1
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Henze E, Ehrlich JJ, Robertson JL, Kawate T. The C-terminal activating domain promotes Panx1 channel opening. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.13.598903. [PMID: 38915727 PMCID: PMC11195165 DOI: 10.1101/2024.06.13.598903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Pannexin 1 (Panx1) constitutes a large pore channel responsible for the release of ATP from apoptotic cells. Strong evidence indicates that caspase-mediated cleavage of the C-terminus promotes the opening of the Panx1 channel by unplugging the pore. However, this simple pore-plugging mechanism alone cannot account for the observation that a Panx1 construct ending before the caspase cleavage site remains closed. Here, we show that a helical region located immediately before the caspase cleavage site, referred to as the "C-terminal activating domain (CAD)," plays a pivotal role in facilitating Panx1 activation. Electrophysiology and mutagenesis studies uncovered that two conserved leucine residues within the CAD plays a pivotal role. Cryo-EM analysis of the construct ending before reaching the CAD demonstrated that the N-terminus extends into an intracellular pocket. In contrast, the construct including the CAD revealed that this domain occupies the intracellular pocket, causing the N-terminus to flip upward within the pore. Analysis of electrostatic free energy landscape in the closed conformation indicated that the intracellular side of the ion permeation pore may be occupied by anions like ATP, creating an electrostatic barrier for anions attempting to permeate the pore. When the N-terminus flips up, it diminishes the positively charged surface, thereby reducing the drive to accumulate anions inside the pore. This dynamic change in the electrostatic landscape likely contributes to the selection of permeant ions. Collectively, these experiments put forth a novel mechanism in which C-terminal cleavage liberates the CAD, causing the repositioning of the N-terminus to promote Panx1 channel opening.
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Affiliation(s)
- Erik Henze
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | | | - Janice L. Robertson
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Toshimitsu Kawate
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
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2
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O'Donnell BL, Penuela S. Skin in the game: pannexin channels in healthy and cancerous skin. Biochem J 2023; 480:1929-1949. [PMID: 38038973 DOI: 10.1042/bcj20230176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/15/2023] [Accepted: 11/20/2023] [Indexed: 12/02/2023]
Abstract
The skin is a highly organized tissue composed of multiple layers and cell types that require coordinated cell to cell communication to maintain tissue homeostasis. In skin cancer, this organized structure and communication is disrupted, prompting the malignant transformation of healthy cells into melanoma, basal cell carcinoma or squamous cell carcinoma tumours. One such family of channel proteins critical for cellular communication is pannexins (PANX1, PANX2, PANX3), all of which are present in the skin. These heptameric single-membrane channels act as conduits for small molecules and ions like ATP and Ca2+ but have also been shown to have channel-independent functions through their interacting partners or action in signalling pathways. Pannexins have diverse roles in the skin such as in skin development, aging, barrier function, keratinocyte differentiation, inflammation, and wound healing, which were discovered through work with pannexin knockout mice, organotypic epidermis models, primary cells, and immortalized cell lines. In the context of cutaneous cancer, PANX1 is present at high levels in melanoma tumours and functions in melanoma carcinogenesis, and both PANX1 and PANX3 expression is altered in non-melanoma skin cancer. PANX2 has thus far not been implicated in any skin cancer. This review will discuss pannexin isoforms, structure, trafficking, post-translational modifications, interactome, and channel activity. We will also outline the expression, localization, and function of pannexin channels within the diverse cell types of the epidermis, dermis, hypodermis, and adnexal structures of the skin, and how these properties are exploited or abrogated in instances of skin cancer.
