1
|
Zhang W, Liu QY, Haqqani AS, Liu Z, Sodja C, Leclerc S, Baumann E, Delaney CE, Brunette E, Stanimirovic DB. Differential Expression of ABC Transporter Genes in Brain Vessels vs. Peripheral Tissues and Vessels from Human, Mouse and Rat. Pharmaceutics 2023; 15:pharmaceutics15051563. [PMID: 37242805 DOI: 10.3390/pharmaceutics15051563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/13/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND ATP-binding cassette (ABC) transporters comprise a superfamily of genes encoding membrane proteins with nucleotide-binding domains (NBD). These transporters, including drug efflux across the blood-brain barrier (BBB), carry a variety of substrates through plasma membranes against substrate gradients, fueled by hydrolyzing ATP. The expression patterns/enrichment of ABC transporter genes in brain microvessels compared to peripheral vessels and tissues are largely uncharacterized. METHODS In this study, the expression patterns of ABC transporter genes in brain microvessels, peripheral tissues (lung, liver and spleen) and lung vessels were investigated using RNA-seq and WesTM analyses in three species: human, mouse and rat. RESULTS The study demonstrated that ABC drug efflux transporter genes (including ABCB1, ABCG2, ABCC4 and ABCC5) were highly expressed in isolated brain microvessels in all three species studied; the expression of ABCB1, ABCG2, ABCC1, ABCC4 and ABCC5 was generally higher in rodent brain microvessels compared to those of humans. In contrast, ABCC2 and ABCC3 expression was low in brain microvessels, but high in rodent liver and lung vessels. Overall, most ABC transporters (with the exception of drug efflux transporters) were enriched in peripheral tissues compared to brain microvessels in humans, while in rodent species, additional ABC transporters were found to be enriched in brain microvessels. CONCLUSIONS This study furthers the understanding of species similarities and differences in the expression patterns of ABC transporter genes; this is important for translational studies in drug development. In particular, CNS drug delivery and toxicity may vary among species depending on their unique profiles of ABC transporter expression in brain microvessels and BBB.
Collapse
Affiliation(s)
- Wandong Zhang
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada
| | - Qing Yan Liu
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada
| | - Arsalan S Haqqani
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada
| | - Ziying Liu
- Scientific Data Mining/Digital Technology Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada
| | - Caroline Sodja
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada
| | - Sonia Leclerc
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada
| | - Ewa Baumann
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada
| | - Christie E Delaney
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada
| | - Eric Brunette
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada
| | - Danica B Stanimirovic
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada
| |
Collapse
|
2
|
Muraleedharan A, Vanderperre B. The endo-lysosomal system in Parkinson's disease: expanding the horizon. J Mol Biol 2023:168140. [PMID: 37148997 DOI: 10.1016/j.jmb.2023.168140] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 04/22/2023] [Accepted: 04/27/2023] [Indexed: 05/08/2023]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease, and its prevalence is increasing with age. A wealth of genetic evidence indicates that the endo-lysosomal system is a major pathway driving PD pathogenesis with a growing number of genes encoding endo-lysosomal proteins identified as risk factors for PD, making it a promising target for therapeutic intervention. However, detailed knowledge and understanding of the molecular mechanisms linking these genes to the disease are available for only a handful of them (e.g. LRRK2, GBA1, VPS35). Taking on the challenge of studying poorly characterized genes and proteins can be daunting, due to the limited availability of tools and knowledge from previous literature. This review aims at providing a valuable source of molecular and cellular insights into the biology of lesser-studied PD-linked endo-lysosomal genes, to help and encourage researchers in filling the knowledge gap around these less popular genetic players. Specific endo-lysosomal pathways discussed range from endocytosis, sorting, and vesicular trafficking to the regulation of membrane lipids of these membrane-bound organelles and the specific enzymatic activities they contain. We also provide perspectives on future challenges that the community needs to tackle and propose approaches to move forward in our understanding of these poorly studied endo-lysosomal genes. This will help harness their potential in designing innovative and efficient treatments to ultimately re-establish neuronal homeostasis in PD but also other diseases involving endo-lysosomal dysfunction.
Collapse
Affiliation(s)
- Amitha Muraleedharan
- Centre d'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois and Biological Sciences Department, Université du Québec à Montréal
| | - Benoît Vanderperre
- Centre d'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois and Biological Sciences Department, Université du Québec à Montréal
| |
Collapse
|
3
|
The lysosomal transporter TAPL has a dual role as peptide translocator and phosphatidylserine floppase. Nat Commun 2022; 13:5851. [PMID: 36195619 PMCID: PMC9532399 DOI: 10.1038/s41467-022-33593-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 09/23/2022] [Indexed: 11/08/2022] Open
Abstract
TAPL is a lysosomal ATP-binding cassette transporter that translocates a broad spectrum of polypeptides from the cytoplasm into the lysosomal lumen. Here we report that, in addition to its well-known role as a peptide translocator, TAPL exhibits an ATP-dependent phosphatidylserine floppase activity that is the possible cause of its high basal ATPase activity and of the lack of coupling between ATP hydrolysis and peptide efflux. We also present the cryo-EM structures of mouse TAPL complexed with (i) phospholipid, (ii) cholesteryl hemisuccinate (CHS) and 9-mer peptide, and (iii) ADP·BeF3. The inward-facing structure reveals that F449 protrudes into the cylindrical transport pathway and divides it into a large hydrophilic central cavity and a sizable hydrophobic upper cavity. In the structure, the peptide binds to TAPL in horizontally-stretched fashion within the central cavity, while lipid molecules plug vertically into the upper cavity. Together, our results suggest that TAPL uses different mechanisms to function as a peptide translocase and a phosphatidylserine floppase.
