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Papa A, del Rivero Morfin PJ, Chen BX, Yang L, Katchman AN, Zakharov SI, Liu G, Bohnen MS, Zheng V, Katz M, Subramaniam S, Hirsch JA, Weiss S, Dascal N, Karlin A, Pitt GS, Colecraft HM, Ben-Johny M, Marx SO. A membrane-associated phosphoswitch in Rad controls adrenergic regulation of cardiac calcium channels. J Clin Invest 2024; 134:e176943. [PMID: 38227371 PMCID: PMC10904049 DOI: 10.1172/jci176943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/11/2024] [Indexed: 01/17/2024] Open
Abstract
The ability to fight or flee from a threat relies on an acute adrenergic surge that augments cardiac output, which is dependent on increased cardiac contractility and heart rate. This cardiac response depends on β-adrenergic-initiated reversal of the small RGK G protein Rad-mediated inhibition of voltage-gated calcium channels (CaV) acting through the Cavβ subunit. Here, we investigate how Rad couples phosphorylation to augmented Ca2+ influx and increased cardiac contraction. We show that reversal required phosphorylation of Ser272 and Ser300 within Rad's polybasic, hydrophobic C-terminal domain (CTD). Phosphorylation of Ser25 and Ser38 in Rad's N-terminal domain (NTD) alone was ineffective. Phosphorylation of Ser272 and Ser300 or the addition of 4 Asp residues to the CTD reduced Rad's association with the negatively charged, cytoplasmic plasmalemmal surface and with CaVβ, even in the absence of CaVα, measured here by FRET. Addition of a posttranslationally prenylated CAAX motif to Rad's C-terminus, which constitutively tethers Rad to the membrane, prevented the physiological and biochemical effects of both phosphorylation and Asp substitution. Thus, dissociation of Rad from the sarcolemma, and consequently from CaVβ, is sufficient for sympathetic upregulation of Ca2+ currents.
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Affiliation(s)
- Arianne Papa
- Division of Cardiology, Department of Medicine, and
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Pedro J. del Rivero Morfin
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Bi-Xing Chen
- Division of Cardiology, Department of Medicine, and
| | - Lin Yang
- Division of Cardiology, Department of Medicine, and
| | | | | | - Guoxia Liu
- Division of Cardiology, Department of Medicine, and
| | | | - Vivian Zheng
- Division of Cardiology, Department of Medicine, and
| | | | | | - Joel A. Hirsch
- Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | | | | | - Arthur Karlin
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Department of Biochemistry and Molecular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Geoffrey S. Pitt
- Cardiovascular Research Institute and Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Henry M. Colecraft
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Department of Pharmacology and Molecular Signaling, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Manu Ben-Johny
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Steven O. Marx
- Division of Cardiology, Department of Medicine, and
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Department of Pharmacology and Molecular Signaling, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
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2
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Blomquist VG, Niu J, Choudhury P, Al Saneh A, Colecraft HM, Ahern CA. Transfer RNA-mediated restoration of potassium current and electrical correction in premature termination long-QT syndrome hERG mutants. Mol Ther Nucleic Acids 2023; 34:102032. [PMID: 37842167 PMCID: PMC10568093 DOI: 10.1016/j.omtn.2023.102032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 09/14/2023] [Indexed: 10/17/2023]
Abstract
Disease-causing premature termination codons (PTCs) individually disrupt the functional expression of hundreds of genes and represent a pernicious clinical challenge. In the heart, loss-of-function mutations in the hERG potassium channel account for approximately 30% of long-QT syndrome arrhythmia, a lethal cardiac disorder with limited treatment options. Premature termination of ribosomal translation produces a truncated and, for potassium channels, a potentially dominant-negative protein that impairs the functional assembly of the wild-type homotetrameric hERG channel complex. We used high-throughput flow cytometry and patch-clamp electrophysiology to assess the trafficking and voltage-dependent activity of hERG channels carrying patient PTC variants that have been corrected by anticodon engineered tRNA. Adenoviral-mediated expression of mutant hERG channels in cultured adult guinea pig cardiomyocytes prolonged action potential durations, and this deleterious effect was corrected upon adenoviral delivery of a human ArgUGA tRNA to restore full-length hERG protein. The results demonstrate mutation-specific, context-agnostic PTC correction and elevate the therapeutic potential of this approach for rare genetic diseases caused by stop codons.
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Affiliation(s)
- Viggo G. Blomquist
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY 10032, USA
| | - Jacqueline Niu
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY 10032, USA
| | - Papiya Choudhury
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY 10032, USA
| | - Ahmad Al Saneh
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Henry M. Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY 10032, USA
| | - Christopher A. Ahern
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA, USA
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3
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Del Rivero Morfin PJ, Chavez DS, Jayaraman S, Yang L, Kochiss AL, Colecraft HM, Liu XS, Marx SO, Rajadhyaksha AM, Ben-Johny M. A Genetically Encoded Actuator Selectively Boosts L-type Calcium Channels in Diverse Physiological Settings. bioRxiv 2023:2023.09.22.558856. [PMID: 37790372 PMCID: PMC10542531 DOI: 10.1101/2023.09.22.558856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
L-type Ca 2+ channels (Ca V 1.2/1.3) convey influx of calcium ions (Ca 2+ ) that orchestrate a bevy of biological responses including muscle contraction and gene transcription. Deficits in Ca V 1 function play a vital role in cardiac and neurodevelopmental disorders. Yet conventional pharmacological approaches to upregulate Ca V 1 are limited, as excessive Ca 2+ influx leads to cytotoxicity. Here, we develop a genetically encoded enhancer of Ca V 1.2/1.3 channels (GeeC) to manipulate Ca 2+ entry in distinct physiological settings. Specifically, we functionalized a nanobody that targets the Ca V macromolecular complex by attaching a minimal effector domain from a Ca V enhancer-leucine rich repeat containing protein 10 (Lrrc10). In cardiomyocytes, GeeC evoked a 3-fold increase in L-type current amplitude. In neurons, GeeC augmented excitation-transcription (E-T) coupling. In all, GeeC represents a powerful strategy to boost Ca V 1.2/1.3 function in distinct physiological settings and, in so doing, lays the groundwork to illuminate new insights on neuronal and cardiac physiology and disease.
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4
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Zou X, Shanmugam SK, Kanner SA, Sampson KJ, Kass RS, Colecraft HM. Divergent regulation of KCNQ1/E1 by targeted recruitment of protein kinase A to distinct sites on the channel complex. eLife 2023; 12:e83466. [PMID: 37650513 PMCID: PMC10499372 DOI: 10.7554/elife.83466] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 08/30/2023] [Indexed: 09/01/2023] Open
Abstract
The slow delayed rectifier potassium current, IKs, conducted through pore-forming Q1 and auxiliary E1 ion channel complexes is important for human cardiac action potential repolarization. During exercise or fright, IKs is up-regulated by protein kinase A (PKA)-mediated Q1 phosphorylation to maintain heart rhythm and optimum cardiac performance. Sympathetic up-regulation of IKs requires recruitment of PKA holoenzyme (two regulatory - RI or RII - and two catalytic Cα subunits) to Q1 C-terminus by an A kinase anchoring protein (AKAP9). Mutations in Q1 or AKAP9 that abolish their functional interaction result in long QT syndrome type 1 and 11, respectively, which increases the risk of sudden cardiac death during exercise. Here, we investigated the utility of a targeted protein phosphorylation (TPP) approach to reconstitute PKA regulation of IKs in the absence of AKAP9. Targeted recruitment of endogenous Cα to E1-YFP using a GFP/YFP nanobody (nano) fused to RIIα enabled acute cAMP-mediated enhancement of IKs, reconstituting physiological regulation of the channel complex. By contrast, nano-mediated tethering of RIIα or Cα to Q1-YFP constitutively inhibited IKs by retaining the channel intracellularly in the endoplasmic reticulum and Golgi. Proteomic analysis revealed that distinct phosphorylation sites are modified by Cα targeted to Q1-YFP compared to free Cα. Thus, functional outcomes of synthetically recruited PKA on IKs regulation is critically dependent on the site of recruitment within the channel complex. The results reveal insights into divergent regulation of IKs by phosphorylation across different spatial and time scales, and suggest a TPP approach to develop new drugs to prevent exercise-induced sudden cardiac death.
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Affiliation(s)
- Xinle Zou
- Department of Molecular Pharmacology and Therapeutics, Columbia UniversityNew YorkUnited States
| | - Sri Karthika Shanmugam
- Department of Physiology and Cellular Biophysics, Columbia UniversityNew YorkUnited States
| | - Scott A Kanner
- Doctoral Program in Neurobiology and Behavior, Columbia UniversityNew YorkUnited States
| | - Kevin J Sampson
- Department of Molecular Pharmacology and Therapeutics, Columbia UniversityNew YorkUnited States
| | - Robert S Kass
- Department of Molecular Pharmacology and Therapeutics, Columbia UniversityNew YorkUnited States
| | - Henry M Colecraft
- Department of Molecular Pharmacology and Therapeutics, Columbia UniversityNew YorkUnited States
- Doctoral Program in Neurobiology and Behavior, Columbia UniversityNew YorkUnited States
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5
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Gavin AC, Colecraft HM. Design and Applications of Genetically-Encoded Voltage-Dependent Calcium Channel Inhibitors. Handb Exp Pharmacol 2023. [PMID: 37306815 DOI: 10.1007/164_2023_656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Ca2+ influx through high-voltage-gated Ca2+ channels (HVGCCs; CaV1/CaV2) is an exceptionally powerful and versatile signal that controls numerous cell and physiological functions including neurotransmission, muscle contraction, and regulation of gene expression. The impressive ability of a singular signal, Ca2+ influx, to have such a plethora of functional outcomes is enabled by: molecular diversity of HVGCC pore-forming α1 and auxiliary subunits; organization of HVGCCs with extrinsic modulatory and effector protein to form discrete macromolecular complexes with unique properties; distinctive distribution of HVGCCs into separate subcellular compartments; and varying expression profiles of HVGCC isoforms among different tissues and organs. The capacity to block HVGCCs with selectivity and specificity with respect to the different levels of their organization is critical for fully understanding the scope of functional consequences of Ca2+ influx through them, and is also important for realizing their full potential as therapeutic targets. In this review, we discuss the gaps in the current landscape of small-molecule HVGCC blockers and how these may be addressed with designer genetically-encoded Ca2+ channel inhibitors (GECCIs) that draw inspiration from physiological protein inhibitors of HVGCCs.
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Affiliation(s)
- Ariana C Gavin
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY, USA
| | - Henry M Colecraft
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY, USA.
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY, USA.
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6
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Poggio E, Vallese F, Hartel AJW, Morgenstern TJ, Kanner SA, Rauh O, Giamogante F, Barazzuol L, Shepard KL, Colecraft HM, Clarke OB, Brini M, Calì T. Perturbation of the host cell Ca 2+ homeostasis and ER-mitochondria contact sites by the SARS-CoV-2 structural proteins E and M. Cell Death Dis 2023; 14:297. [PMID: 37120609 PMCID: PMC10148623 DOI: 10.1038/s41419-023-05817-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 04/11/2023] [Accepted: 04/18/2023] [Indexed: 05/01/2023]
Abstract
Coronavirus disease (COVID-19) is a contagious respiratory disease caused by the SARS-CoV-2 virus. The clinical phenotypes are variable, ranging from spontaneous recovery to serious illness and death. On March 2020, a global COVID-19 pandemic was declared by the World Health Organization (WHO). As of February 2023, almost 670 million cases and 6,8 million deaths have been confirmed worldwide. Coronaviruses, including SARS-CoV-2, contain a single-stranded RNA genome enclosed in a viral capsid consisting of four structural proteins: the nucleocapsid (N) protein, in the ribonucleoprotein core, the spike (S) protein, the envelope (E) protein, and the membrane (M) protein, embedded in the surface envelope. In particular, the E protein is a poorly characterized viroporin with high identity amongst all the β-coronaviruses (SARS-CoV-2, SARS-CoV, MERS-CoV, HCoV-OC43) and a low mutation rate. Here, we focused our attention on the study of SARS-CoV-2 E and M proteins, and we found a general perturbation of the host cell calcium (Ca2+) homeostasis and a selective rearrangement of the interorganelle contact sites. In vitro and in vivo biochemical analyses revealed that the binding of specific nanobodies to soluble regions of SARS-CoV-2 E protein reversed the observed phenotypes, suggesting that the E protein might be an important therapeutic candidate not only for vaccine development, but also for the clinical management of COVID designing drug regimens that, so far, are very limited.
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Affiliation(s)
- Elena Poggio
- Department of Biology, University of Padova, Padova, Italy
| | - Francesca Vallese
- Department of Anesthesiology, Columbia University Irving Medical Center, New York, NY, USA
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
| | - Andreas J W Hartel
- Department of Electrical Engineering, Columbia University, New York, NY, USA
| | - Travis J Morgenstern
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY, USA
| | - Scott A Kanner
- Doctoral Program in Neurobiology and Behavior, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Oliver Rauh
- Membrane Biophysics, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Flavia Giamogante
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Lucia Barazzuol
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Kenneth L Shepard
- Department of Electrical Engineering, Columbia University, New York, NY, USA
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY, USA
- Doctoral Program in Neurobiology and Behavior, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Oliver Biggs Clarke
- Department of Anesthesiology, Columbia University Irving Medical Center, New York, NY, USA
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
| | - Marisa Brini
- Department of Biology, University of Padova, Padova, Italy
- Study Center for Neurodegeneration (CESNE), University of Padova, Padova, Italy
| | - Tito Calì
- Department of Biomedical Sciences, University of Padova, Padova, Italy.
