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Li C, Yang W, Meng Y, Feng L, Sun L, Li Z, Liu X, Li M. Exploring the therapeutic mechanism of Banxia Xiexin Decoction in mild cognitive impairment and diabetes mellitus: a network pharmacology approach. Metab Brain Dis 2023; 38:2315-2325. [PMID: 37556042 DOI: 10.1007/s11011-023-01270-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 07/24/2023] [Indexed: 08/10/2023]
Abstract
The incidence of mild cognitive impairment (MCI) and diabetes mellitus (DM) is increasing year by year. Clinical findings show that Banxia Xiexin Decoction (BXD) can be combined to treat MCI and DM. However, the principle and mechanism of BXD in treating MCI and DM remain unclear. In this study, to explore the common mechanism of BXD in treating MCI and DM by using the method of network pharmacology. Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) was used to screen the main active components of BXD, as well as to predict and screen its potential targets. Using Online Mendelian Inheritance in Man (OMIM), Therapeutic Target Database (TTD), DisGeNET, GeneCards to select the target proteins of two diseases, and intersecting the drug target and the disease target to obtain the common target of drug diseases, which is imported into cytoscape software to draw the network diagram of "drug components-target diseases" and the interaction network diagram between the common target proteins. According to the Database for Annotation, Visualization and Integrated Discovery (DAVID) database, we analyzed the common targets using two methods, gene ontology Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathway enrichment analysis and Gene Ontology (GO) function enrichment analysis, as well as studied the interaction mechanism of the two diseases, with the results validated using molecular docking. A total of 267 main active components of BXD were screened, together with the two diseases shared 233 common targets. The top five key targets identified by the topological analysis were TP53, AKT1, STAT3, TNF, and MAPK3. Go enrichment results indicated that it was primarily related to response to drug, extracellular space, enzyme binding, RNA polymerase II transcription factor activity, ligand-activated sequence-specific DNA binding. t KEGG enrichment pathway analysis identified 20 significant pathways, the majority of which are AGE-RAGE signaling pathways in diabetic complications, lipid and atherosclerosis, fluid shear stress and atherosclerosis, IL-17 signaling pathway, TNF signaling pathway, and so on. The results of molecular docking revealed that the key components of BXD, baicalein, licochalcone a, quercetin, and naringenin, had strong binding ability with core targets TP53, AKT1, STAT3, TNF, MAPK3. BXD can treat MCI and DM by multi-targets and multi-channels,and plays a role of "homotherapy for heteropathy" mainly through response to drug, positive regulation of gene expression, extracellular space and enzyme binding and other ways.
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Affiliation(s)
- Cong Li
- College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Wei Yang
- Neurology Department, Affiliated Hospital of the Changchun University of Chinese Medicine, Changchun, China
| | - Yubo Meng
- Neurology Department, Affiliated Hospital of the Changchun University of Chinese Medicine, Changchun, China
| | - Lina Feng
- Neurology Department, Third Affiliated Clinical Hospital of the Changchun University of Chinese Medicine, Changchun, China
| | - Linlin Sun
- Neurology Department, Affiliated Hospital of the Changchun University of Chinese Medicine, Changchun, China
| | - Zhenghong Li
- Research Department, Swiss University of Traditional Chinese Medicine, Bad Zurzach, Switzerland
| | - Xingfang Liu
- Research Department, Swiss University of Traditional Chinese Medicine, Bad Zurzach, Switzerland
| | - Mingquan Li
- Neurology Department, Third Affiliated Clinical Hospital of the Changchun University of Chinese Medicine, Changchun, China.
