DOCSLIB.ORG

BIOLOGY, STRUCTURE and MECHANISM of P-TYPE Atpases

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
BIOLOGY, STRUCTURE and MECHANISM of P-TYPE Atpases REVIEWS BIOLOGY, STRUCTURE AND MECHANISM OF P-TYPE ATPases Werner Kühlbrandt P-type ATPases are ion pumps that carry out many fundamental processes in biology and medicine, ranging from the generation of membrane potential to muscle contraction and the removal of toxic ions from cells. Making use of the energy stored in ATP, they transport specific ions across the cell membrane against a concentration gradient. Recent X-ray structures and homology models of P-type pumps now provide a basis for understanding the molecular mechanism of ATP-driven ion transport. MEMBRANE POTENTIAL In 1957, Jens Skou examined the effect of various universally accepted and remains useful for identify- The charge difference cations on a homogenate of leg nerves from crabs that ing particular states. A summary of the catalytic cycle (measured in mV) between the were caught on the shores of Denmark. The results — or Post–Albers cycle — is shown in BOX 1.In their two surfaces of a biological led him to suggest that MEMBRANE POTENTIAL is generated normal mode of action, P-type pumps use ATP to membrane that arises from the by a K+-stimulated ATPase — now known as the maintain an ion gradient across the cell membrane, different concentrations of ions + + + such as H+,Na+ or K+ on either Na /K -ATPase — that uses ATP to transport Na and but each step is reversible, so P-type ATPases can, in side. The Na+/K+-ATPase creates K+ ions across the axonal membrane1. Little did he principle, use a membrane potential to produce ATP. a membrane potential by using know that he had just discovered the first P-type For further information about the early literature on the energy stored in ATP to ATPase, and that this would win him the Nobel prize in P-type ATPases, see REF. 6. maintain a low concentration of Na+ and a high concentration chemistry 40 years later. In subsequent years, other ion P-type pumps are a large, ubiquitous and varied of K+ in the cell, against a higher pumps with similar characteristics were found in many family of membrane proteins that are involved in concentration of Na+ and a different tissues and organisms. They include the sar- many transport processes in virtually all living organ- lower concentration of K+ on coplasmic-reticulum (SR) Ca2+-ATPase that helps to isms. A sequence alignment of four main representa- the outside. control the contraction of skeletal muscle2, the gas- tives of the family (FIG. 1) shows a characteristic pattern tric H+/K+-ATPase that acidifies the stomach, and the of conserved residues, most notably the DKTGTLT H+-ATPase that generates membrane potential in fun- sequence motif (in which D is the reversibly phospho- gal and plant cells3.The biochemical characteristics that rylated Asp). Another characteristic is the presence of are common to these ion pumps are an acid-stable, 10 hydrophobic membrane-spanning helices phosphorylated Asp residue that forms during the (M1–M10; although some have only six or eight), and pumping cycle (the phosphorylated (P) intermediate highly conserved cytoplasmic domains that are gives the family its name) and inhibition by ortho- inserted between helices M2 and M3 and between M4 vanadate, a transition-state analogue. and M5. FIGURE 1 shows that 87 of the roughly 900 Almost 30 years ago4, it was established that the residues are invariant, with identical side chains or Max-Planck Institut für Biophysik, Marie-Curie- P-type ATPases undergo large conformational changes conservative substitutions in equivalent positions. As Straße 13–15, 60439 to translocate ions. Originally, two distinct conforma- the four proteins that are compared in FIG. 1 are from Frankfurt am Main, tions were called E1 and E2 (enzyme-1 and enzyme-2), widely different, unrelated organisms, there is no Germany. with each having a different affinity for the nucleotide doubt that these conserved regions are structurally e-mail: and the transported ions. Later, it became clear that the and functionally significant. Werner.Kuehlbrandt@mpi bp-frankfurt.mpg.de pumping cycle involves several further intermediate This article briefly reviews the distribution of P-type doi:10.1038/nrm1354 states5.Nevertheless, the E1/E2 nomenclature is almost ATPases in biology, then presents a short overview of 282 | APRIL 2004 | VOLUME 5 www.nature.com/reviews/molcellbio © 2004 Nature Publishing Group REVIEWS the different subfamilies and their ion specificities, Box 1 | The Post–Albers cycle before examining in some detail what the recent struc- tures of entire enzymes or individual domains tell us Mg2+–ATP ADP about the fundamental mechanism of ATP-driven ion E1 ion 1 E1–P ion 1 translocation. n n mion 2 mion 2 P-type-ATPase genomics Inside Outside In general, P-type-ATPase genes are more widespread nion 1 