- Study Center for Neurodegeneration (CESNE), University of Padova, Padova, Italy.
- Padova Neuroscience Center (PNC), University of Padova, Padova, Italy.
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7
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Qian J, Guan X, Xie B, Xu C, Niu J, Tang X, Li CH, Colecraft HM, Jaenisch R, Liu XS. Multiplex epigenome editing of MECP2 to rescue Rett syndrome neurons. Sci Transl Med 2023; 15:eadd4666. [PMID: 36652535 DOI: 10.1126/scitranslmed.add4666] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Rett syndrome (RTT) is an X-linked neurodevelopmental disorder caused by loss-of-function heterozygous mutations of methyl CpG-binding protein 2 (MECP2) on the X chromosome in young females. Reactivation of the silent wild-type MECP2 allele from the inactive X chromosome (Xi) represents a promising therapeutic opportunity for female patients with RTT. Here, we applied a multiplex epigenome editing approach to reactivate MECP2 from Xi in RTT human embryonic stem cells (hESCs) and derived neurons. Demethylation of the MECP2 promoter by dCas9-Tet1 with target single-guide RNA reactivated MECP2 from Xi in RTT hESCs without detectable off-target effects at the transcriptional level. Neurons derived from methylation-edited RTT hESCs maintained MECP2 reactivation and reversed the smaller soma size and electrophysiological abnormalities, two hallmarks of RTT. In RTT neurons, insulation of the methylation-edited MECP2 locus by dCpf1-CTCF (a catalytically dead Cpf1 fused with CCCTC-binding factor) with target CRISPR RNA enhanced MECP2 reactivation and rescued RTT-related neuronal defects, providing a proof-of-concept study for epigenome editing to treat RTT and potentially other dominant X-linked diseases.
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Affiliation(s)
- Junming Qian
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, Columbia University, New York, NY 10032, USA
| | - Xiaonan Guan
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, Columbia University, New York, NY 10032, USA
| | - Bing Xie
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Chuanyun Xu
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Jacqueline Niu
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, Columbia University, New York, NY 10032, USA
| | - Xin Tang
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.,Department of Neurosurgery, Boston Children's Hospital, Boston, MA 02465, USA
| | - Charles H Li
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, Columbia University, New York, NY 10032, USA
| | - Rudolf Jaenisch
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - X Shawn Liu
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, Columbia University, New York, NY 10032, USA.,Columbia Stem Cell Initiative, Columbia University Medical Center, Columbia University, New York, NY 10032, USA.,Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, Columbia University, New York, NY 10032, USA
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8
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Morgenstern TJ, Nirwan N, Hernández-Ochoa EO, Bibollet H, Choudhury P, Laloudakis YD, Ben Johny M, Bannister RA, Schneider MF, Minor DL, Colecraft HM. Selective posttranslational inhibition of Ca Vβ 1-associated voltage-dependent calcium channels with a functionalized nanobody. Nat Commun 2022; 13:7556. [PMID: 36494348 PMCID: PMC9734117 DOI: 10.1038/s41467-022-35025-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 11/15/2022] [Indexed: 12/13/2022] Open
Abstract
Ca2+ influx through high-voltage-activated calcium channels (HVACCs) controls diverse cellular functions. A critical feature enabling a singular signal, Ca2+ influx, to mediate disparate functions is diversity of HVACC pore-forming α1 and auxiliary CaVβ1-CaVβ4 subunits. Selective CaVα1 blockers have enabled deciphering their unique physiological roles. By contrast, the capacity to post-translationally inhibit HVACCs based on CaVβ isoform is non-existent. Conventional gene knockout/shRNA approaches do not adequately address this deficit owing to subunit reshuffling and partially overlapping functions of CaVβ isoforms. Here, we identify a nanobody (nb.E8) that selectively binds CaVβ1 SH3 domain and inhibits CaVβ1-associated HVACCs by reducing channel surface density, decreasing open probability, and speeding inactivation. Functionalizing nb.E8 with Nedd4L HECT domain yielded Chisel-1 which eliminated current through CaVβ1-reconstituted CaV1/CaV2 and native CaV1.1 channels in skeletal muscle, strongly suppressed depolarization-evoked Ca2+ influx and excitation-transcription coupling in hippocampal neurons, but was inert against CaVβ2-associated CaV1.2 in cardiomyocytes. The results introduce an original method for probing distinctive functions of ion channel auxiliary subunit isoforms, reveal additional dimensions of CaVβ1 signaling in neurons, and describe a genetically-encoded HVACC inhibitor with unique properties.
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Affiliation(s)
- Travis J. Morgenstern
- grid.239585.00000 0001 2285 2675Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY USA
| | - Neha Nirwan
- grid.266102.10000 0001 2297 6811Cardiovascular Research Institute, University of California, San Francisco, CA USA
| | - Erick O. Hernández-Ochoa
- grid.411024.20000 0001 2175 4264Department of Biochemistry and Biology, University of Maryland School of Medicine, Baltimore, MD USA
| | - Hugo Bibollet
- grid.411024.20000 0001 2175 4264Department of Biochemistry and Biology, University of Maryland School of Medicine, Baltimore, MD USA
| | - Papiya Choudhury
- grid.239585.00000 0001 2285 2675Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY USA
| | - Yianni D. Laloudakis
- grid.239585.00000 0001 2285 2675Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY USA
| | - Manu Ben Johny
- grid.239585.00000 0001 2285 2675Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY USA
| | - Roger A. Bannister
- grid.411024.20000 0001 2175 4264Department of Biochemistry and Biology, University of Maryland School of Medicine, Baltimore, MD USA ,grid.411024.20000 0001 2175 4264Department of Pathology, University of Maryland School of Medicine, Baltimore, MD USA
| | - Martin F. Schneider
- grid.411024.20000 0001 2175 4264Department of Biochemistry and Biology, University of Maryland School of Medicine, Baltimore, MD USA
| | - Daniel L. Minor
- grid.266102.10000 0001 2297 6811Cardiovascular Research Institute, University of California, San Francisco, CA USA ,grid.266102.10000 0001 2297 6811Department of Biochemistry and Biophysics, University of California, San Francisco, CA USA ,grid.266102.10000 0001 2297 6811Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA USA ,grid.266102.10000 0001 2297 6811California Institute for Quantitative Biomedical Research, University of California, San Francisco, CA USA ,grid.266102.10000 0001 2297 6811Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA USA ,grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Henry M. Colecraft
- grid.239585.00000 0001 2285 2675Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY USA ,grid.239585.00000 0001 2285 2675Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY USA
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9
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Zou X, Wu X, Sampson KJ, Colecraft HM, Larsson HP, Kass RS. Pharmacological rescue of specific long QT variants of KCNQ1/KCNE1 channels. Front Physiol 2022; 13:902224. [PMID: 36505078 PMCID: PMC9726718 DOI: 10.3389/fphys.2022.902224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 11/02/2022] [Indexed: 11/24/2022] Open
Abstract
The congenital Long QT Syndrome (LQTS) is an inherited disorder in which cardiac ventricular repolarization is delayed and predisposes patients to cardiac arrhythmias and sudden cardiac death. LQT1 and LQT5 are LQTS variants caused by mutations in KCNQ1 or KCNE1 genes respectively. KCNQ1 and KCNE1 co-assemble to form critical IKS potassium channels. Beta-blockers are the standard of care for the treatment of LQT1, however, doing so based on mechanisms other than correcting the loss-of-function of K+ channels. ML277 and R-L3 are compounds that enhance IKS channels and slow channel deactivation in a manner that is dependent on the stoichiometry of KCNE1 subunits in the assembled channels. In this paper, we used expression of IKS channels in Chinese hamster ovary (CHO) cells and Xenopus oocytes to study the potential of these two drugs (ML277 and R-L3) for the rescue of LQT1 and LQT5 mutant channels. We focused on the LQT1 mutation KCNQ1-S546L, and two LQT5 mutations, KCNE1-L51H and KCNE1-G52R. We found ML277 and R-L3 potentiated homozygote LQTS mutations in the IKS complexes-KCNE1-G52R and KCNE1-L51H and in heterogeneous IKS channel complexes which mimic heterogeneous expression of mutations in patients. ML277 and R-L3 increased the mutant IKS current amplitude and slowed current deactivation, but not in wild type (WT) IKS. We obtained similar results in the LQT1 mutant (KCNQ1 S546L/KCNE1) with ML277 and R-L3. ML277 and R-L3 had a similar effect on the LQT1 and LQT5 mutants, however, ML277 was more effective than R-L3 in this modulation. Importantly we found that not all LQT5 mutants expressed with KCNQ1 resulted in channels that are potentiated by these drugs as the KCNE1 mutant D76N inhibited drug action when expressed with KCNQ1. Thus, our work shows that by directly studying the treatment of LQT1 and LQT5 mutations with ML277 and R-L3, we will understand the potential utility of these activators as options in specific LQTS therapeutics.
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Affiliation(s)
- Xinle Zou
- Department of Molecular Pharmacology & Therapeutics, Vagelos College of Physicians & Surgeons of Columbia University Irving Medical Center, New York, NY, United States
| | - Xiaoan Wu
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Kevin J. Sampson
- Department of Molecular Pharmacology & Therapeutics, Vagelos College of Physicians & Surgeons of Columbia University Irving Medical Center, New York, NY, United States
| | - Henry M. Colecraft
- Department of Molecular Pharmacology & Therapeutics, Vagelos College of Physicians & Surgeons of Columbia University Irving Medical Center, New York, NY, United States
| | - H. Peter Larsson
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Robert S. Kass
- Department of Molecular Pharmacology & Therapeutics, Vagelos College of Physicians & Surgeons of Columbia University Irving Medical Center, New York, NY, United States,*Correspondence: Robert S. Kass,
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10
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Papa A, Zakharov SI, Katchman AN, Kushner JS, Chen BX, Yang L, Liu G, Jimenez AS, Eisert RJ, Bradshaw GA, Dun W, Ali SR, Rodriques A, Zhou K, Topkara V, Yang M, Morrow JP, Tsai EJ, Karlin A, Wan E, Kalocsay M, Pitt GS, Colecraft HM, Ben-Johny M, Marx SO. Rad regulation of Ca V1.2 channels controls cardiac fight-or-flight response. Nat Cardiovasc Res 2022; 1:1022-1038. [PMID: 36424916 PMCID: PMC9681059 DOI: 10.1038/s44161-022-00157-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/29/2022] [Indexed: 11/16/2022]
Abstract
Fight-or-flight responses involve β-adrenergic-induced increases in heart rate and contractile force. In the present study, we uncover the primary mechanism underlying the heart's innate contractile reserve. We show that four protein kinase A (PKA)-phosphorylated residues in Rad, a calcium channel inhibitor, are crucial for controlling basal calcium current and essential for β-adrenergic augmentation of calcium influx in cardiomyocytes. Even with intact PKA signaling to other proteins modulating calcium handling, preventing adrenergic activation of calcium channels in Rad-phosphosite-mutant mice (4SA-Rad) has profound physiological effects: reduced heart rate with increased pauses, reduced basal contractility, near-complete attenuation of β-adrenergic contractile response and diminished exercise capacity. Conversely, expression of mutant calcium-channel β-subunits that cannot bind 4SA-Rad is sufficient to enhance basal calcium influx and contractility to adrenergically augmented levels of wild-type mice, rescuing the failing heart phenotype of 4SA-Rad mice. Hence, disruption of interactions between Rad and calcium channels constitutes the foundation toward next-generation therapeutics specifically enhancing cardiac contractility.
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Affiliation(s)
- Arianne Papa
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
- Department of Physiology and Cellular Biophysics, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
- These authors contributed equally: Arianne Papa, Sergey I. Zakharov, Alexander N. Katchman, Jared S. Kushner
| | - Sergey I. Zakharov
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
- These authors contributed equally: Arianne Papa, Sergey I. Zakharov, Alexander N. Katchman, Jared S. Kushner
| | - Alexander N. Katchman
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
- These authors contributed equally: Arianne Papa, Sergey I. Zakharov, Alexander N. Katchman, Jared S. Kushner
| | - Jared S. Kushner
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
- These authors contributed equally: Arianne Papa, Sergey I. Zakharov, Alexander N. Katchman, Jared S. Kushner
| | - Bi-xing Chen
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Lin Yang
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Guoxia Liu
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Alejandro Sanchez Jimenez
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Robyn J. Eisert
- Department of Systems Biology, Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Gary A. Bradshaw
- Department of Systems Biology, Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Wen Dun
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Shah R. Ali
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Aaron Rodriques
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Karen Zhou
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Veli Topkara
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Mu Yang
- Institute for Genomic Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - John P. Morrow
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Emily J. Tsai
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Arthur Karlin
- Department of Biochemistry and Molecular Biophysics, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Elaine Wan
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Marian Kalocsay
- Department of Systems Biology, Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA, USA
- Present address: Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Geoffrey S. Pitt
- Cardiovascular Research Institute and Department of Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Henry M. Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
- Department of Pharmacology and Molecular Signaling, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Manu Ben-Johny
- Department of Physiology and Cellular Biophysics, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Steven O. Marx
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
- Department of Pharmacology and Molecular Signaling, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
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11
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González BJ, Zhao H, Niu J, Williams DJ, Lee J, Goulbourne CN, Xing Y, Wang Y, Oberholzer J, Blumenkrantz MH, Chen X, LeDuc CA, Chung WK, Colecraft HM, Gromada J, Shen Y, Goland RS, Leibel RL, Egli D. Reduced calcium levels and accumulation of abnormal insulin granules in stem cell models of HNF1A deficiency. Commun Biol 2022; 5:779. [PMID: 35918471 PMCID: PMC9345898 DOI: 10.1038/s42003-022-03696-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 07/11/2022] [Indexed: 12/30/2022] Open
Abstract
Mutations in HNF1A cause Maturity Onset Diabetes of the Young (HNF1A-MODY). To understand mechanisms of β-cell dysfunction, we generated stem cell-derived pancreatic endocrine cells with hypomorphic mutations in HNF1A. HNF1A-deficient β-cells display impaired basal and glucose stimulated-insulin secretion, reduced intracellular calcium levels in association with a reduction in CACNA1A expression, and accumulation of abnormal insulin granules in association with SYT13 down-regulation. Knockout of CACNA1A and SYT13 reproduce the relevant phenotypes. In HNF1A deficient β-cells, glibenclamide, a sulfonylurea drug used in the treatment of HNF1A-MODY patients, increases intracellular calcium, and restores insulin secretion. While insulin secretion defects are constitutive in β-cells null for HNF1A, β-cells heterozygous for hypomorphic HNF1A (R200Q) mutations lose the ability to secrete insulin gradually; this phenotype is prevented by correction of the mutation. Our studies illuminate the molecular basis for the efficacy of treatment of HNF1A-MODY with sulfonylureas, and suggest promise for the use of cell therapies.
