DOCSLIB.ORG

Mechanically Induced Hyperpolarization Via K2P Background Potassium Channels

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Mechanically Induced Hyperpolarization Via K2P Background Potassium Channels International Journal of Molecular Sciences Review Negative Influence by the Force: Mechanically Induced Hyperpolarization via K2P Background Potassium Channels Miklós Lengyel ,Péter Enyedi and Gábor Czirják * Department of Physiology, Semmelweis University, P.O. Box 2, H-1428 Budapest, Hungary; [email protected] (M.L.); [email protected] (P.E.) * Correspondence: [email protected] Abstract: The two-pore domain K2P subunits form background (leak) potassium channels, which are characterized by constitutive, although not necessarily constant activity, at all membrane potential values. Among the fifteen pore-forming K2P subunits encoded by the KCNK genes, the three members of the TREK subfamily, TREK-1, TREK-2, and TRAAK are mechanosensitive ion channels. Mechanically induced opening of these channels generally results in outward K+ current under physiological conditions, with consequent hyperpolarization and inhibition of membrane potential- dependent cellular functions. In the past decade, great advances have been made in the investigation of the molecular determinants of mechanosensation, and members of the TREK subfamily have emerged among the best-understood examples of mammalian ion channels directly influenced by the tension of the phospholipid bilayer. In parallel, the crucial contribution of mechano-gated TREK channels to the regulation of membrane potential in several cell types has been reported. In this review, we summarize the general principles underlying the mechanical activation of K2P channels, and focus on the physiological roles of mechanically induced hyperpolarization. Citation: Lengyel, M.; Enyedi, P.; Keywords: mechanosensitive; potassium channel; membrane tension; stretch; KCNK2; KCNK4; Czirják, G. Negative Influence by KCNK10; TREK1; TREK2 the Force: Mechanically Induced Hyperpolarization via K2P Background Potassium Channels. Int. J. Mol. Sci. 2021, 22, 9062. https:// 1. Introduction doi.org/10.3390/ijms22169062 The two-pore domain (K2P) potassium channels are the molecular correlates of back- + Academic Editor: Rashid Giniatullin ground (leak) potassium currents, which mediate K transport through the plasma mem- brane, regulate the value of the membrane potential, and adjust cellular excitability [1]. Received: 29 July 2021 The different K2P channel types are characterized by similar membrane topology, molecular Accepted: 20 August 2021 architecture, and overall electrophysiological properties. The K2P channels have four trans- Published: 23 August 2021 membrane segments and two pore domains in a subunit (4TM/2P architecture, Figure1A) . As in the other families of potassium channels, the selectivity filter of K2P channels is Publisher’s Note: MDPI stays neutral constituted by the TVGYG-like signature sequences of four pore domains, accordingly, with regard to jurisdictional claims in assembled by the dimerization of two-pore domain subunits (Figure1B), and considered published maps and institutional affil- as the major location of channel gating [2–9]. iations. The first extracellular loop of K2P channels is longer than the second one; this first loop contains conserved α-helices to establish a cap structure, through which the extracel- lular ion pathway (EIP) provides access to the narrow outer end of the transmembrane pore (Figure1B,C) [12–14]. Close to the intracellular opening of the pore, below the selectivity filter, Copyright: © 2021 by the authors. a wide central cavity is formed by the diverging transmembrane helices (Figure1C) . This cavity, + Licensee MDPI, Basel, Switzerland. just like the middle part of the EIP, may often accommodate a K ion partially retaining its This article is an open access article hydration shell. The K+ ion in the central cavity may be stabilized by the electric dipole moment distributed under the terms and of the pore helices, whereas in the middle part of the EIP by negatively charged amino acid side conditions of the Creative Commons chains in some K2P channel types (such as TASK-3 or TREK-2) [12,13,15,16]. Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Int. J. Mol. Sci. 2021, 22, 9062. https://doi.org/10.3390/ijms22169062 https://www.mdpi.com/journal/ijms Int.Int. J. J. Mol. Mol. Sci. Sci.2021 2021, 22, 22, 9062, x FOR PEER REVIEW 2 ofof 2728 FigureFigure 1. 