Collapse
|
4
|
Yan Q, Shen Y, Yang X. Cryo-EM Structure of AMP-PNP-bound Human Mitochondrial ATP-binding cassette transporter ABCB7. J Struct Biol 2022; 214:107832. [PMID: 35041979 DOI: 10.1016/j.jsb.2022.107832] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 01/06/2022] [Accepted: 01/10/2022] [Indexed: 12/31/2022]
Abstract
ATP-binding cassette subfamily B member 7 (ABCB7) is localized in the inner membrane of mitochondria, playing a critical role in iron metabolism. Here, we determined the structure of the nonhydrolyzable ATP analog adenosine-5'-(β-γ-imido) triphosphate (AMP-PNP) bound human ABCB7 at 3.3 Å by single-particle electron cryo-microscopy (cryo-EM). The AMP-PNP-bound human ABCB7 shows an inverted V-shaped homodimeric architecture with an inward-facing open conformation. One AMP-PNP molecule and Mg2+ were identified in each nucleotide-binding domain (NBD) of the hABCB7 monomer. Moreover, four disease-causing missense mutations of human ABCB7 have been mapped to the structure, creating a hotspot map for X-linked sideroblastic anemia and ataxia disease. Our results provide a structural basis for further understanding the transport mechanism of the mitochondrial ABC transporter.
Collapse
Affiliation(s)
- Qinqin Yan
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China
| | - Yuequan Shen
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China; Synergetic Innovation Center of Chemical Science and Engineering, Tianjin 300071, China
| | - Xue Yang
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China.
| |
Collapse
|
5
|
Sharma P, Singh N, Sharma S. ATP binding cassette transporters and cancer: revisiting their controversial role. Pharmacogenomics 2021; 22:1211-1235. [PMID: 34783261 DOI: 10.2217/pgs-2021-0116] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The expression of ATP-binding cassette transporter (ABC transporters) has been reported in various tissues such as the lung, liver, kidney, brain and intestine. These proteins account for the efflux of different compounds and metabolites across the membrane, thus decreasing the concentration of the toxic compounds. ABC transporter genes play a vital role in the development of multidrug resistance, which is the main obstacle that hinders the success of chemotherapy. Preclinical and clinical trials have investigated the probability of overcoming drug-associated resistance and substantial toxicities. The focus has been put on several strategies to overcome multidrug resistance. These strategies include the development of modulators that can modulate ABC transporters. This knowledge can be translated for clinical oncology treatment in the future.
Collapse
Affiliation(s)
- Parul Sharma
- Department of Biotechnology, Thapar Institute of Engineering & Technology, Patiala, India
| | - Navneet Singh
- Department of Pulmonary medicine, Post Graduate Institute of Medical Education & Research, Chandigarh, India
| | - Siddharth Sharma
- Department of Biotechnology, Thapar Institute of Engineering & Technology, Patiala, India
| |
Collapse
|
6
|
Rudnik S, Damme M. The lysosomal membrane-export of metabolites and beyond. FEBS J 2021; 288:4168-4182. [PMID: 33067905 DOI: 10.1111/febs.15602] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/01/2020] [Accepted: 10/15/2020] [Indexed: 01/01/2023]
Abstract
Lysosomes are degradative organelles in eukaryotic cells mediating the hydrolytic catabolism of various macromolecules to small basic building blocks. These low-molecular-weight metabolites are transported across the lysosomal membrane and reused in the cytoplasm and other organelles for biosynthetic pathways. Even though in the past 20 years our understanding of the lysosomal membrane regarding various transporters, other integral and peripheral membrane proteins, the lipid composition, but also its turnover has dramatically improved, there are still many unresolved questions concerning key aspects of the function of the lysosomal membrane. These include a possible function of lysosomes as a cellular storage compartment, yet unidentified transporters mediating the export such as various amino acids, mechanisms mediating the transport of lysosomal membrane proteins from the Golgi apparatus to lysosomes, and the turnover of lysosomal membrane proteins. Here, we review the current knowledge about the lysosomal membrane and identify some of the open questions that need to be solved in the future for a comprehensive and complete understanding of how lysosomes communicate with other organelles, cellular processes, and pathways.
