1
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Aryal B, Xia J, Hu Z, Stumpe M, Tsering T, Liu J, Huynh J, Fukao Y, Glöckner N, Huang HY, Sáncho-Andrés G, Pakula K, Ziegler J, Gorzolka K, Zwiewka M, Nodzynski T, Harter K, Sánchez-Rodríguez C, Jasiński M, Rosahl S, Geisler MM. An LRR receptor kinase controls ABC transporter substrate preferences during plant growth-defense decisions. Curr Biol 2023; 33:2008-2023.e8. [PMID: 37146609 DOI: 10.1016/j.cub.2023.04.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 02/27/2023] [Accepted: 04/13/2023] [Indexed: 05/07/2023]
Abstract
The exporter of the auxin precursor indole-3-butyric acid (IBA), ABCG36/PDR8/PEN3, from the model plant Arabidopsis has recently been proposed to also function in the transport of the phytoalexin camalexin. Based on these bonafide substrates, it has been suggested that ABCG36 functions at the interface between growth and defense. Here, we provide evidence that ABCG36 catalyzes the direct, ATP-dependent export of camalexin across the plasma membrane. We identify the leucine-rich repeat receptor kinase, QIAN SHOU KINASE1 (QSK1), as a functional kinase that physically interacts with and phosphorylates ABCG36. Phosphorylation of ABCG36 by QSK1 unilaterally represses IBA export, allowing camalexin export by ABCG36 conferring pathogen resistance. As a consequence, phospho-dead mutants of ABCG36, as well as qsk1 and abcg36 alleles, are hypersensitive to infection with the root pathogen Fusarium oxysporum, caused by elevated fungal progression. Our findings indicate a direct regulatory circuit between a receptor kinase and an ABC transporter that functions to control transporter substrate preference during plant growth and defense balance decisions.
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Affiliation(s)
- Bibek Aryal
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Jian Xia
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Zehan Hu
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Michael Stumpe
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Tashi Tsering
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Jie Liu
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - John Huynh
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Yoichiro Fukao
- College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan
| | - Nina Glöckner
- Zentrum für Molekularbiologie der Pflanzen, Pflanzenphysiologie, Universität Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany
| | - Hsin-Yao Huang
- Department of Biology, ETH Zurich, Universitätstrasse 2, 8092 Zurich, Switzerland
| | - Gloria Sáncho-Andrés
- Department of Biology, ETH Zurich, Universitätstrasse 2, 8092 Zurich, Switzerland
| | - Konrad Pakula
- Department of Plant Molecular Physiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Z. Noskowskiego 12/14, 61-704 Poznań, Poland; NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznań, Poland
| | - Joerg Ziegler
- Department Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120 Halle (Saale), Germany
| | - Karin Gorzolka
- Department Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120 Halle (Saale), Germany
| | - Marta Zwiewka
- Mendel Centre for Plant Genomics and Proteomics Masaryk University, CEITEC MU Kamenice 5, Building A26, 625 00 Brno, Czech Republic
| | - Tomasz Nodzynski
- Mendel Centre for Plant Genomics and Proteomics Masaryk University, CEITEC MU Kamenice 5, Building A26, 625 00 Brno, Czech Republic
| | - Klaus Harter
- Zentrum für Molekularbiologie der Pflanzen, Pflanzenphysiologie, Universität Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany
| | | | - Michał Jasiński
- Department of Plant Molecular Physiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Z. Noskowskiego 12/14, 61-704 Poznań, Poland; Department of Biochemistry and Biotechnology, Poznan University of Life Sciences, Dojazd 11, 60-632 Poznań, Poland
| | - Sabine Rosahl
- Department Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120 Halle (Saale), Germany
| | - Markus M Geisler
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland.
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2
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Im J, Hillenaar T, Yeoh HY, Sahasrabudhe P, Mijnders M, van Willigen M, Hagos A, de Mattos E, van der Sluijs P, Braakman I. ABC-transporter CFTR folds with high fidelity through a modular, stepwise pathway. Cell Mol Life Sci 2023; 80:33. [PMID: 36609925 PMCID: PMC9825563 DOI: 10.1007/s00018-022-04671-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 11/01/2022] [Accepted: 11/28/2022] [Indexed: 01/09/2023]
Abstract
The question how proteins fold is especially pointed for large multi-domain, multi-spanning membrane proteins with complex topologies. We have uncovered the sequence of events that encompass proper folding of the ABC transporter CFTR in live cells by combining kinetic radiolabeling with protease-susceptibility assays. We found that CFTR folds in two clearly distinct stages. The first, co-translational, stage involves folding of the 2 transmembrane domains TMD1 and TMD2, plus one nucleotide-binding domain, NBD1. The second stage is a simultaneous, post-translational increase in protease resistance for both TMDs and NBD2, caused by assembly of these domains onto NBD1. Our assays probe every 2-3 residues (on average) in CFTR. This in-depth analysis at amino-acid level allows detailed analysis of domain folding and importantly also the next level: assembly of the domains into native, folded CFTR. Defects and changes brought about by medicines, chaperones, or mutations also are amenable to analysis. We here show that the well-known disease-causing mutation F508del, which established cystic fibrosis as protein-folding disease, caused co-translational misfolding of NBD1 but not TMD1 nor TMD2 in stage 1, leading to absence of stage-2 folding. Corrector drugs rescued stage 2 without rescuing NBD1. Likewise, the DxD motif in NBD1 that was identified to be required for export of CFTR from the ER we found to be required already upstream of export as CFTR mutated in this motif phenocopies F508del CFTR. The highly modular and stepwise folding process of such a large, complex protein explains the relatively high fidelity and correctability of its folding.
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Affiliation(s)
- Jisu Im
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Tamara Hillenaar
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Hui Ying Yeoh
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands ,Present Address: Center of Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Priyanka Sahasrabudhe
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands ,Present Address: Navigo Proteins GmbH, 06120 Halle, Germany
| | - Marjolein Mijnders
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands ,Present Address: Princess Máxima Center for Pediatric Oncology, 3584 CS Utrecht, The Netherlands
| | - Marcel van Willigen
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands ,Present Address: Julius Clinical Ltd, 3703 CD Zeist, The Netherlands
| | - Azib Hagos
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Eduardo de Mattos
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Peter van der Sluijs
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Ineke Braakman
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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3
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Krasinska L, Fisher D. A Mechanistic Model for Cell Cycle Control in Which CDKs Act as Switches of Disordered Protein Phase Separation. Cells 2022; 11:cells11142189. [PMID: 35883632 PMCID: PMC9321858 DOI: 10.3390/cells11142189] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 12/30/2022] Open
Abstract
Cyclin-dependent kinases (CDKs) are presumed to control the cell cycle by phosphorylating a large number of proteins involved in S-phase and mitosis, two mechanistically disparate biological processes. While the traditional qualitative model of CDK-mediated cell cycle control relies on differences in inherent substrate specificity between distinct CDK-cyclin complexes, they are largely dispensable according to the opposing quantitative model, which states that changes in the overall CDK activity level promote orderly progression through S-phase and mitosis. However, a mechanistic explanation for how such an activity can simultaneously regulate many distinct proteins is lacking. New evidence suggests that the CDK-dependent phosphorylation of ostensibly very diverse proteins might be achieved due to underlying similarity of phosphorylation sites and of the biochemical effects of their phosphorylation: they are preferentially located within intrinsically disordered regions of proteins that are components of membraneless organelles, and they regulate phase separation. Here, we review this evidence and suggest a mechanism for how a single enzyme’s activity can generate the dynamics required to remodel the cell at mitosis.
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Infield DT, Strickland KM, Gaggar A, McCarty NA. The molecular evolution of function in the CFTR chloride channel. J Gen Physiol 2021; 153:212705. [PMID: 34647973 PMCID: PMC8640958 DOI: 10.1085/jgp.202012625] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/11/2021] [Accepted: 09/09/2021] [Indexed: 12/13/2022] Open
Abstract
The ATP-binding cassette (ABC) transporter superfamily includes many proteins of clinical relevance, with genes expressed in all domains of life. Although most members use the energy of ATP binding and hydrolysis to accomplish the active import or export of various substrates across membranes, the cystic fibrosis transmembrane conductance regulator (CFTR) is the only known animal ABC transporter that functions primarily as an ion channel. Defects in CFTR, which is closely related to ABCC subfamily members that bear function as bona fide transporters, underlie the lethal genetic disease cystic fibrosis. This article seeks to integrate structural, functional, and genomic data to begin to answer the critical question of how the function of CFTR evolved to exhibit regulated channel activity. We highlight several examples wherein preexisting features in ABCC transporters were functionally leveraged as is, or altered by molecular evolution, to ultimately support channel function. This includes features that may underlie (1) construction of an anionic channel pore from an anionic substrate transport pathway, (2) establishment and tuning of phosphoregulation, and (3) optimization of channel function by specialized ligand–channel interactions. We also discuss how divergence and conservation may help elucidate the pharmacology of important CFTR modulators.