1. Schematic overview of of the the structure structure of of K K2P2P backgroundbackground potassium potassium channels. channels. (A) (TheA) Thegen- eral transmembrane topology of K2P channels is 4TM/2P. Only one subunit of the dimer is shown. general transmembrane topology of K2P channels is 4TM/2P. Only one subunit of the dimer is The membrane is illustrated with two horizontal black lines, both the N- and C-terminus of the shown. The membrane is illustrated with two horizontal black lines, both the N- and C-terminus subunit (N and C) are intracellular (IC). The subunit contains two pore domains (P), which form of the subunit (N and C) are intracellular (IC). The subunit contains two pore domains (P), which reentrant loops on the extracellular (EC) side (indicated with red). A part of the long first extracel- formlular reentrantloop, N-terminal loops on to the the extracellular first pore domain (EC) side, constitutes (indicated thewith extracellular red). A partcap structure. of the long (B first) The extracellularpanoramic view loop, of N-terminal the crystal tostructure the first of pore TREK-2 domain, homodimer constitutes is shown the extracellular from the extracellular cap structure. side (B(PDB:) The panoramic4BW5). One view subunit of the is crystal orange structure (pore loops of TREK-2 are red) homodimer and the other is shown is blue, from and the extracellularthe α-helical sideregions (PDB: are 4BW5). illustrated One subunitas tubes. is The orange first (poretransmembrane loops are red) segment and the (T otherM1) is is followed blue, and by the theα -helicaltwo cap regionshelices are(C1 illustrated and C2). After as tubes. C2, the The first first pore transmembrane helix (P1) diagonally segment immerses (TM1) is followed into the transmembrane by the two cap helicesspace, (C1and andthe chain C2). After vertically C2, the returns first pore to the helix EC (P1)side diagonallyas the (TVGYG-like) immerses si intognature the transmembrane sequence of the + space,selectivity and thefilter chain (narrow vertically rectangle returns close to to the the EC K side binding as the sites, (TVGYG-like) illustrated with signature spheres). sequence The pore of helix and the signature sequence belong to the first pore domain, as illustrated in panel A. The amino the selectivity filter (narrow rectangle close to the K+ binding sites, illustrated with spheres). The pore acid chain continues as the (not entirely straight) TM2 and TM3 transmembrane helices, followed helix and the signature sequence belong to the first pore domain, as illustrated in panel A. The amino by the second pore domain, which includes the P2 pore helix and the other signature sequence ro- acidtated chain by approx. continues 90 degrees as the (not around entirely the straight) axis of the TM2 pore, and compared TM3 transmembrane to the first one. helices, Finally, followed the chain by thereturns second to porethe IC domain, side as whichthe TM4 includes transmembrane the P2 pore helix. helix Some and the coils other connecting signature the sequence helical elements rotated by(e.g., approx. between 90 degreesC2 and P1, around TM2 theand axis TM3) of theand pore,the long compared C-terminal to the tail first following one. Finally, TM4 are the missing chain returnsfrom the to crystal the IC sidestructure. as the The TM4 figure transmembrane was produced helix. by Some the Cn3D coils software connecting of theNCBI. helical (C) elementsThe extra- (e.g.,cellular between ion pathway C2 and P1, (EIP) TM2 below and TM3)the cap and structure the long connects C-terminal the tail EC following end of the TM4 transmembrane are missing from pore theto the crystal EC space structure. as a T-shaped The figure bi wasfurcation. produced The bynarrow the Cn3D selectivity software filter of region NCBI. of (C the) The transmembrane extracellular + ionpore pathway is illustrated (EIP) below as a series the cap of structurefour K binding connects sites the EC(purple end ofspheres). the transmembrane Below the selectivity pore to the filter, EC the pore widens as the central cavity. The TREK-2 homodimer is rotated by about a quarter turn, space as a T-shaped bifurcation. The narrow selectivity filter region of the transmembrane pore is compared to panel B, the cap helices of the two subunits almost overlap in the illustration. The EIP illustrated as a series of four K+ binding sites (purple spheres). Below the selectivity filter, the pore and central cavity are determined as the spaces accessible by a small sphere (radius 2.1 Å), but not widensby a large as the one central (radius cavity. 4.5 Å The for TREK-2the EIP and homodimer 8.1 Å for is the rotated central by cavity), about a by quarter using turn,PrinCCes compared [10] and to panelVMD B ,[11] the software. cap helices The of green the two spheres subunits are adjacent almost overlap to bulk influid. the illustration. The EIP and central cavity are determined as the spaces accessible by a small sphere (radius 2.1 Å), but not by a large one (radiusThe first 4.5 Å extracellular for the EIP and loop 8.1 Åof for K the2P channels central cavity), is longer by using than PrinCCes the second [10] andone; VMD this [first11] software.loop contains The green conserved spheres α are-helices adjacent to toestablish bulk fluid. a cap structure, through which the extracel- lular ion pathway (EIP) provides access to the narrow outer end of the transmembrane K channels have background (K+-selective leak) characteristics, their macroscopic pore (Figure2P 1B,C) [12–14]. Close to the intracellular opening of the pore, below the selec- current is much better approximated by the Goldman–Hodgkin–Katz (GHK) current equa- tivity filter, a wide central cavity is formed by the diverging transmembrane helices (Fig- tion than the current of the voltage-gated (K ) or inwardly rectifying (K ) channel types.
