DOCSLIB.ORG

Pharmacological Targeting of the Mitochondrial Phosphatase PTPMT1 by Dahlia Doughty Shenton Department of Biochemistry Duke

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Pharmacological Targeting of the Mitochondrial Phosphatase PTPMT1 by Dahlia Doughty Shenton Department of Biochemistry Duke Pharmacological Targeting of the Mitochondrial Phosphatase PTPMT1 by Dahlia Doughty Shenton Department of Biochemistry Duke University Date: May 1 st 2009 Approved: ___________________________ Dr. Patrick J. Casey, Supervisor ___________________________ Dr. Perry J. Blackshear ___________________________ Dr. Anthony R. Means ___________________________ Dr. Christopher B. Newgard ___________________________ Dr. John D. York Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Biochemistry in the Graduate School of Duke University 2009 ABSTRACT Pharmacological Targeting of the Mitochondrial Phosphatase PTPMT1 by Dahlia Doughty Shenton Department of Biochemistry Duke University Date: May 1 st 2009 Approved: ___________________________ Dr. Patrick J. Casey, Supervisor ___________________________ Dr. Perry J. Blackshear ___________________________ Dr. Anthony R. Means ___________________________ Dr. Christopher B. Newgard ___________________________ Dr. John D. York An abstract of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Biochemistry in the Graduate School of Duke University 2009 Copyright by Dahlia Doughty Shenton 2009 Abstract The dual specificity protein tyrosine phosphatases comprise the largest and most diverse group of protein tyrosine phosphatases and play integral roles in the regulation of cell signaling events. The dual specificity protein tyrosine phosphatases impact multiple cellular processes including mitogenesis, differentiation, adhesion, migration, insulin secretion and programmed cell death. Thus, the dysregulation of these enzymes has been implicated in a myriad of human disease states. While the large volume of genetic data that has become available following genome sequencing efforts over the last decade has led to the rapid identification of many new dual specificity protein tyrosine phosphatases, the elucidation of the cellular function and substrates of these enzymes has been much slower. Hence, there is a need for new tools to study the dual specificity protein tyrosine phosphatases and the identification of inhibitors of these enzymes is regarded as an attractive prospect, potentially affording not only new means of studying these enzymes, but also possible therapeutics for the treatment of diseases caused by their dysregulation. However, the identification of potent, selective inhibitors of the dual specificity protein tyrosine phosphatases has proven somewhat difficult. iv PTPMT1, Protein Tyrosine Phosphatase Localized to the Mitochondrion 1 is a recently discovered, mitochondrion-localized, dual specificity phosphatase which has been implicated in the regulation of insulin secretion. However, the details of the mechanism by which PTPMT1 impacts insulin secretion, as well as its substrate in the pancreatic β-cell, have yet to be uncovered. Thus, the identification of a potent, selective inhibitor of the enzyme would aid in further study of PTPMT1. This work describes the identification of such an inhibitor of PTPMT1 following an in vitro screen of small molecule, chemical compounds using an artificial substrate. Following the screen, the lead compound emerged as a potent and potentially selective inhibitor of PTPMT1 both in vitro and in cells. Studies using this compound have shown that the compound induces increased secretion of insulin in a dose-dependent manner and thus support the notion that PTPMT1 may serve as a potential target for the treatment of Type II diabetes. v Dedication To my parents, for giving me the courage to pursue my dreams. vi Table of Contents Abstract ............................................................................................................................... iv List of Tables ...................................................................................................................... xii List of Figures .................................................................................................................... xiii Acknowledgements ........................................................................................................... xiv 1 Introduction .................................................................................................................. 1 1.1 The biological significance of protein phosphorylation ...................................... 1 1.2 Protein tyrosine phosphatases and the dual specificity PTPs ............................ 4 1.3 The biological significance of the dual specificity PTPs .................................... 10 1.3.1 The MAPK phosphatases .............................................................................. 10 1.3.2 The atypical dual specificity PTPs ................................................................. 12 1.3.3 The slingshot phosphatases .......................................................................... 14 1.3.4 The PRLs ........................................................................................................ 15 1.3.5 The CDC14 phosphatases.............................................................................. 16 1.3.6 The PTENs ..................................................................................................... 17 1.3.7 The myotubularins ........................................................................................ 18 1.4 Post-translational mechanisms of control of the dual specificity PTPs ............ 21 1.4.1 Phosphorylation ............................................................................................ 