1
|
Thévenod F, Lee WK. Cadmium transport by mammalian ATP-binding cassette transporters. Biometals 2024; 37:697-719. [PMID: 38319451 PMCID: PMC11101381 DOI: 10.1007/s10534-024-00582-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 01/04/2024] [Indexed: 02/07/2024]
Abstract
Cellular responses to toxic metals depend on metal accessibility to intracellular targets, reaching interaction sites, and the intracellular metal concentration, which is mainly determined by uptake pathways, binding/sequestration and efflux pathways. ATP-binding cassette (ABC) transporters are ubiquitous in the human body-usually in epithelia-and are responsible for the transfer of indispensable physiological substrates (e.g. lipids and heme), protection against potentially toxic substances, maintenance of fluid composition, and excretion of metabolic waste products. Derailed regulation and gene variants of ABC transporters culminate in a wide array of pathophysiological disease states, such as oncogenic multidrug resistance or cystic fibrosis. Cadmium (Cd) has no known physiological role in mammalians and poses a health risk due to its release into the environment as a result of industrial activities, and eventually passes into the food chain. Epithelial cells, especially within the liver, lungs, gastrointestinal tract and kidneys, are particularly susceptible to the multifaceted effects of Cd because of the plethora of uptake pathways available. Pertinent to their broad substrate spectra, ABC transporters represent a major cellular efflux pathway for Cd and Cd complexes. In this review, we summarize current knowledge concerning transport of Cd and its complexes (mainly Cd bound to glutathione) by the ABC transporters ABCB1 (P-glycoprotein, MDR1), ABCB6, ABCC1 (multidrug resistance related protein 1, MRP1), ABCC7 (cystic fibrosis transmembrane regulator, CFTR), and ABCG2 (breast cancer related protein, BCRP). Potential detoxification strategies underlying ABC transporter-mediated efflux of Cd and Cd complexes are discussed.
Collapse
Affiliation(s)
- Frank Thévenod
- Institute for Physiology, Pathophysiology and Toxicology & ZBAF, Witten/Herdecke University, 58453, Witten, Germany
- Physiology and Pathophysiology of Cells and Membranes, Medical School OWL, Bielefeld University, Morgenbreede 1, 33615, Bielefeld, Germany
| | - Wing-Kee Lee
- Physiology and Pathophysiology of Cells and Membranes, Medical School OWL, Bielefeld University, Morgenbreede 1, 33615, Bielefeld, Germany.
| |
Collapse
|
2
|
Bustad HJ, Christie MS, Laitaoja M, Aarsand AK, Martinez A, Jänis J, Kallio JP. One ring closer to a closure: the crystal structure of the ES 3 hydroxymethylbilane synthase intermediate. FEBS J 2024; 291:510-526. [PMID: 37863644 DOI: 10.1111/febs.16982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/08/2023] [Accepted: 10/17/2023] [Indexed: 10/22/2023]
Abstract
Hydroxymethylbilane synthase (HMBS), involved in haem biosynthesis, catalyses the head-to-tail coupling of four porphobilinogens (PBGs) via a dipyrromethane (DPM) cofactor. DPM is composed of two PBGs, and a hexapyrrole is built before the tetrapyrrolic 1-hydroxymethylbilane product is released. During this elongation, stable enzyme (E) intermediates are formed from the holoenzyme, with additional PBG substrates (S): ES, ES2 , ES3 and ES4 . Native PAGE and mass spectrometry of the acute intermittent porphyria (AIP)-associated HMBS variant p.Arg167Gln demonstrated an increased amount of ES3 . Kinetic parameters indicated catalytic dysfunction, however, the product release was not entirely prevented. Isolation and crystal structure analysis of the ES3 intermediate (PDB: 8PND) showed that a pentapyrrole was fully retained within the active site, revealing that polypyrrole elongation proceeds within the active site via a third interaction site, intermediate pyrrole site 3 (IPS3). The AIP-associated HMBS variant p.Arg195Cys, located on the opposite side to p.Arg167Gln in the active site, accumulated the ES4 intermediate in the presence of excess PBG, implying that product hydrolysis was obstructed. Arg167 is thus involved in all elongation steps and is a determinant for the rate of enzyme catalysis, whereas Arg195 is important for releasing the product. Moreover, by substituting residues in the vicinity of IPS3, our results indicate that a fully retained hexapyrrole could be hydrolysed in a novel site in proximity of the IPS3.
Collapse
Affiliation(s)
- Helene J Bustad
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Marthe S Christie
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Mikko Laitaoja
- Department of Chemistry, University of Eastern Finland, Joensuu, Finland
| | - Aasne K Aarsand
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
- Norwegian Organization for Quality Improvement of Laboratory Examinations, Haraldsplass Deaconess Hospital, Bergen, Norway
| | | | - Janne Jänis
- Department of Chemistry, University of Eastern Finland, Joensuu, Finland
| | - Juha P Kallio
- Department of Biomedicine, University of Bergen, Norway
| |
Collapse
|
3
|
Hussain Z, Qi Q, Zhu J, Anderson KE, Ma X. Protoporphyrin IX-induced phototoxicity: Mechanisms and therapeutics. Pharmacol Ther 2023; 248:108487. [PMID: 37392940 PMCID: PMC10529234 DOI: 10.1016/j.pharmthera.2023.108487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/18/2023] [Accepted: 06/27/2023] [Indexed: 07/03/2023]
Abstract
Protoporphyrin IX (PPIX) is an intermediate in the heme biosynthesis pathway. Abnormal accumulation of PPIX due to certain pathological conditions such as erythropoietic protoporphyria and X-linked protoporphyria causes painful phototoxic reactions of the skin, which can significantly impact daily life. Endothelial cells in the skin have been proposed as the primary target for PPIX-induced phototoxicity through light-triggered generation of reactive oxygen species. Current approaches for the management of PPIX-induced phototoxicity include opaque clothing, sunscreens, phototherapy, blood therapy, antioxidants, bone marrow transplantation, and drugs that increase skin pigmentation. In this review, we discuss the present understanding of PPIX-induced phototoxicity including PPIX production and disposition, conditions that lead to PPIX accumulation, symptoms and individual differences, mechanisms, and therapeutics.
Collapse
Affiliation(s)
- Zahir Hussain
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Qian Qi
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Junjie Zhu
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Karl E Anderson
- Porphyria Laboratory and Center, Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Xiaochao Ma
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| |
Collapse
|
4
|
Zhang R, Kang R, Tang D. Ferroptosis in gastrointestinal cancer: From mechanisms to implications. Cancer Lett 2023; 561:216147. [PMID: 36965540 DOI: 10.1016/j.canlet.2023.216147] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/16/2023] [Accepted: 03/22/2023] [Indexed: 03/27/2023]
Abstract
Ferroptosis is a form of regulated cell death that is initiated by excessive lipid peroxidation that results in plasma membrane damage and the release of damage-associated molecular patterns. In recent years, ferroptosis has gained significant attention in cancer research due to its unique mechanism compared to other forms of regulated cell death, especially caspase-dependent apoptotic cell death. Gastrointestinal (GI) cancer encompasses malignancies that arise in the digestive tract, including the stomach, intestines, pancreas, colon, liver, rectum, anus, and biliary system. These cancers are a global health concern, with high incidence and mortality rates. Despite advances in medical treatments, drug resistance caused by defects in apoptotic pathways remains a persistent challenge in the management of GI cancer. Hence, exploring the role of ferroptosis in GI cancers may lead to more efficacious treatment strategies. In this review, we provide a comprehensive overview of the core mechanism of ferroptosis and discuss its function, regulation, and implications in the context of GI cancers.