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Affiliation(s)
- Daniel T Infield
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA
| | | | - Amit Gaggar
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL.,Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, AL.,Program in Protease and Matrix Biology, University of Alabama at Birmingham, Birmingham, AL.,Birmingham Veterans Administration Medical Center, Birmingham, AL
| | - Nael A McCarty
- Department of Pediatrics, Emory University, Atlanta, GA.,Children's Healthcare of Atlanta Center for Cystic Fibrosis and Airways Disease Research, Emory University, Atlanta, GA
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5
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Ramasamy P, Turan D, Tichshenko N, Hulstaert N, Vandermarliere E, Vranken W, Martens L. Scop3P: A Comprehensive Resource of Human Phosphosites within Their Full Context. J Proteome Res 2020; 19:3478-3486. [DOI: 10.1021/acs.jproteome.0c00306] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Pathmanaban Ramasamy
- VIB-UGent Center for Medical Biotechnology, VIB, Ghent 9000, Belgium
- Department of Biomolecular Medicine, Faculty of Health Sciences and Medicine, Ghent University, Ghent 9000, Belgium
- Interuniversity Institute of Bioinformatics in Brussels, ULB-VUB, 1050 Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- Centre for Structural Biology, VIB, 1050 Brussels, Belgium
| | - Demet Turan
- VIB-UGent Center for Medical Biotechnology, VIB, Ghent 9000, Belgium
- Department of Biomolecular Medicine, Faculty of Health Sciences and Medicine, Ghent University, Ghent 9000, Belgium
| | - Natalia Tichshenko
- VIB-UGent Center for Medical Biotechnology, VIB, Ghent 9000, Belgium
- Department of Biomolecular Medicine, Faculty of Health Sciences and Medicine, Ghent University, Ghent 9000, Belgium
| | - Niels Hulstaert
- VIB-UGent Center for Medical Biotechnology, VIB, Ghent 9000, Belgium
- Department of Biomolecular Medicine, Faculty of Health Sciences and Medicine, Ghent University, Ghent 9000, Belgium
| | - Elien Vandermarliere
- VIB-UGent Center for Medical Biotechnology, VIB, Ghent 9000, Belgium
- Department of Biomolecular Medicine, Faculty of Health Sciences and Medicine, Ghent University, Ghent 9000, Belgium
| | - Wim Vranken
- Interuniversity Institute of Bioinformatics in Brussels, ULB-VUB, 1050 Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- Centre for Structural Biology, VIB, 1050 Brussels, Belgium
| | - Lennart Martens
- VIB-UGent Center for Medical Biotechnology, VIB, Ghent 9000, Belgium
- Department of Biomolecular Medicine, Faculty of Health Sciences and Medicine, Ghent University, Ghent 9000, Belgium
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6
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Bickers SC, Sayewich JS, Kanelis V. Intrinsically disordered regions regulate the activities of ATP binding cassette transporters. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183202. [PMID: 31972165 DOI: 10.1016/j.bbamem.2020.183202] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 12/11/2022]
Abstract
ATP binding cassette (ABC) proteins are a large family of membrane proteins present in all kingdoms of life. These multi-domain proteins are comprised, at minimum, of two membrane-spanning domains (MSD1, MSD2) and two cytosolic nucleotide binding domains (NBD1, NBD2). ATP binding and hydrolysis at the NBDs enables ABC proteins to actively transport solutes across membranes, regulate activities of other proteins, or function as channels. Like most eukaryotic membrane proteins, ABC proteins contain intrinsically disordered regions (IDRs). These conformationally dynamic regions in ABC proteins possess residual structure, are sites of phosphorylation, and mediate protein-protein interactions. Here, we review the role of IDRs in regulating ABC protein activity.
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Affiliation(s)
- Sarah C Bickers
- Department of Chemistry, University of Toronto, Toronto, ON, Canada; Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Jonathan S Sayewich
- Department of Chemistry, University of Toronto, Toronto, ON, Canada; Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Voula Kanelis
- Department of Chemistry, University of Toronto, Toronto, ON, Canada; Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON, Canada; Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada.
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7
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Marklew AJ, Patel W, Moore PJ, Tan CD, Smith AJ, Sassano MF, Gray MA, Tarran R. Cigarette Smoke Exposure Induces Retrograde Trafficking of CFTR to the Endoplasmic Reticulum. Sci Rep 2019; 9:13655. [PMID: 31541117 PMCID: PMC6754399 DOI: 10.1038/s41598-019-49544-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 08/12/2019] [Indexed: 12/16/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD), which is most commonly caused by cigarette smoke (CS) exposure, is the third leading cause of death worldwide. The cystic fibrosis transmembrane conductance regulator (CFTR) is an apical membrane anion channel that is widely expressed in epithelia throughout the body. In the airways, CFTR plays an important role in fluid homeostasis and helps flush mucus and inhaled pathogens/toxicants out of the lung. Inhibition of CFTR leads to mucus stasis and severe airway disease. CS exposure also inhibits CFTR, leading to the decreased anion secretion/hydration seen in COPD patients. However, the underlying mechanism is poorly understood. Here, we report that CS causes CFTR to be internalized in a clathrin/dynamin-dependent fashion. This internalization is followed by retrograde trafficking of CFTR to the endoplasmic reticulum. Although this internalization pathway has been described for bacterial toxins and cargo machinery, it has never been reported for mammalian ion channels. Furthermore, the rapid internalization of CFTR is dependent on CFTR dephosphorylation by calcineurin, a protein phosphatase that is upregulated by CS. These results provide new insights into the mechanism of CFTR internalization, and may help in the development of new therapies for CFTR correction and lung rehydration in patients with debilitating airway diseases such as COPD.
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Affiliation(s)
- Abigail J Marklew
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, USA
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne, UK
| | - Waseema Patel
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, USA
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne, UK
| | - Patrick J Moore
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Chong D Tan
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Amanda J Smith
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, USA
- Department of Cell Biology & Physiology, University of North Carolina, Chapel Hill, NC, USA
| | - M Flori Sassano
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Michael A Gray
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne, UK
| | - Robert Tarran
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, USA.
- Department of Cell Biology & Physiology, University of North Carolina, Chapel Hill, NC, USA.
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8
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Kulke M, Uhrhan M, Geist N, Brüggemann D, Ohler B, Langel W, Köppen S. Phosphorylation of Fibronectin Influences the Structural Stability of the Predicted Interchain Domain. J Chem Inf Model 2019; 59:4383-4392. [PMID: 31509400 DOI: 10.1021/acs.jcim.9b00555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As a key player in cell adhesion, the glycoprotein fibronectin is involved in the complex mechanobiology of the extracellular matrix. Although the function of many modules in the fibronectin molecule has already been understood, the structure and biological relevance of the C-terminal cross-linked region (CTXL) still remains unclear. It is known that fibronectin is only phosphorylated in the CTXL domain, but no results have been presented to date, which indicate a biological function based on this phosphorylation. For the first time, we introduce a structural model of the CTXL region in fibronectin, which we obtained by exhaustive replica exchange molecular dynamics simulations (TIGER2hs). The sampling revealed a conformational landscape of the dimerization module, and the global minimum state showed an umbrella-like module body and conspicuous structural region with two feet. We observed that the CTXL foot region exhibits a structural stability in its physiological state, which disappears upon changes in the phosphorylation state. Thus, our in silico studies enabled us to show that the flexibility of the CTXL region is guided by phosphorylation. These results indicate an in vivo function of the CTXL domain in protein binding and cell adhesion, which is controlled by phosphorylation.
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Affiliation(s)
- Martin Kulke
- Biophysical Chemistry , University of Greifswald , Greifswald 17487 , Germany
| | | | - Norman Geist
- Biophysical Chemistry , University of Greifswald , Greifswald 17487 , Germany
| | | | - Bastian Ohler
- Biophysical Chemistry , University of Greifswald , Greifswald 17487 , Germany
| | - Walter Langel
- Biophysical Chemistry , University of Greifswald , Greifswald 17487 , Germany
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9
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VX-770-mediated potentiation of numerous human CFTR disease mutants is influenced by phosphorylation level. Sci Rep 2019; 9:13460. [PMID: 31530897 PMCID: PMC6749054 DOI: 10.1038/s41598-019-49921-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 08/29/2019] [Indexed: 12/20/2022] Open
Abstract
VX-770 (ivacaftor) is approved for clinical use in CF patients bearing multiple CFTR mutations. VX-770 potentiated wildtype CFTR and several disease mutants expressed in oocytes in a manner modulated by PKA-mediated phosphorylation. Potentiation of some other mutants, including G551D-CFTR, was less dependent upon the level of phosphorylation, likely related to the severe gating defects in these mutants exhibited in part by a shift in PKA sensitivity to activation, possibly due to an electrostatic interaction of D551 with K1250. Phosphorylation-dependent potentiation of wildtype CFTR and other variants also was observed in epithelial cells. Hence, the efficacy of potentiators may be obscured by a ceiling effect when drug screening is performed under strongly phosphorylating conditions. These results should be considered in campaigns for CFTR potentiator discovery, and may enable the expansion of VX-770 to CF patients bearing ultra-orphan CFTR mutations.