21 1.4.2 Ubiquitination ............................................................................................... 24 vii 1.4.3 Acetylation .................................................................................................... 25 1.4.4 Oxidation ....................................................................................................... 26 1.4.5 Prenylation .................................................................................................... 29 1.4.6 Oligomerization ............................................................................................. 31 1.5 Inhibitors of the dual specificity PTPs ............................................................... 36 1.5.1 Inhibitors of the MAPK phosphatases .......................................................... 39 1.5.2 Inhibitors of the atypical dual specificity PTPs ............................................. 43 1.5.3 Inhibitors of the PRLs .................................................................................... 48 1.5.4 Inhibitors of the PTENs and related phosphatases....................................... 51 2 Screening for an inhibitor of the dual specificity PTP, PTPMT1 ................................. 69 2.1 Introduction ...................................................................................................... 69 2.2 Methods ............................................................................................................ 72 2.2.1 PTPMT1 phosphatase assays ........................................................................ 72 2.2.2 Screening of the chemical library ................................................................. 72 2.3 Results ............................................................................................................... 74 2+ 2.3.1 Characterization of K m, optimal pH, and Mg dependency of PTPMT1 ...... 74 2.3.2 Identification of lead inhibitors of PTPMT1 .................................................. 76 2.4 Discussion.......................................................................................................... 82 viii 3 Kinetic characterization of alexidine dihydrochloride, an inhibitor of PTPMT1......... 85 3.1 Introduction ...................................................................................................... 85 3.2 Methods ............................................................................................................ 87 3.2.1 Kinetic experiments ...................................................................................... 87 3.2.2 Kinetic modeling and analysis ....................................................................... 88 3.3 Results ............................................................................................................... 90 3.3.1 Selectivity of inhibition of PTPMT1 by alexidine dihydrochloride ................ 90 3.3.2 Kinetic characterization of the inhibition of PTPMT1 by alexidine dihydrochloride ............................................................................................ 93 3.3.3 Importance of the di-biguanide pharmacophore of alexidine dihydrochloride ............................................................................................ 95 3.4 Discussion.......................................................................................................... 99 4 Evaluation of the impact of alexidine dihydrochloride on PTPMT1 in cells ............. 103 4.1 Introduction .................................................................................................... 103 4.2 Methods .......................................................................................................... 106 4.2.1 Tissue culture, insulin secretion and cytotoxicity assays ........................... 106 4.2.2 Analysis of mitochondrial protein phosphorylation
Load more

Recommended publications
  • The Role of PI3P Phosphatases in the Regulation of Autophagy
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector FEBS Letters 584 (2010) 1313–1318 journal homepage: www.FEBSLetters.org Review The role of PI3P phosphatases in the regulation of autophagy Isabelle Vergne a,*, Vojo Deretic a,b a Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA b Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA article info abstract Article history: Autophagy initiation is strictly dependent on phosphatidylinositol 3-phosphate (PI3P) synthesis. Received 31 December 2009 PI3P production is under tight control of PI3Kinase, hVps34, in complex with Beclin-1. Mammalian Revised 15 February 2010 cells express several PI3P phosphatases that belong to the myotubularin family. Even though some Accepted 16 February 2010 of them have been linked to serious human diseases, their cellular function is largely unknown. Two Available online 24 February 2010 recent studies indicate that PI3P metabolism involved in autophagy initiation is further regulated by Edited by Noboru Mizushima the PI3P phosphatases Jumpy and MTMR3. Additional pools of PI3P, upstream of mTOR and on the endocytic pathway, may modulate autophagy indirectly, suggesting that other PI3P phosphatases might be involved in this process. This review sums up our knowledge on PI3P phosphatases and Keywords: Autophagy discusses the recent progress on their role in autophagy. Myotubularin Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies. PI3P Phosphatase Jumpy MTMR14 1. Introduction PI3P phosphatases were one of the likely candidates as it is known that the phosphoinositide, PI3,4,5P3 and its signaling can be down- PI3P synthesis has long been recognized as one of the key regulated by PI3,4,5P3 phosphatase, PTEN.
