, potencies act as modulators of ligand, sucrose. Drug solutions induce conformational changes in the enzyme. (au)


Subject(s)
Sucrose , Binding Sites , Models, Molecular , Low Potencies , beta-Fructofuranosidase , Homeopathy , Mercuric Chloride
20.
Electron. j. biotechnol ; 31: 93-99, Jan. 2018. ilus, graf, tab
Article in English | LILACS | ID: biblio-1022150

ABSTRACT

Background: Peptidoglycan (PGN) recognition proteins (PGRPs) are important pattern recognition receptors of the host innate immune system that are involved in the immune defense against bacterial pathogens. PGRPs have been characterized in several fish species. The PGN-binding ability is important for the function of PGRPs. However, the PGRP-PGN interaction mechanism in fish remains unclear. In the present study, the 3-D model of a long PGRP of half-smooth tongue sole (Cynoglossus semilaevis) (csPGRP-L), a marine teleost with great economic value, was constructed through the comparative modeling method, and the key amino acids involved in the interaction with Lys-type PGNs and Dap-type PGNs were analyzed by molecular dynamics and molecular docking methods. Results: csPGRP-L possessed a typical PGRP structure, consisting of five ß-sheets and four α-helices. Molecular docking showed that the van der Waals forces had a slightly larger contribution than Coulombic interaction in the csPGRP-L-PGN complex. Moreover, the binding energies of csPGRP-L-PGNs computed by MM-PBSA method revealed that csPGRP-L might selectively bind both types of MTP-PGNs and MPP-PGNs. In addition, the binding energy of each residue of csPGRP-L was also calculated, revealing that the residues involved in the interaction with Lys-type PGNs were different from that with Dap-type PGNs. Conclusions: The 3-D structure of csPGRP-L possessed typical PGRP structure and might selectively bind both types of MTP- and MPP-PGNs, which provided useful insights to understanding the functions of fish PGRPs.


Subject(s)
Animals , Tongue/immunology , Flatfishes/immunology , Flatfishes/metabolism , Binding Sites , Flatfishes/genetics , Peptidoglycan , Carrier Proteins , Toll-Like Receptors , Molecular Dynamics Simulation , Molecular Docking Simulation , Ligands
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