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10
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Sharma DK, Siddiqui MQ, Gadewal N, Choudhary RK, Varma AK, Misra HS, Rajpurohit YS. Phosphorylation of deinococcal RecA affects its structural and functional dynamics implicated for its roles in radioresistance of Deinococcus radiodurans. J Biomol Struct Dyn 2019; 38:114-123. [PMID: 30688163 DOI: 10.1080/07391102.2019.1568916] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Deinococcus RecA (DrRecA) protein is a key repair enzyme and contributes to efficient DNA repair of Deinococcus radiodurans. Phosphorylation of DrRecA at Y77 (tyrosine 77) and T318 (threonine 318) residues modifies the structural and conformational switching that impart the efficiency and activity of DrRecA. Dynamics comparisons of DrRecA with its phosphorylated analogues support the idea that phosphorylation of Y77 and T318 sites could change the dynamics and conformation plasticity of DrRecA. Furthermore, docking studies showed that phosphorylation increases the binding preference of DrRecA towards dATP versus ATP and for double-strand DNA versus single-strand DNA. This work supporting the idea that phosphorylation can modulate the crucial functions of this protein and having good concordance with the experimental data. AbbreviationsDrRecADeinococcus RecADSBDNA double-strand breakshDNAheteroduplex DNASTYPKserine/threonine/tyrosine protein kinaseT318threonine 318Y77tyrosine 77Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | | | - Nikhil Gadewal
- Advance Centre for Treatment Research and Education in Cancer, Kharghar, Maharashtra, India
| | - Rajan Kumar Choudhary
- Advance Centre for Treatment Research and Education in Cancer, Kharghar, Maharashtra, India
| | - Ashok Kumar Varma
- Advance Centre for Treatment Research and Education in Cancer, Kharghar, Maharashtra, India
| | - Hari Sharan Misra
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.,Department of Atomic Energy, Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - Yogendra Singh Rajpurohit
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.,Department of Atomic Energy, Homi Bhabha National Institute, Mumbai, Maharashtra, India
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11
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Hoffmann B, Elbahnsi A, Lehn P, Décout JL, Pietrucci F, Mornon JP, Callebaut I. Combining theoretical and experimental data to decipher CFTR 3D structures and functions. Cell Mol Life Sci 2018; 75:3829-3855. [PMID: 29779042 PMCID: PMC11105360 DOI: 10.1007/s00018-018-2835-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 12/15/2022]
Abstract
Cryo-electron microscopy (cryo-EM) has recently provided invaluable experimental data about the full-length cystic fibrosis transmembrane conductance regulator (CFTR) 3D structure. However, this experimental information deals with inactive states of the channel, either in an apo, quiescent conformation, in which nucleotide-binding domains (NBDs) are widely separated or in an ATP-bound, yet closed conformation. Here, we show that 3D structure models of the open and closed forms of the channel, now further supported by metadynamics simulations and by comparison with the cryo-EM data, could be used to gain some insights into critical features of the conformational transition toward active CFTR forms. These critical elements lie within membrane-spanning domains but also within NBD1 and the N-terminal extension, in which conformational plasticity is predicted to occur to help the interaction with filamin, one of the CFTR cellular partners.
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Affiliation(s)
- Brice Hoffmann
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France
- Iktos, Paris, France
| | - Ahmad Elbahnsi
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France
| | - Pierre Lehn
- INSERM U1078, SFR ScInBioS, Université de Bretagne Occidentale, Brest, France
| | | | - Fabio Pietrucci
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France
| | - Jean-Paul Mornon
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France.
| | - Isabelle Callebaut
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France
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12
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Phosphorylation of iRhom2 Controls Stimulated Proteolytic Shedding by the Metalloprotease ADAM17/TACE. Cell Rep 2018; 21:745-757. [PMID: 29045841 PMCID: PMC5656746 DOI: 10.1016/j.celrep.2017.09.074] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 07/12/2017] [Accepted: 09/22/2017] [Indexed: 12/02/2022] Open
Abstract
Cell surface metalloproteases coordinate signaling during development, tissue homeostasis, and disease. TACE (TNF-α-converting enzyme), is responsible for cleavage (“shedding”) of membrane-tethered signaling molecules, including the cytokine TNF, and activating ligands of the EGFR. The trafficking of TACE within the secretory pathway requires its binding to iRhom2, which mediates the exit of TACE from the endoplasmic reticulum. An important, but mechanistically unclear, feature of TACE biology is its ability to be stimulated rapidly on the cell surface by numerous inflammatory and growth-promoting agents. Here, we report a role for iRhom2 in TACE stimulation on the cell surface. TACE shedding stimuli trigger MAP kinase-dependent phosphorylation of iRhom2 N-terminal cytoplasmic tail. This recruits 14-3-3 proteins, enforcing the dissociation of TACE from complexes with iRhom2, promoting the cleavage of TACE substrates. Our data reveal that iRhom2 controls multiple aspects of TACE biology, including stimulated shedding on the cell surface. iRhom2 is phosphorylated in response to stimuli that activate the sheddase TACE Blocking iRhom phosphorylation represses TACE stimulated shedding Phosphorylated iRhom2 recruits 14-3-3 and dissociates from TACE, enabling shedding iRhom2 is thus a signal integrator and transducer of stimulated TACE shedding
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13
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Callebaut I, Hoffmann B, Mornon JP. The implications of CFTR structural studies for cystic fibrosis drug development. Curr Opin Pharmacol 2017; 34:112-118. [PMID: 29096277 DOI: 10.1016/j.coph.2017.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 09/12/2017] [Accepted: 09/14/2017] [Indexed: 02/08/2023]
Abstract
Development of Cystic Fibrosis Transmembrane conductance Regulator (CFTR) modulators, targeting the root cause of cystic fibrosis (CF), represents a challenge in the era of personalized medicine, as CFTR mutations lead to a variety of phenotypes, which likely require different, specific treatments. CF drug development is also complicated by the need to preserve the right balance between stability and flexibility, required for optimal function of the CFTR protein. In this review, we highlight how structural data can be exploited in this context to understand the molecular mechanisms of disease-associated mutations, to characterize the mechanisms of action of known modulators and to rationalize the search for novel, specific compounds.
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Affiliation(s)
- Isabelle Callebaut
- CNRS UMR7590, Sorbonne Universités, Université Pierre et Marie Curie - Paris 6 - MNHN - IRD - IUC, Paris, France.
| | - Brice Hoffmann
- CNRS UMR7590, Sorbonne Universités, Université Pierre et Marie Curie - Paris 6 - MNHN - IRD - IUC, Paris, France
| | - Jean-Paul Mornon
- CNRS UMR7590, Sorbonne Universités, Université Pierre et Marie Curie - Paris 6 - MNHN - IRD - IUC, Paris, France
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14
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Correcting CFTR folding defects by small-molecule correctors to cure cystic fibrosis. Curr Opin Pharmacol 2017; 34:83-90. [PMID: 29055231 DOI: 10.1016/j.coph.2017.09.014] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 09/15/2017] [Accepted: 09/26/2017] [Indexed: 12/18/2022]
Abstract
Pharmacological intervention to treat the lethal genetic disease cystic fibrosis has become reality, even for the severe, most common folding mutant F508del CFTR. CFTR defects range from absence of the protein, misfolding that leads to degradation rather than cell-surface localization (such as F508del), to functional chloride-channel defects on the cell surface. Corrector and potentiator drugs improve cell-surface location and channel activity, respectively, and combination therapy of two correctors and a potentiator have shown synergy. Several combinations are in the drug-development pipeline and although the primary defect is not repaired, rescue levels are reaching those resembling a cure for CF. Combination therapy with correctors may also improve functional CFTR mutants and benefit patients on potentiator therapy.
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15
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Huang WQ, Guo JH, Zhang XH, Yu MK, Chung YW, Ruan YC, Chan HC. Glucose-Sensitive CFTR Suppresses Glucagon Secretion by Potentiating KATP Channels in Pancreatic Islet α Cells. Endocrinology 2017; 158:3188-3199. [PMID: 28977595 DOI: 10.1210/en.2017-00282] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/18/2017] [Indexed: 12/14/2022]
Abstract
The secretion of glucagon by islet α cells is normally suppressed by high blood glucose, but this suppressibility is impaired in patients with diabetes or cystic fibrosis (CF), a disease caused by mutations in the gene encoding CF transmembrane conductance regulator (CFTR), a cyclic adenosine monophosphate-activated Cl- channel. However, precisely how glucose regulates glucagon release remains controversial. Here we report that elevated glucagon secretion, together with increased glucose-induced membrane depolarization and Ca2+ response, is found in CFTR mutant (DF508) mice/islets compared with the wild-type. Overexpression of CFTR in AlphaTC1-9 cells results in membrane hyperpolarization and reduced glucagon release, which can be reversed by CFTR inhibition. CFTR is found to potentiate the adenosine triphosphate-sensitive K+ (KATP) channel because membrane depolarization and whole-cell currents sensitive to KATP blockers are significantly greater in wild-type/CFTR-overexpressed α cells compared with that in DF508/non-overexpressed cells. KATP knockdown also reverses the suppressive effect of CFTR overexpression on glucagon secretion. The results reveal that by potentiating KATP channels, CFTR acts as a glucose-sensing negative regulator of glucagon secretion in α cells, a defect of which may contribute to glucose intolerance in CF and other types of diabetes.