    [Show full text]
  • Myotubularin-Related Protein (MTMR) 9 Determines the Enzymatic Activity, Substrate Specificity, and Role in Autophagy of MTMR8
    Myotubularin-related protein (MTMR) 9 determines the enzymatic activity, substrate specificity, and role in autophagy of MTMR8 Jun Zoua,1, Chunfen Zhangb,1,2, Jasna Marjanovicc, Marina V. Kisselevab, Philip W. Majerusb,d,2, and Monita P. Wilsonb,2 aDepartment of Pathology and Immunology, bDivision of Hematology, Department of Internal Medicine, and dDepartment of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110; and cDivision of Basic and Pharmaceutical Sciences, St. Louis College of Pharmacy, St. Louis, MO 63110 Contributed by Philip W. Majerus, May 1, 2012 (sent for review February 24, 2012) The myotubularins are a large family of inositol polyphosphate myotubularin proteins (16–21). One mechanism that regulates 3-phosphatases that, despite having common substrates, subsume the myotubularins is the formation of heterodimers between unique functions in cells that are disparate. The myotubularin catalytically active and inactive proteins. The interaction between family consists of 16 different proteins, 9 members of which different myotubularin proteins has a significant effect on en- possess catalytic activity, dephosphorylating phosphatidylinositol zymatic activity. For example, the association of myotubularin 3-phosphate [PtdIns(3)P] and phosphatidylinositol 3,5-bisphos- (MTM1) with MTMR12 results in a threefold increase in the 3- phate [PtdIns(3,5)P2] at the D-3 position. Seven members are in- phosphatase activity of MTM1, alters the subcellular localiza- active because they lack the conserved cysteine residue in the tion of MTM1 from the plasma membrane to the cytosol, and CX5R motif required for activity. We studied a subfamily of homol- attenuates the filopodia formation seen with MTM1 overex- ogous myotubularins, including myotubularin-related protein 6 pression (21, 22).
    [Show full text]
  • Myotubularin-Related Phosphatase 5 Is a Critical Determinant of Autophagy in Neurons
    bioRxiv preprint doi: https://doi.org/10.1101/2021.07.20.453106; this version posted July 20, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Myotubularin-related phosphatase 5 is a critical determinant of autophagy in neurons Jason P. Chua*1,8, Karan Bedi2,3,4, Michelle T. Paulsen2,4, Mats Ljungman2,4, Elizabeth M. H. Tank1, Erin S. Kim1, Jennifer M. Colón-Mercado7, Michael E. Ward7, Lois S. Weisman5,6, and Sami J. Barmada*1,8 1Department of Neurology, University of Michigan, Ann Arbor, MI, USA 2Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, USA 3Department of Biostatistics, University of Michigan, Ann Arbor, MI, USA 4Rogel Cancer Center and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA 5Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA 6Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA 7National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA 8Lead contact *Correspondence: [email protected] (J.P.C.), [email protected] (S.J.B.) 1 bioRxiv preprint doi: https://doi.org/10.1101/2021.07.20.453106; this version posted July 20, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. ABSTRACT Autophagy is a conserved, multi-step process of capturing proteolytic cargo in autophagosomes for lysosome degradation. The capacity to remove toxic proteins that accumulate in neurodegenerative disorders attests to the disease-modifying potential of the autophagy pathway.
    [Show full text]
  • Phosphatidylinositol-5-Phosphate Activation and Conserved Substrate Specificity of the Myotubularin Phosphatidylinositol 3-Phosphatases
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Current Biology, Vol. 13, 504–509, March 18, 2003, 2003 Elsevier Science Ltd. All rights reserved. DOI 10.1016/S0960-9822(03)00132-5 Phosphatidylinositol-5-Phosphate Activation and Conserved Substrate Specificity of the Myotubularin Phosphatidylinositol 3-Phosphatases 1 2 Julia Schaletzky, Stephen K. Dove, displayed activity toward PtdIns3P and PtdIns(3,5)P2, Benjamin Short,1 Oscar Lorenzo,3 but not the other naturally occurring phosphoinositides 3 1 Michael J. Clague, and Francis A. Barr (Figure 1A). The activity toward PtdIns(3,5)P2 adds a 1Department of Cell Biology novel substrate specificity for MTM1 [6] and is consis- Max-Planck-Institute of Biochemistry tent with reports that MTMR2 and MTMR3 use PtdIns3P Am Klopferspitz 18a and PtdIns(3,5)P2 as substrates [10, 11]. Purified MTMR6 Martinsried, 82152 showed the same substrate specificity as MTM1 (Figure Germany 1C), while the active site mutant protein MTMR6C336S 2 School of Biosciences lacked any detectable activity toward either PtdIns3P University of Birmingham or PtdIns(3,5)P2. To confirm that MTM1 hydrolyses The Medical School PtdIns(3,5)P2, we performed an alternate analysis of activ- Birmingham B15 2TT ity described previously for MTMR3 [10]. This assay is 3 Physiological Laboratory carried out in living yeast cells and is useful for establishing University of Liverpool 3-phosphatase activity against PtdIns(3,5)P2, since it Crown Street allows detection of the reaction product PtdIns5P, which Liverpool L69 3BX is not normally detectable in yeast [10, 12, 13].