Load more

Recommended publications
  • The Sensors of the Pain Pathway
    Nociceptors: the sensors of the pain pathway Adrienne E. Dubin, Ardem Patapoutian J Clin Invest. 2010;120(11):3760-3772. https://doi.org/10.1172/JCI42843. Review Series Specialized peripheral sensory neurons known as nociceptors alert us to potentially damaging stimuli at the skin by detecting extremes in temperature and pressure and injury-related chemicals, and transducing these stimuli into long- ranging electrical signals that are relayed to higher brain centers. The activation of functionally distinct cutaneous nociceptor populations and the processing of information they convey provide a rich diversity of pain qualities. Current work in this field is providing researchers with a more thorough understanding of nociceptor cell biology at molecular and systems levels and insight that will allow the targeted design of novel pain therapeutics. Find the latest version: https://jci.me/42843/pdf Review series Nociceptors: the sensors of the pain pathway Adrienne E. Dubin1 and Ardem Patapoutian1,2 1Department of Cell Biology, The Scripps Research Institute, La Jolla, California, USA. 2Genomics Institute of the Novartis Research Foundation, San Diego, California, USA. Specialized peripheral sensory neurons known as nociceptors alert us to potentially damaging stimuli at the skin by detecting extremes in temperature and pressure and injury-related chemicals, and transducing these stimuli into long-ranging electrical signals that are relayed to higher brain centers. The activation of functionally distinct cutaneous nociceptor populations and the processing of information they convey provide a rich diversity of pain qualities. Current work in this field is providing researchers with a more thorough understanding of nociceptor cell biology at molecular and systems levels and insight that will allow the targeted design of novel pain therapeutics.
    [Show full text]
  • Potassium Channels in Epilepsy
    Downloaded from http://perspectivesinmedicine.cshlp.org/ on September 28, 2021 - Published by Cold Spring Harbor Laboratory Press Potassium Channels in Epilepsy Ru¨diger Ko¨hling and Jakob Wolfart Oscar Langendorff Institute of Physiology, University of Rostock, Rostock 18057, Germany Correspondence: [email protected] This review attempts to give a concise and up-to-date overview on the role of potassium channels in epilepsies. Their role can be defined from a genetic perspective, focusing on variants and de novo mutations identified in genetic studies or animal models with targeted, specific mutations in genes coding for a member of the large potassium channel family. In these genetic studies, a demonstrated functional link to hyperexcitability often remains elusive. However, their role can also be defined from a functional perspective, based on dy- namic, aggravating, or adaptive transcriptional and posttranslational alterations. In these cases, it often remains elusive whether the alteration is causal or merely incidental. With 80 potassium channel types, of which 10% are known to be associated with epilepsies (in humans) or a seizure phenotype (in animals), if genetically mutated, a comprehensive review is a challenging endeavor. This goal may seem all the more ambitious once the data on posttranslational alterations, found both in human tissue from epilepsy patients and in chronic or acute animal models, are included. We therefore summarize the literature, and expand only on key findings, particularly regarding functional alterations found in patient brain tissue and chronic animal models. INTRODUCTION TO POTASSIUM evolutionary appearance of voltage-gated so- CHANNELS dium (Nav)andcalcium (Cav)channels, Kchan- nels are further diversified in relation to their otassium (K) channels are related to epilepsy newer function, namely, keeping neuronal exci- Psyndromes on many different levels, ranging tation within limits (Anderson and Greenberg from direct control of neuronal excitability and 2001; Hille 2001).