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Affiliation(s)
- Wen Qing Huang
- Epithelial Cell Biology Research Center, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
| | - Jing Hui Guo
- Epithelial Cell Biology Research Center, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
- Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan University, Guangzhou 510632, People's Republic of China
| | - Xiao Hu Zhang
- Epithelial Cell Biology Research Center, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
- Sichuan University-The Chinese University of Hong Kong Joint Laboratory for Reproductive Medicine, Key Laboratory of Obstetric, Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu 610041, People's Republic of China
| | - Mei Kuen Yu
- Epithelial Cell Biology Research Center, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
| | - Yiu Wa Chung
- Epithelial Cell Biology Research Center, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
| | - Ye Chun Ruan
- Epithelial Cell Biology Research Center, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
- Interdisciplinary Division of Biomedical Engineering, the Hong Kong Polytechnic University, Hong Kong, Hong Kong
| | - Hsiao Chang Chan
- Epithelial Cell Biology Research Center, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
- Sichuan University-The Chinese University of Hong Kong Joint Laboratory for Reproductive Medicine, Key Laboratory of Obstetric, Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu 610041, People's Republic of China
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16
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Strategies for the etiological therapy of cystic fibrosis. Cell Death Differ 2017; 24:1825-1844. [PMID: 28937684 PMCID: PMC5635223 DOI: 10.1038/cdd.2017.126] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 06/22/2017] [Accepted: 06/23/2017] [Indexed: 12/14/2022] Open
Abstract
Etiological therapies aim at repairing the underlying cause of cystic fibrosis (CF), which is the functional defect of the cystic fibrosis transmembrane conductance regulator (CFTR) protein owing to mutations in the CFTR gene. Among these, the F508del CFTR mutation accounts for more than two thirds of CF cases worldwide. Two somehow antinomic schools of thought conceive CFTR repair in a different manner. According to one vision, drugs should directly target the mutated CFTR protein to increase its plasma membrane expression (correctors) or improve its ion transport function (potentiators). An alternative strategy consists in modulating the cellular environment and proteostasis networks in which the mutated CFTR protein is synthesized, traffics to its final destination, the plasma membrane, and is turned over. We will analyze distinctive advantages and drawbacks of these strategies in terms of their scientific and clinical dimensions, and we will propose a global strategy for CF research and development based on a reconciliatory approach. Moreover, we will discuss the utility of preclinical biomarkers that may guide the personalized, patient-specific implementation of CF therapies.
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17
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Stauffer BB, Cui G, Cottrill KA, Infield DT, McCarty NA. Bacterial Sphingomyelinase is a State-Dependent Inhibitor of the Cystic Fibrosis Transmembrane conductance Regulator (CFTR). Sci Rep 2017; 7:2931. [PMID: 28592822 PMCID: PMC5462758 DOI: 10.1038/s41598-017-03103-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 04/24/2017] [Indexed: 02/07/2023] Open
Abstract
Sphingomyelinase C (SMase) inhibits CFTR chloride channel activity in multiple cell systems, an effect that could exacerbate disease in CF and COPD patients. The mechanism by which sphingomyelin catalysis inhibits CFTR is not known but evidence suggests that it occurs independently of CFTR's regulatory "R" domain. In this study we utilized the Xenopus oocyte expression system to shed light on how CFTR channel activity is reduced by SMase. We found that the pathway leading to inhibition is not membrane delimited and that inhibited CFTR channels remain at the cell membrane, indicative of a novel silencing mechanism. Consistent with an effect on CFTR gating behavior, we found that altering gating kinetics influenced the sensitivity to inhibition by SMase. Specifically, increasing channel activity by introducing the mutation K1250A or pretreating with the CFTR potentiator VX-770 (Ivacaftor) imparted resistance to inhibition. In primary bronchial epithelial cells, we found that basolateral, but not apical, application of SMase leads to a redistribution of sphingomyelin and a reduction in forskolin- and VX-770-stimulated currents. Taken together, these data suggest that SMase inhibits CFTR channel function by locking channels into a closed state and that endogenous CFTR in HBEs is affected by SMase activity.
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Affiliation(s)
- B B Stauffer
- Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, GA, 30322, USA
- Molecular and Systems Pharmacology program, Emory University, 201 Dowman Drive, Atlanta, GA, 20322, USA
| | - G Cui
- Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, GA, 30322, USA
| | - K A Cottrill
- Molecular and Systems Pharmacology program, Emory University, 201 Dowman Drive, Atlanta, GA, 20322, USA
| | - D T Infield
- Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, GA, 30322, USA
| | - N A McCarty
- Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, GA, 30322, USA.
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18
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Kirchner S, Cai Z, Rauscher R, Kastelic N, Anding M, Czech A, Kleizen B, Ostedgaard LS, Braakman I, Sheppard DN, Ignatova Z. Alteration of protein function by a silent polymorphism linked to tRNA abundance. PLoS Biol 2017; 15:e2000779. [PMID: 28510592 PMCID: PMC5433685 DOI: 10.1371/journal.pbio.2000779] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 04/13/2017] [Indexed: 01/22/2023] Open
Abstract
Synonymous single nucleotide polymorphisms (sSNPs) are considered neutral for protein function, as by definition they exchange only codons, not amino acids. We identified an sSNP that modifies the local translation speed of the cystic fibrosis transmembrane conductance regulator (CFTR), leading to detrimental changes to protein stability and function. This sSNP introduces a codon pairing to a low-abundance tRNA that is particularly rare in human bronchial epithelia, but not in other human tissues, suggesting tissue-specific effects of this sSNP. Up-regulation of the tRNA cognate to the mutated codon counteracts the effects of the sSNP and rescues protein conformation and function. Our results highlight the wide-ranging impact of sSNPs, which invert the programmed local speed of mRNA translation and provide direct evidence for the central role of cellular tRNA levels in mediating the actions of sSNPs in a tissue-specific manner. Synonymous single nucleotide polymorphisms (sSNPs) occur at high frequency in the human genome and are associated with ~50 diseases in humans; the responsible molecular mechanisms remain enigmatic. Here, we investigate the impact of the common sSNP, T2562G, on cystic fibrosis transmembrane conductance regulator (CFTR). Although this sSNP, by itself, does not cause cystic fibrosis (CF), it is prevalent in patients with CFTR-related disorders. T2562G sSNP modifies the local translation speed at the Thr854 codon, leading to changes in CFTR stability and channel function. This sSNP introduces a codon pairing to a low-abundance tRNA, which is particularly rare in human bronchial epithelia, but not in other human tissues, suggesting a tissue-specific effect of this sSNP. Enhancement of the cellular concentration of the tRNA cognate to the mutant ACG codon rescues the stability and conduction defects of T2562G-CFTR. These findings reveal an unanticipated mechanism—inverting the programmed local speed of mRNA translation in a tRNA-dependent manner—for sSNP-associated diseases.
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Affiliation(s)
- Sebastian Kirchner
- Biochemistry, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Zhiwei Cai
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Robert Rauscher
- Institute for Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Nicolai Kastelic
- Biochemistry, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Melanie Anding
- Biochemistry, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Andreas Czech
- Institute for Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Bertrand Kleizen
- Cellular Protein Chemistry, Department of Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Lynda S. Ostedgaard
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Ineke Braakman
- Cellular Protein Chemistry, Department of Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - David N. Sheppard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
- * E-mail: (ZI); (DNS)
| | - Zoya Ignatova
- Biochemistry, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
- Institute for Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
- * E-mail: (ZI); (DNS)
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19
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Zhang J, Hwang JU, Song WY, Martinoia E, Lee Y. Identification of amino acid residues important for the arsenic resistance function of Arabidopsis ABCC1. FEBS Lett 2017; 591:656-666. [PMID: 28130831 DOI: 10.1002/1873-3468.12576] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 01/22/2017] [Accepted: 01/23/2017] [Indexed: 11/11/2022]
Abstract
The Arabidopsis ATP-Binding Cassette (ABC) transporter ABCC1 sequesters arsenic (As)-phytochelatin conjugates into the vacuole, thereby conferring As resistance. Here, we report the results of a screen for phosphorylation-dependent regulation sites of AtABCC1. Variants of AtABCC1 harboring mutations that replaced amino acid residues Tyr682 , Tyr709 , Tyr822 , Ser846 , Ser1278 , or Thr1408 with alanine confer reduced resistance and decrease the intracellular As content relative to wild-type AtABCC1 when heterologously expressed in the SM7 yeast strain. This suggests that these mutations compromise the vacuolar sequestration of As by AtABCC1. Furthermore, through a phosphomimic mutant study, we found that phosphorylation of Ser846 is required for the As resistance function of AtABCC1. Our analysis provides a first clue as to the phosphorylation-mediated regulation of AtABCC1 activity.