    [Show full text]
  • Genes Retina/RPE Choroid Sclera
    Supplementary Materials: Genes Retina/RPE Choroid Sclera Fold Change p-value Fold Change p-value Fold Change p-value PPFIA2 NS NS 2.35 1.3X10-3 1.5 1.6X10-3 PTPRF 1.24 2.65X10-5 6.42 7X10-4 1.11 1X10-4 1.19 2.65X10-5 NS NS 1.11 3.3X10-3 PTPRR 1.44 2.65X10-5 3.04 4.7X10-3 NS NS Supplementary Table S1. Genes Differentially Expressed Related to Candidate Genes from Association. Genes selected for follow up validation by real time quantitative PCR. Multiple values for each gene indicate multiple probes within the same gene. NS indicates the fold change was not statistically significant. Gene/SNP Assay ID rs4764971 C__30866249_10 rs7134216 C__30023434_10 rs17306116 C__33218892_10 rs3803036 C__25749934_20 rs824311 C___8342112_10 PPFIA2 Hs00170308_m1 PTPRF Hs00160858_m1 PTPRR Hs00373136_m1 18S Hs03003631_g1 GAPDH Hs02758991_g1 Supplementary Table S2. Taqman® Genotyping and Gene Expression Assay Identification Numbers. SNP Chimp Orangutan Rhesus Marmoset Mouse Rat Cow Pig Guinea Pig Dog Elephant Opossum Chicken rs3803036 X X X X X X X X X X X X X rs1520562 X X X X X X rs1358228 X X X X X X X X X X X rs17306116 X X X X X X rs790436 X X X X X X X rs1558726 X X X X X X X X rs741525 X X X X X X X X rs7134216 X X X X X X rs4764971 X X X X X X X Supplementary Table S3. Conservation of Top SNPs from Association. X indicates SNP is conserved.
    [Show full text]
  • Supplementary Table S1. Upregulated Genes Differentially
    Supplementary Table S1. Upregulated genes differentially expressed in athletes (p < 0.05 and 1.3-fold change) Gene Symbol p Value Fold Change 221051_s_at NMRK2 0.01 2.38 236518_at CCDC183 0.00 2.05 218804_at ANO1 0.00 2.05 234675_x_at 0.01 2.02 207076_s_at ASS1 0.00 1.85 209135_at ASPH 0.02 1.81 228434_at BTNL9 0.03 1.81 229985_at BTNL9 0.01 1.79 215795_at MYH7B 0.01 1.78 217979_at TSPAN13 0.01 1.77 230992_at BTNL9 0.01 1.75 226884_at LRRN1 0.03 1.74 220039_s_at CDKAL1 0.01 1.73 236520_at 0.02 1.72 219895_at TMEM255A 0.04 1.72 201030_x_at LDHB 0.00 1.69 233824_at 0.00 1.69 232257_s_at 0.05 1.67 236359_at SCN4B 0.04 1.64 242868_at 0.00 1.63 1557286_at 0.01 1.63 202780_at OXCT1 0.01 1.63 1556542_a_at 0.04 1.63 209992_at PFKFB2 0.04 1.63 205247_at NOTCH4 0.01 1.62 1554182_at TRIM73///TRIM74 0.00 1.61 232892_at MIR1-1HG 0.02 1.61 204726_at CDH13 0.01 1.6 1561167_at 0.01 1.6 1565821_at 0.01 1.6 210169_at SEC14L5 0.01 1.6 236963_at 0.02 1.6 1552880_at SEC16B 0.02 1.6 235228_at CCDC85A 0.02 1.6 1568623_a_at SLC35E4 0.00 1.59 204844_at ENPEP 0.00 1.59 1552256_a_at SCARB1 0.02 1.59 1557283_a_at ZNF519 0.02 1.59 1557293_at LINC00969 0.03 1.59 231644_at 0.01 1.58 228115_at GAREM1 0.01 1.58 223687_s_at LY6K 0.02 1.58 231779_at IRAK2 0.03 1.58 243332_at LOC105379610 0.04 1.58 232118_at 0.01 1.57 203423_at RBP1 0.02 1.57 AMY1A///AMY1B///AMY1C///AMY2A///AMY2B// 208498_s_at 0.03 1.57 /AMYP1 237154_at LOC101930114 0.00 1.56 1559691_at 0.01 1.56 243481_at RHOJ 0.03 1.56 238834_at MYLK3 0.01 1.55 213438_at NFASC 0.02 1.55 242290_at TACC1 0.04 1.55 ANKRD20A1///ANKRD20A12P///ANKRD20A2///
    [Show full text]
  • RNA Epigenetics: Fine-Tuning Chromatin Plasticity and Transcriptional Regulation, and the Implications in Human Diseases