Collapse
Affiliation(s)
- Ruoxi Zhang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA
| | - Rui Kang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA.
| | - Daolin Tang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA.
| |
Collapse
|
5
|
Richter AS, Nägele T, Grimm B, Kaufmann K, Schroda M, Leister D, Kleine T. Retrograde signaling in plants: A critical review focusing on the GUN pathway and beyond. PLANT COMMUNICATIONS 2023; 4:100511. [PMID: 36575799 PMCID: PMC9860301 DOI: 10.1016/j.xplc.2022.100511] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 12/05/2022] [Accepted: 12/22/2022] [Indexed: 06/01/2023]
Abstract
Plastids communicate their developmental and physiological status to the nucleus via retrograde signaling, allowing nuclear gene expression to be adjusted appropriately. Signaling during plastid biogenesis and responses of mature chloroplasts to environmental changes are designated "biogenic" and "operational" controls, respectively. A prominent example of the investigation of biogenic signaling is the screen for gun (genomes uncoupled) mutants. Although the first five gun mutants were identified 30 years ago, the functions of GUN proteins in retrograde signaling remain controversial, and that of GUN1 is hotly disputed. Here, we provide background information and critically discuss recently proposed concepts that address GUN-related signaling and some novel gun mutants. Moreover, considering heme as a candidate in retrograde signaling, we revisit the spatial organization of heme biosynthesis and export from plastids. Although this review focuses on GUN pathways, we also highlight recent progress in the identification and elucidation of chloroplast-derived signals that regulate the acclimation response in green algae and plants. Here, stress-induced accumulation of unfolded/misassembled chloroplast proteins evokes a chloroplast-specific unfolded protein response, which leads to changes in the expression levels of nucleus-encoded chaperones and proteases to restore plastid protein homeostasis. We also address the importance of chloroplast-derived signals for activation of flavonoid biosynthesis leading to production of anthocyanins during stress acclimation through sucrose non-fermenting 1-related protein kinase 1. Finally, a framework for identification and quantification of intercompartmental signaling cascades at the proteomic and metabolomic levels is provided, and we discuss future directions of dissection of organelle-nucleus communication.
Collapse
Affiliation(s)
- Andreas S Richter
- Physiology of Plant Metabolism, Institute for Biosciences, University of Rostock, Albert-Einstein-Str. 3, 18059 Rostock, Germany
| | - Thomas Nägele
- Plant Evolutionary Cell Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Bernhard Grimm
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - Kerstin Kaufmann
- Plant Cell and Molecular Biology, Institute of Biology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - Michael Schroda
- Molecular Biotechnology and Systems Biology, TU Kaiserslautern, Kaiserslautern, Germany
| | - Dario Leister
- Plant Molecular Biology (Botany), Faculty of Biology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Tatjana Kleine
- Plant Molecular Biology (Botany), Faculty of Biology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany.
| |
Collapse
|
6
|
Iron Metabolism in the Disorders of Heme Biosynthesis. Metabolites 2022; 12:metabo12090819. [PMID: 36144223 PMCID: PMC9505951 DOI: 10.3390/metabo12090819] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 01/19/2023] Open
Abstract
Given its remarkable property to easily switch between different oxidative states, iron is essential in countless cellular functions which involve redox reactions. At the same time, uncontrolled interactions between iron and its surrounding milieu may be damaging to cells and tissues. Heme—the iron-chelated form of protoporphyrin IX—is a macrocyclic tetrapyrrole and a coordination complex for diatomic gases, accurately engineered by evolution to exploit the catalytic, oxygen-binding, and oxidoreductive properties of iron while minimizing its damaging effects on tissues. The majority of the body production of heme is ultimately incorporated into hemoglobin within mature erythrocytes; thus, regulation of heme biosynthesis by iron is central in erythropoiesis. Additionally, heme is a cofactor in several metabolic pathways, which can be modulated by iron-dependent signals as well. Impairment in some steps of the pathway of heme biosynthesis is the main pathogenetic mechanism of two groups of diseases collectively known as porphyrias and congenital sideroblastic anemias. In porphyrias, according to the specific enzyme involved, heme precursors accumulate up to the enzyme stop in disease-specific patterns and organs. Therefore, different porphyrias manifest themselves under strikingly different clinical pictures. In congenital sideroblastic anemias, instead, an altered utilization of mitochondrial iron by erythroid precursors leads to mitochondrial iron overload and an accumulation of ring sideroblasts in the bone marrow. In line with the complexity of the processes involved, the role of iron in these conditions is then multifarious. This review aims to summarise the most important lines of evidence concerning the interplay between iron and heme metabolism, as well as the clinical and experimental aspects of the role of iron in inherited conditions of altered heme biosynthesis.
Collapse
|
7
|
Kiening M, Lange N. A Recap of Heme Metabolism towards Understanding Protoporphyrin IX Selectivity in Cancer Cells. Int J Mol Sci 2022; 23:ijms23147974. [PMID: 35887311 PMCID: PMC9324066 DOI: 10.3390/ijms23147974] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 02/04/2023] Open
Abstract
Mitochondria are essential organelles of mammalian cells, often emphasized for their function in energy production, iron metabolism and apoptosis as well as heme synthesis. The heme is an iron-loaded porphyrin behaving as a prosthetic group by its interactions with a wide variety of proteins. These complexes are termed hemoproteins and are usually vital to the whole cell comportment, such as the proteins hemoglobin, myoglobin or cytochromes, but also enzymes such as catalase and peroxidases. The building block of porphyrins is the 5-aminolevulinic acid, whose exogenous administration is able to stimulate the entire heme biosynthesis route. In neoplastic cells, this methodology repeatedly demonstrated an accumulation of the ultimate heme precursor, the fluorescent protoporphyrin IX photosensitizer, rather than in healthy tissues. While manifold players have been proposed, numerous discrepancies between research studies still dispute the mechanisms underlying this selective phenomenon that yet requires intensive investigations. In particular, we wonder what are the respective involvements of enzymes and transporters in protoporphyrin IX accretion. Is this mainly due to a boost in protoporphyrin IX anabolism along with a drop of its catabolism, or are its transporters deregulated? Additionally, can we truly expect to find a universal model to explain this selectivity? In this report, we aim to provide our peers with an overview of the currently known mitochondrial heme metabolism and approaches that could explain, at least partly, the mechanism of protoporphyrin IX selectivity towards cancer cells.
Collapse
Affiliation(s)
| | - Norbert Lange
- Correspondence: ; Tel.: +41-22-379-33-35; Fax: +41-22-379-65-67
| |
Collapse
|
8
|
Schary N, Novak B, Kämper L, Yousf A, Lübbert H. Identification and pharmacological modification of resistance mechanisms to protoporphyrin-mediated photodynamic therapy in human cutaneous squamous cell carcinoma cell lines. Photodiagnosis Photodyn Ther 2022; 39:103004. [PMID: 35811052 DOI: 10.1016/j.pdpdt.2022.103004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/21/2022] [Accepted: 07/06/2022] [Indexed: 10/17/2022]
Abstract
BACKGROUND Photodynamic therapy (PDT) is clinically approved to treat neoplastic skin diseases such as precursors of cutaneous squamous cell carcinoma (cSCC). In PDT, 5-aminolevulinic acid (5-ALA) drives the selective formation of the endogenous photosensitizer protoporphyrin IX (PpIX). Although 5-ALA PDT is clinically highly effective, resistance might occur due to decreased accumulation of PpIX in certain tumors. Such resistance may be caused by any fundamental step of PpIX accumulation: 5-ALA uptake, PpIX synthesis and PpIX efflux. METHODS We investigated PpIX accumulation and photodynamically induced cell death in PDT refractory SCC-13, PDT susceptible A431, and normal human epidermal keratinocytes (NHEK). Expression of genes associated with cellular PpIX kinetics was investigated on mRNA and protein level. PpIX accumulation and cell death upon illumination were pharmacologically manipulated using drugs targeting 5-ALA uptake, PpIX synthesis or efflux. RESULTS The experiments indicate that taurine transporter (SLC6A6) is the major pathway for 5-ALA uptake in cSCC cells, while being less important in NHEK. Downregulation of PpIX synthesis enzymes in SCC-13 was counteracted by methotrexate (MTX) treatment, which restored PpIX formation and cell death. PpIX efflux inhibitors targeting ABC transporters led to significantly increased PpIX accumulation in SCC-13, thereby fully overcoming resistance. CONCLUSIONS The results indicate a conserved threshold for PpIX accumulation with respect to PDT-resistance. Cells showed increased viability after PDT at PpIX concentrations below 1.5 nM. Selective uptake of 5-ALA via taurine transporter SLC6A6 in cutaneous tumor cells is novel but unrelated to resistance. MTX can partially abrogate resistance by PpIX synthesis enzyme induction, while efflux mechanisms via ABC transporters seem the main driving force and promising drug targets.