    [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]
  • Circular RNA Hsa Circ 0005114‑Mir‑142‑3P/Mir‑590‑5P‑ Adenomatous
    ONCOLOGY LETTERS 21: 58, 2021 Circular RNA hsa_circ_0005114‑miR‑142‑3p/miR‑590‑5p‑ adenomatous polyposis coli protein axis as a potential target for treatment of glioma BO WEI1*, LE WANG2* and JINGWEI ZHAO1 1Department of Neurosurgery, China‑Japan Union Hospital of Jilin University, Changchun, Jilin 130033; 2Department of Ophthalmology, The First Hospital of Jilin University, Jilin University, Changchun, Jilin 130021, P.R. China Received September 12, 2019; Accepted October 22, 2020 DOI: 10.3892/ol.2020.12320 Abstract. Glioma is the most common type of brain tumor APC expression with a good overall survival rate. UALCAN and is associated with a high mortality rate. Despite recent analysis using TCGA data of glioblastoma multiforme and the advances in treatment options, the overall prognosis in patients GSE25632 and GSE103229 microarray datasets showed that with glioma remains poor. Studies have suggested that circular hsa‑miR‑142‑3p/hsa‑miR‑590‑5p was upregulated and APC (circ)RNAs serve important roles in the development and was downregulated. Thus, hsa‑miR‑142‑3p/hsa‑miR‑590‑5p‑ progression of glioma and may have potential as therapeutic APC‑related circ/ceRNA axes may be important in glioma, targets. However, the expression profiles of circRNAs and their and hsa_circ_0005114 interacted with both of these miRNAs. functions in glioma have rarely been studied. The present study Functional analysis showed that hsa_circ_0005114 was aimed to screen differentially expressed circRNAs (DECs) involved in insulin secretion, while APC was associated with between glioma and normal brain tissues using sequencing the Wnt signaling pathway. In conclusion, hsa_circ_0005114‑ data collected from the Gene Expression Omnibus database miR‑142‑3p/miR‑590‑5p‑APC ceRNA axes may be potential (GSE86202 and GSE92322 datasets) and explain their mecha‑ targets for the treatment of glioma.
    [Show full text]
  • Transcriptomic Analysis of Native Versus Cultured Human and Mouse Dorsal Root Ganglia Focused on Pharmacological Targets Short
    bioRxiv preprint doi: https://doi.org/10.1101/766865; this version posted September 12, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. Transcriptomic analysis of native versus cultured human and mouse dorsal root ganglia focused on pharmacological targets Short title: Comparative transcriptomics of acutely dissected versus cultured DRGs Andi Wangzhou1, Lisa A. McIlvried2, Candler Paige1, Paulino Barragan-Iglesias1, Carolyn A. Guzman1, Gregory Dussor1, Pradipta R. Ray1,#, Robert W. Gereau IV2, # and Theodore J. Price1, # 1The University of Texas at Dallas, School of Behavioral and Brain Sciences and Center for Advanced Pain Studies, 800 W Campbell Rd. Richardson, TX, 75080, USA 2Washington University Pain Center and Department of Anesthesiology, Washington University School of Medicine # corresponding authors [email protected], [email protected] and [email protected] Funding: NIH grants T32DA007261 (LM); NS065926 and NS102161 (TJP); NS106953 and NS042595 (RWG). The authors declare no conflicts of interest Author Contributions Conceived of the Project: PRR, RWG IV and TJP Performed Experiments: AW, LAM, CP, PB-I Supervised Experiments: GD, RWG IV, TJP Analyzed Data: AW, LAM, CP, CAG, PRR Supervised Bioinformatics Analysis: PRR Drew Figures: AW, PRR Wrote and Edited Manuscript: AW, LAM, CP, GD, PRR, RWG IV, TJP All authors approved the final version of the manuscript. 1 bioRxiv preprint doi: https://doi.org/10.1101/766865; this version posted September 12, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