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Affiliation(s)
- Bryan J González
- Naomi Berrie Diabetes Center & Departments of Pediatrics and Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA.,Institute of Human Nutrition, Columbia University Medical Center, New York, NY, 10032, USA
| | - Haoquan Zhao
- Department of Systems Biology, Columbia University Medical Center, New York, NY, 10032, USA
| | - Jacqueline Niu
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Damian J Williams
- Stem Cell Core Facility, Department of Rehabilitation and Regenerative Medicine, Columbia University, New York, NY, 10032, USA
| | - Jaeyop Lee
- Department of Systems Biology, Columbia University Medical Center, New York, NY, 10032, USA
| | - Chris N Goulbourne
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, 10962, USA
| | - Yuan Xing
- Department of Surgery, University of Virginia, Charlottesville, VA, 22908, USA
| | - Yong Wang
- Department of Surgery, University of Virginia, Charlottesville, VA, 22908, USA
| | - Jose Oberholzer
- Department of Surgery, University of Virginia, Charlottesville, VA, 22908, USA
| | - Maria H Blumenkrantz
- Naomi Berrie Diabetes Center & Departments of Pediatrics and Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Xiaojuan Chen
- Columbia Center for Translational Immunology, Department of Surgery, Columbia University Medical Center, New York, NY, 10032, USA
| | - Charles A LeDuc
- Naomi Berrie Diabetes Center & Departments of Pediatrics and Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Wendy K Chung
- Naomi Berrie Diabetes Center & Departments of Pediatrics and Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Jesper Gromada
- Regeneron Pharmaceuticals, Tarrytown, NY, 10591, USA.,Vertex Cell and Genetic Therapies, Watertown, MA, 02472, USA
| | - Yufeng Shen
- Department of Systems Biology, Columbia University Medical Center, New York, NY, 10032, USA
| | - Robin S Goland
- Naomi Berrie Diabetes Center & Departments of Pediatrics and Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Rudolph L Leibel
- Naomi Berrie Diabetes Center & Departments of Pediatrics and Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Dieter Egli
- Naomi Berrie Diabetes Center & Departments of Pediatrics and Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA.
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12
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Sun L, Tong CK, Morgenstern TJ, Zhou H, Yang G, Colecraft HM. Targeted ubiquitination of sensory neuron calcium channels reduces the development of neuropathic pain. Proc Natl Acad Sci U S A 2022; 119:e2118129119. [PMID: 35561213 PMCID: PMC9171802 DOI: 10.1073/pnas.2118129119] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 04/01/2022] [Indexed: 11/18/2022] Open
Abstract
Neuropathic pain caused by lesions to somatosensory neurons due to injury or disease is a widespread public health problem that is inadequately managed by small-molecule therapeutics due to incomplete pain relief and devastating side effects. Genetically encoded molecules capable of interrupting nociception have the potential to confer long-lasting analgesia with minimal off-target effects. Here, we utilize a targeted ubiquitination approach to achieve a unique posttranslational functional knockdown of high-voltage-activated calcium channels (HVACCs) that are obligatory for neurotransmission in dorsal root ganglion (DRG) neurons. CaV-aβlator comprises a nanobody targeted to CaV channel cytosolic auxiliary β subunits fused to the catalytic HECT domain of the Nedd4-2 E3 ubiquitin ligase. Subcutaneous injection of adeno-associated virus serotype 9 encoding CaV-aβlator in the hind paw of mice resulted in the expression of the protein in a subset of DRG neurons that displayed a concomitant ablation of CaV currents and also led to an increase in the frequency of spontaneous inhibitory postsynaptic currents in the dorsal horn of the spinal cord. Mice subjected to spare nerve injury displayed a characteristic long-lasting mechanical, thermal, and cold hyperalgesia underlain by a dramatic increase in coordinated phasic firing of DRG neurons as reported by in vivo Ca2+ spike recordings. CaV-aβlator significantly dampened the integrated Ca2+ spike activity and the hyperalgesia in response to nerve injury. The results advance the principle of targeting HVACCs as a gene therapy for neuropathic pain and demonstrate the therapeutic potential of posttranslational functional knockdown of ion channels achieved by exploiting the ubiquitin-proteasome system.
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Affiliation(s)
- Linlin Sun
- Department of Anesthesiology, Columbia University Medical Center, New York, NY 10032
| | - Chi-Kun Tong
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY 10032
| | - Travis J. Morgenstern
- Department of Molecular Pharmacology and Therapeutics, Columbia University Medical Center, New York, NY 10032
| | - Hang Zhou
- Department of Anesthesiology, Columbia University Medical Center, New York, NY 10032
| | - Guang Yang
- Department of Anesthesiology, Columbia University Medical Center, New York, NY 10032
| | - Henry M. Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY 10032
- Department of Molecular Pharmacology and Therapeutics, Columbia University Medical Center, New York, NY 10032
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13
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Colecraft HM, Trimmer JS. Controlling ion channel function with renewable recombinant antibodies. J Physiol 2022; 600:2023-2036. [PMID: 35238051 PMCID: PMC9058206 DOI: 10.1113/jp282403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/11/2022] [Indexed: 11/08/2022] Open
Abstract
Selective ion channel modulators play a critical role in physiology in defining the contribution of specific ion channels to physiological function and as proof of concept for novel therapeutic strategies. Antibodies are valuable research tools that have broad uses including defining the expression and localization of ion channels in native tissue, and capturing ion channel proteins for subsequent analyses. In this review, we detail how renewable and recombinant antibodies can be used to control ion channel function. We describe the different forms of renewable and recombinant antibodies that have been used and the mechanisms by which they modulate ion channel function. We highlight the use of recombinant antibodies that are expressed intracellularly (intrabodies) as genetically-encoded tools to control ion channel function. We also offer perspectives of avenues of future research that may be opened by the application of emerging technologies for engineering recombinant antibodies for enhanced utility in ion channel research. Overall, this review provides insights that may help stimulate and guide interested researchers to develop and incorporate renewable and recombinant antibodies as valuable tools to control ion channel function. Abstract figure legend Two different approaches for controlling ion channel function using renewable recombinant antibodies. On the left, an externally applied intact IgG antibody (purple) binds to an extracellular domain of an ion channel (light blue) to control ion channel function. On the right, a genetically-encoded intrabody, in this example a camelid nanobody (green) fused to an effector molecule (red) binds to an intracellular auxiliary subunit of an ion channel (dark blue) to control ion channel function. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, 10032, USA
| | - James S Trimmer
- Department of Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA, 95616, USA
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14
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Blomquist VG, Niu J, Colecraft HM, Ahern CA. Suppressor TRNA-mediated rescue of hERG LQTS2 nonsense mutations. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.1853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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15
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Morgenstern TJ, Darko-Boateng A, Choudhury P, Karthika Shanmugam S, Zou X, Colecraft HM. Bidirectional modulation of ion channels with divalent nanobodies. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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16
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Zou X, Karthika Shanmugam S, Kanner SA, Sampson KJ, Kass RS, Colecraft HM. Differential regulation of IKs by targeted recruitment of protein kinase A to distinct sites on the KCNQ1/KCNE1 channel complex. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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17
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Rivero Morfin PJD, Chakouri N, Choudhury P, Borowik S, Colecraft HM, Ben-Johny M. Lrrc10 is a versatile modulator of cardiac four-domain voltage-gated channels. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.2588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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18
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Saponaro A, Bauer D, Giese MH, Swuec P, Porro A, Gasparri F, Sharifzadeh AS, Chaves-Sanjuan A, Alberio L, Parisi G, Cerutti G, Clarke OB, Hamacher K, Colecraft HM, Mancia F, Hendrickson WA, Siegelbaum SA, DiFrancesco D, Bolognesi M, Thiel G, Santoro B, Moroni A. Gating movements and ion permeation in HCN4 pacemaker channels. Mol Cell 2021; 81:2929-2943.e6. [PMID: 34166608 PMCID: PMC8294335 DOI: 10.1016/j.molcel.2021.05.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/12/2021] [Accepted: 05/27/2021] [Indexed: 10/31/2022]
Abstract
The HCN1-4 channel family is responsible for the hyperpolarization-activated cation current If/Ih that controls automaticity in cardiac and neuronal pacemaker cells. We present cryoelectron microscopy (cryo-EM) structures of HCN4 in the presence or absence of bound cAMP, displaying the pore domain in closed and open conformations. Analysis of cAMP-bound and -unbound structures sheds light on how ligand-induced transitions in the channel cytosolic portion mediate the effect of cAMP on channel gating and highlights the regulatory role of a Mg2+ coordination site formed between the C-linker and the S4-S5 linker. Comparison of open/closed pore states shows that the cytosolic gate opens through concerted movements of the S5 and S6 transmembrane helices. Furthermore, in combination with molecular dynamics analyses, the open pore structures provide insights into the mechanisms of K+/Na+ permeation. Our results contribute mechanistic understanding on HCN channel gating, cyclic nucleotide-dependent modulation, and ion permeation.
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Affiliation(s)
- Andrea Saponaro
- Department of Biosciences, University of Milan, Milan, Italy
| | - Daniel Bauer
- Department of Biology, TU-Darmstadt, Darmstadt, Germany
| | - M Hunter Giese
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
| | - Paolo Swuec
- Department of Biosciences, University of Milan, Milan, Italy; Pediatric Research Center "Romeo ed Enrica Invernizzi," University of Milan, Milan, Italy
| | | | | | | | - Antonio Chaves-Sanjuan
- Department of Biosciences, University of Milan, Milan, Italy; Pediatric Research Center "Romeo ed Enrica Invernizzi," University of Milan, Milan, Italy
| | - Laura Alberio
- Department of Biosciences, University of Milan, Milan, Italy; Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Giacomo Parisi
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome, Italy
| | - Gabriele Cerutti
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy
| | - Oliver B Clarke
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA; Department of Anesthesiology, Columbia University, New York, NY, USA
| | - Kay Hamacher
- Department of Biology, TU-Darmstadt, Darmstadt, Germany
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
| | - Filippo Mancia
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
| | - Wayne A Hendrickson
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Steven A Siegelbaum
- Department of Neuroscience, Zuckerman Institute, Columbia University, New York, NY, USA
| | - Dario DiFrancesco
- Department of Biosciences, University of Milan, Milan, Italy; Institute of Biophysics-Milano, Consiglio Nazionale delle Ricerche, Rome, Italy
| | - Martino Bolognesi
- Department of Biosciences, University of Milan, Milan, Italy; Pediatric Research Center "Romeo ed Enrica Invernizzi," University of Milan, Milan, Italy
| | - Gerhard Thiel
- Department of Biology, TU-Darmstadt, Darmstadt, Germany
| | - Bina Santoro
- Department of Neuroscience, Zuckerman Institute, Columbia University, New York, NY, USA.
| | - Anna Moroni
- Department of Biosciences, University of Milan, Milan, Italy; Institute of Biophysics-Milano, Consiglio Nazionale delle Ricerche, Rome, Italy.