Collapse
Affiliation(s)
- Nicole Schary
- Department of Animal Physiology, Ruhr-University Bochum, Germany
| | - Ben Novak
- Department of Animal Physiology, Ruhr-University Bochum, Germany; Biofrontera Bioscience GmbH, Leverkusen, Germany.
| | - Laura Kämper
- Department of Animal Physiology, Ruhr-University Bochum, Germany
| | - Aisha Yousf
- Department of Animal Physiology, Ruhr-University Bochum, Germany
| | - Hermann Lübbert
- Department of Animal Physiology, Ruhr-University Bochum, Germany
| |
Collapse
|
9
|
Yien YY, Perfetto M. Regulation of Heme Synthesis by Mitochondrial Homeostasis Proteins. Front Cell Dev Biol 2022; 10:895521. [PMID: 35832791 PMCID: PMC9272004 DOI: 10.3389/fcell.2022.895521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 05/12/2022] [Indexed: 11/19/2022] Open
Abstract
Heme plays a central role in diverse, life-essential processes that range from ubiquitous, housekeeping pathways such as respiration, to highly cell-specific ones such as oxygen transport by hemoglobin. The regulation of heme synthesis and its utilization is highly regulated and cell-specific. In this review, we have attempted to describe how the heme synthesis machinery is regulated by mitochondrial homeostasis as a means of coupling heme synthesis to its utilization and to the metabolic requirements of the cell. We have focused on discussing the regulation of mitochondrial heme synthesis enzymes by housekeeping proteins, transport of heme intermediates, and regulation of heme synthesis by macromolecular complex formation and mitochondrial metabolism. Recently discovered mechanisms are discussed in the context of the model organisms in which they were identified, while more established work is discussed in light of technological advancements.
Collapse
|
10
|
Deferasirox-induced robust and dose-dependent reversal of anemia in a patient with variants in the TRIB2 and ABCB6 genes. Blood Adv 2022; 6:3551-3555. [PMID: 35320338 PMCID: PMC9198926 DOI: 10.1182/bloodadvances.2021006277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 03/02/2022] [Indexed: 11/25/2022] Open
|
11
|
Di Pierro E, Granata F, De Canio M, Rossi M, Ricci A, Marcacci M, De Luca G, Sarno L, Barbieri L, Ventura P, Graziadei G. Recognized and Emerging Features of Erythropoietic and X-Linked Protoporphyria. Diagnostics (Basel) 2022; 12:diagnostics12010151. [PMID: 35054318 PMCID: PMC8775248 DOI: 10.3390/diagnostics12010151] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/31/2021] [Accepted: 01/06/2022] [Indexed: 02/06/2023] Open
Abstract
Erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) are inherited disorders resulting from defects in two different enzymes of the heme biosynthetic pathway, i.e., ferrochelatase (FECH) and delta-aminolevulinic acid synthase-2 (ALAS2), respectively. The ubiquitous FECH catalyzes the insertion of iron into the protoporphyrin ring to generate the final product, heme. After hemoglobinization, FECH can utilize other metals like zinc to bind the remainder of the protoporphyrin molecules, leading to the formation of zinc protoporphyrin. Therefore, FECH deficiency in EPP limits the formation of both heme and zinc protoporphyrin molecules. The erythroid-specific ALAS2 catalyses the synthesis of delta-aminolevulinic acid (ALA), from the union of glycine and succinyl-coenzyme A, in the first step of the pathway in the erythron. In XLP, ALAS2 activity increases, resulting in the amplified formation of ALA, and iron becomes the rate-limiting factor for heme synthesis in the erythroid tissue. Both EPP and XLP lead to the systemic accumulation of protoporphyrin IX (PPIX) in blood, erythrocytes, and tissues causing the major symptom of cutaneous photosensitivity and several other less recognized signs that need to be considered. Although significant advances have been made in our understanding of EPP and XLP in recent years, a complete understanding of the factors governing the variability in clinical expression and the severity (progression) of the disease remains elusive. The present review provides an overview of both well-established facts and the latest findings regarding these rare diseases.
Collapse
Affiliation(s)
- Elena Di Pierro
- Dipartimento di Medicina Interna, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (F.G.); (G.D.L.); (G.G.)
- Correspondence: or ; Tel.: +39-0255036155
| | - Francesca Granata
- Dipartimento di Medicina Interna, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (F.G.); (G.D.L.); (G.G.)
| | - Michele De Canio
- Porphyria and Rare Diseases Centre, San Gallicano Dermatological Institute IRCCS, 00144 Rome, Italy; (M.D.C.); (L.B.)
| | - Mariateresa Rossi
- Department of Dermatology, ASST Spedali Civili di Brescia, University of Brescia, 25123 Brescia, Italy; (M.R.); (L.S.)
| | - Andrea Ricci
- Internal Medicine Unit, Department of Medical and Surgical Science for Children and Adults, University of Modena e Reggio Emilia, 41124 Modena, Italy; (A.R.); (M.M.); (P.V.)
| | - Matteo Marcacci
- Internal Medicine Unit, Department of Medical and Surgical Science for Children and Adults, University of Modena e Reggio Emilia, 41124 Modena, Italy; (A.R.); (M.M.); (P.V.)
| | - Giacomo De Luca
- Dipartimento di Medicina Interna, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (F.G.); (G.D.L.); (G.G.)
| | - Luisa Sarno
- Department of Dermatology, ASST Spedali Civili di Brescia, University of Brescia, 25123 Brescia, Italy; (M.R.); (L.S.)
| | - Luca Barbieri
- Porphyria and Rare Diseases Centre, San Gallicano Dermatological Institute IRCCS, 00144 Rome, Italy; (M.D.C.); (L.B.)
| | - Paolo Ventura
- Internal Medicine Unit, Department of Medical and Surgical Science for Children and Adults, University of Modena e Reggio Emilia, 41124 Modena, Italy; (A.R.); (M.M.); (P.V.)
| | - Giovanna Graziadei
- Dipartimento di Medicina Interna, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (F.G.); (G.D.L.); (G.G.)
| |
Collapse
|
12
|
ABCB6 Polymorphisms are not Overly Represented in Patients with Porphyria. Blood Adv 2021; 6:760-766. [PMID: 34724702 PMCID: PMC8945301 DOI: 10.1182/bloodadvances.2021005484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/14/2021] [Indexed: 11/22/2022] Open
Abstract
ABCB6 is expressed on the cell surface and by multiple organelles, but transport specificity is incompletely understood. In all types of porphyria, ABCB6 polymorphisms are not overrepresented when compared with the overall population.