Collapse
Affiliation(s)
- Sönke Rudnik
- Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Markus Damme
- Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| |
Collapse
|
7
|
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
|
8
|
Praest P, Liaci AM, Förster F, Wiertz EJ. New insights into the structure of the MHC class I peptide-loading complex and mechanisms of TAP inhibition by viral immune evasion proteins. Mol Immunol 2019; 113:103-114. [DOI: 10.1016/j.molimm.2018.03.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 03/16/2018] [Accepted: 03/22/2018] [Indexed: 01/08/2023]
|
9
|
Bock C, Zollmann T, Lindt KA, Tampé R, Abele R. Peptide translocation by the lysosomal ABC transporter TAPL is regulated by coupling efficiency and activation energy. Sci Rep 2019; 9:11884. [PMID: 31417173 PMCID: PMC6695453 DOI: 10.1038/s41598-019-48343-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 07/25/2019] [Indexed: 11/15/2022] Open
Abstract
The lysosomal polypeptide transporter TAPL belongs to the superfamily of ATP-binding cassette transporters. TAPL forms a homodimeric transport complex, which translocates oligo- and polypeptides into the lumen of lysosomes driven by ATP hydrolysis. Although the structure and the function of ABC transporters were intensively studied in the past, details about the single steps of the transport cycle are still elusive. Therefore, we analyzed the coupling of peptide binding, transport and ATP hydrolysis for different substrate sizes. Although longer and shorter peptides bind with the same affinity and are transported with identical Km values, they differ significantly in their transport rates. This difference can be attributed to a higher activation energy for the longer peptide. TAPL shows a basal ATPase activity, which is inhibited in the presence of longer peptides. Uncoupling between ATP hydrolysis and peptide transport increases with peptide length. Remarkably, also the type of nucleotide determines the uncoupling. While GTP is hydrolyzed as good as ATP, peptide transport is significantly reduced. In conclusion, TAPL does not differentiate between transport substrates in the binding process but during the following steps in the transport cycle, whereas, on the other hand, not only the coupling efficiency but also the activation energy varies depending on the size of peptide substrate.
Collapse
Affiliation(s)
- Christoph Bock
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Tina Zollmann
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Katharina-Astrid Lindt
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Rupert Abele
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany.
| |
Collapse
|
10
|
Barkhash AV, Yurchenko AA, Yudin NS, Kozlova IV, Borishchuk IA, Smolnikova MV, Zaitseva OI, Pozdnyakova LL, Voevoda MI, Romaschenko AG. Association of ABCB9 and COL22A1 Gene Polymorphism with Human Predisposition to Severe Forms of Tick-Borne Encephalitis. RUSS J GENET+ 2019. [DOI: 10.1134/s1022795419030025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
11
|
Graab P, Bock C, Weiss K, Hirth A, Koller N, Braner M, Jung J, Loehr F, Tampé R, Behrends C, Abele R. Lysosomal targeting of the ABC transporter TAPL is determined by membrane-localized charged residues. J Biol Chem 2019; 294:7308-7323. [PMID: 30877195 DOI: 10.1074/jbc.ra118.007071] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/08/2019] [Indexed: 01/16/2023] Open
Abstract
The human lysosomal polypeptide ABC transporter TAPL (ABC subfamily B member 9, ABCB9) transports 6-59-amino-acid-long polypeptides from the cytosol into lysosomes. The subcellular localization of TAPL depends solely on its N-terminal transmembrane domain, TMD0, which lacks conventional targeting sequences. However, the intracellular route and the molecular mechanisms that control TAPL localization remain unclear. Here, we delineated the route of TAPL to lysosomes and investigated the determinants of single trafficking steps. By synchronizing trafficking events by a retention using selective hooks (RUSH) assay and visualizing individual intermediate steps through immunostaining and confocal microscopy, we demonstrate that TAPL takes the direct route to lysosomes. We further identified conserved charged residues within TMD0 transmembrane helices that are essential for individual steps of lysosomal targeting. Substitutions of these residues retained TAPL in the endoplasmic reticulum (ER) or Golgi. We also observed that for release from the ER, a salt bridge between Asp-17 and Arg-57 is essential. An interactome analysis revealed that Yip1-interacting factor homolog B membrane-trafficking protein (YIF1B) interacts with TAPL. We also found that YIF1B is involved in ER-to-Golgi trafficking and interacts with TMD0 of TAPL via its transmembrane domain and that this interaction strongly depends on the newly identified salt bridge within TMD0. These results expand our knowledge about lysosomal trafficking of TAPL and the general function of extra transmembrane domains of ABC transporters.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Jennifer Jung
- the Institute of Biochemistry II, Medical School, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany, and
| | - Frank Loehr
- the Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue-Strasse 9, 60438 Frankfurt am Main, Germany
| | - Robert Tampé
- From the Institute of Biochemistry, Biocenter, and
| | - Christian Behrends
- the Institute of Biochemistry II, Medical School, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany, and.,the Munich Cluster for Systems Neurology, Ludwig Maximilians University Munich, Feodor-Lynen-Strasse 17, 81377 Munich, Germany
| | - Rupert Abele
- From the Institute of Biochemistry, Biocenter, and
| |
Collapse
|
12
|
Bock C, Löhr F, Tumulka F, Reichel K, Würz J, Hummer G, Schäfer L, Tampé R, Joseph B, Bernhard F, Dötsch V, Abele R. Structural and functional insights into the interaction and targeting hub TMD0 of the polypeptide transporter TAPL. Sci Rep 2018; 8:15662. [PMID: 30353140 PMCID: PMC6199259 DOI: 10.1038/s41598-018-33841-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 10/04/2018] [Indexed: 11/09/2022] Open
Abstract
The ATP-binding cassette transporter TAPL translocates polypeptides from the cytosol into the lysosomal lumen. TAPL can be divided into two functional units: coreTAPL, active in ATP-dependent peptide translocation, and the N-terminal membrane spanning domain, TMD0, responsible for cellular localization and interaction with the lysosomal associated membrane proteins LAMP-1 and LAMP-2. Although the structure and function of ABC transporters were intensively analyzed in the past, the knowledge about accessory membrane embedded domains is limited. Therefore, we expressed the TMD0 of TAPL via a cell-free expression system and confirmed its correct folding by NMR and interaction studies. In cell as well as cell-free expressed TMD0 forms oligomers, which were assigned as dimers by PELDOR spectroscopy and static light scattering. By NMR spectroscopy of uniformly and selectively isotope labeled TMD0 we performed a complete backbone and partial side chain assignment. Accordingly, TMD0 has a four transmembrane helix topology with a short helical segment in a lysosomal loop. The topology of TMD0 was confirmed by paramagnetic relaxation enhancement with paramagnetic stearic acid as well as by nuclear Overhauser effects with c6-DHPC and cross-peaks with water.