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19
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Minor DL, Colecraft HM. Preface. Methods Enzymol 2021; 652:xv-xvi. [PMID: 34059292 DOI: 10.1016/s0076-6879(21)00205-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Daniel L Minor
- Professor, Cardiovascular Research Institute, Departments of Biochemistry and Biophysics and Cellular and Molecular Pharmacology, University of California, San Francisco San Francisco, CA, United States; Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Henry M Colecraft
- Professor, Departments of Physiology and Cellular Biophysics and Molecular Pharmacology and Therapeutics, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, United States
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20
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Minor DL, Colecraft HM. Preface. Methods Enzymol 2021; 654:xvii-xviii. [PMID: 34120727 DOI: 10.1016/s0076-6879(21)00249-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Daniel L Minor
- Professor, Cardiovascular Research Institute, Departments of Biochemistry and Biophysics and Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, United States; Molecular Biophysics and Integrated Bio-Imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Henry M Colecraft
- Professor, Departments of Physiology and Cellular Biophysics and Molecular Pharmacology and Therapeutics, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, United States
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21
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Jenewein T, Kanner SA, Bauer D, Hertel B, Colecraft HM, Moroni A, Thiel G, Kauferstein S. The mutation L69P in the PAS domain of the hERG potassium channel results in LQTS by trafficking deficiency. Channels (Austin) 2021; 14:163-174. [PMID: 32253972 PMCID: PMC7188350 DOI: 10.1080/19336950.2020.1751522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The congenital long QT syndrome (LQTS) is a cardiac disorder characterized by a prolonged QT interval on the electrocardiogram and an increased susceptibility to ventricular arrhythmias and sudden cardiac death. A frequent cause for LQTS is mutations in the KCNH2 gene (also known as the human ether-a-go-go-related gene or hERG), which reduce or modulate the potassium current IKr and hence alter cardiac repolarization. In a patient with a clinically diagnosed LQTS, we identified the mutation L69P in the N-terminal PAS (Per-Arnt-Sim) domain of hERG. Functional expression in HEK293 cells shows that a homotetrameric hERG channel reconstituted with only mutant subunits exhibits a drastically reduced surface expression of the channel protein thus leading to a diminished hERG current. Unlike many other mutations in the hERG-PAS domain the negative impact of the L69P substitution cannot be rescued by facilitated protein folding at a lower incubation temperature. Further, co-expression of wt and mutant monomers does not restore either wt like surface expression or the full hERG current. These results indicate L69P is a dominant negative mutation, with deficits which most likely occurs at the level of protein folding and subsequently inhibits trafficking to the plasma membrane. The functional deficits of the mutant channel support the clinical diagnosis of a LQTS.
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Affiliation(s)
- Tina Jenewein
- Institute of Legal Medicine, University of Frankfurt, Frankfurt Am Main, Germany
| | - Scott A Kanner
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Daniel Bauer
- Computational Biology and Simulation Group, Department of Biology, Technische Universita ̈t Darmstadt, Darmstadt, Germany
| | - Brigitte Hertel
- Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Anna Moroni
- Department of Biosciences and CNR IBF-Mi, University of Milano, Milano, Italy
| | - Gerhard Thiel
- Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Silke Kauferstein
- Institute of Legal Medicine, University of Frankfurt, Frankfurt Am Main, Germany
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22
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Morgenstern TJ, Colecraft HM. Controlling ion channel trafficking by targeted ubiquitination and deubiquitination. Methods Enzymol 2021; 654:139-167. [PMID: 34120711 DOI: 10.1016/bs.mie.2021.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Plasma membrane-localized ion channels are essential for diverse physiological processes such as neurotransmission, muscle contraction, and osmotic homeostasis. The surface density of such ion channels is a major determinant of their function, and tuning this variable is a powerful way to regulate physiology. Dysregulation of ion channel surface density due to inherited or de novo mutations underlies many serious diseases, and molecules that can correct trafficking deficits are potential therapeutics and useful research tools. We have developed targeted ubiquitination and deubiquitination approaches that enable selective posttranslational down- or up-regulation, respectively, of desired ion channels. The method employs bivalent molecules comprised of an ion-channel-targeted nanobody fused to catalytic domains of either an E3 ubiquitin ligase or a deubiquitinase. Here, we use two examples to provide detailed protocols that illustrate the utility of the approach-rescued surface expression of a trafficking-deficient mutant KV7.1 (KCNQ1) channel that causes long QT syndrome, and selective elimination of the CaV2.2 voltage-gated calcium channel from the plasma membrane using targeted ubiquitination. Important aspects of the approach include having a robust assay to measure ion channel surface density and generating nanobody binders to cytosolic domains or subunits of targeted ion channels. Accordingly, we also review available methods for determining ion channel surface density and nanobody selection.
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Affiliation(s)
- Travis J Morgenstern
- Department of Molecular Pharmacology and Therapeutics, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, United States
| | - Henry M Colecraft
- Department of Molecular Pharmacology and Therapeutics, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, United States; Department of Physiology and Cellular Biophysics, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, United States.
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Darko-Boateng A, Colecraft HM. Regulation of Low Voltage-Activated Calcium Channels by NEDD4 Family of E3 Ubiquitin Ligases. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.1143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Papa A, Kushner J, Hennessey JA, Katchman AN, Zakharov SI, Chen BX, Yang L, Lu R, Leong S, Diaz J, Liu G, Roybal D, Liao X, del Rivero Morfin PJ, Colecraft HM, Pitt GS, Clarke O, Topkara V, Ben-Johny M, Marx SO. Adrenergic Ca V1.2 Activation via Rad Phosphorylation Converges at α 1C I-II Loop. Circ Res 2021; 128:76-88. [PMID: 33086983 PMCID: PMC7790865 DOI: 10.1161/circresaha.120.317839] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
RATIONALE Changing activity of cardiac CaV1.2 channels under basal conditions, during sympathetic activation, and in heart failure is a major determinant of cardiac physiology and pathophysiology. Although cardiac CaV1.2 channels are prominently upregulated via activation of PKA (protein kinase A), essential molecular details remained stubbornly enigmatic. OBJECTIVE The primary goal of this study was to determine how various factors converging at the CaV1.2 I-II loop interact to regulate channel activity under basal conditions, during β-adrenergic stimulation, and in heart failure. METHODS AND RESULTS We generated transgenic mice with expression of CaV1.2 α1C subunits with (1) mutations ablating interaction between α1C and β-subunits, (2) flexibility-inducing polyglycine substitutions in the I-II loop (GGG-α1C), or (3) introduction of the alternatively spliced 25-amino acid exon 9* mimicking a splice variant of α1C upregulated in the hypertrophied heart. Introducing 3 glycine residues that disrupt a rigid IS6-α-interaction domain helix markedly reduced basal open probability despite intact binding of CaVβ to α1C I-II loop and eliminated β-adrenergic agonist stimulation of CaV1.2 current. In contrast, introduction of the exon 9* splice variant in the α1C I-II loop, which is increased in ventricles of patients with end-stage heart failure, increased basal open probability but did not attenuate stimulatory response to β-adrenergic agonists when reconstituted heterologously with β2B and Rad or transgenically expressed in cardiomyocytes. CONCLUSIONS Ca2+ channel activity is dynamically modulated under basal conditions, during β-adrenergic stimulation, and in heart failure by mechanisms converging at the α1C I-II loop. CaVβ binding to α1C stabilizes an increased channel open probability gating mode by a mechanism that requires an intact rigid linker between the β-subunit binding site in the I-II loop and the channel pore. Release of Rad-mediated inhibition of Ca2+ channel activity by β-adrenergic agonists/PKA also requires this rigid linker and β-binding to α1C.
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Affiliation(s)
- Arianne Papa
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
- Department of Physiology and Cellular Biophysics
| | - Jared Kushner
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
| | - Jessica A. Hennessey
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
| | - Alexander N. Katchman
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
| | - Sergey I. Zakharov
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
| | - Bi-xing Chen
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
| | - Lin Yang
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
| | - Ree Lu
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
| | - Stephen Leong
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
| | - Johanna Diaz
- Department of Physiology and Cellular Biophysics
| | - Guoxia Liu
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
| | - Daniel Roybal
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
- Department of Pharmacology and Molecular Signaling, Columbia University, Vagelos College of Physicians and Surgeons
| | - Xianghai Liao
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
| | | | - Henry M. Colecraft
- Department of Physiology and Cellular Biophysics
- Department of Pharmacology and Molecular Signaling, Columbia University, Vagelos College of Physicians and Surgeons
| | - Geoffrey S. Pitt
- Cardiovascular Research Institute, Weill Cornell Medical College
| | | | - Veli Topkara
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
| | | | - Steven O. Marx
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY 10032
- Department of Pharmacology and Molecular Signaling, Columbia University, Vagelos College of Physicians and Surgeons
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Kanner SA, Shuja Z, Choudhury P, Jain A, Colecraft HM. Targeted deubiquitination rescues distinct trafficking-deficient ion channelopathies. Nat Methods 2020; 17:1245-1253. [PMID: 33169015 PMCID: PMC9335257 DOI: 10.1038/s41592-020-00992-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/07/2020] [Indexed: 12/11/2022]
Abstract
Impaired protein stability/trafficking underlies diverse ion channelopathies and represents an unexploited unifying principle to develop common treatments for otherwise dissimilar diseases. Ubiquitination limits ion channel surface density, but targeting this pathway for basic study or therapy is challenging because of its prevalent role in proteostasis. We developed engineered deubiquitinases (enDUBs) that enable ubiquitin chain removal selectively from target proteins to rescue functional expression of disparate mutant ion channels underlying Long QT syndrome (LQT1) and cystic fibrosis (CF). In a LQT1 cardiomyocyte model, enDUB treatment restored delayed rectifier K+ currents and normalized action potential duration. CF-targeted enDUBs synergistically rescued common (F508del) and pharmacotherapy-resistant (N1303K) CF mutations when combined with the FDA-approved drugs, Orkambi and Trikafta. Altogether, targeted deubiquitination via enDUBs provides a powerful protein stabilization method that not only corrects diverse diseases caused by impaired ion channel trafficking, but also introduces a new tool for deconstructing the ubiquitin code in situ.
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Affiliation(s)
- Scott A Kanner
- Doctoral Program in Neurobiology and Behavior, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Zunaira Shuja
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Papiya Choudhury
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | | | - Henry M Colecraft
- Doctoral Program in Neurobiology and Behavior, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA. .,Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA. .,Department of Molecular Pharmacology and Therapeutics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA.
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27
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Colecraft HM. Designer genetically encoded voltage-dependent calcium channel inhibitors inspired by RGK GTPases. J Physiol 2020; 598:1683-1693. [PMID: 32104913 PMCID: PMC7195252 DOI: 10.1113/jp276544] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/07/2020] [Indexed: 12/28/2022] Open
Abstract
High‐voltage‐activated calcium (CaV1/CaV2) channels translate action potentials into Ca2+ influx in excitable cells to control essential biological processes that include; muscle contraction, synaptic transmission, hormone secretion and activity‐dependent regulation of gene expression. Modulation of CaV1/CaV2 channel activity is a powerful mechanism to regulate physiology, and there are a host of intracellular signalling molecules that tune different aspects of CaV channel trafficking and gating for this purpose. Beyond normal physiological regulation, the diverse CaV channel modulatory mechanisms may potentially be co‐opted or interfered with for therapeutic benefits. CaV1/CaV2 channels are potently inhibited by a four‐member sub‐family of Ras‐like GTPases known as RGK (Rad, Rem, Rem2, Gem/Kir) proteins. Understanding the mechanisms by which RGK proteins inhibit CaV1/CaV2 channels has led to the development of novel genetically encoded CaV channel blockers with unique properties; including, chemo‐ and optogenetic control of channel activity, and blocking channels either on the basis of their subcellular localization or by targeting an auxiliary subunit. These genetically encoded CaV channel inhibitors have outstanding utility as enabling research tools and potential therapeutics.
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Affiliation(s)
- Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Department of Pharmacology and Molecular Signaling, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
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28
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Colecraft HM, Khanna R. The 2019 FASEB Science Research Conference on Ion Channel Regulation: Molecules to Disease, July 7-12, 2019, Lisbon, Portugal. FASEB J 2020; 34:4828-4831. [PMID: 32157730 DOI: 10.1096/fj.202000367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA.,Department of Pharmacology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Rajesh Khanna
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, USA.,Department of Anesthesiology, College of Medicine, University of Arizona, Tucson, AZ, USA.,The Center for Innovation in Brain Sciences, The University of Arizona Health Sciences, Tucson, AZ, USA
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Papa A, Kushner J, Hennessey J, Katchman AN, Zakharov SI, Chen BX, Yang L, Lu R, Leong S, Diaz J, Colecraft HM, Pitt GS, Ben-Johny M, Marx SO. Beta-Adrenergic Stimulation of CAV1.2 Channels is Transduced via the IS6-Aid Linker. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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30
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Kanner SA, Shuja Z, Choudhury P, Jain A, Colecraft HM. Targeted Deubiquitination as a General Strategy to Rescue Trafficking-Deficient Ion Channelopathies. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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31
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Liu G, Papa A, Katchman AN, Zakharov SI, Roybal D, Hennessey JA, Kushner J, Yang L, Chen BX, Kushnir A, Dangas K, Gygi SP, Pitt GS, Colecraft HM, Ben-Johny M, Kalocsay M, Marx SO. Mechanism of adrenergic Ca V1.2 stimulation revealed by proximity proteomics. Nature 2020; 577:695-700. [PMID: 31969708 PMCID: PMC7018383 DOI: 10.1038/s41586-020-1947-z] [Citation(s) in RCA: 126] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 12/09/2019] [Indexed: 12/20/2022]
Abstract
Increased cardiac contractility during the fight-or-flight response is caused by β-adrenergic augmentation of CaV1.2 voltage-gated calcium channels1-4. However, this augmentation persists in transgenic murine hearts expressing mutant CaV1.2 α1C and β subunits that can no longer be phosphorylated by protein kinase A-an essential downstream mediator of β-adrenergic signalling-suggesting that non-channel factors are also required. Here we identify the mechanism by which β-adrenergic agonists stimulate voltage-gated calcium channels. We express α1C or β2B subunits conjugated to ascorbate peroxidase5 in mouse hearts, and use multiplexed quantitative proteomics6,7 to track hundreds of proteins in the proximity of CaV1.2. We observe that the calcium-channel inhibitor Rad8,9, a monomeric G protein, is enriched in the CaV1.2 microenvironment but is depleted during β-adrenergic stimulation. Phosphorylation by protein kinase A of specific serine residues on Rad decreases its affinity for β subunits and relieves constitutive inhibition of CaV1.2, observed as an increase in channel open probability. Expression of Rad or its homologue Rem in HEK293T cells also imparts stimulation of CaV1.3 and CaV2.2 by protein kinase A, revealing an evolutionarily conserved mechanism that confers adrenergic modulation upon voltage-gated calcium channels.