The Mendelian inheritance pattern of acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria is autosomal dominant, but the clinical phenotype is heterogeneous. Within the general population, penetrance is low, but among first-degree relatives of a symptomatic proband, penetrance is higher. These observations suggest that genetic factors, in addition to mutation of the specific enzyme of the biosynthetic pathway of heme, contribute to the clinical phenotype. Recent studies by others suggested that the genotype of the transporter protein ABCB6 contribute to the porphyria phenotype. Identifying the molecule(s) that are transported by ABCB6 has been problematic and has led to uncertainty with respect to how or if variants/mutants contribute to phenotypic heterogeneity. Knockout mouse models of Abcb6 have not provided a direction for investigation as homozygous knockout animals do not have a discrete phenotype. To address the proposed link between ABC6 genotype and porphyria phenotype, a large cohort of patients with acute hepatic porphyria and erythropoietic protoporphyria was analyzed. Our studies showed that ABCB6 genotype did not correlate with disease severity. Therefore, genotyping of ABCB6 in patients with acute hepatic porphyria and erythropoietic protoporphyria is not warranted.
Collapse
|
13
|
Abstract
ABCB6 plays a crucial role in energy-dependent porphyrin transport, drug resistance, toxic metal resistance, porphyrin biosynthesis, protection against stress, and encoding a blood group system Langereis antigen. However, the mechanism underlying porphyrin transport is still unclear. Here, we determined the cryo-electron microscopy (cryo-EM) structures of nanodisc-reconstituted human ABCB6 trapped in an apo-state and an ATP-bound state at resolutions of 3.6 and 3.5 Å, respectively. Our structures reveal a unique loop in the transmembrane domain (TMD) of ABCB6, which divides the TMD into two cavities. It restrains the access of substrates in the inward-facing state and is removed by ATP-driven conformational change. No ligand cavities were observed in the nucleotide-bound state, indicating a state following substrate release but prior to ATP hydrolysis. Structural analyses and functional characterizations suggest an "ATP-switch" model and further reveal the conformational changes of the substrate-binding pockets triggered by the ATP-driven regulation.
Collapse
|
14
|
Meli A, McAndrew M, Frary A, Rehnstrom K, Stevens-Hernandez CJ, Flatt JF, Griffiths A, Stefanucci L, Astle W, Anand R, New HV, Bruce LJ, Cardigan R. Familial pseudohyperkalemia induces significantly higher levels of extracellular potassium in early storage of red cell concentrates without affecting other standard measures of quality: A case control and allele frequency study. Transfusion 2021; 61:2439-2449. [PMID: 33960432 DOI: 10.1111/trf.16440] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/15/2021] [Accepted: 04/03/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND Familial pseudohyperkalemia (FP) is characterized by an increased rate of potassium leakage in refrigerated red cells and is associated with the minor allele of the single nucleotide polymorphism rs148211042 (R723Q) in the ABCB6 gene. The study aims were to obtain the minor allele frequencies of ABCB6 variants and to measure supernatant potassium accumulation, and other red cell storage parameters, in red cell concentrates (RCC) from carriers of variant rs148211042 under standard blood bank conditions. STUDY DESIGN Whole blood units were collected from 6 FP individuals and 11 controls and processed into RCC in additive solution. RCC were sampled and tested over cold storage for full blood count, extracellular potassium, glucose, lactate, microvesicle release, deformability, hemolysis, pH, adenosine triphosphate, and 2,3-diphosphoglycerate. RESULTS Screening of genotyped cohorts identified that variant rs148211042 is present in 1 in 394 British citizens of European ancestry. FP RCC had significantly higher supernatant potassium at all time points from day 3 onwards (p < .001) and higher mean cell volume (p = .032) than controls. The initial rate of potassium release was higher in FP RCC; supernatant potassium reached 46.0 (23.8-57.6) mmol/L (mean [range]) by day 5, increasing to 68.9 (58.8-73.7) mmol/L by day 35. Other quality parameters were not significantly different between FP RCC and controls. CONCLUSION These data suggest that if a blood donor has FP, reducing the RCC shelf-life to 5 days may be insufficient to reduce the risk of hyperkalemia in clinical scenarios such as neonatal large volume transfusion.
Collapse
Affiliation(s)
- Athinoula Meli
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK
| | - Margaret McAndrew
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK
| | - Amy Frary
- Department of Haematology, University of Cambridge, Cambridge, UK.,National Institute for Health Research BioResource-Rare Diseases, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Karola Rehnstrom
- Department of Haematology, University of Cambridge, Cambridge, UK.,National Institute for Health Research BioResource-Rare Diseases, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Christian J Stevens-Hernandez
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK.,Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, UK.,School of Biochemistry, University of Bristol, Bristol, UK
| | - Joanna F Flatt
- Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, UK
| | | | - Luca Stefanucci
- Department of Haematology, University of Cambridge, Cambridge, UK.,British Heart Foundation Centre of Excellence, Cambridge, UK
| | - William Astle
- Medical Research Council Biostatistics Unit, Cambridge Institute of Public Health, Cambridge, UK.,MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
| | - Rekha Anand
- Clinical Directorate, NHS Blood and Transplant, Birmingham, UK
| | - Helen V New
- Clinical Directorate, NHS Blood and Transplant, London, UK.,Centre for Haematology, Imperial College London, London, UK
| | - Lesley J Bruce
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK.,Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, UK
| | - Rebecca Cardigan
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK.,Department of Haematology, University of Cambridge, Cambridge, UK
| |
Collapse
|
15
|
Li P, Maitra D, Kuo N, Bonkovsky HL, Omary MB. Geographic prevalence variation and phenotype penetrance in porphyria: insights from a Chinese population database. Blood Adv 2021; 5:12-15. [PMID: 33570620 PMCID: PMC7805317 DOI: 10.1182/bloodadvances.2020003150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/10/2020] [Indexed: 11/20/2022] Open
Affiliation(s)
- Pei Li
- Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ; and
| | - Dhiman Maitra
- Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ; and
| | - Ning Kuo
- Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ; and
| | - Herbert L Bonkovsky
- Gastroenterology & Hepatology and Molecular Medicine & Translational Science, Wake Forest University School of Medicine/NC Baptist Hospital, Winston-Salem, NC
| | - M Bishr Omary
- Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ; and
| |
Collapse
|
16
|
Szakacs G, Abele R. An inventory of lysosomal ABC transporters. FEBS Lett 2020; 594:3965-3985. [DOI: 10.1002/1873-3468.13967] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/23/2020] [Accepted: 10/15/2020] [Indexed: 12/13/2022]
Affiliation(s)
- Gergely Szakacs
- Institute of Enzymology Research Centre of Natural Sciences Eötvös Loránd Research Network Budapest Hungary
- Institute of Cancer Research Medical University of Vienna Vienna Austria
| | - Rupert Abele
- Institute of Biochemistry Goethe‐University Frankfurt am Main Frankfurt am Main Germany
| |
Collapse
|
17
|
de Oliveira Neves AC, Galván I. Models for human porphyrias: Have animals in the wild been overlooked?: Some birds and mammals accumulate significant amounts of porphyrins in the body without showing the injurious symptoms observed in human porphyrias. Bioessays 2020; 42:e2000155. [PMID: 33155299 DOI: 10.1002/bies.202000155] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/27/2020] [Indexed: 11/06/2022]
Abstract
Humans accumulate porphyrins in the body mostly during the course of porphyrias, diseases caused by defects in the enzymes of the heme biosynthesis pathway and that produce acute attacks, skin lesions and liver cancer. In contrast, some wild mammals and birds are adapted to accumulate porphyrins without injurious consequences. Here we propose viewing such physiological adaptations as potential solutions to human porphyrias, and suggest certain wild animals as models. Given the enzymatic activity and/or the patterns of porphyrin excretion and accumulation, the fox squirrel, the great bustard and the Eurasian eagle owl may constitute overlooked models for different porphyrias. The Harderian gland of rodents, where large amounts of porphyrins are synthesized, presents an underexplored potential for understanding the carcinogenic/toxic effect of porphyrin accumulation. Investigating how these animals avoid porphyrin pathogenicity may complement the use of laboratory models for porphyrias and provide new insights into the treatment of these disorders.