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Affiliation(s)
- Brooke L O'Donnell
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A 5C1
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A 5C1
- Department of Oncology, Division of Experimental Oncology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A 5C1
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3
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Boudreault F, Tan JJ, Grygorczyk R. Propidium uptake and ATP release in A549 cells share similar transport mechanisms. Biophys J 2022; 121:1593-1609. [PMID: 35398020 PMCID: PMC9117937 DOI: 10.1016/j.bpj.2022.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 03/03/2022] [Accepted: 04/04/2022] [Indexed: 11/02/2022] Open
Abstract
The lipid bilayer of eukaryotic cells' plasma membrane is almost impermeable to small ions and large polar molecules, but its miniscule basal permeability in intact cells is poorly characterized. This report describes the intrinsic membrane permeability of A549 cells toward the charged molecules propidium (Pr2+) and ATP4-. Under isotonic conditions, we detected with quantitative fluorescence microscopy, a continuous low-rate uptake of Pr (∼150 × 10-21 moles (zmol)/h/cell, [Pr]o = 150 μM, 32°C). It was stimulated transiently but strongly by 66% hypotonic cell swelling reaching an influx amplitude of ∼1500 (zmol/h)/cell. The progressive Pr uptake with increasing [Pr]o (30, 150, and 750 μM) suggested a permeation mechanism by simple diffusion. We quantified separately ATP release with custom wide-field-of-view chemiluminescence imaging. The strong proportionality between ATP efflux and Pr2+ influx during hypotonic challenge, and the absence of stimulation of transmembrane transport following 300% hypertonic shock, indicated that ATP and Pr travel the same conductive pathway. The fluorescence images revealed a homogeneously distributed intracellular uptake of Pr not consistent with high-conductance channels expressed at low density on the plasma membrane. We hypothesized that the pathway consists of transiently formed water pores evenly spread across the plasma membrane. The abolition of cell swelling-induced Pr uptake with 500 μM gadolinium, a known modulator of membrane fluidity, supported the involvement of water pores whose formation depends on the membrane fluidity. Our study suggests an alternative model of a direct permeation of ATP (and other molecules) through the phospholipid bilayer, which may have important physiological implications.
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Luu R, Valdebenito S, Scemes E, Cibelli A, Spray DC, Rovegno M, Tichauer J, Cottignies-Calamarte A, Rosenberg A, Capron C, Belouzard S, Dubuisson J, Annane D, de la Grandmaison GL, Cramer-Bordé E, Bomsel M, Eugenin E. Pannexin-1 channel opening is critical for COVID-19 pathogenesis. iScience 2021; 24:103478. [PMID: 34841222 PMCID: PMC8603863 DOI: 10.1016/j.isci.2021.103478] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/30/2021] [Accepted: 11/16/2021] [Indexed: 12/24/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly rampaged worldwide, causing a pandemic of coronavirus disease (COVID -19), but the biology of SARS-CoV-2 remains under investigation. We demonstrate that both SARS-CoV-2 spike protein and human coronavirus 229E (hCoV-229E) or its purified S protein, one of the main viruses responsible for the common cold, induce the transient opening of Pannexin-1 (Panx-1) channels in human lung epithelial cells. However, the Panx-1 channel opening induced by SARS-CoV-2 is greater and more prolonged than hCoV-229E/S protein, resulting in an enhanced ATP, PGE2, and IL-1β release. Analysis of lung lavages and tissues indicate that Panx-1 mRNA expression is associated with increased ATP, PGE2, and IL-1β levels. Panx-1 channel opening induced by SARS-CoV-2 spike protein is angiotensin-converting enzyme 2 (ACE-2), endocytosis, and furin dependent. Overall, we demonstrated that Panx-1 channel is a critical contributor to SARS-CoV-2 infection and should be considered as an alternative therapy.