Collapse
Affiliation(s)
- Christoph Bock
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Frank Löhr
- Institute of Biophysical Chemistry & Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Franz Tumulka
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Katrin Reichel
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Julia Würz
- Institute of Biophysical Chemistry & Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438, Frankfurt am Main, Germany
| | - Lars Schäfer
- Lehrstuhl für Theoretische Chemie, Ruhr-University Bochum, 4780, Bochum, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Benesh Joseph
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Frank Bernhard
- Institute of Biophysical Chemistry & Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Volker Dötsch
- Institute of Biophysical Chemistry & Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany
| | - Rupert Abele
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, 60438, Frankfurt am Main, Germany.
| |
Collapse
|
13
|
Trowitzsch S, Tampé R. ABC Transporters in Dynamic Macromolecular Assemblies. J Mol Biol 2018; 430:4481-4495. [DOI: 10.1016/j.jmb.2018.07.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 07/24/2018] [Accepted: 07/30/2018] [Indexed: 12/28/2022]
|
14
|
Al Feteisi H, Al-Majdoub ZM, Achour B, Couto N, Rostami-Hodjegan A, Barber J. Identification and quantification of blood-brain barrier transporters in isolated rat brain microvessels. J Neurochem 2018; 146:670-685. [PMID: 29675872 DOI: 10.1111/jnc.14446] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 03/26/2018] [Accepted: 04/05/2018] [Indexed: 12/20/2022]
Abstract
The blood-brain barrier (BBB) maintains brain homeostasis by tightly regulating the exchange of molecules with systemic circulation. It consists primarily of microvascular endothelial cells surrounded by astrocytic endfeet, pericytes, and microglia. Understanding the make-up of transporters in rat BBB is essential to the translation of pharmacological and toxicological observations into humans. In this study, experimental workflows are presented in which the optimization of (a) isolation of rat brain microvessels (b) enrichment of endothelial cells, and (c) extraction and digestion of proteins were evaluated, followed by identification and quantification of BBB proteins. Optimization of microvessel isolation was indicated by 15-fold enrichment of endothelial cell marker Glut1 mRNA, whereas markers for other cell types were not enriched. Filter-aided sample preparation was shown to be superior to in-solution sample preparation (10251 peptides vs. 7533 peptides). Label-free proteomics was used to identify nearly 2000 proteins and quantify 1276 proteins in isolated microvessels. A combination of targeted and global proteomics was adopted to measure protein abundance of 6 ATP-binding cassette and 27 solute carrier transporters. Data analysis using proprietary Progenesis and open access MaxQuant software showed overall agreement; however, Abcb9 and Slc22a8 were quantified only by MaxQuant, whereas Abcc9 and Abcd3 were quantified only by Progenesis. Agreement between targeted and untargeted quantification was demonstrated for Abcb1 (19.7 ± 1.4 vs. 17.8 ± 2.3) and Abcc4 (2.2 ± 0.7 vs. 2.1 ± 0.4), respectively. Rigorous quantification of BBB proteins, as reported in this study, should assist with translational modeling efforts involving brain disposition of xenobiotics.