Collapse
Affiliation(s)
| | - Ismael Galván
- Department of Evolutionary Ecology, Doñana Biological Station, CSIC, Sevilla, 41092, Spain
| |
Collapse
|
18
|
Ma L, Tian Y, Peng C, Zhang Y, Zhang S. Recent advances in the epidemiology and genetics of acute intermittent porphyria. Intractable Rare Dis Res 2020; 9:196-204. [PMID: 33139978 PMCID: PMC7586877 DOI: 10.5582/irdr.2020.03082] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/07/2020] [Accepted: 08/11/2020] [Indexed: 02/07/2023] Open
Abstract
Acute intermittent porphyria (AIP) is a dominant inherited disorder with a low penetrance that is caused by mutations in the gene coding for hydroxymethylbilane synthase (HMBS). Information about the epidemiology and molecular genetic features of this rare disorder is crucial to clinical research, and particularly to the evaluation of new treatments. Variations in the prevalence and penetrance of AIP in various studies may due to the different inclusion criteria and methods of assessment. Here, the prevalence and penetrance of AIP are analyzed systematically, and the genetic traits of different populations and findings regarding the genotype-phenotype correlation are summarized. In addition, quite a few studies have indicated that AIP susceptibility was affected by other factors, such as modifying genes. Findings regarding possible modifying genes are documented here, helping to reveal the pathogenesis of and treatments for AIP. The status of research on AIP in China reveals the lack of epidemiological and genetic studies of the Chinese population, a situation that needs to be promptly remedied.
Collapse
Affiliation(s)
- Liyan Ma
- Department of Endocrinology, The second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yu Tian
- Department of Endocrinology, The second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Chenxing Peng
- Department of Endocrinology, The second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yiran Zhang
- School of First Clinical Medical College, Southern Medical University, Guangzhou, Guangdong, China
| | - Songyun Zhang
- Department of Endocrinology, The second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| |
Collapse
|
19
|
Wang C, Cao C, Wang N, Wang X, Wang X, Zhang XC. Cryo-electron microscopy structure of human ABCB6 transporter. Protein Sci 2020; 29:2363-2374. [PMID: 33007128 DOI: 10.1002/pro.3960] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 01/12/2023]
Abstract
Human ATP-binding cassette transporter 6 of subfamily B (ABCB6) is an ABC transporter involved in the translocation toxic metals and anti-cancer drugs. Using cryo-electron microscopy, we determined the molecular structure of full-length ABCB6 in an apo state. The structure of ABCB6 unravels the architecture of a full-length ABCB transporter that harbors two N-terminal transmembrane domains which is indispensable for its ATPase activity in our in vitro assay. A slit-like substrate binding pocket of ABCB6 may accommodate the planar shape of porphyrins, and the existence of a secondary cavity near the mitochondrial intermembrane space side would further facilitate substrate release. Furthermore, the ATPase activity of ABCB6 stimulated with a variety of porphyrin substrates showed different profiles in the presence of glutathione (GSH), suggesting the action of a distinct substrate translocation mechanism depending on the use of GSH as a cofactor.
Collapse
Affiliation(s)
- Chunyu Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Can Cao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Nan Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xiangxi Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xianping Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xuejun C Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
20
|
Systematic analysis of the ABC transporter family in hepatocellular carcinoma reveals the importance of ABCB6 in regulating ferroptosis. Life Sci 2020; 257:118131. [PMID: 32710948 DOI: 10.1016/j.lfs.2020.118131] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 07/11/2020] [Accepted: 07/18/2020] [Indexed: 02/07/2023]
Abstract
AIMS ATP-binding cassette (ABC) transporters constitute one of the largest families of membrane proteins in most organisms; however, their functions in hepatocellular carcinoma (HCC) remain unclear. MAIN METHODS A set of bioinformatic tools was integrated to analyze the expression of 49 members of the ABC transporter family. The function of members which had prognostic values in HCC was explored by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. KEY FINDINGS ABCA8 and ABCA9 were significantly down-regulated in HCC. Prognostic analysis indicated that HCC patients with low expression of ABCA8 and ABCA9 had significantly shorter survival time. On the contrary, ABCB6 was over-expressed in the disease and high expression of ABCB6 was associated with worse prognosis. Co-expression analysis, and subsequently GO and KEGG analysis indicated that ABCA8 and ABCA9 might participate in the catabolic processes of multiple metabolites, while ABCB6 might regulate ferroptosis. SIGNIFICANCE This study reveals a previously unrecognized function of ABCB6 in HCC, by regulating ferroptosis. Since ABCB6 is over-expressed in HCC and ferroptosis involves in cancer development, ABCB6 might be a promising therapeutic target in the disease.
Collapse
|
21
|
Kumar V, Santhosh Kumar TR, Kartha CC. Mitochondrial membrane transporters and metabolic switch in heart failure. Heart Fail Rev 2020; 24:255-267. [PMID: 30535838 DOI: 10.1007/s10741-018-9756-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mitochondrial dysfunction is widely recognized as a major factor for the progression of cardiac failure. Mitochondrial uptake of metabolic substrates and their utilization for ATP synthesis, electron transport chain activity, reactive oxygen species levels, ion homeostasis, mitochondrial biogenesis, and dynamics as well as levels of reactive oxygen species in the mitochondria are key factors which regulate mitochondrial function in the normal heart. Alterations in these functions contribute to adverse outcomes in heart failure. Iron imbalance and oxidative stress are also major factors for the evolution of cardiac hypertrophy, heart failure, and aging-associated pathological changes in the heart. Mitochondrial ATP-binding cassette (ABC) transporters have a key role in regulating iron metabolism and maintenance of redox status in cells. Deficiency of mitochondrial ABC transporters is associated with an impaired mitochondrial electron transport chain complex activity, iron overload, and increased levels of reactive oxygen species, all of which can result in mitochondrial dysfunction. In this review, we discuss the role of mitochondrial ABC transporters in mitochondrial metabolism and metabolic switch, alterations in the functioning of ABC transporters in heart failure, and mitochondrial ABC transporters as possible targets for therapeutic intervention in cardiac failure.
Collapse
Affiliation(s)
- Vikas Kumar
- Cardiovascular Diseases and Diabetes Biology group, Rajiv Gandhi Centre for Biotechnology (RGCB), Poojappura, Thycaud Post, Trivandrum, Kerala, 695014, India.,Graduate Studies, Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
| | - T R Santhosh Kumar
- Cardiovascular Diseases and Diabetes Biology group, Rajiv Gandhi Centre for Biotechnology (RGCB), Poojappura, Thycaud Post, Trivandrum, Kerala, 695014, India.,Graduate Studies, Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India.,Cancer Research Program, Rajiv Gandhi Centre for Biotechnology (RGCB), Trivandrum, Kerala, India
| | - C C Kartha
- Cardiovascular Diseases and Diabetes Biology group, Rajiv Gandhi Centre for Biotechnology (RGCB), Poojappura, Thycaud Post, Trivandrum, Kerala, 695014, India.
| |
Collapse
|
22
|
Cunningham CN, Rutter J. 20,000 picometers under the OMM: diving into the vastness of mitochondrial metabolite transport. EMBO Rep 2020; 21:e50071. [PMID: 32329174 DOI: 10.15252/embr.202050071] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/17/2020] [Accepted: 03/27/2020] [Indexed: 12/14/2022] Open
Abstract
The metabolic compartmentalization enabled by mitochondria is key feature of many cellular processes such as energy conversion to ATP production, redox balance, and the biosynthesis of heme, urea, nucleotides, lipids, and others. For a majority of these functions, metabolites need to be transported across the impermeable inner mitochondrial membrane by dedicated carrier proteins. Here, we examine the substrates, structural features, and human health implications of four mitochondrial metabolite carrier families: the SLC25A family, the mitochondrial ABCB transporters, the mitochondrial pyruvate carrier (MPC), and the sideroflexin proteins.