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Affiliation(s)
- Guoxia Liu
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Arianne Papa
- Department of Physiology and Cellular Biophysics, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Alexander N Katchman
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Sergey I Zakharov
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Daniel Roybal
- Department of Pharmacology, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Jessica A Hennessey
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Jared Kushner
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Lin Yang
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Bi-Xing Chen
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Alexander Kushnir
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Katerina Dangas
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Geoffrey S Pitt
- Cardiovascular Research Institute, Weill Cornell Medical College, New York, NY, USA
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
- Department of Pharmacology, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Manu Ben-Johny
- Department of Physiology and Cellular Biophysics, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Marian Kalocsay
- Department of Systems Biology, Laboratory of Systems Pharmacology, Harvard Medical School, Boston, MA, USA.
| | - Steven O Marx
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA.
- Department of Pharmacology, Columbia University, Vagelos College of Physicians and Surgeons, New York, NY, USA.
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Joseph LC, Avula UMR, Wan EY, Reyes MV, Lakkadi KR, Subramanyam P, Nakanishi K, Homma S, Muchir A, Pajvani UB, Thorp EB, Reiken SR, Marks AR, Colecraft HM, Morrow JP. Dietary Saturated Fat Promotes Arrhythmia by Activating NOX2 (NADPH Oxidase 2). Circ Arrhythm Electrophysiol 2019; 12:e007573. [PMID: 31665913 PMCID: PMC7004280 DOI: 10.1161/circep.119.007573] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Obesity and diets high in saturated fat increase the risk of arrhythmias and sudden cardiac death. However, the molecular mechanisms are not well understood. We hypothesized that an increase in dietary saturated fat could lead to abnormalities of calcium homeostasis and heart rhythm by a NOX2 (NADPH oxidase 2)-dependent mechanism. METHODS We investigated this hypothesis by feeding mice high-fat diets. In vivo heart rhythm telemetry, optical mapping, and isolated cardiac myocyte imaging were used to quantify arrhythmias, repolarization, calcium transients, and intracellular calcium sparks. RESULTS We found that saturated fat activates NOX (NADPH oxidase), whereas polyunsaturated fat does not. The high saturated fat diet increased repolarization heterogeneity and ventricular tachycardia inducibility in perfused hearts. Pharmacological inhibition or genetic deletion of NOX2 prevented arrhythmogenic abnormalities in vivo during high statured fat diet and resulted in less inducible ventricular tachycardia. High saturated fat diet activates CaMK (Ca2+/calmodulin-dependent protein kinase) in the heart, which contributes to abnormal calcium handling, promoting arrhythmia. CONCLUSIONS We conclude that NOX2 deletion or pharmacological inhibition prevents the arrhythmogenic effects of a high saturated fat diet, in part mediated by activation of CaMK. This work reveals a molecular mechanism linking cardiac metabolism to arrhythmia and suggests that NOX2 inhibitors could be a novel therapy for heart rhythm abnormalities caused by cardiac lipid overload.
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Affiliation(s)
- Leroy C. Joseph
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY
| | - Uma Mahesh R. Avula
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY
| | - Elaine Y. Wan
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY
| | - Michael V. Reyes
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY
| | - Kundanika R. Lakkadi
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY
| | - Prakash Subramanyam
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons of Columbia University, New York, NY
| | - Koki Nakanishi
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY
| | - Shunichi Homma
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY
| | - Antoine Muchir
- Center of Research in Myology, UPMC-Inserm UMR974, CNRS FRE3617, Institut de Myologie, G.H. Pitie Salpetriere, Paris, France
| | - Utpal B. Pajvani
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY
| | - Edward B. Thorp
- Departments of Pathology and Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Steven R. Reiken
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons of Columbia University, New York, NY
| | - Andrew R. Marks
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons of Columbia University, New York, NY
| | - Henry M. Colecraft
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons of Columbia University, New York, NY
| | - John P. Morrow
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY
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Hu Z, Li G, Wang JW, Chong SY, Yu D, Wang X, Soon JL, Liang MC, Wong YP, Huang N, Colecraft HM, Liao P, Soong TW. Regulation of Blood Pressure by Targeting Ca V1.2-Galectin-1 Protein Interaction. Circulation 2019; 138:1431-1445. [PMID: 29650545 DOI: 10.1161/circulationaha.117.031231] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND L-type CaV1.2 channels play crucial roles in the regulation of blood pressure. Galectin-1 (Gal-1) has been reported to bind to the I-II loop of CaV1.2 channels to reduce their current density. However, the mechanistic understanding for the downregulation of CaV1.2 channels by Gal-1 and whether Gal-1 plays a direct role in blood pressure regulation remain unclear. METHODS In vitro experiments involving coimmunoprecipitation, Western blot, patch-clamp recordings, immunohistochemistry, and pressure myography were used to evaluate the molecular mechanisms by which Gal-1 downregulates CaV1.2 channel in transfected, human embryonic kidney 293 cells, smooth muscle cells, arteries from Lgasl1-/- mice, rat, and human patients. In vivo experiments involving the delivery of Tat-e9c peptide and AAV5-Gal-1 into rats were performed to investigate the effect of targeting CaV1.2-Gal-1 interaction on blood pressure monitored by tail-cuff or telemetry methods. RESULTS Our study reveals that Gal-1 is a key regulator for proteasomal degradation of CaV1.2 channels. Gal-1 competed allosterically with the CaVβ subunit for binding to the I-II loop of the CaV1.2 channel. This competitive disruption of CaVβ binding led to CaV1.2 degradation by exposing the channels to polyubiquitination. It is notable that we demonstrated that the inverse relationship of reduced Gal-1 and increased CaV1.2 protein levels in arteries was associated with hypertension in hypertensive rats and patients, and Gal-1 deficiency induces higher blood pressure in mice because of the upregulated CaV1.2 protein level in arteries. To directly regulate blood pressure by targeting the CaV1.2-Gal-1 interaction, we administered Tat-e9c, a peptide that competed for binding of Gal-1 by a miniosmotic pump, and this specific disruption of CaV1.2-Gal-1 coupling increased smooth muscle CaV1.2 currents, induced larger arterial contraction, and caused hypertension in rats. In contrasting experiments, overexpression of Gal-1 in smooth muscle by a single bolus of AAV5-Gal-1 significantly reduced blood pressure in spontaneously hypertensive rats. CONCLUSIONS We have defined molecularly that Gal-1 promotes CaV1.2 degradation by replacing CaVβ and thereby exposing specific lysines for polyubiquitination and by masking I-II loop endoplasmic reticulum export signals. This mechanistic understanding provided the basis for targeting CaV1.2-Gal-1 interaction to demonstrate clearly the modulatory role that Gal-1 plays in regulating blood pressure, and offering a potential approach for therapeutic management of hypertension.
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Affiliation(s)
- Zhenyu Hu
- Department of Physiology, Yong Loo Lin School of Medicine (Z.Y.H., J.-W.W., D.Y., M.C.L., Y.P.W., T.W.S.), National University of Singapore
| | - Guang Li
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China (G.L.)
| | - Jiong-Wei Wang
- Department of Physiology, Yong Loo Lin School of Medicine (Z.Y.H., J.-W.W., D.Y., M.C.L., Y.P.W., T.W.S.), National University of Singapore.,Department of Surgery, Yong Loo Lin School of Medicine (J.-W.W., S.Y.C., X.W.), National University of Singapore.,Cardiovascular Research Institute, National University Heart Center, National University Health Systems, Centre for Translational Medicine, Singapore (J.-W.W., S.Y.C., X.W.)
| | - Suet Yen Chong
- Department of Surgery, Yong Loo Lin School of Medicine (J.-W.W., S.Y.C., X.W.), National University of Singapore.,Cardiovascular Research Institute, National University Heart Center, National University Health Systems, Centre for Translational Medicine, Singapore (J.-W.W., S.Y.C., X.W.)
| | - Dejie Yu
- Department of Physiology, Yong Loo Lin School of Medicine (Z.Y.H., J.-W.W., D.Y., M.C.L., Y.P.W., T.W.S.), National University of Singapore
| | - Xiaoyuan Wang
- Department of Surgery, Yong Loo Lin School of Medicine (J.-W.W., S.Y.C., X.W.), National University of Singapore.,Cardiovascular Research Institute, National University Heart Center, National University Health Systems, Centre for Translational Medicine, Singapore (J.-W.W., S.Y.C., X.W.)
| | | | - Mui Cheng Liang
- Department of Physiology, Yong Loo Lin School of Medicine (Z.Y.H., J.-W.W., D.Y., M.C.L., Y.P.W., T.W.S.), National University of Singapore
| | - Yuk Peng Wong
- Department of Physiology, Yong Loo Lin School of Medicine (Z.Y.H., J.-W.W., D.Y., M.C.L., Y.P.W., T.W.S.), National University of Singapore
| | - Na Huang
- National Heart Centre Singapore (J.L.S., N.H.)
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, College of Physicians and Surgeons, New York (H.M.C.)
| | | | - Tuck Wah Soong
- Department of Physiology, Yong Loo Lin School of Medicine (Z.Y.H., J.-W.W., D.Y., M.C.L., Y.P.W., T.W.S.), National University of Singapore.,Neurobiology/Ageing Programme (T.W.S.), National University of Singapore.,Graduate School for Integrative Sciences and Engineering (T.W.S.), National University of Singapore.,National Neuroscience Institute, Singapore (T.W.S.)
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34
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Morgenstern TJ, Park J, Fan QR, Colecraft HM. A potent voltage-gated calcium channel inhibitor engineered from a nanobody targeted to auxiliary Ca Vβ subunits. eLife 2019; 8:49253. [PMID: 31403402 PMCID: PMC6701945 DOI: 10.7554/elife.49253] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 08/10/2019] [Indexed: 12/15/2022] Open
Abstract
Inhibiting high-voltage-activated calcium channels (HVACCs; CaV1/CaV2) is therapeutic for myriad cardiovascular and neurological diseases. For particular applications, genetically-encoded HVACC blockers may enable channel inhibition with greater tissue-specificity and versatility than is achievable with small molecules. Here, we engineered a genetically-encoded HVACC inhibitor by first isolating an immunized llama nanobody (nb.F3) that binds auxiliary HVACC CaVβ subunits. Nb.F3 by itself is functionally inert, providing a convenient vehicle to target active moieties to CaVβ-associated channels. Nb.F3 fused to the catalytic HECT domain of Nedd4L (CaV-aβlator), an E3 ubiquitin ligase, ablated currents from diverse HVACCs reconstituted in HEK293 cells, and from endogenous CaV1/CaV2 channels in mammalian cardiomyocytes, dorsal root ganglion neurons, and pancreatic β cells. In cardiomyocytes, CaV-aβlator redistributed CaV1.2 channels from dyads to Rab-7-positive late endosomes. This work introduces CaV-aβlator as a potent genetically-encoded HVACC inhibitor, and describes a general approach that can be broadly adapted to generate versatile modulators for macro-molecular membrane protein complexes.
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Affiliation(s)
- Travis J Morgenstern
- Department of Pharmacology, Columbia University, Vagelos College of Physicians and Surgeons, New York, United States
| | - Jinseo Park
- Department of Pharmacology, Columbia University, Vagelos College of Physicians and Surgeons, New York, United States
| | - Qing R Fan
- Department of Pharmacology, Columbia University, Vagelos College of Physicians and Surgeons, New York, United States
| | - Henry M Colecraft
- Department of Pharmacology, Columbia University, Vagelos College of Physicians and Surgeons, New York, United States.,Department of Physiology and Cellular Biophysics, Columbia University, Vagelos College of Physicians and Surgeons, New York, United States
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35
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Rivas S, Diaz J, Colecraft HM, Ben Johny M. Auxiliary Beta Subunits are not Obligatory for CaV1.3 Function. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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36
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Yang L, Katchman A, Kushner J, Kushnir A, Zakharov SI, Chen BX, Shuja Z, Subramanyam P, Liu G, Papa A, Roybal D, Pitt GS, Colecraft HM, Marx SO. Cardiac CaV1.2 channels require β subunits for β-adrenergic-mediated modulation but not trafficking. J Clin Invest 2019; 129:647-658. [PMID: 30422117 DOI: 10.1172/jci123878] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 11/06/2018] [Indexed: 01/01/2023] Open
Abstract
Ca2+ channel β-subunit interactions with pore-forming α-subunits are long-thought to be obligatory for channel trafficking to the cell surface and for tuning of basal biophysical properties in many tissues. Unexpectedly, we demonstrate that transgenic expression of mutant α1C subunits lacking capacity to bind CaVβ can traffic to the sarcolemma in adult cardiomyocytes in vivo and sustain normal excitation-contraction coupling. However, these β-less Ca2+ channels cannot be stimulated by β-adrenergic pathway agonists, and thus adrenergic augmentation of contractility is markedly impaired in isolated cardiomyocytes and in hearts. Similarly, viral-mediated expression of a β-subunit-sequestering peptide sharply curtailed β-adrenergic stimulation of WT Ca2+ channels, identifying an approach to specifically modulate β-adrenergic regulation of cardiac contractility. Our data demonstrate that β subunits are required for β-adrenergic regulation of CaV1.2 channels and positive inotropy in the heart, but are dispensable for CaV1.2 trafficking to the adult cardiomyocyte cell surface, and for basal function and excitation-contraction coupling.