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2
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Cheng Y, Zhu Y, Xu J, Yang M, Chen P, Xu W, Zhao J, Geng L, Gong S. PKN2 in colon cancer cells inhibits M2 phenotype polarization of tumor-associated macrophages via regulating DUSP6-Erk1/2 pathway. Mol Cancer 2018; 17:13. [PMID: 29368606 PMCID: PMC5784528 DOI: 10.1186/s12943-017-0747-z] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 12/03/2017] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Protein kinase N2 (PKN2) is a PKC-related serine/threonine-protein kinase. PKN2 is required for tumor cell migration, invasion and apoptosis. However, the functional role of PKN2 in regulating tumor associated macrophages (TAMs) polarization in colon cancer has never been reported. METHODS PKN2 expression in human colon cancer tissues was examined with immunohistochemistry (IHC). M1/M2 macrophage signatures were evaluated by RT-PCR, IHC and flow cytometry. The effects of PKN2 on tumor growth and TAM polarization were investigated both in vitro and in vivo. PKN2 targeted cytokines/pathway were analyzed by gene expression analysis and further confirmed by PCR, luciferase assay or western blot. Correlations between PKN2 and transcriptional factors for IL4 and IL10 were confirmed by ChIP-qPCR. The catalytic activities of PKN2 and DUSP6 were determined by kinase activity assay. Interactions between PKN2 and DUSP6 were confirmed by Co-IP. RESULTS The expression of PKN2 in colon cancer cells predicted a favorable prognosis and was associated with low M2 macrophage content in human colon cancer tissues. PKN2 inhibited tumor growth in mice xenograft model and inhibited M2 phenotype polarization both in vitro and in vivo. Mechanistically, PKN2 suppresses the expression of IL4 and IL10 from colon cancer cells by inhibiting Erk1/2 phosphorylation, which is required for phosphorylation and binding of CREB and Elk-1 to the promoters of IL4 and IL10. DUSP6, which is phosphorylated and activated through direct association with PKN2, suppresses Erk1/2 activation. CONCLUSIONS The expression of PKN2 in colon cancer cells suppresses tumor associated M2 macrophage polarization and tumor growth. Targeting PKN2 signaling pathway may provide a potential therapeutic strategy for colon cancer.
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Affiliation(s)
- Yang Cheng
- Digestive Department, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, No.9 Jinsui Road, Guangzhou, Guangdong, 510623, China.,Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, Guangdong, 510623, China
| | - Yun Zhu
- Liver Tumor Center, Department of Infectious Diseases and Hepatology Unit, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510623, China
| | - Jiajia Xu
- Digestive Department, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, No.9 Jinsui Road, Guangzhou, Guangdong, 510623, China
| | - Min Yang
- Digestive Department, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, No.9 Jinsui Road, Guangzhou, Guangdong, 510623, China
| | - Peiyu Chen
- Digestive Department, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, No.9 Jinsui Road, Guangzhou, Guangdong, 510623, China
| | - Wanfu Xu
- Digestive Department, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, No.9 Jinsui Road, Guangzhou, Guangdong, 510623, China.,Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, Guangdong, 510623, China
| | - Junhong Zhao
- Digestive Department, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, No.9 Jinsui Road, Guangzhou, Guangdong, 510623, China
| | - Lanlan Geng
- Digestive Department, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, No.9 Jinsui Road, Guangzhou, Guangdong, 510623, China
| | - Sitang Gong
- Digestive Department, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, No.9 Jinsui Road, Guangzhou, Guangdong, 510623, China.
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3
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Lu C, Liu X, Zhang CS, Gong H, Wu JW, Wang ZX. Structural and Dynamic Insights into the Mechanism of Allosteric Signal Transmission in ERK2-Mediated MKP3 Activation. Biochemistry 2017; 56:6165-6175. [PMID: 29077400 DOI: 10.1021/acs.biochem.7b00827] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The mitogen-activated protein kinases (MAPKs) are key components of cellular signal transduction pathways, which are down-regulated by the MAPK phosphatases (MKPs). Catalytic activity of the MKPs is controlled both by their ability to recognize selective MAPKs and by allosteric activation upon binding to MAPK substrates. Here, we use a combination of experimental and computational techniques to elucidate the molecular mechanism for the ERK2-induced MKP3 activation. Mutational and kinetic study shows that the 334FNFM337 motif in the MKP3 catalytic domain is essential for MKP3-mediated ERK2 inactivation and is responsible for ERK2-mediated MKP3 activation. The long-term molecular dynamics (MD) simulations further reveal a complete dynamic process in which the catalytic domain of MKP3 gradually changes to a conformation that resembles an active MKP catalytic domain over the time scale of the simulation, providing a direct time-dependent observation of allosteric signal transmission in ERK2-induced MKP3 activation.