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Affiliation(s)
- Jie Zhang
- Department of Life Science, Pohang University of Science and Technology, Korea
| | - Jae-Ung Hwang
- Department of Life Science, Pohang University of Science and Technology, Korea
| | - Won-Yong Song
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Korea
| | - Enrico Martinoia
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Korea.,Institut für Pflanzenbiologie, Universität Zürich, Switzerland
| | - Youngsook Lee
- Department of Life Science, Pohang University of Science and Technology, Korea.,Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Korea
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20
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Nene A, Chen CH, Disatnik MH, Cruz L, Mochly-Rosen D. Aldehyde dehydrogenase 2 activation and coevolution of its εPKC-mediated phosphorylation sites. J Biomed Sci 2017; 24:3. [PMID: 28056995 PMCID: PMC5217657 DOI: 10.1186/s12929-016-0312-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 12/13/2016] [Indexed: 02/07/2023] Open
Abstract
Background Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is a key enzyme for the metabolism of many toxic aldehydes such as acetaldehyde, derived from alcohol drinking, and 4HNE, an oxidative stress-derived lipid peroxidation aldehyde. Post-translational enhancement of ALDH2 activity can be achieved by serine/threonine phosphorylation by epsilon protein kinase C (εPKC). Elevated ALDH2 is beneficial in reducing injury following myocardial infarction, stroke and other oxidative stress and aldehyde toxicity-related diseases. We have previously identified three εPKC phosphorylation sites, threonine 185 (T185), serine 279 (S279) and threonine 412 (T412), on ALDH2. Here we further characterized the role and contribution of each phosphorylation site to the enhancement of enzymatic activity by εPKC. Methods Each individual phosphorylation site was mutated to a negatively charged amino acid, glutamate, to mimic a phosphorylation, or to a non-phosphorylatable amino acid, alanine. ALDH2 enzyme activities and protection against 4HNE inactivation were measured in the presence or absence of εPKC phosphorylation in vitro. Coevolution of ALDH2 and its εPKC phosphorylation sites was delineated by multiple sequence alignments among a diverse range of species and within the ALDH multigene family. Results We identified S279 as a critical εPKC phosphorylation site in the activation of ALDH2. The critical catalytic site, cysteine 302 (C302) of ALDH2 is susceptible to adduct formation by reactive aldehyde, 4HNE, which readily renders the enzyme inactive. We show that phosphomimetic mutations of T185E, S279E and T412E confer protection of ALDH2 against 4HNE-induced inactivation, indicating that phosphorylation on these three sites by εPKC likely also protects the enzyme against reactive aldehydes. Finally, we demonstrate that the three ALDH2 phosphorylation sites co-evolved with εPKC over a wide range of species. Alignment of 18 human ALDH isozymes, indicates that T185 and S279 are unique ALDH2, εPKC specific phosphorylation sites, while T412 is found in other ALDH isozymes. We further identified three highly conserved serine/threonine residues (T384, T433 and S471) in all 18 ALDH isozymes that may play an important phosphorylation-mediated regulatory role in this important family of detoxifying enzymes. Conclusion εPKC phosphorylation and its coevolution with ALDH2 play an important role in the regulation and protection of ALDH2 enzyme activity. Electronic supplementary material The online version of this article (doi:10.1186/s12929-016-0312-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aishwarya Nene
- Department of Chemical and Systems Biology, Stanford University, School of Medicine, Stanford, CA, 94305-5174, USA
| | - Che-Hong Chen
- Department of Chemical and Systems Biology, Stanford University, School of Medicine, Stanford, CA, 94305-5174, USA.
| | - Marie-Hélène Disatnik
- Department of Chemical and Systems Biology, Stanford University, School of Medicine, Stanford, CA, 94305-5174, USA
| | - Leslie Cruz
- Department of Chemical and Systems Biology, Stanford University, School of Medicine, Stanford, CA, 94305-5174, USA
| | - Daria Mochly-Rosen
- Department of Chemical and Systems Biology, Stanford University, School of Medicine, Stanford, CA, 94305-5174, USA
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21
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Callebaut I, Hoffmann B, Lehn P, Mornon JP. Molecular modelling and molecular dynamics of CFTR. Cell Mol Life Sci 2017; 74:3-22. [PMID: 27717958 PMCID: PMC11107702 DOI: 10.1007/s00018-016-2385-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 09/28/2016] [Indexed: 12/11/2022]
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) protein is a member of the ATP-binding cassette (ABC) transporter superfamily that functions as an ATP-gated channel. Considerable progress has been made over the last years in the understanding of the molecular basis of the CFTR functions, as well as dysfunctions causing the common genetic disease cystic fibrosis (CF). This review provides a global overview of the theoretical studies that have been performed so far, especially molecular modelling and molecular dynamics (MD) simulations. A special emphasis is placed on the CFTR-specific evolution of an ABC transporter framework towards a channel function, as well as on the understanding of the effects of disease-causing mutations and their specific modulation. This in silico work should help structure-based drug discovery and design, with a view to develop CFTR-specific pharmacotherapeutic approaches for the treatment of CF in the context of precision medicine.
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Affiliation(s)
- Isabelle Callebaut
- UMR CNRS 7590, Museum National d'Histoire Naturelle, IRD UMR 206, IUC, Case 115, IMPMC, Sorbonne Universités, UPMC Univ Paris 06, 4 Place Jussieu, 75005, Paris Cedex 05, France.
| | - Brice Hoffmann
- UMR CNRS 7590, Museum National d'Histoire Naturelle, IRD UMR 206, IUC, Case 115, IMPMC, Sorbonne Universités, UPMC Univ Paris 06, 4 Place Jussieu, 75005, Paris Cedex 05, France
| | - Pierre Lehn
- INSERM U1078, SFR ScInBioS, Université de Bretagne Occidentale, Brest, France
| | - Jean-Paul Mornon
- UMR CNRS 7590, Museum National d'Histoire Naturelle, IRD UMR 206, IUC, Case 115, IMPMC, Sorbonne Universités, UPMC Univ Paris 06, 4 Place Jussieu, 75005, Paris Cedex 05, France
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22
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Schmidt BZ, Haaf JB, Leal T, Noel S. Cystic fibrosis transmembrane conductance regulator modulators in cystic fibrosis: current perspectives. Clin Pharmacol 2016; 8:127-140. [PMID: 27703398 PMCID: PMC5036583 DOI: 10.2147/cpaa.s100759] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Mutations of the CFTR gene cause cystic fibrosis (CF), the most common recessive monogenic disease worldwide. These mutations alter the synthesis, processing, function, or half-life of CFTR, the main chloride channel expressed in the apical membrane of epithelial cells in the airway, intestine, pancreas, and reproductive tract. Lung disease is the most critical manifestation of CF. It is characterized by airway obstruction, infection, and inflammation that lead to fatal tissue destruction. In spite of great advances in early and multidisciplinary medical care, and in our understanding of the pathophysiology, CF is still considerably reducing the life expectancy of patients. This review highlights the current development in pharmacological modulators of CFTR, which aim at rescuing the expression and/or function of mutated CFTR. While only Kalydeco® and Orkambi® are currently available to patients, many other families of CFTR modulators are undergoing preclinical and clinical investigations. Drug repositioning and personalized medicine are particularly detailed in this review as they represent the most promising strategies for restoring CFTR function in CF.
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Affiliation(s)
- Béla Z Schmidt
- Stem Cell Biology and Embryology, Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven
| | - Jérémy B Haaf
- Louvain Center for Toxicology and Applied Pharmacology, Université Catholique de Louvain, Brussels, Belgium
| | - Teresinha Leal
- Louvain Center for Toxicology and Applied Pharmacology, Université Catholique de Louvain, Brussels, Belgium
| | - Sabrina Noel
- Louvain Center for Toxicology and Applied Pharmacology, Université Catholique de Louvain, Brussels, Belgium
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23
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Abstract
The anion channel cystic fibrosis transmembrane conductance regulator (CFTR) is a unique ATP-binding cassette (ABC) transporter. CFTR plays a pivotal role in transepithelial ion transport as its dysfunction in the genetic disease cystic fibrosis (CF) dramatically demonstrates. Phylogenetic analysis suggests that CFTR first appeared in aquatic vertebrates fulfilling important roles in osmosensing and organ development. Here, we review selectively, knowledge of CFTR structure, function and pharmacology, gleaned from cross-species comparative studies of recombinant CFTR proteins, including CFTR chimeras. The data argue that subtle changes in CFTR structure can affect strongly channel function and the action of CF mutations.