nion 1 and varied in eukaryotes than in bacteria and E2 ion 2 E2–P ion 2 archaea. Only four P-type ATPases have been identi- m m fied in Escherchia coli 7.The thermophilic archaean 2+ Methanococcus jannaschii has only one8, and certain par- Pi, Mg asitic bacteria seem to have none7.By contrast, the 9 The general ion-translocation cycle of P-type ATPases Saccharomyces cerevisiae genome has 16 P-type ATPases , (see figure) is based on the Post–Albers scheme for the and no fewer than 45 have been identified in the Na+/K+-ATPase96,97.In simple terms, ion 1 (X+ in FIG. 6) 10 Arabidopsis thaliana genome ,which points to their from the cell interior binds to a high-affinity site in the importance in vascular plants. Genome-wide searches in ATPase E1 state. Ion binding triggers phosphorylation of Caenorhabditis elegans and Drosophila melanogaster have the enzyme by Mg2+–ATP,which leads to the turned up 21 and 15 genes, respectively11.A correspond- phosphorylated E1–P state. The phosphorylated E2–P ing analysis of P-type pumps in the human or mouse state then forms, which is unable to phosphorylate ADP, genome would be interesting, but has not yet been and this state has a reduced affinity for ion 1, which reported. escapes to the outside. Ion 2 (Y+ in FIG. 6) binds from the All P-type ATPases are multi-domain membrane outside and, on hydrolysis of the phosphorylated Asp, proteins with molecular masses of 70–150 kDa. Both the enzyme releases ion 2 to the interior and re-binds ion 1. the carboxyl and amino termini are on the cytoplas- The enzyme is then ready to start another cycle. As a net mic side of the membrane, so they all have an even result of this process, n ions of type 1 are expelled and number of transmembrane segments. Based on m ions of type 2 are imported per molecule of ATP sequence homology, the P-type-ATPase family can be consumed — n and m are small integral numbers divided into five branches (FIG. 2),which are referred between 1 and 3. Pi, inorganic phosphate. to as types I–V.Within these branches, a total of 10 different subtypes or classes can be distinguished7,12. Each subtype is specific for a particular substrate ion the consensus sequence (FIG. 1),but have an extra two (FIG. 2).Functional studies might lead to further rami- helices at the amino-terminal end. Although most fications of the family tree, but it seems unlikely that type-IB ATPases are bacterial, close homologues have entirely new, as yet undiscovered, branches will turn been found in S. cerevisiae 9, plants7 and animals18. up in future genome searches. Mutations in human Cu+-efflux pumps cause the rare,but lethal, hereditary Menkes and Wilson dis- Substrate specificity eases. Because of their medical relevance, these Type-I ATPases. The simplest, and presumably most pumps have received much attention since their dis- ancient, ion pumps are type-I pumps (FIG. 2).Type IA is covery 10 years ago19,20–21. a small class that contains bacterial ion pumps, with the E. coli Kdp K+-pump as the prototype. The Kdp pump Type-IV and -V ATPases. The closest relatives of the is a complex of four different membrane proteins — type-I enzymes are types IV and V (FIG. 2).Type-IV that is, KdpF, KdpA, KdpB and KdpC.The 72-kDa ATPases have so far been found only in eukaryotes, in KdpB subunit contains the catalytic core and ion- which they are involved in lipid transport and the translocation site13 and, with only six membrane-span- maintenance of lipid-bilayer asymmetry. These ‘lipid ning helices, the KdpB subunit is the smallest P-type flippases’ are thought to translocate phospholipids ATPase. from the outer to the inner leaflet of, for example, red- Although most P-type ATPases translocate the small, blood-cell22 and S. cerevisiae 23 plasma membranes. The ‘hard’ cations H+,Na+,K+,Ca2+ and Mg2+, the substrates erythrocyte lipid flippase is a Mg2+-ATPase24.Sequence of type-IB ATPases are ‘soft’-transition-metal ions. comparisons show that they have the main features of Type-IB ATPases — for example, the bacterial metal- the ion-translocating P-type ATPases7,including the resistance proteins CopA14, ZntA15 and CadA16 — ion-binding site in the membrane. In view of the close remove toxic ions such as Cu+,Ag+,Zn2+,Cd2+ or structural homology of the known P-type ATPases, it is Pb2+ from the cell. The homeostasis of indispensable difficult to imagine how the binding site at the centre trace elements, such as Cu+ and Zn2+, is achieved by of a 10-helix bundle can adapt to translocate both ions balancing the activity of these efflux pumps against and phospholipids. Perhaps the lipid flippases are ion ABC-type metal-uptake proteins16,17.Unlike the pumps that work in close association with ion-depen- type-IA ATPases, type-IB ATPases work as single- dent, lipid-transport proteins such as the lipid-translo- chain proteins and have eight membrane-spanning cating ABC transporters22.Even more elusive than the helices.