Collapse
Affiliation(s)
- Corey N Cunningham
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Jared Rutter
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA.,Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT, USA
| |
Collapse
|
23
|
Swenson SA, Moore CM, Marcero JR, Medlock AE, Reddi AR, Khalimonchuk O. From Synthesis to Utilization: The Ins and Outs of Mitochondrial Heme. Cells 2020; 9:E579. [PMID: 32121449 PMCID: PMC7140478 DOI: 10.3390/cells9030579] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/19/2020] [Accepted: 02/23/2020] [Indexed: 12/14/2022] Open
Abstract
Heme is a ubiquitous and essential iron containing metallo-organic cofactor required for virtually all aerobic life. Heme synthesis is initiated and completed in mitochondria, followed by certain covalent modifications and/or its delivery to apo-hemoproteins residing throughout the cell. While the biochemical aspects of heme biosynthetic reactions are well understood, the trafficking of newly synthesized heme-a highly reactive and inherently toxic compound-and its subsequent delivery to target proteins remain far from clear. In this review, we summarize current knowledge about heme biosynthesis and trafficking within and outside of the mitochondria.
Collapse
Affiliation(s)
| | - Courtney M. Moore
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Jason R. Marcero
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA;
| | - Amy E. Medlock
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA;
- Augusta University/University of Georgia Medical Partnership, Athens, GA 30602, USA
| | - Amit R. Reddi
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA;
- Parker Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, USA;
- Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA
- Fred and Pamela Buffett Cancer Center, Omaha, NE 68105, USA
| |
Collapse
|
24
|
Gose T, Shafi T, Fukuda Y, Das S, Wang Y, Allcock A, Gavan McHarg A, Lynch J, Chen T, Tamai I, Shelat A, Ford RC, Schuetz JD. ABCG2 requires a single aromatic amino acid to "clamp" substrates and inhibitors into the binding pocket. FASEB J 2020; 34:4890-4903. [PMID: 32067270 DOI: 10.1096/fj.201902338rr] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/26/2019] [Accepted: 01/16/2020] [Indexed: 12/12/2022]
Abstract
ATP-binding cassette sub-family G member 2 (ABCG2) is a homodimeric ATP-binding cassette (ABC) transporter that not only has a key role in helping cancer cells to evade the cytotoxic effects of chemotherapy, but also in protecting organisms from multiple xeno- and endobiotics. Structural studies indicate that substrate and inhibitor (ligands) binding to ABCG2 can be differentiated quantitatively by the number of amino acid contacts, with inhibitors displaying more contacts. Although binding is the obligate initial step in the transport cycle, there is no empirical evidence for one amino acid being primarily responsible for ligand binding. By mutagenesis and biochemical studies, we demonstrated that the phylogenetically conserved amino acid residue, F439, was critical for both transport and the binding of multiple substrates and inhibitors. Structural modeling implied that the π-π interactions from each F439 monomer mediated the binding of a surprisingly diverse array of structurally unrelated substrates and inhibitors and that this symmetrical π-π interaction "clamps" the ligand into the binding pocket. Key molecular features of diverse ABCG2 ligands using the π-π clamp along with structural studies created a pharmacophore model. These novel findings have important therapeutic implications because key properties of ligands interacting with ABCG2 have been disovered. Furthermore, mechanistic insights have been revealed by demonstrating that for ABCG2 a single amino acid is essential for engaging and initiating transport of multiple drugs and xenobiotics.
Collapse
Affiliation(s)
- Tomoka Gose
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Talha Shafi
- School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Yu Fukuda
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Sourav Das
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Yao Wang
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Alice Allcock
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Ailsa Gavan McHarg
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - John Lynch
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Ikumi Tamai
- Department of Pharmaceutical Sciences, Kanazawa University, Kanazawa, Japan
| | - Anang Shelat
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Robert C Ford
- School of Biological Sciences, The University of Manchester, Manchester, UK
| | - John D Schuetz
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| |
Collapse
|
25
|
Linker Domains: Why ABC Transporters 'Live in Fragments no Longer'. Trends Biochem Sci 2019; 45:137-148. [PMID: 31839525 DOI: 10.1016/j.tibs.2019.11.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/30/2019] [Accepted: 11/13/2019] [Indexed: 11/20/2022]
Abstract
ATP-binding cassette (ABC) transporters are membrane proteins present in all kingdoms of life. We have considered the disordered region that connects the N- and C-terminal halves in many eukaryotic ABC transporters, allowing all four consensus functional domains to be linked. The recent availability of structures of ABC transporters containing linker regions has allowed us to identify the start and end points of the connectors as well as hinting at their localisation. We address questions such as: Where did the linker regions come from? Why do some ABC transporters have connectors and others not? What are the rules and roles of the linker regions? What are the consequences of mutations in these connector regions for disease in humans?
Collapse
|
26
|
Rakvács Z, Kucsma N, Gera M, Igriczi B, Kiss K, Barna J, Kovács D, Vellai T, Bencs L, Reisecker JM, Szoboszlai N, Szakács G. The human ABCB6 protein is the functional homologue of HMT-1 proteins mediating cadmium detoxification. Cell Mol Life Sci 2019; 76:4131-4144. [PMID: 31053883 PMCID: PMC6785578 DOI: 10.1007/s00018-019-03105-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 12/31/2022]
Abstract
ABCB6 belongs to the family of ATP-binding cassette (ABC) transporters, which transport various molecules across extra- and intra-cellular membranes, bearing significant impact on human disease and pharmacology. Although mutations in the ABCB6 gene have been linked to a variety of pathophysiological conditions ranging from transfusion incompatibility to pigmentation defects, its precise cellular localization and function is not understood. In particular, the intracellular localization of ABCB6 has been a matter of debate, with conflicting reports suggesting mitochondrial or endolysosomal expression. ABCB6 shows significant sequence identity to HMT-1 (heavy metal tolerance factor 1) proteins, whose evolutionarily conserved role is to confer tolerance to heavy metals through the intracellular sequestration of metal complexes. Here, we show that the cadmium-sensitive phenotype of Schizosaccharomyces pombe and Caenorhabditis elegans strains defective for HMT-1 is rescued by the human ABCB6 protein. Overexpression of ABCB6 conferred tolerance to cadmium and As(III) (As2O3), but not to As(V) (Na2HAsO4), Sb(V), Hg(II), or Zn(II). Inactivating mutations of ABCB6 abolished vacuolar sequestration of cadmium, effectively suppressing the cadmium tolerance phenotype. Modulation of ABCB6 expression levels in human glioblastoma cells resulted in a concomitant change in cadmium sensitivity. Our findings reveal ABCB6 as a functional homologue of the HMT-1 proteins, linking endolysosomal ABCB6 to the highly conserved mechanism of intracellular cadmium detoxification.