    [Show full text]
  • Transcriptional Control of Tissue-Resident Memory T Cell Generation
    Transcriptional control of tissue-resident memory T cell generation Filip Cvetkovski Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY 2019 © 2019 Filip Cvetkovski All rights reserved ABSTRACT Transcriptional control of tissue-resident memory T cell generation Filip Cvetkovski Tissue-resident memory T cells (TRM) are a non-circulating subset of memory that are maintained at sites of pathogen entry and mediate optimal protection against reinfection. Lung TRM can be generated in response to respiratory infection or vaccination, however, the molecular pathways involved in CD4+TRM establishment have not been defined. Here, we performed transcriptional profiling of influenza-specific lung CD4+TRM following influenza infection to identify pathways implicated in CD4+TRM generation and homeostasis. Lung CD4+TRM displayed a unique transcriptional profile distinct from spleen memory, including up-regulation of a gene network induced by the transcription factor IRF4, a known regulator of effector T cell differentiation. In addition, the gene expression profile of lung CD4+TRM was enriched in gene sets previously described in tissue-resident regulatory T cells. Up-regulation of immunomodulatory molecules such as CTLA-4, PD-1, and ICOS, suggested a potential regulatory role for CD4+TRM in tissues. Using loss-of-function genetic experiments in mice, we demonstrate that IRF4 is required for the generation of lung-localized pathogen-specific effector CD4+T cells during acute influenza infection. Influenza-specific IRF4−/− T cells failed to fully express CD44, and maintained high levels of CD62L compared to wild type, suggesting a defect in complete differentiation into lung-tropic effector T cells.
    [Show full text]
  • Tibbo, Amy J. (2020) Compartmentalized Camp Signaling Via the PDE4- Popeye Protein Complex
    Tibbo, Amy J. (2020) Compartmentalized cAMP Signaling via the PDE4- Popeye Protein Complex. PhD thesis. http://theses.gla.ac.uk/81454/ Copyright and moral rights for this work are retained by the author A copy can be downloaded for personal non-commercial research or study, without prior permission or charge This work cannot be reproduced or quoted extensively from without first obtaining permission in writing from the author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Enlighten: Theses https://theses.gla.ac.uk/ [email protected] 1 Compartmentalized cAMP Signaling via the PDE4-Popeye Protein Complex Amy Jane Tibbo (BSc Hons) Thesis submitted in fulfilment of the requirements for Degree of Doctor of Philosophy Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow April 2020 2 Abstract The Popeye domain containing (POPDC) protein family are a unique family of transmembrane proteins with several proposed functions that are not fully understood. POPDC proteins are abundantly expressed in cardiac and skeletal muscle. Within the heart, POPDC1 has been shown to be highly expressed in the pace making centres and at moderate to low levels in the atria and ventricles. Given this localisation, a role for POPDC1 was hypothesised to be in the maintenance of normal heartbeat rhythm. Studies involving POPDC1 mutant mice and zebrafish provided evidence for this proposed function as the genetically modified model animals displayed cardiac arrhythmias as the predominant phenotype.