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Affiliation(s)
- Chang Lu
- Key Laboratory of Ministry of Education for Protein Science, School of Life Sciences, Tsinghua University , Beijing 100084, PR China
| | - Xin Liu
- Key Laboratory of Ministry of Education for Protein Science, School of Life Sciences, Tsinghua University , Beijing 100084, PR China
| | - Chen-Song Zhang
- State Key Laboratory of Stress Cell Biology, School of Life Sciences, Xiamen University , Xiamen, Fujian 361005, PR China
| | - Haipeng Gong
- Key Laboratory of Ministry of Education for Protein Science, School of Life Sciences, Tsinghua University , Beijing 100084, PR China
| | - Jia-Wei Wu
- Key Laboratory of Ministry of Education for Protein Science, School of Life Sciences, Tsinghua University , Beijing 100084, PR China
| | - Zhi-Xin Wang
- Key Laboratory of Ministry of Education for Protein Science, School of Life Sciences, Tsinghua University , Beijing 100084, PR China
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Neumann TS, Span EA, Kalous KS, Bongard R, Gastonguay A, Lepley MA, Kutty RG, Nayak J, Bohl C, Lange RG, Sarker MI, Talipov MR, Rathore R, Ramchandran R, Sem DS. Identification of inhibitors that target dual-specificity phosphatase 5 provide new insights into the binding requirements for the two phosphate pockets. BMC BIOCHEMISTRY 2015; 16:19. [PMID: 26286528 PMCID: PMC4545774 DOI: 10.1186/s12858-015-0048-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 08/04/2015] [Indexed: 12/02/2022]
Abstract
BACKGROUND Dual-specificity phosphatase-5 (DUSP5) plays a central role in vascular development and disease. We present a p-nitrophenol phosphate (pNPP) based enzymatic assay to screen for inhibitors of the phosphatase domain of DUSP5. METHODS pNPP is a mimic of the phosphorylated tyrosine on the ERK2 substrate (pERK2) and binds the DUSP5 phosphatase domain with a Km of 7.6 ± 0.4 mM. Docking followed by inhibitor verification using the pNPP assay identified a series of polysulfonated aromatic inhibitors that occupy the DUSP5 active site in the region that is likely occupied by the dual-phosphorylated ERK2 substrate tripeptide (pThr-Glu-pTyr). Secondary assays were performed with full length DUSP5 with ERK2 as substrate. RESULTS The most potent inhibitor has a naphthalene trisulfonate (NTS) core. A search for similar compounds in a drug database identified suramin, a dimerized form of NTS. While suramin appears to be a potent and competitive inhibitor (25 ± 5 μM), binding to the DUSP5 phosphatase domain more tightly than the monomeric ligands of which it is comprised, it also aggregates. Further ligand-based screening, based on a pharmacophore derived from the 7 Å separation of sulfonates on inhibitors and on sulfates present in the DUSP5 crystal structure, identified a disulfonated and phenolic naphthalene inhibitor (CSD (3) _2320) with IC₅₀ of 33 μM that is similar to NTS and does not aggregate. CONCLUSIONS The new DUSP5 inhibitors we identify in this study typically have sulfonates 7 Å apart, likely positioning them where the two phosphates of the substrate peptide (pThr-Glu-pTyr) bind, with one inhibitor also positioning a phenolic hydroxyl where the water nucleophile may reside. Polysulfonated aromatic compounds do not commonly appear in drugs and have a tendency to aggregate. One FDA-approved polysulfonated drug, suramin, inhibits DUSP5 and also aggregates. Docking and modeling studies presented herein identify polysulfonated aromatic inhibitors that do not aggregate, and provide insights to guide future design of mimics of the dual-phosphate loops of the ERK substrates for DUSPs.
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Affiliation(s)
- Terrence S Neumann
- Department of Chemistry and Biochemistry, Texas Wesleyan University, 1201 Wesleyan Ave., Fort Worth, TX, 76105, USA.