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Affiliation(s)
- Ross Luu
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX 77555, USA
| | - Silvana Valdebenito
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX 77555, USA
| | - Eliana Scemes
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY, USA
| | - Antonio Cibelli
- Dominick P. Purpura Department of Neuroscience & Department of Medicine (Cardiology), Albert Einstein College of Medicine, New York, NY 10461, USA
| | - David C Spray
- Dominick P. Purpura Department of Neuroscience & Department of Medicine (Cardiology), Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Maximiliano Rovegno
- Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Tichauer
- Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Andrea Cottignies-Calamarte
- Hôpital Cochin, Service de Virologie, Hôpital Cochin (AP-HP), Paris, France.,Service d'Hématologie Hôpital Ambroise Paré (AP-HP), Boulogne-Billancourt, France
| | - Arielle Rosenberg
- Hôpital Cochin, Service de Virologie, Hôpital Cochin (AP-HP), Paris, France.,Service d'Hématologie Hôpital Ambroise Paré (AP-HP), Boulogne-Billancourt, France.,Virologie Moléculaire et Cellulaire des Coronavirus, Centre d'infection et d'immunité de Lille, Institut Pasteur de Lille, Université de Lille, CNRS, Inserm, CHRU, 59000 Lille, France
| | - Calude Capron
- Service des Maladies Infectieuses, Centre Hospitalier Universitaire Raymond Poincaré, AP-HP, Garches, France
| | | | - Jean Dubuisson
- Intensive Care Unit, Raymond Poincaré Hospital (AP-HP), Paris, France
| | - Djillali Annane
- Simone Veil School of Medicine, Université of Versailles, Versailles, France.,University Paris Saclay, Garches, France
| | - Geoffroy Lorin de la Grandmaison
- Department of Forensic Medicine and Pathology, Versailles Saint-Quentin Université, AP-HP, Raymond Poincaré Hospital, Garches, France
| | | | - Morgane Bomsel
- Mucosal Entry of HIV and Mucosal Immunity, Institut Cochin, Université de Paris, Paris, France.,INSERM U1016, Paris, France
| | - Eliseo Eugenin
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX 77555, USA
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5
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D'Amico D, Valdebenito S, Eugenin EA. The role of Pannexin-1 channels and extracellular ATP in the pathogenesis of the human immunodeficiency virus. Purinergic Signal 2021; 17:563-576. [PMID: 34542793 DOI: 10.1007/s11302-021-09817-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022] Open
Abstract
Only recently, the role of large ionic channels such as Pannexin-1 channels and Connexin hemichannels has been implicated in several physiological and pathological conditions, including HIV infection and associated comorbidities. These channels are in a closed stage in healthy conditions, but in pathological conditions including HIV, Pannexin-1 channels and Connexin hemichannels become open. Our data demonstrate that acute and chronic HIV infection induces channel opening (Pannexin and Connexin channels), ATP release into the extracellular space, and subsequent activation of purinergic receptors in immune and non-immune cells. We demonstrated that Pannexin and Connexin channels contribute to HIV infection and replication, the long-term survival of viral reservoirs, and comorbidities such as NeuroHIV. Here, we discuss the available data to support the participation of these channels in the HIV life cycle and the potential therapeutic approach to prevent HIV-associated comorbidities.
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Affiliation(s)
- Daniela D'Amico
- Department of Neuroscience , Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX, 77555, USA
| | - Silvana Valdebenito
- Department of Neuroscience , Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX, 77555, USA
| | - Eliseo A Eugenin
- Department of Neuroscience , Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Research Building 17, 105 11th Street, Galveston, TX, 77555, USA.
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6
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Epp AL, Ebert SN, Sanchez-Arias JC, Wicki-Stordeur LE, Boyce AKJ, Swayne LA. A novel motif in the proximal C-terminus of Pannexin 1 regulates cell surface localization. Sci Rep 2019; 9:9721. [PMID: 31278290 PMCID: PMC6611761 DOI: 10.1038/s41598-019-46144-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/24/2019] [Indexed: 12/11/2022] Open
Abstract
The Pannexin 1 (Panx1) ion and metabolite channel is expressed in a wide variety of cells where it regulates a number of cell behaviours including proliferation and differentiation. Panx1 is expressed on the cell surface as well as intracellular membranes. Previous work suggests that a region within the proximal Panx1 C-terminus (Panx1CT) regulates cell surface localization. Here we report the discovery of a putative leucine-rich repeat (LRR) motif in the proximal Panx1CT necessary for Panx1 cell surface expression in HEK293T cells. Deletion of the putative LRR motif results in significant loss of Panx1 cell surface distribution. Outcomes of complementary cell surface oligomerization and glycosylation state analyses were consistent with reduced cell surface expression of Panx1 LRR deletion mutants. Of note, the oligomerization analysis revealed the presence of putative dimers and trimers of Panx1 at the cell surface. Expression of Panx1 increased HEK293T cell growth and reduced doubling time, while expression of a Panx1 LRR deletion mutant (highly conserved segment) did not reproduce this effect. In summary, here we discovered the presence of a putative LRR motif in the Panx1CT that impacts on Panx1 cell surface localization. Overall these findings provide new insights into the molecular mechanisms underlying C-terminal regulation of Panx1 trafficking and raise potential new lines of investigation with respect to Panx1 oligomerization and glycosylation.