Collapse
Affiliation(s)
- Hajar Al Feteisi
- Centre for Applied Pharmacokinetic Research (CAPKR), University of Manchester, Manchester, UK
| | - Zubida M Al-Majdoub
- Centre for Applied Pharmacokinetic Research (CAPKR), University of Manchester, Manchester, UK
| | - Brahim Achour
- Centre for Applied Pharmacokinetic Research (CAPKR), University of Manchester, Manchester, UK
| | - Narciso Couto
- ChELSI Institute, Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | - Amin Rostami-Hodjegan
- Centre for Applied Pharmacokinetic Research (CAPKR), University of Manchester, Manchester, UK.,Simcyp Limited (a Certara Company), Sheffield, UK
| | - Jill Barber
- Centre for Applied Pharmacokinetic Research (CAPKR), University of Manchester, Manchester, UK
| |
Collapse
|
15
|
Lawand M, Evnouchidou I, Baranek T, Montealegre S, Tao S, Drexler I, Saveanu L, Si-Tahar M, van Endert P. Impact of the TAP-like transporter in antigen presentation and phagosome maturation. Mol Immunol 2018; 113:75-86. [PMID: 29941219 DOI: 10.1016/j.molimm.2018.06.268] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 04/23/2018] [Accepted: 06/14/2018] [Indexed: 02/06/2023]
Abstract
Cross-presentation is thought to require transport of proteasome-generated peptides by the TAP transporters into MHC class I loading compartments for most antigens. However, a proteasome-dependent but TAP-independent pathway has also been described. Depletion of the pool of recycling cell surface MHC class I molecules available for loading with cross-presented peptides might partly or largely account for the critical role of TAP in cross-presentation of phagocytosed antigens. Here we examined a potential role of the homodimeric lysosomal TAP-like transporter in cross-presentation and in presentation of endogenous peptides by MHC class II molecules. We find that TAP-L is strongly recruited to dendritic cell phagosomes at a late stage, when internalized antigen and MHC class I molecules have been degraded or sorted away from phagosomes. Cross-presentation of a receptor-targeted antigen in vitro and of a phagocytosed antigen in vivo, as well as presentation of a cytosolic antigen by MHC class II molecules, is not affected by TAP-L deficiency. However, accumulation in vitro of a peptide optimally adapted to TAP-L selectivity in purified phagosomes is abolished by TAP-L deficiency. Unexpectedly, we find that TAP-L deficiency accelerates phagosome maturation, as reflected in increased Lamp2b recruitment and enhanced proteolytic degradation of phagocytosed antigen and in vitro transported peptides. Although additional experimentation will be required to definitely conclude on the role of TAP-L in transport of peptides presented by MHC class I and class II molecules, our data suggest that the principal role of TAP-L in dendritic cells may be related to regulation of phagosome maturation.
Collapse
Affiliation(s)
- Myriam Lawand
- Institut National de la Sante et de la Recherche Médicale, Unité 1151; Université Paris Descartes, Faculté de médecine; Centre National de la Recherche Scientifique, UMR8253; 149 rue de Sèvres, 75743 Paris Cedex 15, France
| | - Irini Evnouchidou
- Institut National de la Sante et de la Recherche Médicale, Unité 1151; Université Paris Descartes, Faculté de médecine; Centre National de la Recherche Scientifique, UMR8253; 149 rue de Sèvres, 75743 Paris Cedex 15, France
| | - Thomas Baranek
- Institut National de la Santé et de la Recherche Médicale, Unité 1100, Université F. Rabelais, Faculté de médecine, Centre d'études des pathologies respiratoires, 10 Boulevard Tonnellé, 37032 Tours Cedex, France
| | - Sebastian Montealegre
- Institut National de la Sante et de la Recherche Médicale, Unité 1151; Université Paris Descartes, Faculté de médecine; Centre National de la Recherche Scientifique, UMR8253; 149 rue de Sèvres, 75743 Paris Cedex 15, France
| | - Sha Tao
- Institut für Virologie, Universitätsklinikum Düsseldorf, Heinrich-Heine Universität, 40225 Düsseldorf, Germany
| | - Ingo Drexler
- Institut für Virologie, Universitätsklinikum Düsseldorf, Heinrich-Heine Universität, 40225 Düsseldorf, Germany
| | - Loredana Saveanu
- Institut National de la Sante et de la Recherche Médicale, Unité 1151; Université Paris Descartes, Faculté de médecine; Centre National de la Recherche Scientifique, UMR8253; 149 rue de Sèvres, 75743 Paris Cedex 15, France
| | - Mustapha Si-Tahar
- Institut National de la Santé et de la Recherche Médicale, Unité 1100, Université F. Rabelais, Faculté de médecine, Centre d'études des pathologies respiratoires, 10 Boulevard Tonnellé, 37032 Tours Cedex, France
| | - Peter van Endert
- Institut National de la Sante et de la Recherche Médicale, Unité 1151; Université Paris Descartes, Faculté de médecine; Centre National de la Recherche Scientifique, UMR8253; 149 rue de Sèvres, 75743 Paris Cedex 15, France.
| |
Collapse
|
16
|
Abele R, Tampé R. Moving the Cellular Peptidome by Transporters. Front Cell Dev Biol 2018; 6:43. [PMID: 29761100 PMCID: PMC5937356 DOI: 10.3389/fcell.2018.00043] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 04/03/2018] [Indexed: 12/18/2022] Open
Abstract
Living matter is defined by metastability, implying a tightly balanced synthesis and turnover of cellular components. The first step of eukaryotic protein degradation via the ubiquitin-proteasome system (UPS) leads to peptides, which are subsequently degraded to single amino acids by an armada of proteases. A small fraction of peptides, however, escapes further cytosolic destruction and is transported by ATP-binding cassette (ABC) transporters into the endoplasmic reticulum (ER) and lysosomes. The ER-resident heterodimeric transporter associated with antigen processing (TAP) is a crucial component in adaptive immunity for the transport and loading of peptides onto major histocompatibility complex class I (MHC I) molecules. Although the function of the lysosomal resident homodimeric TAPL-like (TAPL) remains, until today, only loosely defined, an involvement in immune defense is anticipated since it is highly expressed in dendritic cells and macrophages. Here, we compare the gene organization and the function of single domains of both peptide transporters. We highlight the structural organization, the modes of substrate binding and translocation as well as physiological functions of both organellar transporters.