- Center for Structure-based Drug Design and Development, Department of Pharmaceutical Sciences, and School of Pharmacy, Concordia University of Wisconsin, 12800 N. Lake Shore Drive, Mequon, WI 53097, USA.
| | - Elise A Span
- Center for Structure-based Drug Design and Development, Department of Pharmaceutical Sciences, and School of Pharmacy, Concordia University of Wisconsin, 12800 N. Lake Shore Drive, Mequon, WI 53097, USA.
| | - Kelsey S Kalous
- Center for Structure-based Drug Design and Development, Department of Pharmaceutical Sciences, and School of Pharmacy, Concordia University of Wisconsin, 12800 N. Lake Shore Drive, Mequon, WI 53097, USA.
| | - Robert Bongard
- Center for Structure-based Drug Design and Development, Department of Pharmaceutical Sciences, and School of Pharmacy, Concordia University of Wisconsin, 12800 N. Lake Shore Drive, Mequon, WI 53097, USA.
| | - Adam Gastonguay
- Department of Pediatrics, Department of Obstetrics and Gynecology, Medical College of Wisconsin, Children's Research Institute (CRI) Developmental Vascular Biology Program, Translational and Biomedical Research Center, Milwaukee, WI 53226, USA.
| | - Michael A Lepley
- Department of Pediatrics, Department of Obstetrics and Gynecology, Medical College of Wisconsin, Children's Research Institute (CRI) Developmental Vascular Biology Program, Translational and Biomedical Research Center, Milwaukee, WI 53226, USA.
| | - Raman G Kutty
- Department of Pediatrics, Department of Obstetrics and Gynecology, Medical College of Wisconsin, Children's Research Institute (CRI) Developmental Vascular Biology Program, Translational and Biomedical Research Center, Milwaukee, WI 53226, USA.
| | - Jaladhi Nayak
- Department of Pediatrics, Department of Obstetrics and Gynecology, Medical College of Wisconsin, Children's Research Institute (CRI) Developmental Vascular Biology Program, Translational and Biomedical Research Center, Milwaukee, WI 53226, USA.
| | - Chris Bohl
- Center for Structure-based Drug Design and Development, Department of Pharmaceutical Sciences, and School of Pharmacy, Concordia University of Wisconsin, 12800 N. Lake Shore Drive, Mequon, WI 53097, USA
| | - Rachel G Lange
- Center for Structure-based Drug Design and Development, Department of Pharmaceutical Sciences, and School of Pharmacy, Concordia University of Wisconsin, 12800 N. Lake Shore Drive, Mequon, WI 53097, USA
| | - Majher I Sarker
- Department of Chemistry, Wehr Chemistry Building, P.O. Box 1881, 535 N. 14th Street, Milwaukee, WI 53201, USA.
| | - Marat R Talipov
- Department of Chemistry, Wehr Chemistry Building, P.O. Box 1881, 535 N. 14th Street, Milwaukee, WI 53201, USA.
| | - Rajendra Rathore
- Department of Chemistry, Wehr Chemistry Building, P.O. Box 1881, 535 N. 14th Street, Milwaukee, WI 53201, USA.
| | - Ramani Ramchandran
- Department of Pediatrics, Department of Obstetrics and Gynecology, Medical College of Wisconsin, Children's Research Institute (CRI) Developmental Vascular Biology Program, Translational and Biomedical Research Center, Milwaukee, WI 53226, USA.
| | - Daniel S Sem
- Center for Structure-based Drug Design and Development, Department of Pharmaceutical Sciences, and School of Pharmacy, Concordia University of Wisconsin, 12800 N. Lake Shore Drive, Mequon, WI 53097, USA.
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5
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Protein expression, characterization and activity comparisons of wild type and mutant DUSP5 proteins. BMC BIOCHEMISTRY 2014; 15:27. [PMID: 25519881 PMCID: PMC4299175 DOI: 10.1186/s12858-014-0027-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 12/08/2014] [Indexed: 11/10/2022]
Abstract
Background The mitogen-activated protein kinases (MAPKs) pathway is critical for cellular signaling, and proteins such as phosphatases that regulate this pathway are important for normal tissue development. Based on our previous work on dual specificity phosphatase-5 (DUSP5), and its role in embryonic vascular development and disease, we hypothesized that mutations in DUSP5 will affect its function. Results In this study, we tested this hypothesis by generating full-length glutathione-S-transferase-tagged DUSP5 and serine 147 proline mutant (S147P) proteins from bacteria. Light scattering analysis, circular dichroism, enzymatic assays and molecular modeling approaches have been performed to extensively characterize the protein form and function. We demonstrate that both proteins are active and, interestingly, the S147P protein is hypoactive as compared to the DUSP5 WT protein in two distinct biochemical substrate assays. Furthermore, due to the novel positioning of the S147P mutation, we utilize computational modeling to reconstruct full-length DUSP5 and S147P to predict a possible mechanism for the reduced activity of S147P. Conclusion Taken together, this is the first evidence of the generation and characterization of an active, full-length, mutant DUSP5 protein which will facilitate future structure-function and drug development-based studies. Electronic supplementary material The online version of this article (doi:10.1186/s12858-014-0027-0) contains supplementary material, which is available to authorized users.