Load more

Recommended publications
  • Molecular Profile of Tumor-Specific CD8+ T Cell Hypofunction in a Transplantable Murine Cancer Model
    Downloaded from http://www.jimmunol.org/ by guest on September 25, 2021 T + is online at: average * The Journal of Immunology , 34 of which you can access for free at: 2016; 197:1477-1488; Prepublished online 1 July from submission to initial decision 4 weeks from acceptance to publication 2016; doi: 10.4049/jimmunol.1600589 http://www.jimmunol.org/content/197/4/1477 Molecular Profile of Tumor-Specific CD8 Cell Hypofunction in a Transplantable Murine Cancer Model Katherine A. Waugh, Sonia M. Leach, Brandon L. Moore, Tullia C. Bruno, Jonathan D. Buhrman and Jill E. Slansky J Immunol cites 95 articles Submit online. Every submission reviewed by practicing scientists ? is published twice each month by Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts http://jimmunol.org/subscription Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html http://www.jimmunol.org/content/suppl/2016/07/01/jimmunol.160058 9.DCSupplemental This article http://www.jimmunol.org/content/197/4/1477.full#ref-list-1 Information about subscribing to The JI No Triage! Fast Publication! Rapid Reviews! 30 days* Why • • • Material References Permissions Email Alerts Subscription Supplementary The Journal of Immunology The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2016 by The American Association of Immunologists, Inc. All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. This information is current as of September 25, 2021. The Journal of Immunology Molecular Profile of Tumor-Specific CD8+ T Cell Hypofunction in a Transplantable Murine Cancer Model Katherine A.
    [Show full text]
  • Plasma Membrane Ca2+–Atpase in Rat and Human Odontoblasts Mediates Dentin Mineralization
    biomolecules Article Plasma Membrane Ca2+–ATPase in Rat and Human Odontoblasts Mediates Dentin Mineralization Maki Kimura 1,†, Hiroyuki Mochizuki 1,†, Ryouichi Satou 2, Miyu Iwasaki 2, Eitoyo Kokubu 3, Kyosuke Kono 1, Sachie Nomura 1, Takeshi Sakurai 1, Hidetaka Kuroda 1,4,† and Yoshiyuki Shibukawa 1,*,† 1 Department of Physiology, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan; [email protected] (M.K.); [email protected] (H.M.); [email protected] (K.K.); [email protected] (S.N.); [email protected] (T.S.); [email protected] (H.K.) 2 Department of Epidemiology and Public Health, Tokyo Dental College, Chiyodaku, Tokyo 101-0061, Japan; [email protected] (R.S.); [email protected] (M.I.) 3 Department of Microbiology, Tokyo Dental College, Chiyodaku, Tokyo 101-0061, Japan; [email protected] 4 Department of Dental Anesthesiology, Kanagawa Dental University, 1-23, Ogawacho, Kanagawa, Yokosuka-shi 238-8570, Japan * Correspondence: [email protected] † These authors contributed equally to this study. Abstract: Intracellular Ca2+ signaling engendered by Ca2+ influx and mobilization in odontoblasts is critical for dentinogenesis induced by multiple stimuli at the dentin surface. Increased Ca2+ is exported by the Na+–Ca2+ exchanger (NCX) and plasma membrane Ca2+–ATPase (PMCA) to Citation: Kimura, M.; Mochizuki, H.; maintain Ca2+ homeostasis. We previously demonstrated a functional coupling between Ca2+ Satou, R.; Iwasaki, M.; Kokubu, E.; extrusion by NCX and its influx through transient receptor potential channels in odontoblasts. Kono, K.; Nomura, S.; Sakurai, T.; Although the presence of PMCA in odontoblasts has been previously described, steady-state levels of Kuroda, H.; Shibukawa, Y.