    G C A T T A C G G C A T genes Review RNA Epigenetics: Fine-Tuning Chromatin Plasticity and Transcriptional Regulation, and the Implications in Human Diseases Amber Willbanks, Shaun Wood and Jason X. Cheng * Department of Pathology, Hematopathology Section, University of Chicago, Chicago, IL 60637, USA; [email protected] (A.W.); [email protected] (S.W.) * Correspondence: [email protected] Abstract: Chromatin structure plays an essential role in eukaryotic gene expression and cell identity. Traditionally, DNA and histone modifications have been the focus of chromatin regulation; however, recent molecular and imaging studies have revealed an intimate connection between RNA epigenetics and chromatin structure. Accumulating evidence suggests that RNA serves as the interplay between chromatin and the transcription and splicing machineries within the cell. Additionally, epigenetic modifications of nascent RNAs fine-tune these interactions to regulate gene expression at the co- and post-transcriptional levels in normal cell development and human diseases. This review will provide an overview of recent advances in the emerging field of RNA epigenetics, specifically the role of RNA modifications and RNA modifying proteins in chromatin remodeling, transcription activation and RNA processing, as well as translational implications in human diseases. Keywords: 5’ cap (5’ cap); 7-methylguanosine (m7G); R-loops; N6-methyladenosine (m6A); RNA editing; A-to-I; C-to-U; 2’-O-methylation (Nm); 5-methylcytosine (m5C); NOL1/NOP2/sun domain Citation: Willbanks, A.; Wood, S.; (NSUN); MYC Cheng, J.X. RNA Epigenetics: Fine-Tuning Chromatin Plasticity and Transcriptional Regulation, and the Implications in Human Diseases. Genes 2021, 12, 627.
    [Show full text]
  • A Computational Approach for Defining a Signature of Β-Cell Golgi Stress in Diabetes Mellitus
    Page 1 of 781 Diabetes A Computational Approach for Defining a Signature of β-Cell Golgi Stress in Diabetes Mellitus Robert N. Bone1,6,7, Olufunmilola Oyebamiji2, Sayali Talware2, Sharmila Selvaraj2, Preethi Krishnan3,6, Farooq Syed1,6,7, Huanmei Wu2, Carmella Evans-Molina 1,3,4,5,6,7,8* Departments of 1Pediatrics, 3Medicine, 4Anatomy, Cell Biology & Physiology, 5Biochemistry & Molecular Biology, the 6Center for Diabetes & Metabolic Diseases, and the 7Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202; 2Department of BioHealth Informatics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202; 8Roudebush VA Medical Center, Indianapolis, IN 46202. *Corresponding Author(s): Carmella Evans-Molina, MD, PhD ([email protected]) Indiana University School of Medicine, 635 Barnhill Drive, MS 2031A, Indianapolis, IN 46202, Telephone: (317) 274-4145, Fax (317) 274-4107 Running Title: Golgi Stress Response in Diabetes Word Count: 4358 Number of Figures: 6 Keywords: Golgi apparatus stress, Islets, β cell, Type 1 diabetes, Type 2 diabetes 1 Diabetes Publish Ahead of Print, published online August 20, 2020 Diabetes Page 2 of 781 ABSTRACT The Golgi apparatus (GA) is an important site of insulin processing and granule maturation, but whether GA organelle dysfunction and GA stress are present in the diabetic β-cell has not been tested. We utilized an informatics-based approach to develop a transcriptional signature of β-cell GA stress using existing RNA sequencing and microarray datasets generated using human islets from donors with diabetes and islets where type 1(T1D) and type 2 diabetes (T2D) had been modeled ex vivo. To narrow our results to GA-specific genes, we applied a filter set of 1,030 genes accepted as GA associated.