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24
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Chong PA, Forman-Kay JD. Liquid-liquid phase separation in cellular signaling systems. Curr Opin Struct Biol 2016; 41:180-186. [PMID: 27552079 DOI: 10.1016/j.sbi.2016.08.001] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 07/29/2016] [Accepted: 08/01/2016] [Indexed: 12/29/2022]
Abstract
Liquid-liquid demixing or phase separation of protein with RNA is now recognized to be a key part of the mechanism for assembly of ribonucleoprotein granules. Cellular signaling also appears to employ phase separation as a mechanism for amplification or control of signal transduction both within the cytoplasm and at the membrane. The concept of receptor clustering, identified more than 3 decades ago, is now being examined through the lens of phase separation leading to new insights. Intrinsically disordered proteins or regions are central to these processes owing to their flexibility and accessibility for dynamic protein-protein interactions and post-translational modifications. We review some recent examples, examine the mechanisms driving phase separation and delineate the implications for signal transduction systems.
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Affiliation(s)
- P Andrew Chong
- Program in Molecular Structure and Function, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Julie D Forman-Kay
- Program in Molecular Structure and Function, Hospital for Sick Children, Toronto, Ontario, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
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25
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Bhowmick A, Brookes DH, Yost SR, Dyson HJ, Forman-Kay JD, Gunter D, Head-Gordon M, Hura GL, Pande VS, Wemmer DE, Wright PE, Head-Gordon T. Finding Our Way in the Dark Proteome. J Am Chem Soc 2016; 138:9730-42. [PMID: 27387657 PMCID: PMC5051545 DOI: 10.1021/jacs.6b06543] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The traditional structure-function paradigm has provided significant insights for well-folded proteins in which structures can be easily and rapidly revealed by X-ray crystallography beamlines. However, approximately one-third of the human proteome is comprised of intrinsically disordered proteins and regions (IDPs/IDRs) that do not adopt a dominant well-folded structure, and therefore remain "unseen" by traditional structural biology methods. This Perspective considers the challenges raised by the "Dark Proteome", in which determining the diverse conformational substates of IDPs in their free states, in encounter complexes of bound states, and in complexes retaining significant disorder requires an unprecedented level of integration of multiple and complementary solution-based experiments that are analyzed with state-of-the art molecular simulation, Bayesian probabilistic models, and high-throughput computation. We envision how these diverse experimental and computational tools can work together through formation of a "computational beamline" that will allow key functional features to be identified in IDP structural ensembles.
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Affiliation(s)
- Asmit Bhowmick
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720
| | - David H. Brookes
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Shane R. Yost
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - H. Jane Dyson
- Department of Integrative Structural and Computational Biology, Scripps Research Institute, La Jolla, California 92037
| | - Julie D. Forman-Kay
- Molecular Structure and Function Program, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Daniel Gunter
- Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley CA, 94720
| | | | - Gregory L. Hura
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley CA, 94720
| | - Vijay S. Pande
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - David E. Wemmer
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Peter E. Wright
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Teresa Head-Gordon
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720
- Department of Chemistry, University of California, Berkeley, CA 94720
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley CA, 94720
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26
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Zwick M, Esposito C, Hellstern M, Seelig A. How Phosphorylation and ATPase Activity Regulate Anion Flux though the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). J Biol Chem 2016; 291:14483-98. [PMID: 27226582 DOI: 10.1074/jbc.m116.721415] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Indexed: 01/25/2023] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR, ABCC7), mutations of which cause cystic fibrosis, belongs to the ATP-binding cassette (ABC) transporter family and works as a channel for small anions, such as chloride and bicarbonate. Anion channel activity is known to depend on phosphorylation by cAMP-dependent protein kinase A (PKA) and CFTR-ATPase activity. Whereas anion channel activity has been extensively investigated, phosphorylation and CFTR-ATPase activity are still poorly understood. Here, we show that the two processes can be measured in a label-free and non-invasive manner in real time in live cells, stably transfected with CFTR. This study reveals three key findings. (i) The major contribution (≥90%) to the total CFTR-related ATP hydrolysis rate is due to phosphorylation by PKA and the minor contribution (≤10%) to CFTR-ATPase activity. (ii) The mutant CFTR-E1371S that is still conductive, but defective in ATP hydrolysis, is not phosphorylated, suggesting that phosphorylation requires a functional nucleotide binding domain and occurs in the post-hydrolysis transition state. (iii) CFTR-ATPase activity is inversely related to CFTR anion flux. The present data are consistent with a model in which CFTR is in a closed conformation with two ATPs bound. The open conformation is induced by ATP hydrolysis and corresponds to the post-hydrolysis transition state that is stabilized by phosphorylation and binding of chloride channel potentiators.
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Affiliation(s)
- Matthias Zwick
- From the Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Cinzia Esposito
- From the Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Manuel Hellstern
- From the Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Anna Seelig
- From the Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
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27
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Bah A, Forman-Kay JD. Modulation of Intrinsically Disordered Protein Function by Post-translational Modifications. J Biol Chem 2016; 291:6696-705. [PMID: 26851279 DOI: 10.1074/jbc.r115.695056] [Citation(s) in RCA: 344] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Post-translational modifications (PTMs) produce significant changes in the structural properties of intrinsically disordered proteins (IDPs) by affecting their energy landscapes. PTMs can induce a range of effects, from local stabilization or destabilization of transient secondary structure to global disorder-to-order transitions, potentially driving complete state changes between intrinsically disordered and folded states or dispersed monomeric and phase-separated states. Here, we discuss diverse biological processes that are dependent on PTM regulation of IDPs. We also present recent tools for generating homogenously modified IDPs for studies of PTM-mediated IDP regulatory mechanisms.
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Affiliation(s)
- Alaji Bah
- From the Program in Molecular Structure & Function, The Hospital for Sick Children, Toronto, Ontario M5G 0A4 and the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Julie D Forman-Kay
- From the Program in Molecular Structure & Function, The Hospital for Sick Children, Toronto, Ontario M5G 0A4 and the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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28
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Abstract
Specific conformations of signaling proteins can serve as “signals” in signal transduction by being recognized by receptors.
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Affiliation(s)
- Peter Tompa
- VIB Structural Biology Research Center (SBRC)
- Brussels
- Belgium
- Vrije Universiteit Brussel
- Brussels
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29
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Pre-Anchoring of Pin1 to Unphosphorylated c-Myc in a Fuzzy Complex Regulates c-Myc Activity. Structure 2015; 23:2267-2279. [PMID: 26655473 DOI: 10.1016/j.str.2015.10.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 09/30/2015] [Accepted: 10/01/2015] [Indexed: 12/27/2022]
Abstract
Hierarchic phosphorylation and concomitant Pin1-mediated proline isomerization of the oncoprotein c-Myc controls its cellular stability and activity. However, the molecular basis for Pin1 recognition and catalysis of c-Myc and other multisite, disordered substrates in cell regulation and disease is unclear. By nuclear magnetic resonance, surface plasmon resonance, and molecular modeling, we show that Pin1 subdomains jointly pre-anchor unphosphorylated c-Myc1-88 in the Pin1 interdomain cleft in a disordered, or "fuzzy", complex at the herein named Myc Box 0 (MB0) conserved region N-terminal to the highly conserved Myc Box I (MBI). Ser62 phosphorylation in MBI intensifies previously transient MBI-Pin1 interactions in c-Myc1-88 binding, and increasingly engages Pin1PPIase and its catalytic region with maintained MB0 interactions. In cellular assays, MB0 mutated c-Myc shows decreased Pin1 interaction, increased protein half-life, but lowered rates of Myc-driven transcription and cell proliferation. We propose that dynamic Pin1 recognition of MB0 contributes to the regulation of c-Myc activity in cells.
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30
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Tompa P, Schad E, Tantos A, Kalmar L. Intrinsically disordered proteins: emerging interaction specialists. Curr Opin Struct Biol 2015; 35:49-59. [PMID: 26402567 DOI: 10.1016/j.sbi.2015.08.009] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/23/2015] [Accepted: 08/28/2015] [Indexed: 12/22/2022]
Abstract
Intrinsically disordered proteins or regions of proteins (IDPs/IDRs) most often function through protein-protein interactions, when they permanently or transiently bind partner molecules with diverse functional consequences. There is a rapid advance in our understanding of the ensuing functional modes, obtained from describing atomic details of individual complexes, proteome-wide studies of interactomes and characterizing loosely assembled hydrogels and tightly packed amyloids. Here we briefly survey the most important recent methodological developments and structural-functional observations, with the aim of increasing the general appreciation of IDPs/IDRs as 'interaction specialists'.
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Affiliation(s)
- Peter Tompa
- VIB Structural Biology Research Center (SBRC), Brussels, Belgium; Vrije Universiteit Brussel, Brussels, Belgium; Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Budapest, Hungary.
| | - Eva Schad
- Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Budapest, Hungary
| | - Agnes Tantos
- Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Budapest, Hungary
| | - Lajos Kalmar
- Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Budapest, Hungary
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31
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Affiliation(s)
- Scott C Bell
- QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia; The Prince Charles Hospital, Brisbane, QLD, Australia.