    [Show full text]
  • Crystal Structures of the Gastric Proton Pump Reveal the Mechanism for Proton Extrusion
    Life Science Research Frontiers 2018 Research Frontiers 2018 Crystal structures of the gastric proton pump reveal the mechanism for proton extrusion After intaking food, the pH inside our stomach phosphorylation (P), and actuator (A) domains reaches around 1. This acidic environment, (Fig. 2(a)). The β-subunit has a single TM helix and generated by the gastric proton pump H+,K+-ATPase a large ectodomain with three of the six N-linked [1], is indispensable for food digestion and is also glycosylation sites visualized in the structure. The an important barrier to pathogen invasion via the electron density maps define the binding mode of oral route. However, excess stomach acidification vonoprazan (now available for clinical treatment) and induces ulcers, which considerably impair the health SCH28080 (a prototype of P-CAB), and the residues of those affected. Acid suppression in combination coordinating them, in a luminal-facing conduit that with antibiotics is a widely recognized treatment to extends to the cation-binding site (Figs. 2(b) and 2(c)). eradicate Helicobactor pylori, a strong risk factor for The binding sites of these P-CABs were previously gastric cancer. Proton pump inhibitors (PPIs) and a thought to overlap owing to similar inhibitory actions. recently developed class of acid suppressants called Our structures show that they do indeed partially K+-competitive acid blockers (P-CABs) are commonly overlap but are also distinct. The binding mode used for the treatment of acid-related diseases. of P-CABs determined in the crystal structure is Gastric H+,K+-ATPase therefore continues to be a consistent with mutagenesis studies, providing prominent target for the treatment of excess stomach the molecular basis for P-CAB binding to H+,K+- acidification.
    [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]
  • To Study Mutant P53 Gain of Function, Various Tumor-Derived P53 Mutants
    Differential effects of mutant TAp63γ on transactivation of p53 and/or p63 responsive genes and their effects on global gene expression. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science By Shama K Khokhar M.Sc., Bilaspur University, 2004 B.Sc., Bhopal University, 2002 2007 1 COPYRIGHT SHAMA K KHOKHAR 2007 2 WRIGHT STATE UNIVERSITY SCHOOL OF GRADUATE STUDIES Date of Defense: 12-03-07 I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPERVISION BY SHAMA KHAN KHOKHAR ENTITLED Differential effects of mutant TAp63γ on transactivation of p53 and/or p63 responsive genes and their effects on global gene expression BE ACCEPTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Master of Science Madhavi P. Kadakia, Ph.D. Thesis Director Daniel Organisciak , Ph.D. Department Chair Committee on Final Examination Madhavi P. Kadakia, Ph.D. Steven J. Berberich, Ph.D. Michael Leffak, Ph.D. Joseph F. Thomas, Jr., Ph.D. Dean, School of Graduate Studies 3 Abstract Khokhar, Shama K. M.S., Department of Biochemistry and Molecular Biology, Wright State University, 2007 Differential effect of TAp63γ mutants on transactivation of p53 and/or p63 responsive genes and their effects on global gene expression. p63, a member of the p53 gene family, known to play a role in development, has more recently also been implicated in cancer progression. Mice lacking p63 exhibit severe developmental defects such as limb truncations, abnormal skin, and absence of hair follicles, teeth, and mammary glands. Germline missense mutations of p63 have been shown to be responsible for several human developmental syndromes including SHFM, EEC and ADULT syndromes and are associated with anomalies in the development of organs of epithelial origin.