Collapse
Affiliation(s)
- Zsófia Rakvács
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Nóra Kucsma
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Melinda Gera
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Barbara Igriczi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Katalin Kiss
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - János Barna
- Department of Genetics, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - Dániel Kovács
- Department of Genetics, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - Tibor Vellai
- Department of Genetics, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - László Bencs
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Budapest, Hungary
| | - Johannes M Reisecker
- Department of Medicine I, Comprehensive Cancer Center, Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Norbert Szoboszlai
- Department of Analytical Chemistry, Institute of Chemistry, Eötvös Loránd University, Budapest, Hungary
| | - Gergely Szakács
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary.
- Department of Medicine I, Comprehensive Cancer Center, Institute of Cancer Research, Medical University of Vienna, Vienna, Austria.
| |
Collapse
|
27
|
Wang P, Sachar M, Lu J, Shehu AI, Zhu J, Chen J, Liu K, Anderson KE, Xie W, Gonzalez FJ, Klaassen CD, Ma X. The essential role of the transporter ABCG2 in the pathophysiology of erythropoietic protoporphyria. SCIENCE ADVANCES 2019; 5:eaaw6127. [PMID: 31555729 PMCID: PMC6750912 DOI: 10.1126/sciadv.aaw6127] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 08/23/2019] [Indexed: 06/10/2023]
Abstract
Erythropoietic protoporphyria (EPP) is an inherited disease caused by loss-of-function mutations of ferrochelatase, an enzyme in the heme biosynthesis pathway that converts protoporphyrin IX (PPIX) into heme. PPIX accumulation in patients with EPP leads to phototoxicity and hepatotoxicity, and there is no cure. Here, we demonstrated that the PPIX efflux transporter ABCG2 (also called BCRP) determines EPP-associated phototoxicity and hepatotoxicity. We found that ABCG2 deficiency decreases PPIX distribution to the skin and therefore prevents EPP-associated phototoxicity. We also found that ABCG2 deficiency protects against EPP-associated hepatotoxicity by modulating PPIX distribution, metabolism, and excretion. In summary, our work has uncovered an essential role of ABCG2 in the pathophysiology of EPP, which suggests the potential for novel strategies in the development of therapy for EPP.
Collapse
Affiliation(s)
- Pengcheng Wang
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Madhav Sachar
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Jie Lu
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Amina I. Shehu
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Junjie Zhu
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Jing Chen
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Ke Liu
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Karl E. Anderson
- Porphyria Laboratory and Center, Departments of Preventive Medicine and Community Health, and Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Wen Xie
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Frank J. Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Curtis D. Klaassen
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Xiaochao Ma
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| |
Collapse
|
28
|
McNicholas K, MacGregor MN, Gleadle JM. In order for the light to shine so brightly, the darkness must be present-why do cancers fluoresce with 5-aminolaevulinic acid? Br J Cancer 2019; 121:631-639. [PMID: 31406300 PMCID: PMC6889380 DOI: 10.1038/s41416-019-0516-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 05/23/2019] [Accepted: 06/14/2019] [Indexed: 02/07/2023] Open
Abstract
Photodynamic diagnosis and therapy have emerged as a promising tool in oncology. Using the visible fluorescence from photosensitisers excited by light, clinicians can both identify and treat tumour cells in situ. Protoporphyrin IX, produced in the penultimate step of the haem synthesis pathway, is a naturally occurring photosensitiser that visibly fluoresces when exposed to light. This fluorescence is enhanced considerably by the exogenous administration of the substrate 5-aminolaevulinic acid (5-ALA). Significantly, 5-ALA-induced protoporphyrin IX accumulates preferentially in cancer cells, and this enhanced fluorescence has been harnessed for the detection and photodynamic treatment of brain, skin and bladder tumours. However, surprisingly little is known about the mechanistic basis for this phenomenon. This review focuses on alterations in the haem pathway in cancer and considers the unique features of the cancer environment, such as altered glucose metabolism, oncogenic mutations and hypoxia, and their potential effects on the protoporphyrin IX phenomenon. A better understanding of why cancer cells fluoresce with 5-ALA would improve its use in cancer diagnostics and therapies.
Collapse
Affiliation(s)
- Kym McNicholas
- Department of Renal Medicine, Flinders Medical Centre, Flinders University, Bedford Park, SA, 5042, Australia. .,College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia.
| | - Melanie N MacGregor
- Future Industries Institute, School of Engineering, University of South Australia, Adelaide, SA, 5095, Australia
| | - Jonathan M Gleadle
- Department of Renal Medicine, Flinders Medical Centre, Flinders University, Bedford Park, SA, 5042, Australia.,College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia
| |
Collapse
|
29
|
Maitra D, Bragazzi Cunha J, Elenbaas JS, Bonkovsky HL, Shavit JA, Omary MB. Porphyrin-Induced Protein Oxidation and Aggregation as a Mechanism of Porphyria-Associated Cell Injury. Cell Mol Gastroenterol Hepatol 2019; 8:535-548. [PMID: 31233899 PMCID: PMC6820234 DOI: 10.1016/j.jcmgh.2019.06.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/14/2019] [Accepted: 06/14/2019] [Indexed: 12/12/2022]
Abstract
Genetic porphyrias comprise eight diseases caused by defects in the heme biosynthetic pathway that lead to accumulation of heme precursors. Consequences of porphyria include photosensitivity, liver damage and increased risk of hepatocellular carcinoma, and neurovisceral involvement, including seizures. Fluorescent porphyrins that include protoporphyrin-IX, uroporphyrin and coproporphyrin, are photo-reactive; they absorb light energy and are excited to high-energy singlet and triplet states. Decay of the porphyrin excited to ground state releases energy and generates singlet oxygen. Porphyrin-induced oxidative stress is thought to be the major mechanism of porphyrin-mediated tissue damage. Although this explains the acute photosensitivity in most porphyrias, light-induced porphyrin-mediated oxidative stress does not account for the effect of porphyrins on internal organs. Recent findings demonstrate the unique role of fluorescent porphyrins in causing subcellular compartment-selective protein aggregation. Porphyrin-mediated protein aggregation associates with nuclear deformation, cytoplasmic vacuole formation and endoplasmic reticulum dilation. Porphyrin-triggered proteotoxicity is compounded by inhibition of the proteasome due to aggregation of some of its subunits. The ensuing disruption in proteostasis also manifests in cell cycle arrest coupled with aggregation of cell proliferation-related proteins, including PCNA, cdk4 and cyclin B1. Porphyrins bind to native proteins and, in presence of light and oxygen, oxidize several amino acids, particularly methionine. Noncovalent interaction of oxidized proteins with porphyrins leads to formation of protein aggregates. In internal organs, particularly the liver, light-independent porphyrin-mediated protein aggregation occurs after secondary triggers of oxidative stress. Thus, porphyrin-induced protein aggregation provides a novel mechanism for external and internal tissue damage in porphyrias that involve fluorescent porphyrin accumulation.
Collapse
Affiliation(s)
- Dhiman Maitra
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan.
| | - Juliana Bragazzi Cunha
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Jared S Elenbaas
- Medical Scientist Training Program, Washington University in St. Louis, St. Louis, Missouri
| | - Herbert L Bonkovsky
- Gastroenterology & Hepatology, and Molecular Medicine & Translational Science, Wake Forest University School of Medicine/NC Baptist Hospital, Winston-Salem, North Carolina
| | - Jordan A Shavit
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, University of Michigan Medical School, Ann Arbor, Michigan
| | - M Bishr Omary
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan; Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan; Cell Biology, Faculty of Science and Technology, Åbo Akademi University, Turku, Finland
| |
Collapse
|
30
|
Abstract
The transport of specific molecules across lipid membranes is an essential function of all living organisms. The processes are usually mediated by specific transporters. One of the largest transporter families is the ATP-binding cassette (ABC) family. More than 40 ABC transporters have been identified in human, which are divided into 7 subfamilies (ABCA to ABCG) based on their gene structure, amino acid sequence, domain organization, and phylogenetic analysis. Of them, at least 11 ABC transporters including P-glycoprotein (P-GP/ABCB1), multidrug resistance-associated proteins (MRPs/ABCCs), and breast cancer resistance protein (BCRP/ABCG2) are involved in multidrug resistance (MDR) development. These ABC transporters are expressed in various tissues such as the liver, intestine, kidney, and brain, playing important roles in absorption, distribution, and excretion of drugs. Some ABC transporters are also involved in diverse cellular processes such as maintenance of osmotic homeostasis, antigen processing, cell division, immunity, cholesterol, and lipid trafficking. Several human diseases such as cystic fibrosis, sitosterolemia, Tangier disease, intrahepatic cholestasis, and retinal degeneration are associated with mutations in corresponding transporters. This chapter will describe function and expression of several ABC transporters (such as P-GP, BCRP, and MRPs), their substrates and inhibitors, as well as their clinical significance.