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Affiliation(s)
- Lin Yang
- Division of Cardiology, Department of Medicine, Columbia University
| | | | - Jared Kushner
- Division of Cardiology, Department of Medicine, Columbia University
| | | | | | - Bi-Xing Chen
- Division of Cardiology, Department of Medicine, Columbia University
| | - Zunaira Shuja
- Department of Physiology and Cellular Biophysics, and
| | | | - Guoxia Liu
- Division of Cardiology, Department of Medicine, Columbia University
| | - Arianne Papa
- Department of Physiology and Cellular Biophysics, and
| | - Daniel Roybal
- Department of Pharmacology, Vagelos College of Physicians and Surgeons, New York, New York, USA
| | - Geoffrey S Pitt
- Cardiovascular Research Institute, Weill Cornell Medical College, New York, New York, USA
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, and.,Department of Pharmacology, Vagelos College of Physicians and Surgeons, New York, New York, USA
| | - Steven O Marx
- Division of Cardiology, Department of Medicine, Columbia University.,Department of Pharmacology, Vagelos College of Physicians and Surgeons, New York, New York, USA
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37
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Kanner SA, Jain A, Colecraft HM. Development of a High-Throughput Flow Cytometry Assay to Monitor Defective Trafficking and Rescue of Long QT2 Mutant hERG Channels. Front Physiol 2018; 9:397. [PMID: 29725305 PMCID: PMC5917007 DOI: 10.3389/fphys.2018.00397] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 04/04/2018] [Indexed: 11/24/2022] Open
Abstract
Long QT Syndrome (LQTS) is an acquired or inherited disorder characterized by prolonged QT interval, exertion-triggered arrhythmias, and sudden cardiac death. One of the most prevalent hereditary LQTS subtypes, LQT2, results from loss-of-function mutations in the hERG channel, which conducts IKr, the rapid component of the delayed rectifier K+ current, critical for cardiac repolarization. The majority of LQT2 mutations result in Class 2 deficits characterized by impaired maturation and trafficking of hERG channels. Here, we have developed a high-throughput flow cytometric assay to analyze the surface and total expression of wild-type (WT) and mutant hERG channels with single-cell resolution. To test our method, we focused on 16 LQT2 mutations in the hERG Per-Arnt-Sim (PAS) domain that were previously studied via a widely used biochemical approach that compares levels of 135-kDa immature and 155-kDa fully glycosylated hERG protein to infer surface expression. We confirmed that LQT2 mutants expressed in HEK293 cells displayed a decreased surface density compared to WT hERG, and were differentially rescued by low temperature. However, we also uncovered some notable differences from the findings obtained via the biochemical approach. In particular, three mutations (N33T, R56Q, and A57P) with apparent WT-like hERG glycosylation patterns displayed up to 50% decreased surface expression. Furthermore, despite WT-like levels of complex glycosylation, these mutants have impaired forward trafficking, and exhibit varying half-lives at the cell surface. The results highlight utility of the surface labeling/flow cytometry approach to quantitatively assess trafficking deficiencies associated with LQT2 mutations, to discern underlying mechanisms, and to report on interventions that rescue deficits in hERG surface expression.
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Affiliation(s)
- Scott A Kanner
- Doctoral Program in Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, New York, NY, United States
| | - Ananya Jain
- Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York, NY, United States
| | - Henry M Colecraft
- Doctoral Program in Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, New York, NY, United States.,Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York, NY, United States.,Department of Pharmacology, Columbia University College of Physicians and Surgeons, New York, NY, United States
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38
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Kanner SA, Morgenstern T, Colecraft HM. Sculpting ion channel functional expression with engineered ubiquitin ligases. eLife 2017; 6:29744. [PMID: 29256394 PMCID: PMC5764571 DOI: 10.7554/elife.29744] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 12/13/2017] [Indexed: 12/18/2022] Open
Abstract
The functional repertoire of surface ion channels is sustained by dynamic processes of trafficking, sorting, and degradation. Dysregulation of these processes underlies diverse ion channelopathies including cardiac arrhythmias and cystic fibrosis. Ubiquitination powerfully regulates multiple steps in the channel lifecycle, yet basic mechanistic understanding is confounded by promiscuity among E3 ligase/substrate interactions and ubiquitin code complexity. Here we targeted the catalytic domain of E3 ligase, CHIP, to YFP-tagged KCNQ1 ± KCNE1 subunits with a GFP-nanobody to selectively manipulate this channel complex in heterologous cells and adult rat cardiomyocytes. Engineered CHIP enhanced KCNQ1 ubiquitination, eliminated KCNQ1 surface-density, and abolished reconstituted K+ currents without affecting protein expression. A chemo-genetic variation enabling chemical control of ubiquitination revealed KCNQ1 surface-density declined with a ~ 3.5 hr t1/2 by impaired forward trafficking. The results illustrate utility of engineered E3 ligases to elucidate mechanisms underlying ubiquitin regulation of membrane proteins, and to achieve effective post-translational functional knockdown of ion channels. Cells are surrounded by a membrane that separates the outside of the cell from its inside. Proteins called ion channels are embedded within this membrane and allow charged ions to move in and out of the cell. The movement of ions generates electrical currents that are essential for many processes that keep us alive, including our heartbeat and the activity within our brain. Like many other proteins, newly made ion channels undergo several steps before they mature and become active. Cells destroy any proteins that do not mature properly, as well as those that become damaged or are simply no longer needed. A small protein called ubiquitin helps to mark such unwanted proteins for destruction. Enzymes known as E3 ligases attach ubiquitin to target proteins in a process known as ubiquitination. This process regulates both the quality and amount of proteins within cells. To understand the role of a particular protein, it is often necessary to remove it from the cell and then examine the consequences. In the past, researchers have harnessed the ubiquitin system to remove many kinds of proteins, but this approach had not previously been used to target an ion channel. Now, Kanner et al. set out to selectively eliminate ion channels via targeted ubiquitination. The experiments showed that previous approaches that could destroy proteins within the cell were not effective against ion channels. Kanner et al. then engineered a particular E3 ligase so that it could selectively attach ubiquitin to the desired ion channels. This approach successfully prevented the channels from reaching the cell membrane, thereby silencing the electrical currents that they normally generate. Additionally, a new tool was developed to stop ion channels in their tracks, essentially with a flip of a chemical switch. Kanner et al. then used this approach to manipulate ion channels in a highly controlled manner, within their normal environment of heart muscle cells. These new approaches form a toolset that scientists can now exploit to study diverse ion channels. In the future, the toolkit could potentially be used to develop treatments for disorders such as epilepsy, chronic pain, and irregular heartbeats, where too many channels are active or present at the cell membrane.
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Affiliation(s)
- Scott A Kanner
- Doctoral Program in Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, New York, United States
| | - Travis Morgenstern
- Department of Pharmacology, Columbia University College of Physicians and Surgeons, New York, United States
| | - Henry M Colecraft
- Doctoral Program in Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, New York, United States.,Department of Pharmacology, Columbia University College of Physicians and Surgeons, New York, United States.,Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York, United States
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39
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Joseph LC, Kokkinaki D, Valenti MC, Kim GJ, Barca E, Tomar D, Hoffman NE, Subramanyam P, Colecraft HM, Hirano M, Ratner AJ, Madesh M, Drosatos K, Morrow JP. Inhibition of NADPH oxidase 2 (NOX2) prevents sepsis-induced cardiomyopathy by improving calcium handling and mitochondrial function. JCI Insight 2017; 2:94248. [PMID: 28878116 PMCID: PMC5621873 DOI: 10.1172/jci.insight.94248] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/25/2017] [Indexed: 01/12/2023] Open
Abstract
Cardiomyopathy frequently complicates sepsis and is associated with increased mortality. Increased cardiac oxidative stress and mitochondrial dysfunction have been observed during sepsis, but the mechanisms responsible for these abnormalities have not been determined. We hypothesized that NADPH oxidase 2 (NOX2) activation could be responsible for sepsis-induced oxidative stress and cardiomyopathy. Treatment of isolated adult mouse cardiomyocytes with low concentrations of the endotoxin lipopolysaccharide (LPS) increased total cellular reactive oxygen species (ROS) and mitochondrial superoxide. Elevated mitochondrial superoxide was accompanied by depolarization of the mitochondrial inner membrane potential, an indication of mitochondrial dysfunction, and mitochondrial calcium overload. NOX2 inhibition decreased LPS-induced superoxide and prevented mitochondrial dysfunction. Further, cardiomyocytes from mice with genetic ablation of NOX2 did not have LPS-induced superoxide or mitochondrial dysfunction. LPS decreased contractility and calcium transient amplitude in isolated cardiomyocytes, and these abnormalities were prevented by inhibition of NOX2. LPS decreased systolic function in mice, measured by echocardiography. NOX2 inhibition was cardioprotective in 2 mouse models of sepsis, preserving systolic function after LPS injection or cecal ligation and puncture (CLP). These data show that inhibition of NOX2 decreases oxidative stress, preserves intracellular calcium handling and mitochondrial function, and alleviates sepsis-induced systolic dysfunction in vivo. Thus, NOX2 is a potential target for pharmacotherapy of sepsis-induced cardiomyopathy.
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Affiliation(s)
- Leroy C. Joseph
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Dimitra Kokkinaki
- Metabolic Biology Laboratory, Center for Translational Medicine, Department of Pharmacology, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
- The Molecular Basis of Human Diseases Graduate Program, Faculty of Medicine, University of Crete, Voutes, 71003 Heraklion-Crete, Greece
| | - Mesele-Christina Valenti
- Metabolic Biology Laboratory, Center for Translational Medicine, Department of Pharmacology, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Grace J. Kim
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Emanuele Barca
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, USA
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Dhanendra Tomar
- Department of Medical Genetics and Molecular Biochemistry, Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Nicholas E. Hoffman
- Department of Medical Genetics and Molecular Biochemistry, Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Prakash Subramanyam
- Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Henry M. Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Michio Hirano
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Adam J. Ratner
- Departments of Pediatrics and Microbiology, New York University School of Medicine, New York, New York, USA
| | - Muniswamy Madesh
- Department of Medical Genetics and Molecular Biochemistry, Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Konstantinos Drosatos
- Metabolic Biology Laboratory, Center for Translational Medicine, Department of Pharmacology, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - John P. Morrow
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
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40
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Liu N, Yang Y, Ge L, Liu M, Colecraft HM, Liu X. Cooperative and acute inhibition by multiple C-terminal motifs of L-type Ca 2+ channels. eLife 2017; 6. [PMID: 28059704 PMCID: PMC5279948 DOI: 10.7554/elife.21989] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/05/2017] [Indexed: 12/31/2022] Open
Abstract
Inhibitions and antagonists of L-type Ca2+ channels are important to both research and therapeutics. Here, we report C-terminus mediated inhibition (CMI) for CaV1.3 that multiple motifs coordinate to tune down Ca2+ current and Ca2+ influx toward the lower limits determined by end-stage CDI (Ca2+-dependent inactivation). Among IQV (preIQ3-IQ domain), PCRD and DCRD (proximal or distal C-terminal regulatory domain), spatial closeness of any two modules, e.g., by constitutive fusion, facilitates the trio to form the complex, compete against calmodulin, and alter the gating. Acute CMI by rapamycin-inducible heterodimerization helps reconcile the concurrent activation/inactivation attenuations to ensure Ca2+ influx is reduced, in that Ca2+ current activated by depolarization is potently (~65%) inhibited at the peak (full activation), but not later on (end-stage inactivation, ~300 ms). Meanwhile, CMI provides a new paradigm to develop CaV1 inhibitors, the therapeutic potential of which is implied by computational modeling of CaV1.3 dysregulations related to Parkinson’s disease. DOI:http://dx.doi.org/10.7554/eLife.21989.001 All cells need calcium ions to stay healthy, but having too many calcium ions can interfere with important processes in the cell and cause severe problems. Proteins known as calcium channels on the cell surface allow calcium ions to flow into the cell from the surrounding environment. Cells carefully control the opening and closing of these channels to prevent too many calcium ions entering the cell at once. CaV1.3 channels are a type of calcium channel that are important for the heart and brain to work properly. Defects in CaV1.3 channels can lead to irregular heart rhythms and neurodegenerative diseases such as Parkinson’s disease. Studies have shown that part of the CaV1.3 channel that sits inside the cell – known as the “tail” – responds to increases in the levels of calcium ions inside the cell by closing the channel. The tail region of CaV1.3 contains three modules, but how these modules work together to regulate channel activity is not clear. Liu, Yang et al. investigated whether the three modules need to be physically connected to each other in the channel protein. For the experiments, several versions of the protein were constructed with different combinations of tail modules being directly linked as part of the same molecule or present as separate molecules. When any two modules were directly linked, the third module could bind to them and this was enough to close the CaV1.3 channel. However, the channel did not close if the modules were totally isolated from each other as three separate molecules. Certain types of neurons in the brain produce electrical signals in a rhythmic fashion that depends on CaV1.3 channels. In Parkinson’s disease, increased movement of calcium ions into these neurons via CaV1.3 channels interferes with the rhythms of the signals and can cause these cells to die. Liu, Yang et al. performed computer simulations to analyse the effects of closing CaV1.3 channels in these neurons. The results suggest that this can restore normal rhythms of electrical activity and prevent these cells from dying. The next step is to understand the molecular details of how the tail region closes CaV1.3 channels and its role in healthy and diseased cells. This may lead to new ways to block CaV1.3 channels in different types of diseases. DOI:http://dx.doi.org/10.7554/eLife.21989.002
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Affiliation(s)
- Nan Liu
- X-Lab for Transmembrane Signaling Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Yaxiong Yang
- X-Lab for Transmembrane Signaling Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Lin Ge
- X-Lab for Transmembrane Signaling Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Min Liu
- X-Lab for Transmembrane Signaling Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, New York, United States
| | - Xiaodong Liu
- X-Lab for Transmembrane Signaling Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China.,IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
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41
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Grandi E, Sanguinetti MC, Bartos DC, Bers DM, Chen-Izu Y, Chiamvimonvat N, Colecraft HM, Delisle BP, Heijman J, Navedo MF, Noskov S, Proenza C, Vandenberg JI, Yarov-Yarovoy V. Potassium channels in the heart: structure, function and regulation. J Physiol 2016; 595:2209-2228. [PMID: 27861921 DOI: 10.1113/jp272864] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Accepted: 07/18/2016] [Indexed: 12/22/2022] Open
Abstract
This paper is the outcome of the fourth UC Davis Systems Approach to Understanding Cardiac Excitation-Contraction Coupling and Arrhythmias Symposium, a biannual event that aims to bring together leading experts in subfields of cardiovascular biomedicine to focus on topics of importance to the field. The theme of the 2016 symposium was 'K+ Channels and Regulation'. Experts in the field contributed their experimental and mathematical modelling perspectives and discussed emerging questions, controversies and challenges on the topic of cardiac K+ channels. This paper summarizes the topics of formal presentations and informal discussions from the symposium on the structural basis of voltage-gated K+ channel function, as well as the mechanisms involved in regulation of K+ channel gating, expression and membrane localization. Given the critical role for K+ channels in determining the rate of cardiac repolarization, it is hardly surprising that essentially every aspect of K+ channel function is exquisitely regulated in cardiac myocytes. This regulation is complex and highly interrelated to other aspects of myocardial function. K+ channel regulatory mechanisms alter, and are altered by, physiological challenges, pathophysiological conditions, and pharmacological agents. An accompanying paper focuses on the integrative role of K+ channels in cardiac electrophysiology, i.e. how K+ currents shape the cardiac action potential, and how their dysfunction can lead to arrhythmias, and discusses K+ channel-based therapeutics. A fundamental understanding of K+ channel regulatory mechanisms and disease processes is fundamental to reveal new targets for human therapy.