    [Show full text]
  • Molecular Regulation and Physiology of the H ,K -Atpases in Kidney
    Molecular Regulation and Physiology of the H؉,K؉-ATPases in Kidney Juan Codina and Thomas D. DuBose Jr Two H؉,K؉-adenosine triphosphatase (ATPase) proteins participate in K؉ absorption and ؉ ؉ ؉ H secretion in the renal medulla. Both the gastric (HK␣1) and colonic (HK␣2)H,K - ATPases have been localized and characterized by a number of techniques, and are known to be highly regulated in response to acid-base and electrolyte disturbances. Both ATPases are dimers of composition ␣/␤ that localize to the apical membrane and both interact with the tetraspanin protein CD63. Although CD63 interacts with the carboxy-terminus of the subunit of the colonic H؉,K؉-ATPase, it interacts with the ␤-subunit of the gastric-␣ H؉,K؉-ATPase. Pharmacologically, both ATPases are distinct; for example, the gastric H؉,K؉-ATPase is inhibited by Sch-28080, but the colonic H؉,K؉-ATPase is inhibited by .ouabain (a classic inhibitor of the Na؉-pump) and is completely insensitive to Sch-28080 The ␣-subunit of the colonic H؉,K؉-ATPase is the only subunit of the X؉,K؉-ATPase superfamily that has 3 different splice variants that emerge by deletion or elongation of the amino-terminus. The messenger RNA and protein of one of these splice variants (HK␣2C)is specifically up-regulated in newborn rats and becomes undetectable in adult rats. There- fore, HK␣2, in addition to its role in potassium and acid-base homeostasis, appears to play a significant role in early growth and development. Finally, because chronic hypokalemia appears to be the most potent stimulus for upregulation of HK␣2, we propose that the HK␣2 participates importantly in the maintenance of chronic metabolic alkalosis.
    [Show full text]
  • A Model of Mitochonrial Calcium Induced Calcium
    A MODEL OF MITOCHONRIAL CALCIUM INDUCED CALCIUM RELEASE DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Balbir Thomas, The Ohio State University 2007 Dissertation Committee: Approved by David Terman, Adviser Douglas R. Pfeiffer Adviser Edward Overman Biophysics Graduate Program Christopher P. Fall ABSTRACT Cytoplasmic calcium plays a dual role in cellular physiology. On one hand it acts as a second messenger in intra-cellular signalling, and on the other hand it is also the trigger for calcium dependent apopotosis. A mechanistic explanation of this dual role of cytoplasmic calcium was proposed by Ichas and Mazat. Their hypothesis involved the permeability transition pore was based on the observation that the permeability transition pore can exist in multiple conductance states. Specifically there exist a persistent high conductance state and a transitory low conductance state. Ichas et.al. also observed that the low conductance state is opened by a rise in mitochondrial matrix pH, in contrast to what was already know about the high conductance state, which opens in response to prolonged elevation of mitochondrial calcium. In this dissertation we build a detailed, physiological model of the mitochondrial switch between calcium signalling and cell death based on a simple three state model of the permeability transition pore. This model agrees with the substance of the Ichas and Mazat hypothesis and provides a substrate for further modeling to study the spatial and temporal dynamics of mitochondrial involvement in intracellular calcium signalling, and the interaction of mitochondria and endoplasmic reticulum during this process.