Collapse
Affiliation(s)
- Rupert Abele
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt, Germany.,Cluster of Excellence - Macromolecular Complexes, Goethe University Frankfurt, Frankfurt, Germany
| |
Collapse
|
17
|
do Imperio GE, Bloise E, Javam M, Lye P, Constantinof A, Dunk C, Dos Reis FM, Lye SJ, Gibb W, Ortiga-Carvalho TM, Matthews SG. Chorioamnionitis Induces a Specific Signature of Placental ABC Transporters Associated with an Increase of miR-331-5p in the Human Preterm Placenta. Cell Physiol Biochem 2018; 45:591-604. [PMID: 29402780 PMCID: PMC7202864 DOI: 10.1159/000487100] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/10/2017] [Indexed: 12/16/2022] Open
Abstract
Background/Aims The ATP-binding cassette (ABC) transporters mediate drug biodisposition and immunological responses in the placental barrier. In vitro infective challenges alter expression of specific placental ABC transporters. We hypothesized that chorioamnionitis induces a distinct pattern of ABC transporter expression. Methods Gene expression of 50 ABC transporters was assessed using TaqMan® Human ABC Transporter Array, in preterm human placentas without (PTD; n=6) or with histological chorioamnionitis (PTDC; n=6). Validation was performed using qPCR, immunohistochemistry and Western blot. MicroRNAs known to regulate P-glycoprotein (P-gp) were examined by qPCR. Results Up-regulation of ABCB9, ABCC2 and ABCF2 mRNA was detected in chorioamnionitis (p<0.05), whereas placental ABCB1 (P-gp; p=0.051) and ABCG2 (breast cancer resistance protein-BCRP) mRNA levels (p=0.055) approached near significant up-regulation. In most cases, the magnitude of the effect significantly correlated to the severity of inflammation. Upon validation, increased placental ABCB1 and ABCG2 mRNA levels (p<0.05) were observed. At the level of immunohistochemistry, while BCRP was increased (p<0.05), P-gp staining intensity was significantly decreased (p<0.05) in PTDC. miR-331-5p, involved in P-gp suppression, was upregulated in PTDC (p<0.01) and correlated to the grade of chorioamnionitis (p<0.01). Conclusions Alterations in the expression of ABC transporters will likely lead to modified transport of clinically relevant compounds at the inflamed placenta. A better understanding of the potential role of these transporters in the events surrounding PTD may also enable new strategies to be developed for prevention and treatment of PTD.
Collapse
Affiliation(s)
- Guinever Eustaquio do Imperio
- Departments of Physiology, Toronto, Ontario, Canada.,Laboratory of Translational Endocrinology, Biophysics Institute Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Enrrico Bloise
- Laboratory of Translational Endocrinology, Biophysics Institute Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Departments of Morphology, Belo Horizonte, Brazil
| | - Mohsen Javam
- Departments of Physiology, Toronto, Ontario, Canada
| | | | | | - Caroline Dunk
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | | | - Stephen James Lye
- Departments of Physiology, Toronto, Ontario, Canada.,Obstetrics and Gynecology, Toronto, Ontario, Canada.,Medicine, University of Toronto, Toronto, Ontario, Canada.,Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - William Gibb
- Departments of Obstetrics & Gynecology and Department of Cellular & Molecular Medicine, University of Ottawa, Toronto, Ontario, Canada
| | - Tania M Ortiga-Carvalho
- Laboratory of Translational Endocrinology, Biophysics Institute Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Stephen Giles Matthews
- Departments of Physiology, Toronto, Ontario, Canada.,Obstetrics and Gynecology, Toronto, Ontario, Canada.,Medicine, University of Toronto, Toronto, Ontario, Canada.,Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| |
Collapse
|
18
|
Tanji T, Shiraishi H, Nishikori K, Aoyama R, Ohashi K, Maeda M, Ohashi-Kobayashi A. Molecular dissection of Caenorhabditis elegans ATP-binding cassette transporter protein HAF-4 to investigate its subcellular localization and dimerization. Biochem Biophys Res Commun 2017; 490:78-83. [PMID: 28427936 DOI: 10.1016/j.bbrc.2017.04.081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 04/15/2017] [Indexed: 11/29/2022]
Abstract
Caenorhabditis elegans HAF-4 and HAF-9 are half-type ATP-binding cassette (ABC) transporter proteins, which are highly homologous to the human peptide transporter protein, transporter associated with antigen processing-like (TAPL, ABCB9). TAPL forms homodimers and localizes to lysosomes, whereas HAF-4 and HAF-9 form heterodimers and localize to intestine-specific non-acidified organelles. Both TAPL and HAF-4/HAF-9 are predicted to have four amino-terminal transmembrane helices [transmembrane domain 0 (TMD0)] additional to the six transmembrane helices that form the canonical core domain of ABC transporters with a cytosolic ABC region. TAPL requires its amino-terminal domain for localization to lysosomes; however, molecular mechanisms underlying HAF-4 and HAF-9 localization to their target organelles had not been elucidated. Here, we demonstrate that the mechanisms underlying HAF-4 localization differ from those underlying TAPL localization. Using transgenic C. elegans expressing mutant HAF-4 proteins labeled with green fluorescent protein, we reveal that the TMD0 of HAF-4 was not sufficient for proper localization of the protein. The mutant HAF-4, which lacked TMD0, localized to intracellular organelles similarly to the wild-type protein and functioned normally in the biogenesis of its localizing organelles, indicating that the TMD0 of HAF-4 is dispensable for both its localization and function.