Collapse
Affiliation(s)
- Xiaodong Liu
- China Pharmaceutical University, Nanjing, China.
| |
Collapse
|
31
|
Bergam P, Reisecker JM, Rakvács Z, Kucsma N, Raposo G, Szakacs G, van Niel G. ABCB6 Resides in Melanosomes and Regulates Early Steps of Melanogenesis Required for PMEL Amyloid Matrix Formation. J Mol Biol 2018; 430:3802-3818. [PMID: 29940187 DOI: 10.1016/j.jmb.2018.06.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 06/11/2018] [Accepted: 06/15/2018] [Indexed: 01/08/2023]
Abstract
Genetically inheritable pigmentation defects provide a unique opportunity to reveal the function of proteins contributing to melanogenesis. Dyschromatosis universalis hereditaria (DUH) is a rare pigmentary genodermatosis associated with mutations in the ABCB6 gene. Here we use optical and electron microscopy imaging combined with biochemical tools to investigate the localization and function of ABCB6 in pigment cells. We show that ABCB6 localizes to the membrane of early melanosomes and lysosomes of the human melanocytic cell line MNT-1. Depletion of ABCB6 by siRNA impaired PMEL amyloidogenesis in early melanosomes and induced aberrant accumulation of multilamellar aggregates in pigmented melanosomes. PMEL fibril formation and normal maturation of pigmented melanosomes could be restored by the overexpression of wild-type ABCB6 but not by variants containing an inactivating catalytic mutation (K629M) or the G579E DUH mutation. In line with the impairment of PMEL matrix formation in the absence of ABCB6, morphological analysis of the retinal pigment epithelium of ABCB6 knockout mice revealed a significant decrease of melanosome numbers. Our study extends the localization of ABCB6 to melanosomes, suggesting a potential link between the function of ABCB6 and the etiology of DUH to amyloid formation in pigment cells.
Collapse
Affiliation(s)
- Ptissam Bergam
- Institut Curie, PSL Research University, UMR144, Centre de Recherche, 26 rue d'Ulm, 75231 Paris, France; Centre National de la Recherche Scientifique, UMR144, Paris F-75248, France; Cell and Tissue Imaging Core Facility PICT-IBiSA, Institut Curie, Paris, France
| | | | - Zsófia Rakvács
- Institute of Enzymology, Research Centre for National Sciences, HAS, Budapest 1117, Hungary
| | - Nóra Kucsma
- Institute of Enzymology, Research Centre for National Sciences, HAS, Budapest 1117, Hungary
| | - Graça Raposo
- Institut Curie, PSL Research University, UMR144, Centre de Recherche, 26 rue d'Ulm, 75231 Paris, France; Centre National de la Recherche Scientifique, UMR144, Paris F-75248, France; Cell and Tissue Imaging Core Facility PICT-IBiSA, Institut Curie, Paris, France
| | - Gergely Szakacs
- Institute of Cancer Research, Medical University Vienna, Vienna, Austria; Institute of Enzymology, Research Centre for National Sciences, HAS, Budapest 1117, Hungary.
| | - Guillaume van Niel
- Institut Curie, PSL Research University, UMR144, Centre de Recherche, 26 rue d'Ulm, 75231 Paris, France; Centre National de la Recherche Scientifique, UMR144, Paris F-75248, France; Cell and Tissue Imaging Core Facility PICT-IBiSA, Institut Curie, Paris, France; Center for Psychiatry and Neuroscience, Hopital Saint-Anne, Université Descartes, INSERM U894, Paris, France.
| |
Collapse
|
32
|
Erythrocytes lacking the Langereis blood group protein ABCB6 are resistant to the malaria parasite Plasmodium falciparum. Commun Biol 2018; 1:45. [PMID: 30271928 PMCID: PMC6123700 DOI: 10.1038/s42003-018-0046-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 04/04/2018] [Indexed: 12/17/2022] Open
Abstract
The ATP-binding cassette transporter ABCB6 was recently discovered to encode the Langereis (Lan) blood group antigen. Lan null individuals are asymptomatic, and the function of ABCB6 in mature erythrocytes is not understood. Here, we assessed ABCB6 as a host factor for Plasmodium falciparum malaria parasites during erythrocyte invasion. We show that Lan null erythrocytes are highly resistant to invasion by P. falciparum, in a strain-transcendent manner. Although both Lan null and Jr(a-) erythrocytes harbor excess porphyrin, only Lan null erythrocytes exhibit a P. falciparum invasion defect. Further, the zoonotic parasite P. knowlesi invades Lan null and control cells with similar efficiency, suggesting that ABCB6 may mediate P. falciparum invasion through species-specific molecular interactions. Using tandem mass tag-based proteomics, we find that the only consistent difference in membrane proteins between Lan null and control cells is absence of ABCB6. Our results demonstrate that a newly identified naturally occurring blood group variant is associated with resistance to Plasmodium falciparum. Elizabeth Egan and colleagues demonstrate that host ATP binding cassette transporter ABCB6, which encodes the Langereis blood group antigen, promotes erythrocyte invasion by the malaria parasite Plasmodium falciparum. This study suggests that asymptomatic Langereis null individuals may be better protected from malaria.
Collapse
|
33
|
Boswell-Casteel RC, Fukuda Y, Schuetz JD. ABCB6, an ABC Transporter Impacting Drug Response and Disease. AAPS JOURNAL 2017; 20:8. [PMID: 29192381 DOI: 10.1208/s12248-017-0165-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 10/16/2017] [Indexed: 12/11/2022]
Abstract
Recent findings have discovered how insufficiency of ATP-binding cassette (ABC) transporter, ABCB6, can negatively impact human health. These advances were made possible by, first, finding that ABCB6 deficiency was the genetic basis for some severe transfusion reactions and by, second, determining that functionally impaired ABCB6 variants enhanced the severity of porphyria, i.e., diseases associated with defects in heme synthesis. ABCB6 is a broad-spectrum porphyrin transporter that is capable of both exporting and importing heme and its precursors across the plasma membrane and outer mitochondrial membrane, respectively. Biochemical studies have demonstrated that while ABCB6 influences the antioxidant system by reducing the levels of reactive oxygen species, the exact mechanism is currently unknown, though effects on heme synthesis are likely. Furthermore, it is unknown what biochemical or cellular signals determine where ABCB6 localizes in the cell. This review highlights the major recent findings on ABCB6 and focuses on details of its structure, mechanism, transport, contributions to cellular stress, and current clinical implications.
Collapse
Affiliation(s)
- Rebba C Boswell-Casteel
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee, 38105-2794, USA
| | - Yu Fukuda
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee, 38105-2794, USA
| | - John D Schuetz
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee, 38105-2794, USA.
| |
Collapse
|
34
|
|