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Affiliation(s)
- Anna L Epp
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada
| | - Sarah N Ebert
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada
| | - Juan C Sanchez-Arias
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada
| | - Leigh E Wicki-Stordeur
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada
| | - Andrew K J Boyce
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada
| | - Leigh Anne Swayne
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria, V8P 5C2, Canada.
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7
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Multiple and complex influences of connexins and pannexins on cell death. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017. [PMID: 28625689 DOI: 10.1016/j.bbamem.2017.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cell death is a fundamental process for organogenesis, immunity and cell renewal. During the last decades a broad range of molecular tools were identified as important players for several different cell death pathways (apoptosis, pyroptosis, necrosis, autosis…). Aside from these direct regulators of cell death programs, several lines of evidence proposed connexins and pannexins as potent effectors of cell death. In the present review we discussed the potential roles played by connexins, pannexins and innexins in the different cell death programs at different scales from gap junction intercellular communication to protein-protein interactions. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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8
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Boyce AKJ, Epp AL, Nagarajan A, Swayne LA. Transcriptional and post-translational regulation of pannexins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:72-82. [PMID: 28279657 DOI: 10.1016/j.bbamem.2017.03.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/02/2017] [Accepted: 03/03/2017] [Indexed: 12/21/2022]
Abstract
Pannexins are a 3-membered family of proteins that form large pore ion and metabolite channels in vertebrates. The impact of pannexins on vertebrate biology is intricately tied to where and when they are expressed, and how they are modified, once produced. The purpose of this review is therefore to outline our current understanding of transcriptional and post-translational regulation of pannexins. First, we briefly summarize their discovery and characteristics. Next, we describe several aspects of transcriptional regulation, including cell and tissue-specific expression, dynamic expression over development and disease, as well as new insights into the underlying molecular machinery involved. Following this, we delve into the role of post-translational modifications in the regulation of trafficking and channel properties, highlighting important work on glycosylation, phosphorylation, S-nitrosylation and proteolytic cleavage. Embedded throughout, we also highlight important knowledge gaps and avenues of future research. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Andrew K J Boyce
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria V8P 5C2, Canada
| | - Anna L Epp
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria V8P 5C2, Canada
| | - Archana Nagarajan
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria V8P 5C2, Canada
| | - Leigh Anne Swayne
- Division of Medical Sciences and Island Medical Program, University of Victoria, Victoria V8P 5C2, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver V6T 1Z3, Canada.
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9
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Pavšič M, Ilc G, Vidmar T, Plavec J, Lenarčič B. The cytosolic tail of the tumor marker protein Trop2--a structural switch triggered by phosphorylation. Sci Rep 2015; 5:10324. [PMID: 25981199 PMCID: PMC4434849 DOI: 10.1038/srep10324] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 04/08/2015] [Indexed: 01/23/2023] Open
Abstract
Trop2 is a transmembrane signaling glycoprotein upregulated in stem and carcinoma cells. Proliferation-enhancing signaling involves regulated intramembrane proteolytic release of a short cytoplasmic fragment, which is later engaged in a cytosolic signaling complex. We propose that Trop2 function is modulated by phosphorylation of a specific serine residue within this cytosolic region (Ser303), and by proximity effects exerted on the cytosolic tail by Trop2 dimerization. Structural characterization of both the transmembrane (Trop2TM) and cytosolic regions (Trop2IC) support this hypothesis, and shows that the central region of Trop2IC forms an α-helix. Comparison of NMR structures of non-phosphorylated and phosphorylated forms suggest that phosphorylation of Trop2IC triggers salt bridge reshuffling, resulting in significant conformational changes including ordering of the C-terminal tail. In addition, we demonstrate that the cytosolic regions of two Trop2 subunits can be brought into close proximity via transmembrane part dimerization. Finally, we show that Ser303-phosphorylation significantly affects the structure and accessibility of functionally important regions of the cytosolic tail. These observed structural features of Trop2 at the membrane-cytosol interface could be important for regulation of Trop2 signaling activity.