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Affiliation(s)
- Eleonora Grandi
- Department of Pharmacology, University of California, Davis, Davis, CA, 95616, USA
| | - Michael C Sanguinetti
- Department of Internal Medicine, University of Utah, Nora Eccles Harrison Cardiovascular Research and Training Institute, Salt Lake City, UT, 84112, USA
| | - Daniel C Bartos
- Department of Pharmacology, University of California, Davis, Davis, CA, 95616, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, Davis, CA, 95616, USA
| | - Ye Chen-Izu
- Department of Pharmacology, University of California, Davis, Davis, CA, 95616, USA.,Department of Internal Medicine, Division of Cardiology, University of California, Davis, CA, 95616, USA
| | - Nipavan Chiamvimonvat
- Department of Internal Medicine, Division of Cardiology, University of California, Davis, CA, 95616, USA
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, 10032, USA
| | - Brian P Delisle
- Department of Physiology, University of Kentucky, Lexington, KY, 40536, USA
| | - Jordi Heijman
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, Davis, CA, 95616, USA
| | - Sergei Noskov
- Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Catherine Proenza
- Department of Physiology and Biophysics, University of Colorado - Anschutz Medical Campus, Denver, CO, 80045, USA
| | - Jamie I Vandenberg
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California, Davis, CA, 95616, USA
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42
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Hu Z, Wang JW, Yu D, Soon JL, de Kleijn DPV, Foo R, Liao P, Colecraft HM, Soong TW. Aberrant Splicing Promotes Proteasomal Degradation of L-type Ca V1.2 Calcium Channels by Competitive Binding for Ca Vβ Subunits in Cardiac Hypertrophy. Sci Rep 2016; 6:35247. [PMID: 27731386 PMCID: PMC5059693 DOI: 10.1038/srep35247] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/27/2016] [Indexed: 12/13/2022] Open
Abstract
Decreased expression and activity of CaV1.2 calcium channels has been reported in pressure overload-induced cardiac hypertrophy and heart failure. However, the underlying mechanisms remain unknown. Here we identified in rodents a splice variant of CaV1.2 channel, named CaV1.2e21+22, that contained the pair of mutually exclusive exons 21 and 22. This variant was highly expressed in neonatal hearts. The abundance of this variant was gradually increased by 12.5-folds within 14 days of transverse aortic banding that induced cardiac hypertrophy in adult mouse hearts and was also elevated in left ventricles from patients with dilated cardiomyopathy. Although this variant did not conduct Ca2+ ions, it reduced the cell-surface expression of wild-type CaV1.2 channels and consequently decreased the whole-cell Ca2+ influx via the CaV1.2 channels. In addition, the CaV1.2e21+22 variant interacted with CaVβ subunits significantly more than wild-type CaV1.2 channels, and competition of CaVβ subunits by CaV1.2e21+22 consequently enhanced ubiquitination and subsequent proteasomal degradation of the wild-type CaV1.2 channels. Our findings show that the resurgence of a specific neonatal splice variant of CaV1.2 channels in adult heart under stress may contribute to heart failure.
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Affiliation(s)
- Zhenyu Hu
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore 117597, Singapore
| | - Jiong-Wei Wang
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore.,Cardiovascular Research Institute, National University Health Systems, Centre for Translational Medicine, 117599, Singapore
| | - Dejie Yu
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore 117597, Singapore
| | - Jia Lin Soon
- National Heart Centre Singapore, 5 hospital drive, 169609, Singapore
| | - Dominique P V de Kleijn
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore.,Cardiovascular Research Institute, National University Health Systems, Centre for Translational Medicine, 117599, Singapore.,Dept of Cardiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Roger Foo
- Cardiovascular Research Institute, National University Health Systems, Centre for Translational Medicine, 117599, Singapore
| | - Ping Liao
- Calcium Signaling Laboratory, National Neuroscience Institute, 11 Jalan Tan Tock Seng 308433, Singapore
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA
| | - Tuck Wah Soong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore 117597, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, 117456, Singapore.,Neurobiology/Ageing Programme, National University of Singapore, 117456, Singapore
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43
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Chang DD, Colecraft HM. Rad and Rem are non-canonical G-proteins with respect to the regulatory role of guanine nucleotide binding in Ca(V)1.2 channel regulation. J Physiol 2016; 593:5075-90. [PMID: 26426338 DOI: 10.1113/jp270889] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 09/27/2015] [Indexed: 12/15/2022] Open
Abstract
Rad and Rem are Ras-like G-proteins linked to diverse cardiovascular functions and pathophysiology. Understanding how Rad and Rem are regulated is important for deepened insights into their pathophysiological roles. As in other Ras-like G-proteins, Rad and Rem contain a conserved guanine-nucleotide binding domain (G-domain). Canonically, G-domains are key control modules, functioning as nucleotide-regulated switches of G-protein activity. Whether Rad and Rem G-domains conform to this canonical paradigm is ambiguous. Here, we used multiple functional measurements in HEK293 cells and cardiomyocytes (Ca(V)1.2 currents, Ca(2+) transients, Ca(V)β binding) as biosensors to probe the role of the G-domain in regulation of Rad and Rem function. We utilized Rad(S105N) and Rem(T94N), which are the cognate mutants to Ras(S17N), a dominant-negative variant of Ras that displays decreased nucleotide binding affinity. In HEK293 cells, over-expression of either Rad(S105N) or Rem(T94N) strongly inhibited reconstituted Ca(V)1.2 currents to the same extent as their wild-type (wt) counterparts, contrasting with reports that Rad(S105N) is functionally inert in HEK293 cells. Adenovirus-mediated expression of either wt Rad or Rad(S105N) in cardiomyocytes dramatically blocked L-type calcium current (I(Ca,L)) and inhibited Ca(2+)-induced Ca(2+) release, contradicting reports that Rad(S105N) acts as a dominant negative in heart. By contrast, Rem(T94N) was significantly less effective than wt Rem at inhibiting I(Ca,L) and Ca(2+) transients in cardiomyocytes. FRET analyses in cardiomyocytes revealed that both Rad(S105N) and Rem(T94N) had moderately reduced binding affinity for Ca(V)βs relative to their wt counterparts. The results indicate Rad and Rem are non-canonical G-proteins with respect to the regulatory role of their G-domain in Ca(V)1.2 regulation.
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Affiliation(s)
- Donald D Chang
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, 10032, USA
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, 10032, USA
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Ortuño MJ, Robinson ST, Subramanyam P, Paone R, Huang YY, Guo XE, Colecraft HM, Mann JJ, Ducy P. Serotonin-reuptake inhibitors act centrally to cause bone loss in mice by counteracting a local anti-resorptive effect. Nat Med 2016; 22:1170-1179. [PMID: 27595322 PMCID: PMC5053870 DOI: 10.1038/nm.4166] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 07/19/2016] [Indexed: 02/06/2023]
Abstract
The use of selective serotonin-reuptake inhibitors (SSRIs) has been associated with an increased risk of bone fracture, raising concerns about their increasingly broader usage. This deleterious effect is poorly understood, and thus strategies to avoid this side effect remain elusive. We show here that fluoxetine (Flx), one of the most-prescribed SSRIs, acts on bone remodeling through two distinct mechanisms. Peripherally, Flx has anti-resorptive properties, directly impairing osteoclast differentiation and function through a serotonin-reuptake-independent mechanism that is dependent on intracellular Ca2+ levels and the transcription factor Nfatc1. With time, however, Flx also triggers a brain-serotonin-dependent rise in sympathetic output that increases bone resorption sufficiently to counteract its local anti-resorptive effect, thus leading to a net effect of impaired bone formation and bone loss. Accordingly, neutralizing this second mode of action through co-treatment with the β-blocker propranolol, while leaving the peripheral effect intact, prevents Flx-induced bone loss in mice. Hence, this study identifies a dual mode of action of SSRIs on bone remodeling and suggests a therapeutic strategy to block the deleterious effect on bone homeostasis from their chronic use.