    [Show full text]
  • Molecular Cloning and Sequence of Cdna Encoding the Plasma
    Proc. Nad. Acad. Sci. USA Vol. 86, 1234-1238, February 1989 Botany Molecular cloning and sequence of cDNA encoding the plasma membrane proton pump (H+-ATPase) of Arabidopsis thaliana (cation pumps/nucleotide sequence/amino add homology/oligonucleotide screening/transmembrane segments) JEFFREY F. HARPER, TERRY K. SUROWY*, AND MICHAEL R. SUSSMAN Department of Horticulture, University of Wisconsin, 1575 Linden Drive, Madison, WI 53706 Communicated by Luis Sequeira, November 14, 1988 ABSTRACT In plants, the transport of solutes across the synthesized an oligonucleotide probe to screen an oat cDNA plasma membrane is driven by a proton pump (H -ATPase) library and then used a purified oat clone to isolate a that produces an electric potential and pH gradient. We have full-length A. thaliana cDNA clone. Here we provide evi- isolated and sequenced a full-length cDNA clone that encodes dence for the presence of at least two genes encoding plasma this enzyme inArabidopsis thaiana. The protein predicted from membrane proton pumps in A. thaliana and report the its nucleotide sequence encodes 959 amino acids and has a predicted amino acid sequence from one. molecular mass of 104,207 Da. The plant protein shows structural features common to a family of cation-translocating MATERIALS AND METHODS ATPases found in the plasma membrane of prokaryotic and eukaryotic cells, with the greatest overall identity in amino acid Plants. A. thaliana L. cv. Columbia and Avena sativa L. sequence (36%) to the H+-ATPase observed in the plasma cv. Gary (oat) were plant materials used in this study. Unless membrane of fungi. The structure predicted from a hydropa- otherwise noted, standard molecular techniques were per- thy plot contains at least eight transmembrane segments, with formed according to Maniatis et al.
    [Show full text]
  • Research Article Identification of ATP8B1 As a Tumor Suppressor Gene for Colorectal Cancer and Its Involvement in Phospholipid Homeostasis
    Hindawi BioMed Research International Volume 2020, Article ID 2015648, 16 pages https://doi.org/10.1155/2020/2015648 Research Article Identification of ATP8B1 as a Tumor Suppressor Gene for Colorectal Cancer and Its Involvement in Phospholipid Homeostasis Li Deng,1,2 Geng-Ming Niu,1 Jun Ren,1 and Chong-Wei Ke 1 1Department of General Surgery, The Fifth People’s Hospital of Shanghai, Fudan University, Shanghai, China 2Department of General Surgery, The Shanghai Public Health Clinical Center, Fudan University, Shanghai, China Correspondence should be addressed to Chong-Wei Ke; [email protected] Received 5 May 2020; Revised 16 July 2020; Accepted 17 August 2020; Published 29 September 2020 Academic Editor: Luis Loura Copyright © 2020 Li Deng et al. 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. Homeostasis of membrane phospholipids plays an important role in cell oncogenesis and cancer progression. The flippase ATPase class I type 8b member 1 (ATP8B1), one of the P4-ATPases, translocates specific phospholipids from the exoplasmic to the cytoplasmic leaflet of membranes. ATP8B1 is critical for maintaining the epithelium membrane stability and polarity. However, the prognostic values of ATP8B1 in colorectal cancer (CRC) patients remain unclear. We analyzed transcriptomics, genomics, and clinical data of CRC samples from The Cancer Genome Atlas (TCGA). ATP8B1 was the only potential biomarker of phospholipid transporters in CRC. Its prognostic value was also validated with the data from the Gene Expression Omnibus (GEO). Compared to the normal group, the expression of ATP8B1 was downregulated in the tumor group and the CRC cell lines, which declined with disease progression.
    [Show full text]
  • Optimisation and Validation of a High Throughput Screening Compatible
    J Pharm Pharmaceut Sci (www.cspsCanada.org) 16(2) 217 - 230, 2013 Optimisation and Validation of a High Throughput Screening Compatible Assay to Identify Inhibitors of the Plasma Membrane Calcium ATPase Pump - a Novel Therapeutic Target for Contraception and Malaria Tamer M A Mohamed1,2, Simon A Zakeri1, Florence Baudoin1, Markus Wolf3, Delvac Oceandy1, Elizabeth J Cartwright1, Sheraz Gul3, Ludwig Neyses1 1 Institute of Cardiovascular Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, UK. 2 Dept. of Biochemistry, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt. 3 European ScreeningPort GmbH, 22525 Hamburg, Germany. Received, March 13, 2013; Revised, April 25, 2013; Accepted, May 8th, 2013; Published, May 10th, 2013. ABSTRACT – Purpose. ATPases, which constitute a major category of ion transporters in the human body, have a variety of significant biological and pathological roles. However, the lack of high throughput assays for ATPases has significantly limited drug discovery in this area. We have recently found that the genetic deletion of the ATP dependent calcium pump PMCA4 (plasma membrane calcium/calmodulin dependent ATPase, isoform 4) results in infertility in male mice due to a selective defect in sperm motility. In addition, recent discoveries in humans have indicated that a single nucleotide polymorphism (SNP) in the PMCA4 gene determines the susceptibility towards malaria plasmodium infection. Therefore, there is an urgent need to develop specific PMCA4 inhibitors. In the current study, we aim to optimise and validate a high throughput screening compatible assay using recombinantly expressed PMCA4 and the HTRF® Transcreener® ADP (TR-FRET) assay to screen a drug library. Methods and Results.