Collapse
Affiliation(s)
- Takahiro Tanji
- Department of Immunobiology, School of Pharmacy, Iwate Medical University, 2-1-1 Nishi-tokuta, Yahaba, Shiwa, Iwate 028-3694, Japan
| | - Hirohisa Shiraishi
- Department of Immunobiology, School of Pharmacy, Iwate Medical University, 2-1-1 Nishi-tokuta, Yahaba, Shiwa, Iwate 028-3694, Japan
| | - Kenji Nishikori
- Department of Immunobiology, School of Pharmacy, Iwate Medical University, 2-1-1 Nishi-tokuta, Yahaba, Shiwa, Iwate 028-3694, Japan
| | - Reiko Aoyama
- Department of Immunobiology, School of Pharmacy, Iwate Medical University, 2-1-1 Nishi-tokuta, Yahaba, Shiwa, Iwate 028-3694, Japan
| | - Kazuaki Ohashi
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Masatomo Maeda
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Ayako Ohashi-Kobayashi
- Department of Immunobiology, School of Pharmacy, Iwate Medical University, 2-1-1 Nishi-tokuta, Yahaba, Shiwa, Iwate 028-3694, Japan; Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan.
| |
Collapse
|
19
|
Moody HL, Lind MJ, Maher SG. MicroRNA-31 Regulates Chemosensitivity in Malignant Pleural Mesothelioma. MOLECULAR THERAPY. NUCLEIC ACIDS 2017; 8:317-329. [PMID: 28918032 PMCID: PMC5537169 DOI: 10.1016/j.omtn.2017.07.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 07/03/2017] [Accepted: 07/03/2017] [Indexed: 11/25/2022]
Abstract
Malignant pleural mesothelioma (MPM) is associated with an extremely poor prognosis, and most patients initially are or rapidly become unresponsive to platinum-based chemotherapy. MicroRNA-31 (miR-31) is encoded on a genomic fragile site, 9p21.3, which is reportedly lost in many MPM tumors. Based on previous findings in a variety of other cancers, we hypothesized that miR-31 alters chemosensitivity and that miR-31 reconstitution may influence sensitivity to chemotherapeutics in MPM. Reintroduction of miR-31 into miR-31 null NCI-H2452 cells significantly enhanced clonogenic resistance to cisplatin and carboplatin. Although miR-31 re-expression increased chemoresistance, paradoxically, a higher relative intracellular accumulation of platinum was detected. This was coupled to a significantly decreased intranuclear concentration of platinum. Linked with a downregulation of OCT1, a bipotential transcriptional regulator with multiple miR-31 target binding sites, we subsequently identified an indirect miR-31-mediated upregulation of ABCB9, a transporter associated with drug accumulation in lysosomes, and increased uptake of platinum to lysosomes. However, when overexpressed directly, ABCB9 promoted cellular chemosensitivity, suggesting that miR-31 promotes chemoresistance largely via an ABCB9-independent mechanism. Overall, our data suggest that miR-31 loss from MPM tumors promotes chemosensitivity and may be prognostically beneficial in the context of therapeutic sensitivity.
Collapse
Affiliation(s)
- Hannah L Moody
- School of Life Sciences, University of Hull, Hull HU6 7RX, UK; Hull York Medical School, Hull HU6 7RX, UK
| | - Michael J Lind
- Hull York Medical School, Hull HU6 7RX, UK; Centre for Oncology and Haematology, Castle Hill Hospital, Hull and East Yorkshire NHS Trust, Cottingham HU16 5JQ, UK
| | - Stephen G Maher
- School of Life Sciences, University of Hull, Hull HU6 7RX, UK; Trinity Translational Medicine Institute, Department of Surgery, Trinity College Dublin, Dublin 8, Ireland.
| |
Collapse
|
20
|
Kwon WS, Rha SY, Jeung HC, Ahn JB, Jung JJ, Ki DH, Kim TS, Chung HC. ABCB1 2677G>T/A variant enhances chemosensitivity to anti-cancer agents acting on microtubule dynamics through LAMP1 inhibition. Biochem Pharmacol 2017; 123:73-84. [PMID: 27832934 DOI: 10.1016/j.bcp.2016.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/03/2016] [Indexed: 11/23/2022]
Abstract
Overexpression of ABCB1 associated with single nucleotide variants in cancers was reported to encode a protein responsible for drug resistance. We studied chemosensitivity-related genes associated with ABCB1 2677G>T/A variant. The associated genes were identified based on the results of the significance analysis of microarray, and then prediction accuracy was evaluated using the prediction analysis of microarray. Functional assay of the selected gene was performed by using siRNA and drug accumulation study. A higher frequency of chemoresistance to microtubule-modulating agents was found in cell lines with wild-type ABCB1 compared to cell lines with 2677G>T/A ABCB1 variant. Based on the pharmacogenetic association study with 2677 variant, we identified seven genes that could predict chemosensitivity to microtubule dynamics modulators. The classification accuracy with these seven genes was 90.0%, and the predicted probability was 0.73. LAMP1 was the only gene that was commonly related to chemosensitivity. LAMP1 expression levels were relatively higher in chemoresistant ABCB1 wild-type compared to chemosensitive polymorphic cells. But, there was no difference in ABCB1 expression levels between the two groups. Following LAMP1 siRNA, chemosensitivity was restored due to increased intracellular drug accumulation in wild type cell line. In conclusion, ABCB1 2677G>T/A variant enhances chemosensitivity on microtubule dynamics through LAMP1 inhibition.