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Affiliation(s)
- María José Ortuño
- Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Samuel T Robinson
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Prakash Subramanyam
- Department of Physiology and Cellular Biophysics, Columbia University, New York, New York, USA
| | - Riccardo Paone
- Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - Yung-Yu Huang
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - X Edward Guo
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, New York, New York, USA
| | - J John Mann
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Patricia Ducy
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
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Geng Y, Mosyak L, Kurinov I, Zuo H, Sturchler E, Cheng TC, Subramanyam P, Brown AP, Brennan SC, Mun HC, Bush M, Chen Y, Nguyen TX, Cao B, Chang DD, Quick M, Conigrave AD, Colecraft HM, McDonald P, Fan QR. Structural mechanism of ligand activation in human calcium-sensing receptor. eLife 2016; 5. [PMID: 27434672 PMCID: PMC4977154 DOI: 10.7554/elife.13662] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 07/18/2016] [Indexed: 12/21/2022] Open
Abstract
Human calcium-sensing receptor (CaSR) is a G-protein-coupled receptor (GPCR) that maintains extracellular Ca2+ homeostasis through the regulation of parathyroid hormone secretion. It functions as a disulfide-tethered homodimer composed of three main domains, the Venus Flytrap module, cysteine-rich domain, and seven-helix transmembrane region. Here, we present the crystal structures of the entire extracellular domain of CaSR in the resting and active conformations. We provide direct evidence that L-amino acids are agonists of the receptor. In the active structure, L-Trp occupies the orthosteric agonist-binding site at the interdomain cleft and is primarily responsible for inducing extracellular domain closure to initiate receptor activation. Our structures reveal multiple binding sites for Ca2+ and PO43- ions. Both ions are crucial for structural integrity of the receptor. While Ca2+ ions stabilize the active state, PO43- ions reinforce the inactive conformation. The activation mechanism of CaSR involves the formation of a novel dimer interface between subunits. DOI:http://dx.doi.org/10.7554/eLife.13662.001 Calcium ions regulate many processes in the human body. The calcium-sensing receptor, called CaSR, is responsible for maintaining a stable level of calcium ions in the blood. This receptor can detect small changes in the concentration of calcium ions, and activates signalling events within the cell to restore the level of calcium ions back to normal. Abnormal activity of this receptor is associated with severe diseases in humans CaSR is found in the surface membrane of cells and belongs to a family of proteins called G-protein coupled receptors. Much of the protein extends out of the cell and interacts with calcium ions, phosphate ions and certain other molecules such as amino acids. However, it was not well understood how these small molecules bind to CaSR and how this activates the receptor. Geng et al. have now used a technique called X-ray crystallography to view the three-dimensional structure of the exterior domain of CaSR in its resting state and active state. These structures revealed that, contrary to expectations, calcium ions are not the main activator of the receptor. Instead, Geng et al. found that CaSR adopts an inactive state in the absence or presence of calcium ions, while the active state only forms when an amino acid is bound. Furthermore investigation showed that calcium ions are needed to stabilise the active form, while phosphate ions keep the inactive form stable. Geng et al. also identified the shape changes that must occur as CaSR transitions from its inactive to its active state. In particular, an amino acid binding to the exterior domain causes it to close like a venus flytrap, which is a crucial step in activating the receptor. Taken together, the findings show that the amino acids and calcium ions act jointly to fully activate CaSR. The next steps are to determine the structure of the entire receptor with and without its small molecule partners and to use these structures to design drugs that can alter CaSR’s activity in order to treat human diseases. DOI:http://dx.doi.org/10.7554/eLife.13662.002
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Affiliation(s)
- Yong Geng
- Department of Pharmacology, Columbia University, New York, United States.,Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Lidia Mosyak
- Department of Pharmacology, Columbia University, New York, United States
| | - Igor Kurinov
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, United States
| | - Hao Zuo
- Department of Pharmacology, Columbia University, New York, United States
| | - Emmanuel Sturchler
- Department of Molecular Therapeutics, The Scripps Translational Science Institute, Jupiter, United States
| | - Tat Cheung Cheng
- Department of Pharmacology, Columbia University, New York, United States
| | - Prakash Subramanyam
- Department of Physiology and Cellular Biophysics, Columbia University, New York, United States
| | - Alice P Brown
- School of Life and Environmental Sciences, University of Sydney, New South Wales, Australia
| | - Sarah C Brennan
- School of Life and Environmental Sciences, University of Sydney, New South Wales, Australia
| | - Hee-Chang Mun
- School of Life and Environmental Sciences, University of Sydney, New South Wales, Australia
| | - Martin Bush
- Department of Pharmacology, Columbia University, New York, United States
| | - Yan Chen
- Department of Pharmacology, Columbia University, New York, United States
| | - Trang X Nguyen
- Department of Psychiatry, Columbia University, New York, United States
| | - Baohua Cao
- Department of Pharmacology, Columbia University, New York, United States
| | - Donald D Chang
- Department of Physiology and Cellular Biophysics, Columbia University, New York, United States
| | - Matthias Quick
- Department of Psychiatry, Columbia University, New York, United States
| | - Arthur D Conigrave
- School of Life and Environmental Sciences, University of Sydney, New South Wales, Australia
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University, New York, United States
| | - Patricia McDonald
- Department of Molecular Therapeutics, The Scripps Translational Science Institute, Jupiter, United States
| | - Qing R Fan
- Department of Pharmacology, Columbia University, New York, United States.,Department of Pathology and Cell Biology, Columbia University, New York, United States
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Joseph LC, Subramanyam P, Radlicz C, Trent CM, Iyer V, Colecraft HM, Morrow JP. Mitochondrial oxidative stress during cardiac lipid overload causes intracellular calcium leak and arrhythmia. Heart Rhythm 2016; 13:1699-706. [PMID: 27154230 DOI: 10.1016/j.hrthm.2016.05.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Indexed: 01/29/2023]
Abstract
BACKGROUND Diabetes and obesity are associated with an increased risk of arrhythmia and sudden cardiac death. Abnormal lipid accumulation is observed in cardiomyocytes of obese and diabetic patients, which may contribute to arrhythmia, but the mechanisms are poorly understood. A transgenic mouse model of cardiac lipid overload, the peroxisome proliferator-activated receptor-γ (PPARg) cardiac overexpression mouse, has long QT and increased ventricular ectopy. OBJECTIVE The purpose of this study was to evaluate the hypothesis that the increase in ventricular ectopy during cardiac lipid overload is caused by abnormalities in calcium handling due to increased mitochondrial oxidative stress. METHODS Ventricular myocytes were isolated from adult mouse hearts to record sparks and calcium transients. Mice were implanted with heart rhythm monitors for in vivo recordings. RESULTS PPARg cardiomyocytes have more frequent triggered activity and increased sparks compared to control. Sparks and triggered activity are reduced by mitotempo, a mitochondrial-targeted antioxidant. This is explained by a significant increase in oxidation of RyR2. Calcium transients are increased in amplitude, and sarcoplasmic reticulum (SR) calcium stores are increased in PPARg cardiomyocytes. Computer modeling of the cardiac action potential demonstrates that long QT contributes to increased SR calcium. Mitotempo decreased ventricular ectopy in vivo. CONCLUSION During cardiac lipid overload, mitochondrial oxidative stress causes increased SR calcium leak by oxidizing RyR2 channels. This promotes ventricular ectopy, which is significantly reduced in vivo by a mitochondrial-targeted antioxidant. These results suggest a potential role for mitochondrial-targeted antioxidants in preventing arrhythmia and sudden cardiac death in obese and diabetic patients.
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Affiliation(s)
- Leroy C Joseph
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, New York
| | - Prakash Subramanyam
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons of Columbia University, New York, New York
| | - Christopher Radlicz
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, New York
| | - Chad M Trent
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, New York
| | - Vivek Iyer
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, New York
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons of Columbia University, New York, New York
| | - John P Morrow
- Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, New York,.
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Abstract
Rad/Rem/Rem2/Gem (RGK) proteins are Ras-like GTPases that potently inhibit all high-voltage-gated calcium (CaV1/CaV2) channels and are, thus, well-positioned to tune diverse physiological processes. Understanding how RGK proteins inhibit CaV channels is important for perspectives on their (patho)physiological roles and could advance their development and use as genetically-encoded CaV channel blockers. We previously reported that Rem can block surface CaV1.2 channels in 2 independent ways that engage distinct components of the channel complex: (1) by binding auxiliary β subunits (β-binding-dependent inhibition, or BBD); and (2) by binding the pore-forming α1C subunit N-terminus (α1C-binding-dependent inhibition, or ABD). By contrast, Gem uses only the BBD mechanism to block CaV1.2. Rem molecular determinants required for BBD CaV1.2 inhibition are the distal C-terminus and the guanine nucleotide binding G-domain which interact with the plasma membrane and CaVβ, respectively. However, Rem determinants for ABD CaV1.2 inhibition are unknown. Here, combining fluorescence resonance energy transfer, electrophysiology, systematic truncations, and Rem/Gem chimeras we found that the same Rem distal C-terminus and G-domain also mediate ABD CaV1.2 inhibition, but with different interaction partners. Rem distal C-terminus interacts with α1C N-terminus to anchor the G-domain which likely interacts with an as-yet-unidentified site. In contrast to some previous studies, neither the C-terminus of Rem nor Gem was sufficient to inhibit CaV1/CaV2 channels. The results reveal that similar molecular determinants on Rem are repurposed to initiate 2 independent mechanisms of CaV1.2 inhibition.
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Affiliation(s)
- Akil A Puckerin
- a Department of Pharmacology & Molecular Signaling , Columbia University , New York , NY , USA
| | - Donald D Chang
- b Department of Physiology & Cellular Biophysics , Columbia University , New York , NY , USA
| | - Prakash Subramanyam
- b Department of Physiology & Cellular Biophysics , Columbia University , New York , NY , USA
| | - Henry M Colecraft
- a Department of Pharmacology & Molecular Signaling , Columbia University , New York , NY , USA.,b Department of Physiology & Cellular Biophysics , Columbia University , New York , NY , USA
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Aromolaran AS, Colecraft HM, Boutjdir M. High-fat diet-dependent modulation of the delayed rectifier K(+) current in adult guinea pig atrial myocytes. Biochem Biophys Res Commun 2016; 474:554-559. [PMID: 27130822 DOI: 10.1016/j.bbrc.2016.04.113] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 04/20/2016] [Indexed: 12/11/2022]
Abstract
Obesity is associated with hyperlipidemia, electrical remodeling of the heart, and increased risk of supraventricular arrhythmias in both male and female patients. The delayed rectifier K(+) current (IK), is an important regulator of atrial repolarization. There is a paucity of studies on the functional role of IK in response to obesity. Here, we assessed the obesity-mediated functional modulation of IK in low-fat diet (LFD), and high-fat diet (HFD) fed adult guinea pigs. Guinea pigs were randomly divided into control and obese groups fed, ad libitum, with a LFD (10 kcal% fat) or a HFD (45 kcal% fat) respectively. Action potential duration (APD), and IK were studied in atrial myocytes and IKr and IKs in HEK293 cells using whole-cell patch clamp electrophysiology. HFD guinea pigs displayed a significant increase in body weight, total cholesterol and total triglycerides within 50 days. Atrial APD at 30% (APD30) and 90% (APD90) repolarization were shorter, while atrial IK density was significantly increased in HFD guinea pigs. Exposure to palmitic acid (PA) increased heterologously expressed IKr and IKs densities, while oleic acid (OA), severely reduced IKr and had no effect on IKs. The data are first to show that in obese guinea pigs abbreviated APD is due to increased IK density likely through elevations of PA. Our findings may have crucial implications for targeted treatment options for obesity-related arrhythmias.
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Affiliation(s)
- Ademuyiwa S Aromolaran
- Department of Physiology & Cellular Biophysics, Columbia University, New York, NY, United States
| | - Henry M Colecraft
- Department of Physiology & Cellular Biophysics, Columbia University, New York, NY, United States
| | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, United States; Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, New York, NY, United States; Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York, NY, United States; Department of Pharmacology, State University of New York Downstate Medical Center, Brooklyn, New York, NY, United States; Department of Medicine, New York University School of Medicine, New York, NY, United States.
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Puckerin A, Aromolaran KA, Chang DD, Zukin RS, Colecraft HM, Boutjdir M, Aromolaran AS. hERG 1a LQT2 C-terminus truncation mutants display hERG 1b-dependent dominant negative mechanisms. Heart Rhythm 2016; 13:1121-1130. [PMID: 26775140 DOI: 10.1016/j.hrthm.2016.01.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Indexed: 12/01/2022]
Abstract
BACKGROUND The human ether-à-go-go-related gene (hERG 1a) potassium channel is critical for cardiac repolarization. hERG 1b, another variant subunit, co-assembles with hERG 1a, modulates channel biophysical properties and plays an important role in repolarization. Mutations of hERG 1a lead to type 2 long QT syndrome (LQT2), and increased risk for fatal arrhythmias. The functional consequences of these mutations in the presence of hERG 1b are not known. OBJECTIVE To investigate whether hERG 1a mutants exert dominant negative gating and trafficking defects when co-expressed with hERG 1b. METHODS Electrophysiology, co-immunoprecipitation, and fluorescence resonance energy transfer (FRET) experiments in HEK293 cells and guinea pig cardiomyocytes were used to assess the mutants on gating and trafficking. Mutations of 1a-G965X and 1a-R1014X, relevant to gating and trafficking were introduced in the C-terminus region. RESULTS The hERG 1a mutants when expressed alone did not result in decreased current amplitude. Compared to wild-type hERG 1a currents, 1a-G965X currents were significantly larger, whereas those produced by the 1a-R1014X mutant were similar in magnitude. Only when co-expressed with wild-type hERG 1a and 1b did a mutant phenotype emerge, with a marked reduction in surface expression, current amplitude, and a corresponding positive shift in the V1/2 of the activation curve. Co-immunoprecipitation and FRET assays confirmed association of mutant and wild-type subunits. CONCLUSION Heterologously expressed hERG 1a C-terminus truncation mutants, exert a dominant negative gating and trafficking effect only when co-expressed with hERG 1b. These findings may have potentially profound implications for LQT2 therapy.
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Affiliation(s)
- Akil Puckerin
- Department of Physiology & Cellular Biophysics, Columbia University, New York, New York
| | - Kelly A Aromolaran
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, New York
| | - Donald D Chang
- Department of Physiology & Cellular Biophysics, Columbia University, New York, New York
| | - R Suzanne Zukin
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, New York
| | - Henry M Colecraft
- Department of Physiology & Cellular Biophysics, Columbia University, New York, New York
| | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn, New York; Departments of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Medical Center, Brooklyn, New York,; Department of Medicine, New York University School of Medicine, New York, New York
| | - Ademuyiwa S Aromolaran
- Department of Physiology & Cellular Biophysics, Columbia University, New York, New York.
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Abstract
Ca(2+)-activated chloride channels encoded by TMEM16A and 16B are important for regulating epithelial mucus secretion, cardiac and neuronal excitability, smooth muscle contraction, olfactory transduction, and cell proliferation. Whether and how the ubiquitous Ca(2+) sensor calmodulin (CaM) regulates the activity of TMEM16A and 16B channels has been controversial and the subject of an ongoing debate. Recently, using a bioengineering approach termed ChIMP (Channel Inactivation induced by Membrane-tethering of an associated Protein) we argued that Ca(2+)-free CaM (apoCaM) is pre-associated with functioning TMEM16A and 16B channel complexes in live cells. Further, the pre-associated apoCaM mediates Ca(2+)-dependent sensitization of activation (CDSA) and Ca(2+)-dependent inactivation (CDI) of some TMEM16A splice variants. In this review, we discuss these findings in the context of previous and recent results relating to Ca(2+)-dependent regulation of TMEM16A/16B channels and the putative role of CaM. We further discuss potential future directions for these nascent ideas on apoCaM regulation of TMEM16A/16B channels, noting that such future efforts will benefit greatly from the pioneering work of Dr. David T. Yue and colleagues on CaM regulation of voltage-dependent calcium channels.
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Affiliation(s)
- Tingting Yang
- a Department of Physiology and Cellular Biophysics ; Columbia University; College of Physicians and Surgeons ; New York , NY USA
| | - Henry M Colecraft
- a Department of Physiology and Cellular Biophysics ; Columbia University; College of Physicians and Surgeons ; New York , NY USA
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