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6
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Annenkov A. Receptor tyrosine kinase (RTK) signalling in the control of neural stem and progenitor cell (NSPC) development. Mol Neurobiol 2013; 49:440-71. [PMID: 23982746 DOI: 10.1007/s12035-013-8532-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 08/09/2013] [Indexed: 01/04/2023]
Abstract
Important developmental responses are elicited in neural stem and progenitor cells (NSPC) by activation of the receptor tyrosine kinases (RTK), including the fibroblast growth factor receptors, epidermal growth factor receptor, platelet-derived growth factor receptors and insulin-like growth factor receptor (IGF1R). Signalling through these RTK is necessary and sufficient for driving a number of developmental processes in the central nervous system. Within each of the four RTK families discussed here, receptors are activated by sets of ligands that do not cross-activate receptors of the other three families, and therefore, their activation can be independently regulated by ligand availability. These RTK pathways converge on a conserved core of signalling molecules, but differences between the receptors in utilisation of signalling molecules and molecular adaptors for intracellular signal propagation become increasingly apparent. Intracellular inhibitors of RTK signalling are widely involved in the regulation of developmental signalling in NSPC and often determine developmental outcomes of RTK activation. In addition, cellular responses of NSPC to the activation of a given RTK may be significantly modulated by signal strength. Cellular propensity to respond also plays a role in developmental outcomes of RTK signalling. In combination, these mechanisms regulate the balance between NSPC maintenance and differentiation during development and in adulthood. Attribution of particular developmental responses of NSPC to specific pathways of RTK signalling becomes increasingly elucidated. Co-activation of several RTK in developing NSPC is common, and analysis of co-operation between their signalling pathways may advance knowledge of RTK role in NSPC development.
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Affiliation(s)
- Alexander Annenkov
- Bone and Joint Research Unit, William Harvey Research Institute, Bart's and The London School of Medicine, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK,
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Cejudo-Marín R, Tárrega C, Nunes-Xavier CE, Pulido R. Caspase-3 Cleavage of DUSP6/MKP3 at the Interdomain Region Generates Active MKP3 Fragments That Regulate ERK1/2 Subcellular Localization and Function. J Mol Biol 2012; 420:128-38. [DOI: 10.1016/j.jmb.2012.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 04/01/2012] [Accepted: 04/04/2012] [Indexed: 12/17/2022]
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8
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Messina S, Frati L, Leonetti C, Zuchegna C, Di Zazzo E, Calogero A, Porcellini A. Dual-specificity phosphatase DUSP6 has tumor-promoting properties in human glioblastomas. Oncogene 2011; 30:3813-20. [DOI: 10.1038/onc.2011.99] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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9
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Marion JD, Van DN, Bell JE, Bell JK. Measuring the effect of ligand binding on the interface stability of multimeric proteins using dynamic light scattering. Anal Biochem 2010; 407:278-80. [PMID: 20732291 DOI: 10.1016/j.ab.2010.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 08/17/2010] [Accepted: 08/18/2010] [Indexed: 11/28/2022]
Abstract
We have demonstrated that an approach using guanidine hydrochloride at low concentrations to progressively disrupt protein-protein interactions can be quantitated using dynamic light scattering. This approach is sensitive enough to detect ligand-induced changes of subunit-subunit interactions for homo-hexameric glutamate dehydrogenase, allowing ΔΔG of reversible subunit dissociation to be calculated. The use of dynamic light scattering makes this approach generally applicable to soluble proteins to monitor the relative strength of protein-protein interactions with a particular emphasis on assessing the impact of ligand binding on such interfaces.