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32
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Billet A, Jia Y, Jensen T, Riordan JR, Hanrahan JW. Regulation of the cystic fibrosis transmembrane conductance regulator anion channel by tyrosine phosphorylation. FASEB J 2015; 29:3945-53. [PMID: 26062600 DOI: 10.1096/fj.15-273151] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 05/26/2015] [Indexed: 11/11/2022]
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) channel is activated by PKA phosphorylation of a regulatory domain that interacts dynamically with multiple CFTR domains and with other proteins. The large number of consensus sequences for phosphorylation by PKA has naturally focused most attention on regulation by this kinase. We report here that human CFTR is also phosphorylated by the tyrosine kinases p60c-Src (proto-oncogene tyrosine-protein kinase) and the proline-rich tyrosine kinase 2 (Pyk2), and they can also cause robust activation of quiescent CFTR channels. In excised patch-clamp experiments, CFTR activity during exposure to Src or Pyk2 reached ∼80% of that stimulated by PKA. Exposure to PKA after Src or Pyk2 caused a further increase to the level induced by PKA alone, implying a common limiting step. Channels became spontaneously active when v-Src or the catalytic domain of Pyk2 was coexpressed with CFTR and were further stimulated by the tyrosine phosphatase inhibitor dephostatin. Exogenous Src also activated 15SA-CFTR, a variant that lacks 15 potential PKA sites and has little response to PKA. PKA-independent activation by tyrosine phosphorylation has implications for the mechanism of regulation by the R domain and for the physiologic functions of CFTR.
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Affiliation(s)
- Arnaud Billet
- *Department of Physiology and Cystic Fibrosis Translational Research Centre, McGill University, Montreal, Quebec, Canada; Department of Biochemistry and Biophysics and Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, USA; and Research Institute of the McGill University Hospital Centre, Montreal, Quebec, Canada
| | - Yanlin Jia
- *Department of Physiology and Cystic Fibrosis Translational Research Centre, McGill University, Montreal, Quebec, Canada; Department of Biochemistry and Biophysics and Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, USA; and Research Institute of the McGill University Hospital Centre, Montreal, Quebec, Canada
| | - Tim Jensen
- *Department of Physiology and Cystic Fibrosis Translational Research Centre, McGill University, Montreal, Quebec, Canada; Department of Biochemistry and Biophysics and Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, USA; and Research Institute of the McGill University Hospital Centre, Montreal, Quebec, Canada
| | - John R Riordan
- *Department of Physiology and Cystic Fibrosis Translational Research Centre, McGill University, Montreal, Quebec, Canada; Department of Biochemistry and Biophysics and Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, USA; and Research Institute of the McGill University Hospital Centre, Montreal, Quebec, Canada
| | - John W Hanrahan
- *Department of Physiology and Cystic Fibrosis Translational Research Centre, McGill University, Montreal, Quebec, Canada; Department of Biochemistry and Biophysics and Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, USA; and Research Institute of the McGill University Hospital Centre, Montreal, Quebec, Canada
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33
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Liu W, Landgraf R. Phosphorylated and unphosphorylated serine 13 of CDC37 stabilize distinct interactions between its client and HSP90 binding domains. Biochemistry 2015; 54:1493-504. [PMID: 25619116 DOI: 10.1021/bi501129g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Folding and maturation of most protein kinases require chaperone assistance. In higher eukaryotes, CDC37 is the predominant cochaperone that facilitates the transfer of kinase clients to HSP90. Kinase recognition is thought to occur through the N-terminal domain, which has, thus far, eluded structure determination. Client processing also requires the phosphorylation of the N-terminal tail at Ser13 by protein kinase CK2 (casein kinase 2). How phosphorylation alters the molecular properties of CDC37 is not understood. We show that the phosphorylation at Ser13 induces a large shift toward a more compact structure, based on ANS fluorescence, while modestly increasing secondary structure. Moreover, this transition requires interactions of the N-terminal domain and the remainder of CDC37. The stabilizing property of the phosphorylation event can be recreated in trans by a (phospho-Ser13) peptide derived from the N-terminal tail. However, the phosphorylation-induced transition is not dependent on the transferred phosphate group but rather the loss of serine-like properties at position 13. The complete absence of the N-terminal tail results in reduced secondary structure and unresponsiveness to subsequent addition of peptides. The N-terminal tail may therefore serve as an intramolecular chaperone that ensures that CDC37 assumes one of two readily interconvertible states in a manner that impacts the interaction of the client binding N-domain and the MC-domains, involved in dimerization and HSP90 binding.
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Affiliation(s)
- Wenjun Liu
- Department of Biochemistry and Molecular Biology and ‡Sylvester Comprehensive Cancer Center, University of Miami, Miller School of Medicine , Miami, Florida 33136, United States
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34
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Nussinov R, Jang H. Dynamic multiprotein assemblies shape the spatial structure of cell signaling. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 116:158-64. [PMID: 25046855 PMCID: PMC4250281 DOI: 10.1016/j.pbiomolbio.2014.07.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 07/07/2014] [Indexed: 11/25/2022]
Abstract
Cell signaling underlies critical cellular decisions. Coordination, efficiency as well as fail-safe mechanisms are key elements. How the cell ensures that these hallmarks are at play are important questions. Cell signaling is often viewed as taking place through discrete and cross-talking pathways; oftentimes these are modularized to emphasize distinct functions. While simple, convenient and clear, such models largely neglect the spatial structure of cell signaling; they also convey inter-modular (or inter-protein) spatial separation that may not exist. Here our thesis is that cell signaling is shaped by a network of multiprotein assemblies. While pre-organized, the assemblies and network are loose and dynamic. They contain transiently-associated multiprotein complexes which are often mediated by scaffolding proteins. They are also typically anchored in the membrane, and their continuum may span the cell. IQGAP1 scaffolding protein which binds proteins including Raf, calmodulin, Mek, Erk, actin, and tens more, with actin shaping B-cell (and likely other) membrane-anchored nanoclusters and allosterically polymerizing in dynamic cytoskeleton formation, and Raf anchoring in the membrane along with Ras, provides a striking example. The multivalent network of dynamic proteins and lipids, with specific interactions forming and breaking, can be viewed as endowing gel-like properties. Collectively, this reasons that efficient, productive and reliable cell signaling takes place primarily through transient, preorganized and cooperative protein-protein interactions spanning the cell rather than stochastic, diffusion-controlled processes.
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Affiliation(s)
- Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA; Sackler Inst. of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
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35
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Nishi H, Shaytan A, Panchenko AR. Physicochemical mechanisms of protein regulation by phosphorylation. Front Genet 2014; 5:270. [PMID: 25147561 PMCID: PMC4124799 DOI: 10.3389/fgene.2014.00270] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 07/22/2014] [Indexed: 12/17/2022] Open
Abstract
Phosphorylation offers a dynamic way to regulate protein activity and subcellular localization, which is achieved through its reversibility and fast kinetics. Adding or removing a dianionic phosphate group somewhere on a protein often changes the protein’s structural properties, its stability and dynamics. Moreover, the majority of signaling pathways involve an extensive set of protein–protein interactions, and phosphorylation can be used to regulate and modulate protein–protein binding. Losses of phosphorylation sites, as a result of disease mutations, might disrupt protein binding and deregulate signal transduction. In this paper we focus on the effects of phosphorylation on protein stability, dynamics, and binding. We describe several physico-chemical mechanisms of protein regulation through phosphorylation and pay particular attention to phosphorylation in protein complexes and phosphorylation in the context of disorder–order and order–disorder transitions. Finally we assess the role of multiple phosphorylation sites in a protein molecule, their possible cooperativity and function.
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Affiliation(s)
- Hafumi Nishi
- Graduate School of Medical Life Science, Yokohama City University Yokohama Japan
| | - Alexey Shaytan
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health Bethesda, MD USA
| | - Anna R Panchenko
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health Bethesda, MD USA
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36
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Hildebrandt E, Zhang Q, Cant N, Ding H, Dai Q, Peng L, Fu Y, DeLucas LJ, Ford R, Kappes JC, Urbatsch IL. A survey of detergents for the purification of stable, active human cystic fibrosis transmembrane conductance regulator (CFTR). BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2825-37. [PMID: 25065669 DOI: 10.1016/j.bbamem.2014.07.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 07/15/2014] [Accepted: 07/17/2014] [Indexed: 01/12/2023]
Abstract
Structural knowledge of the cystic fibrosis transmembrane conductance regulator (CFTR) requires developing methods to purify and stabilize this aggregation-prone membrane protein above 1mg/ml. Starting with green fluorescent protein- and epitope-tagged human CFTR produced in mammalian cells known to properly fold and process CFTR, we devised a rapid tandem affinity purification scheme to minimize CFTR exposure to detergent in order to preserve its ATPase function. We compared a panel of detergents, including widely used detergents (maltosides, neopentyl glycols (MNG), C12E8, lysolipids, Chaps) and innovative detergents (branched alkylmaltosides, facial amphiphiles) for CFTR purification, function, monodispersity and stability. ATPase activity after reconstitution into proteoliposomes was 2-3 times higher when CFTR was purified using facial amphiphiles. ATPase activity was also demonstrated in purified CFTR samples without detergent removal using a novel lipid supplementation assay. By electron microscopy, negatively stained CFTR samples were monodisperse at low concentration, and size exclusion chromatography showed a predominance of monomer even after CFTR concentration above 1mg/ml. Rates of CFTR aggregation quantified in an electrophoretic mobility shift assay showed that detergents which best preserved reconstituted ATPase activity also supported the greatest stability, with CFTR monomer half-lives of 6-9days in MNG or Chaps, and 12-17days in facial amphiphile. Cryoelectron microscopy of concentrated CFTR in MNG or facial amphiphile confirmed mostly monomeric protein, producing low resolution reconstructions in conformity with similar proteins. These protocols can be used to generate samples of pure, functional, stable CFTR at concentrations amenable to biophysical characterization.