    [Show full text]
  • Targeting Oncogenic Notch Signaling with SERCA Inhibitors Luca Pagliaro, Matteo Marchesini and Giovanni Roti*
    Pagliaro et al. J Hematol Oncol (2021) 14:8 https://doi.org/10.1186/s13045-020-01015-9 REVIEW Open Access Targeting oncogenic Notch signaling with SERCA inhibitors Luca Pagliaro, Matteo Marchesini and Giovanni Roti* Abstract P-type ATPase inhibitors are among the most successful and widely prescribed therapeutics in modern pharmacol- ogy. Clinical transition has been safely achieved for H+/K+ ATPase inhibitors such as omeprazole and Na+/K+-ATPase 2 inhibitors like digoxin. However, this is more challenging for Ca +-ATPase modulators due to the physiological role of 2 2 Ca + in cardiac dynamics. Over the past two decades, sarco-endoplasmic reticulum Ca +-ATPase (SERCA) modula- 2 tors have been studied as potential chemotherapy agents because of their Ca +-mediated pan-cancer lethal efects. Instead, recent evidence suggests that SERCA inhibition suppresses oncogenic Notch1 signaling emerging as an alternative to γ-secretase modulators that showed limited clinical activity due to severe side efects. In this review, we focus on how SERCA inhibitors alter Notch1 signaling and show that Notch on-target-mediated antileukemia proper- 2 ties of these molecules can be achieved without causing overt Ca + cellular overload. Keywords: SERCA , T cell acute lymphoblastic leukemia, Thapsigargin, Notch signaling, NOTCH1, CAD204520, T-ALL Background metalloprotease (ADAM-10 or TACE/ADAM-17). Te NOTCH receptors are transmembrane cell-surface pro- resulting short-lived protein fragments are substrates teins that control cell to cell communication, embryo-
    [Show full text]
  • SERCA in Genesis of Arrhythmias: What We Already Know and What Is New?
    Review 43 SERCA in genesis of arrhythmias: what we already know and what is new? Nilüfer Erkasap Department of Physiology, Medical Faculty, Eskiflehir Osmangazi University, Eskiflehir, Turkey ABSTRACT This review mainly focuses on the structure, function of the sarco(endo)plasmic reticulum calcium pump (SERCA) and its role in genesis of arrhythmias. SERCA is a membrane protein that belongs to the family of P-type ion translocating ATPases and pumps free cytosolic calcium into intracellular stores. Active transport of Ca2+ is achieved, according to the E1-E2 model, changing of SERCA structure by Ca2+. The affinity of Ca2+ -binding sites varies from high (E1) to low (E2). Three different SERCA genes were identified-SERCA1, SERCA2, and SERCA3. SERCA is mainly represented by the SERCA2a isoform in the heart. In heart muscle, during systole, depolarization triggers the release of Ca2+ from the sarcoplasmic reticulum (SR) and starts contraction. During diastole, muscle relaxation occurs as Ca2+ is again removed from cytosol, predominantly by accumulation into SR via the action of SERCA2a. The main regulator of SERCA2a is phospholamban and another regulator proteolipid of SERCA is sarcolipin. There are a lot of studies on the effect of decreased and/or increased SERCA activity in genesis of arrhythmia. Actually both decrease and increase of SERCA activity in the heart result in some pathological mechanisms such as heart failure and arrhythmia. (Anadolu Kardiyol Derg 2007: 7 Suppl 1; 43-6) Key words: sarco(endo)plasmic reticulum, SERCA, arrhythmia, calcium channels Introduction from cytosol, predominantly by accumulation into sarcoplasmic reticulum via the action of sarco(endo)plasmic reticulum Cardiac physiology is a major area of research in basic and Ca ATPase (SERCA).
    [Show full text]