    [Show full text]
  • Review Article PTEN Gene: a Model for Genetic Diseases in Dermatology
    The Scientific World Journal Volume 2012, Article ID 252457, 8 pages The cientificWorldJOURNAL doi:10.1100/2012/252457 Review Article PTEN Gene: A Model for Genetic Diseases in Dermatology Corrado Romano1 and Carmelo Schepis2 1 Unit of Pediatrics and Medical Genetics, I.R.C.C.S. Associazione Oasi Maria Santissima, 94018 Troina, Italy 2 Unit of Dermatology, I.R.C.C.S. Associazione Oasi Maria Santissima, 94018 Troina, Italy Correspondence should be addressed to Carmelo Schepis, [email protected] Received 19 October 2011; Accepted 4 January 2012 Academic Editors: G. Vecchio and H. Zitzelsberger Copyright © 2012 C. Romano and C. Schepis. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. PTEN gene is considered one of the most mutated tumor suppressor genes in human cancer, and it’s likely to become the first one in the near future. Since 1997, its involvement in tumor suppression has smoothly increased, up to the current importance. Germline mutations of PTEN cause the PTEN hamartoma tumor syndrome (PHTS), which include the past-called Cowden, Bannayan- Riley-Ruvalcaba, Proteus, Proteus-like, and Lhermitte-Duclos syndromes. Somatic mutations of PTEN have been observed in glioblastoma, prostate cancer, and brest cancer cell lines, quoting only the first tissues where the involvement has been proven. The negative regulation of cell interactions with the extracellular matrix could be the way PTEN phosphatase acts as a tumor suppressor. PTEN gene plays an essential role in human development. A recent model sees PTEN function as a stepwise gradation, which can be impaired not only by heterozygous mutations and homozygous losses, but also by other molecular mechanisms, such as transcriptional regression, epigenetic silencing, regulation by microRNAs, posttranslational modification, and aberrant localization.
    [Show full text]
  • Molecular and Genetic Medicine
    Bertazzi et al., J Mol Genet Med 2015, 8:2 Molecular and Genetic Medicine http://dx.doi.org/10.4172/1747-0862.1000116 Review Article Open Access Myotubularin MTM1 Involved in Centronuclear Myopathy and its Roles in Human and Yeast Cells Dimitri L. Bertazzi#, Johan-Owen De Craene# and Sylvie Friant* Department of Molecular and Cellular Genetics, UMR7156, Université de Strasbourg and CNRS, France #Authors contributed equally to this work. *Corresponding author: Friant S, Department of Molecular and Cellular Genetics, UMR7156, Université de Strasbourg and CNRS, 67084 Strasbourg, France, E-mail: [email protected] Received date: April 17, 2014; Accepted date: July 21, 2014; Published date: July 28, 2014 Copyright: © 2014 Bertazzi DL, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract Mutations in the MTM1 gene, encoding the phosphoinositide phosphatase myotubularin, are responsible for the X-linked centronuclear myopathy (XLCNM) or X-linked myotubular myopathy (XLMTM). The MTM1 gene was first identified in 1996 and its function as a PtdIns3P and PtdIns(,5)P2 phosphatase was discovered in 2000. In recent years, very important progress has been made to set up good models to study MTM1 and the XLCNM disease such as knockout or knockin mice, the Labrador Retriever dog, the zebrafish and the yeast Saccharomyces cerevisiae. These helped to better understand the cellular function of MTM1 and of its four conserved domains: PH-GRAM (Pleckstrin Homology-Glucosyltransferase, Rab-like GTPase Activator and Myotubularin), RID (Rac1-Induced recruitment Domain), PTP/DSP (Protein Tyrosine Phosphatase/Dual-Specificity Phosphatase) and SID (SET-protein Interaction Domain).