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Affiliation(s)
- Ellen Hildebrandt
- Department of Cell Biology and Biochemistry and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, 3601 4th Street, Stop 6540, Lubbock, TX 79430, USA
| | - Qinghai Zhang
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Natasha Cant
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, 701 19th Street South, Birmingham, AL 35294-0007, USA
| | - Qun Dai
- Department of Medicine, University of Alabama at Birmingham, 701 19th Street South, Birmingham, AL 35294-0007, USA
| | - Lingling Peng
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Yu Fu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Lawrence J DeLucas
- Department of Optometry, University of Alabama at Birmingham, 701 19th Street South, Birmingham, AL 35294-0007, USA
| | - Robert Ford
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - John C Kappes
- Department of Medicine, University of Alabama at Birmingham, 701 19th Street South, Birmingham, AL 35294-0007, USA; Department of Microbiology, University of Alabama at Birmingham, 701 19th Street South, Birmingham, AL 35294-0007, USA; Department of Pathology, University of Alabama at Birmingham, 701 19th Street South, Birmingham, AL 35294-0007, USA; Birmingham Veterans Medical Center, Research Service, Birmingham, AL 35233, USA
| | - Ina L Urbatsch
- Department of Cell Biology and Biochemistry and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, 3601 4th Street, Stop 6540, Lubbock, TX 79430, USA.
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37
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Veley KM, Maksaev G, Frick EM, January E, Kloepper SC, Haswell ES. Arabidopsis MSL10 has a regulated cell death signaling activity that is separable from its mechanosensitive ion channel activity. THE PLANT CELL 2014; 26:3115-31. [PMID: 25052715 PMCID: PMC4145136 DOI: 10.1105/tpc.114.128082] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 06/19/2014] [Accepted: 06/27/2014] [Indexed: 05/08/2023]
Abstract
Members of the MscS superfamily of mechanosensitive ion channels function as osmotic safety valves, releasing osmolytes under increased membrane tension. MscS homologs exhibit diverse topology and domain structure, and it has been proposed that the more complex members of the family might have novel regulatory mechanisms or molecular functions. Here, we present a study of MscS-Like (MSL)10 from Arabidopsis thaliana that supports these ideas. High-level expression of MSL10-GFP in Arabidopsis induced small stature, hydrogen peroxide accumulation, ectopic cell death, and reactive oxygen species- and cell death-associated gene expression. Phosphomimetic mutations in the MSL10 N-terminal domain prevented these phenotypes. The phosphorylation state of MSL10 also regulated its ability to induce cell death when transiently expressed in Nicotiana benthamiana leaves but did not affect subcellular localization, assembly, or channel behavior. Finally, the N-terminal domain of MSL10 was sufficient to induce cell death in tobacco, independent of phosphorylation state. We conclude that the plant-specific N-terminal domain of MSL10 is capable of inducing cell death, this activity is regulated by phosphorylation, and MSL10 has two separable activities-one as an ion channel and one as an inducer of cell death. These findings further our understanding of the evolution and significance of mechanosensitive ion channels.
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Affiliation(s)
- Kira M Veley
- Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Grigory Maksaev
- Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Elizabeth M Frick
- Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Emma January
- Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Sarah C Kloepper
- Department of Biology, Washington University, St. Louis, Missouri 63130
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38
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Reddy KD, DeForte S, Uversky VN. Digested disorder: Quarterly intrinsic disorder digest (July-August-September, 2013). INTRINSICALLY DISORDERED PROTEINS 2014; 2:e27833. [PMID: 28232877 PMCID: PMC5314876 DOI: 10.4161/idp.27833] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 01/13/2014] [Indexed: 12/26/2022]
Abstract
The current literature on intrinsically disordered proteins grows fast. To keep interested readers up to speed with this literature, we continue a "Digested Disorder" project and represent a new issue of reader's digest of the research papers and reviews on intrinsically disordered proteins. The only 2 criteria for inclusion in this digest are the publication date (a paper should be published within the covered time frame) and topic (a paper should be dedicated to any aspect of protein intrinsic disorder). The current digest issue covers papers published during the third quarter of 2013; i.e., during the period of June, July, and September of 2013. Similar to previous issues, the papers are grouped hierarchically by topics they cover, and for each of the included paper a short description is given on its major findings.
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Affiliation(s)
- Krishna D Reddy
- Department of Molecular Medicine; Morsani College of Medicine; University of South Florida; Tampa, FL USA
| | - Shelly DeForte
- Department of Molecular Medicine; Morsani College of Medicine; University of South Florida; Tampa, FL USA
| | - Vladimir N Uversky
- Department of Molecular Medicine; Morsani College of Medicine; University of South Florida; Tampa, FL USA; USF Health Byrd Alzheimer's Research Institute; Morsani College of Medicine; University of South Florida; Tampa, FL USA; Department of Biological Sciences; Faculty of Science; King Abdulaziz University; Jeddah, Saudi Arabia; Institute for Biological Instrumentation; Russian Academy of Sciences; Pushchino, Moscow Region, Russia
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39
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Wang Y, Wrennall JA, Cai Z, Li H, Sheppard DN. Understanding how cystic fibrosis mutations disrupt CFTR function: from single molecules to animal models. Int J Biochem Cell Biol 2014; 52:47-57. [PMID: 24727426 DOI: 10.1016/j.biocel.2014.04.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 04/01/2014] [Accepted: 04/02/2014] [Indexed: 12/21/2022]
Abstract
Defective epithelial ion transport is the hallmark of the life-limiting genetic disease cystic fibrosis (CF). This abnormality is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), the ATP-binding cassette transporter that functions as a ligand-gated anion channel. Since the identification of the CFTR gene, almost 2000 disease-causing mutations associated with a spectrum of clinical phenotypes have been reported, but the majority remain poorly characterised. Studies of a small number of mutations including the most common, F508del-CFTR, have identified six general mechanisms of CFTR dysfunction. Here, we review selectively progress to understand how CF mutations disrupt CFTR processing, stability and function. We explore CFTR structure and function to explain the molecular mechanisms of CFTR dysfunction and highlight new knowledge of disease pathophysiology emerging from large animal models of CF. Understanding CFTR dysfunction is crucial to the development of transformational therapies for CF patients.
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Affiliation(s)
- Yiting Wang
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Joe A Wrennall
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Zhiwei Cai
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Hongyu Li
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - David N Sheppard
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK.
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It Takes More Than Two to Tango: Regulation of Plant ABC Transporters. SIGNALING AND COMMUNICATION IN PLANTS 2014. [DOI: 10.1007/978-3-319-06511-3_13] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Abstract
Cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), a member of the ATP-binding cassette (ABC) family of membrane transport proteins. CFTR is unique among ABC proteins in that it functions not as an active transporter but as an ATP-gated Cl(-) channel. As an ion channel, the function of the CFTR transmembrane channel pore that mediates Cl(-) movement has been studied in great detail. On the other hand, only low resolution structural data is available on the transmembrane parts of the protein. The structure of the channel pore has, however, been modeled on the known structure of active transporter ABC proteins. Currently, significant barriers exist to building a unified view of CFTR pore structure and function. Reconciling functional data on the channel with indirect structural data based on other proteins with very different transport functions and substrates has proven problematic. This review summarizes current structural and functional models of the CFTR Cl(-) channel pore, including a comprehensive review of previous electrophysiological investigations of channel structure and function. In addition, functional data on the three-dimensional arrangement of pore-lining helices, as well as contemporary hypotheses concerning conformational changes in the pore that occur during channel opening and closing, are discussed. Important similarities and differences between different models of the pore highlight current gaps in our knowledge of CFTR structure and function. In order to fill these gaps, structural and functional models of the membrane-spanning pore need to become better integrated.
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Affiliation(s)
- Paul Linsdell
- Department of Physiology & Biophysics, Dalhousie University , Halifax, Nova Scotia , Canada
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