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Affiliation(s)
- James D Marion
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298, USA
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10
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Rich RL, Myszka DG. Grading the commercial optical biosensor literature-Class of 2008: 'The Mighty Binders'. J Mol Recognit 2010; 23:1-64. [PMID: 20017116 DOI: 10.1002/jmr.1004] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Optical biosensor technology continues to be the method of choice for label-free, real-time interaction analysis. But when it comes to improving the quality of the biosensor literature, education should be fundamental. Of the 1413 articles published in 2008, less than 30% would pass the requirements for high-school chemistry. To teach by example, we spotlight 10 papers that illustrate how to implement the technology properly. Then we grade every paper published in 2008 on a scale from A to F and outline what features make a biosensor article fabulous, middling or abysmal. To help improve the quality of published data, we focus on a few experimental, analysis and presentation mistakes that are alarmingly common. With the literature as a guide, we want to ensure that no user is left behind.
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Affiliation(s)
- Rebecca L Rich
- Center for Biomolecular Interaction Analysis, University of Utah, Salt Lake City, UT 84132, USA
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11
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Doughty-Shenton D, Joseph JD, Zhang J, Pagliarini DJ, Kim Y, Lu D, Dixon JE, Casey PJ. Pharmacological targeting of the mitochondrial phosphatase PTPMT1. J Pharmacol Exp Ther 2010; 333:584-92. [PMID: 20167843 DOI: 10.1124/jpet.109.163329] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The dual-specificity protein tyrosine phosphatases (PTPs) play integral roles in the regulation of cell signaling. There is a need for new tools to study these phosphatases, and the identification of inhibitors potentially affords not only new means for their study, but also possible therapeutics for the treatment of diseases caused by their dysregulation. However, the identification of selective inhibitors of the protein phosphatases has proven somewhat difficult. PTP localized to mitochondrion 1 (PTPMT1) is a recently discovered dual-specificity phosphatase that has been implicated in the regulation of insulin secretion. Screening of a commercially available small-molecule library yielded alexidine dihydrochloride, a dibiguanide compound, as an effective and selective inhibitor of PTPMT1 with an in vitro concentration that inhibits response by 50% of 1.08 microM. A related dibiguanide analog, chlorhexidine dihydrochloride, also significantly inhibited PTPMT1, albeit with lower potency, while a monobiguanide analog showed very weak inhibition. Treatment of isolated rat pancreatic islets with alexidine dihydrochloride resulted in a dose-dependent increase in insulin secretion, whereas treatment of a pancreatic beta-cell line with the drug affected the phosphorylation of mitochondrial proteins in a manner similar to genetic inhibition of PTPMT1. Furthermore, knockdown of PTPMT1 in rat islets rendered them insensitive to alexidine dihydrochloride treatment, providing evidence for mechanism-based activity of the inhibitor. Taken together, these studies establish alexidine dihydrochloride as an effective inhibitor of PTPMT1, both in vitro and in cells, and support the notion that PTPMT1 could serve as a pharmacological target in the treatment of type II diabetes.
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Affiliation(s)
- Dahlia Doughty-Shenton
- Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina 27710-3813, USA
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12
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Tárrega C, Nunes-Xavier C, Cejudo-Marín R, Martín-Pérez J, Pulido R. Studying the regulation of MAP Kinase by MAP Kinase phosphatases in vitro and in cell systems. Methods Mol Biol 2010; 661:305-21. [PMID: 20811991 DOI: 10.1007/978-1-60761-795-2_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Signaling through MAPK pathways involves a network of activating kinases and inactivating phosphatases. While single MAPK kinases account for specific activation of the distinct MAPKs, inactivation of MAPKs by phosphatases involves a wider spectrum of enzymes, with phosphatases from distinct families displaying specificity toward MAPKs. The dual-specificity family of MAPK phosphatases, MKPs, constitutes the major group of MAPK inactivating phosphatases. MKPs are widely expressed, in a tissue- and development-regulated manner, and the control of their expression and function is crucial for the regulation of MAPK signaling. Here, we present three methods to analyze the regulation of MAPKs by MKPs, using transient and stable-inducible MKP overexpression cell systems and in vitro phosphatase experiments.
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Affiliation(s)
- Céline Tárrega
- Centro de Investigación Príncipe Felipe, Valencia, Spain
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