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Affiliation(s)
- Miha Pavšič
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Gregor Ilc
- 1] Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia [2] EN-FIST Centre of Excellence, Dunajska 156, SI-1000 Ljubljana, Slovenia
| | - Tilen Vidmar
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Janez Plavec
- 1] Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia [2] Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia [3] EN-FIST Centre of Excellence, Dunajska 156, SI-1000 Ljubljana, Slovenia
| | - Brigita Lenarčič
- 1] Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia [2] J. Stefan Institute, Department of Biochemistry, Molecular and Structural Biology, Jamova 39, SI-1000 Ljubljana, Slovenia
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10
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Billaud M, Chiu YH, Lohman AW, Parpaite T, Butcher JT, Mutchler SM, DeLalio LJ, Artamonov MV, Sandilos JK, Best AK, Somlyo AV, Thompson RJ, Le TH, Ravichandran KS, Bayliss DA, Isakson BE. A molecular signature in the pannexin1 intracellular loop confers channel activation by the α1 adrenoreceptor in smooth muscle cells. Sci Signal 2015; 8:ra17. [PMID: 25690012 DOI: 10.1126/scisignal.2005824] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Both purinergic signaling through nucleotides such as ATP (adenosine 5'-triphosphate) and noradrenergic signaling through molecules such as norepinephrine regulate vascular tone and blood pressure. Pannexin1 (Panx1), which forms large-pore, ATP-releasing channels, is present in vascular smooth muscle cells in peripheral blood vessels and participates in noradrenergic responses. Using pharmacological approaches and mice conditionally lacking Panx1 in smooth muscle cells, we found that Panx1 contributed to vasoconstriction mediated by the α1 adrenoreceptor (α1AR), whereas vasoconstriction in response to serotonin or endothelin-1 was independent of Panx1. Analysis of the Panx1-deficient mice showed that Panx1 contributed to blood pressure regulation especially during the night cycle when sympathetic nervous activity is highest. Using mimetic peptides and site-directed mutagenesis, we identified a specific amino acid sequence in the Panx1 intracellular loop that is essential for activation by α1AR signaling. Collectively, these data describe a specific link between noradrenergic and purinergic signaling in blood pressure homeostasis.
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Affiliation(s)
- Marie Billaud
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA. Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Yu-Hsin Chiu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Alexander W Lohman
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA. Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Thibaud Parpaite
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Joshua T Butcher
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Stephanie M Mutchler
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Leon J DeLalio
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA. Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Mykhaylo V Artamonov
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Joanna K Sandilos
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Angela K Best
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Avril V Somlyo
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA. Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Roger J Thompson
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Thu H Le
- Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Kodi S Ravichandran
- Center for Cell Clearance, University of Virginia, Charlottesville, VA 22908, USA. Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA. Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA 22908, USA
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA. Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
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11
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Effects on channel properties and induction of cell death induced by c-terminal truncations of pannexin1 depend on domain length. J Membr Biol 2015; 248:285-94. [PMID: 25567359 DOI: 10.1007/s00232-014-9767-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 12/22/2014] [Indexed: 10/24/2022]
Abstract
Pannexin1 (Panx1) is an integral membrane protein and known to form multifunctional hexameric channels. Recently, Panx1 was identified to be responsible for the release of ATP and UTP from apoptotic cells after site-specific proteolysis by caspases 3/7. Cleavage at the carboxy-terminal (CT) position aa 376-379 irreversibly opens human Panx1 channels and leads to the release of the respective nucleotides resulting in recruitment of macrophages and in subsequent activation of the immunologic response. The fact that cleavage of the CT at this particular residues terminates in a permanently open channel raised the issue of functional relevance of the CT of Panx1 for regulating channel properties. To analyze the impact of the CT on channel gating, we generated 14 truncated versions of rat Panx1 cleaved at different positions in the C-terminus. This allowed elaboration of the influence of defined residues on channel formation, voltage-dependent gating, execution of cell mortality, and susceptibility to the Panx1 inhibitor carbenoxolone. We demonstrate that expression of Panx1 proteins, which were truncated to lengths between 370 and 393 residues, induces differential effects after expression in Xenopus laevis oocytes as well as in Neuro2A cells with strongest impact downstream the caspase 3/7 cleavage site.
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