    [Show full text]
  • Mutant Three-Repeat Tau Expression Initiates Retinal Ganglion Cell Death Through Caspase-2
    UC San Diego UC San Diego Previously Published Works Title Mutant three-repeat tau expression initiates retinal ganglion cell death through Caspase-2. Permalink https://escholarship.org/uc/item/4gr7f6tn Authors Ngolab, Jennifer Canchi, Saranya Rasool, Suhail et al. Publication Date 2021-05-01 DOI 10.1016/j.nbd.2021.105277 Peer reviewed eScholarship.org Powered by the California Digital Library University of California HHS Public Access Author manuscript Author ManuscriptAuthor Manuscript Author Neurobiol Manuscript Author Dis. Author manuscript; Manuscript Author available in PMC 2021 August 18. Published in final edited form as: Neurobiol Dis. 2021 May ; 152: 105277. doi:10.1016/j.nbd.2021.105277. Mutant three-repeat tau expression initiates retinal ganglion cell death through Caspase-2 Jennifer Ngolaba, Saranya Canchia,c, Suhail Rasoola,d, Abderrahman Elmaaroufb, Kimberly Thomasb, Floyd Sarsozaa,c, Jennifer Grundmana, Michael Mantea, Jazmin Florioa, Nimisha Nandankara, Shaina Korouria, Wagner Zagob, Eliezer Masliahe, Robert A. Rissmana,c,* aDepartment of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA 92093, United States of America bProthena Biosciences, South San Francisco, CA 94080, United States of America cVeterans Affairs San Diego Healthcare System, San Diego, CA 92161, United States of America dAmydis Inc, San Diego, CA 92121, United States of America eDivision of Neuroscience and Laboratory of Neurogenetics, National Institutes on Aging, NIH, Bethesda, MD 20892, United States of America Abstract The microtubule-associated protein tau is implicated in multiple degenerative diseases including retinal diseases such as glaucoma; however, the way tau initiates retinopathy is unclear. Previous retinal assessments in mouse models of tauopathy suggest that mutations in four-repeat (4R) tau are associated with disease-induced retinal dysfunction, while shifting tau isoform ratio to favor three-repeat (3R) tau production enhanced photoreceptor function.
    [Show full text]
  • RKIP Regulates Differentiation- Related Features in Melanocytic Cells
    Cancers 2020. 12 S1 of S14 Supplementary Materials: RKIP Regulates Differentiation- Related Features in Melanocytic Cells Cristina Penas, Aintzane Apraiz, Iraia Muñoa, Yoana Arroyo-Berdugo, Javier Rasero, Pilar A. Ezkurra, Veronica Velasco, Nerea Subiran, Anja K. Bosserhoff, Santos Alonso, Aintzane Asumendi and Maria D. Boyano Figure S1. Representative images of manually scored RKIP staining categories in FFPE biopsies from patients. At the feft: Hematoxylin-Eosin staining (H-E). At the right: Immunohistochemistry (IHC) of RKIP for increasing Breslow Index. (a-b) Strong staining for intradermal nevus and in situ melanoma, respectively; (c) weak staining for a melanoma with Breslow Index between 1 and 2 mm; (d-e) negative staining for melanomas thicker than 2 mm. Cancers 2020. 12 S2 of S14 Figure S2. RNA Sequencing data analysis. Each row of the figure represents an over-represented gene signature generated by analyzing the up-regulated and down-regulated genes from a differential expression analysis of RKIP Knockdown melanocytes HEMn-LP. Results from the EnrichR Website with a p-value > 0.05. Figure S3. RNA Sequencing data quality. (a) Read counts normalization per sample; (b) Spearman correlation coefficient between replicates; (c) Principal component analysis for replicates. Cancers 2020. 12 S3 of S14 Figure S4. Details of Western Blot from Figure 2 related with RKIP expression in several cell lines. (a) Blots for RKIP and Tubulin in primary and metastatic melanoma and in three primary melanocytes HEMn-DP (dark pigmented), HEMn-LP (light pigmented) and HEM2710. On the right, original blot for each analyzed protein. Highlighted with a red square the information included in the Figure 3 (horizontal rotation).
    [Show full text]
  • Ion Channels 3 1
    r r r Cell Signalling Biology Michael J. Berridge Module 3 Ion Channels 3 1 Module 3 Ion Channels Synopsis Ion channels have two main signalling functions: either they can generate second messengers or they can function as effectors by responding to such messengers. Their role in signal generation is mainly centred on the Ca2 + signalling pathway, which has a large number of Ca2+ entry channels and internal Ca2+ release channels, both of which contribute to the generation of Ca2 + signals. Ion channels are also important effectors in that they mediate the action of different intracellular signalling pathways. There are a large number of K+ channels and many of these function in different + aspects of cell signalling. The voltage-dependent K (KV) channels regulate membrane potential and + excitability. The inward rectifier K (Kir) channel family has a number of important groups of channels + + such as the G protein-gated inward rectifier K (GIRK) channels and the ATP-sensitive K (KATP) + + channels. The two-pore domain K (K2P) channels are responsible for the large background K current. Some of the actions of Ca2 + are carried out by Ca2+-sensitive K+ channels and Ca2+-sensitive Cl − channels. The latter are members of a large group of chloride channels and transporters with multiple functions. There is a large family of ATP-binding cassette (ABC) transporters some of which have a signalling role in that they extrude signalling components from the cell. One of the ABC transporters is the cystic − − fibrosis transmembrane conductance regulator (CFTR) that conducts anions (Cl and HCO3 )and contributes to the osmotic gradient for the parallel flow of water in various transporting epithelia.