    [Show full text]
  • Bioinformatics-Based Screening of Key Genes for Transformation of Liver
    Jiang et al. J Transl Med (2020) 18:40 https://doi.org/10.1186/s12967-020-02229-8 Journal of Translational Medicine RESEARCH Open Access Bioinformatics-based screening of key genes for transformation of liver cirrhosis to hepatocellular carcinoma Chen Hao Jiang1,2, Xin Yuan1,2, Jiang Fen Li1,2, Yu Fang Xie1,2, An Zhi Zhang1,2, Xue Li Wang1,2, Lan Yang1,2, Chun Xia Liu1,2, Wei Hua Liang1,2, Li Juan Pang1,2, Hong Zou1,2, Xiao Bin Cui1,2, Xi Hua Shen1,2, Yan Qi1,2, Jin Fang Jiang1,2, Wen Yi Gu4, Feng Li1,2,3 and Jian Ming Hu1,2* Abstract Background: Hepatocellular carcinoma (HCC) is the most common type of liver tumour, and is closely related to liver cirrhosis. Previous studies have focussed on the pathogenesis of liver cirrhosis developing into HCC, but the molecular mechanism remains unclear. The aims of the present study were to identify key genes related to the transformation of cirrhosis into HCC, and explore the associated molecular mechanisms. Methods: GSE89377, GSE17548, GSE63898 and GSE54236 mRNA microarray datasets from Gene Expression Omni- bus (GEO) were analysed to obtain diferentially expressed genes (DEGs) between HCC and liver cirrhosis tissues, and network analysis of protein–protein interactions (PPIs) was carried out. String and Cytoscape were used to analyse modules and identify hub genes, Kaplan–Meier Plotter and Oncomine databases were used to explore relationships between hub genes and disease occurrence, development and prognosis of HCC, and the molecular mechanism of the main hub gene was probed using Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analysis.
    [Show full text]
  • Understanding Drug-Drug Interactions Due to Mechanism-Based Inhibition in Clinical Practice
    pharmaceutics Review Mechanisms of CYP450 Inhibition: Understanding Drug-Drug Interactions Due to Mechanism-Based Inhibition in Clinical Practice Malavika Deodhar 1, Sweilem B Al Rihani 1 , Meghan J. Arwood 1, Lucy Darakjian 1, Pamela Dow 1 , Jacques Turgeon 1,2 and Veronique Michaud 1,2,* 1 Tabula Rasa HealthCare Precision Pharmacotherapy Research and Development Institute, Orlando, FL 32827, USA; [email protected] (M.D.); [email protected] (S.B.A.R.); [email protected] (M.J.A.); [email protected] (L.D.); [email protected] (P.D.); [email protected] (J.T.) 2 Faculty of Pharmacy, Université de Montréal, Montreal, QC H3C 3J7, Canada * Correspondence: [email protected]; Tel.: +1-856-938-8697 Received: 5 August 2020; Accepted: 31 August 2020; Published: 4 September 2020 Abstract: In an ageing society, polypharmacy has become a major public health and economic issue. Overuse of medications, especially in patients with chronic diseases, carries major health risks. One common consequence of polypharmacy is the increased emergence of adverse drug events, mainly from drug–drug interactions. The majority of currently available drugs are metabolized by CYP450 enzymes. Interactions due to shared CYP450-mediated metabolic pathways for two or more drugs are frequent, especially through reversible or irreversible CYP450 inhibition. The magnitude of these interactions depends on several factors, including varying affinity and concentration of substrates, time delay between the administration of the drugs, and mechanisms of CYP450 inhibition. Various types of CYP450 inhibition (competitive, non-competitive, mechanism-based) have been observed clinically, and interactions of these types require a distinct clinical management strategy. This review focuses on mechanism-based inhibition, which occurs when a substrate forms a reactive intermediate, creating a stable enzyme–intermediate complex that irreversibly reduces enzyme activity.
    [Show full text]