    [Show full text]
  • (Popdc2). Generation and Functional Characterization of a Null Mutant in Mice and Promoter Analysis
    The Popeye domain containing gene 2 (Popdc2). Generation and functional characterization of a null mutant in mice and promoter analysis. Dissertation For completion of the Doctorate degree in Natural Sciences at the Bayerische Julius-Maximilians-Universität Würzburg Alexander Froese from Dushanbe Würzburg 2007 Declaration: I hereby declare that the submitted dissertation was completed by myself and no other. I have not used any sources or materials other than those enclosed. Moreover I declare that the following dissertation has not been submitted further in this form or any other form, and has not been used to obtain any other equivalent qualifications at any other organisation/institution. Additionally, I have not applied for, nor will I attempt to apply for any other degree or qualification in relation to this work. Würzburg, den 21.12.2007 Alexander Froese The hereby submitted thesis was completed from January 2001 until April 2005 at the Cell and Molecular Biology Department, Technical University Braunschweig, Braunschweig and from May 2005 until December 2007 at the Department of Cell and Developmental Biology, University of Würzburg, under the supervision of Professor Dr. T. Brand. Members of the thesis committee: Chairman: Professor Dr. M. Müller Examiner: Professor Dr. T. Brand Examiner: PD Dr. S. Maier Submitted on: 21.12.2007 Date of oral exam: 20.02.2008 Wahrlich, wahrlich, ich sage euch: Wenn das Weizenkorn nicht in die Erde fällt und stirbt, bleibt es allein; wenn es aber stirbt, bringt es viel Frucht. Johannes 12;23-25 Истинно, истинно говорю вам: если пшеничное зерно, падши в землю, не умрёт, то останется одно; а если умрёт, то принесёт много плода.
    [Show full text]
  • Stem Cells and Ion Channels
    Stem Cells International Stem Cells and Ion Channels Guest Editors: Stefan Liebau, Alexander Kleger, Michael Levin, and Shan Ping Yu Stem Cells and Ion Channels Stem Cells International Stem Cells and Ion Channels Guest Editors: Stefan Liebau, Alexander Kleger, Michael Levin, and Shan Ping Yu Copyright © 2013 Hindawi Publishing Corporation. All rights reserved. This is a special issue published in “Stem Cells International.” All articles are open access articles distributed under the Creative Com- mons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Editorial Board Nadire N. Ali, UK Joseph Itskovitz-Eldor, Israel Pranela Rameshwar, USA Anthony Atala, USA Pavla Jendelova, Czech Republic Hannele T. Ruohola-Baker, USA Nissim Benvenisty, Israel Arne Jensen, Germany D. S. Sakaguchi, USA Kenneth Boheler, USA Sue Kimber, UK Paul R. Sanberg, USA Dominique Bonnet, UK Mark D. Kirk, USA Paul T. Sharpe, UK B. Bunnell, USA Gary E. Lyons, USA Ashok Shetty, USA Kevin D. Bunting, USA Athanasios Mantalaris, UK Igor Slukvin, USA Richard K. Burt, USA Pilar Martin-Duque, Spain Ann Steele, USA Gerald A. Colvin, USA EvaMezey,USA Alexander Storch, Germany Stephen Dalton, USA Karim Nayernia, UK Marc Turner, UK Leonard M. Eisenberg, USA K. Sue O’Shea, USA Su-Chun Zhang, USA Marina Emborg, USA J. Parent, USA Weian Zhao, USA Josef Fulka, Czech Republic Bruno Peault, USA Joel C. Glover, Norway Stefan Przyborski, UK Contents Stem Cells and Ion Channels, Stefan Liebau,
    [Show full text]