Collapse
Affiliation(s)
- Woo Sun Kwon
- Song-Dang Institute for Cancer Research, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Sun Young Rha
- Song-Dang Institute for Cancer Research, Yonsei University College of Medicine, Seoul, Republic of Korea; Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea; Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; Brain Korea 21 Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hei-Cheul Jeung
- Song-Dang Institute for Cancer Research, Yonsei University College of Medicine, Seoul, Republic of Korea; Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea; Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Joong Bae Ahn
- Song-Dang Institute for Cancer Research, Yonsei University College of Medicine, Seoul, Republic of Korea; Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea; Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jae-Joon Jung
- Song-Dang Institute for Cancer Research, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Dong Hyuk Ki
- Song-Dang Institute for Cancer Research, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Tae Soo Kim
- Song-Dang Institute for Cancer Research, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hyun Cheol Chung
- Song-Dang Institute for Cancer Research, Yonsei University College of Medicine, Seoul, Republic of Korea; Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea; Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; Brain Korea 21 Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Republic of Korea.
| |
Collapse
|
21
|
Translocation of the ABC transporter ABCD4 from the endoplasmic reticulum to lysosomes requires the escort protein LMBD1. Sci Rep 2016; 6:30183. [PMID: 27456980 PMCID: PMC4960490 DOI: 10.1038/srep30183] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 06/30/2016] [Indexed: 11/29/2022] Open
Abstract
We previously demonstrated that ABCD4 does not localize to peroxisomes but rather, the endoplasmic reticulum (ER), because it lacks the NH2-terminal hydrophilic region required for peroxisomal targeting. It was recently reported that mutations in ABCD4 result in a failure to release vitamin B12 from lysosomes. A similar phenotype is caused by mutations in LMBRD1, which encodes the lysosomal membrane protein LMBD1. These findings suggested to us that ABCD4 translocated from the ER to lysosomes in association with LMBD1. In this report, it is demonstrated that ABCD4 interacts with LMBD1 and then localizes to lysosomes, and this translocation depends on the lysosomal targeting ability of LMBD1. Furthermore, endogenous ABCD4 was localized to both lysosomes and the ER, and its lysosomal localization was disturbed by knockout of LMBRD1. To the best of our knowledge, this is the first report demonstrating that the subcellular localization of the ABC transporter is determined by its association with an adaptor protein.
Collapse
|
22
|
Antigen Translocation Machineries in Adaptive Immunity and Viral Immune Evasion. J Mol Biol 2015; 427:1102-18. [DOI: 10.1016/j.jmb.2014.09.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/04/2014] [Accepted: 09/05/2014] [Indexed: 11/23/2022]
|
23
|
Single liposome analysis of peptide translocation by the ABC transporter TAPL. Proc Natl Acad Sci U S A 2015; 112:2046-51. [PMID: 25646430 DOI: 10.1073/pnas.1418100112] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
ATP-binding cassette (ABC) transporters use ATP to drive solute transport across biological membranes. Members of this superfamily have crucial roles in cell physiology, and some of the transporters are linked to severe diseases. However, understanding of the transport mechanism, especially of human ABC exporters, is scarce. We reconstituted the human lysosomal polypeptide ABC transporter TAPL, expressed in Pichia pastoris, into lipid vesicles (liposomes) and performed explicit transport measurements. We analyzed solute transport at the single liposome level by monitoring the coincident fluorescence of solutes and proteoliposomes in the focal volume of a confocal microscope. We determined a turnover number of eight peptides per minute, which is two orders of magnitude higher than previously estimated from macroscopic measurements. Moreover, we show that TAPL translocates peptides against a large concentration gradient. Maximal filling is not limited by an electrochemical gradient but by trans-inhibition. Countertransport and reversibility studies demonstrate that peptide translocation is a strictly unidirectional process. Altogether, these data are included in a refined model of solute transport by ABC exporters.
Collapse
|
24
|
Dong Z, Zhong Z, Yang L, Wang S, Gong Z. MicroRNA-31 inhibits cisplatin-induced apoptosis in non-small cell lung cancer cells by regulating the drug transporter ABCB9. Cancer Lett 2014; 343:249-57. [DOI: 10.1016/j.canlet.2013.09.034] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 09/22/2013] [Accepted: 09/26/2013] [Indexed: 01/08/2023]
|
25
|
Motohashi Y, Ohashi-Kobayashi A, Nakanishi-Matsui M, Fujimoto Y, Maeda M. Intracellular Localization of ABC Transporter TAPL Differs between Transient and Stable Expression. Cell 2014. [DOI: 10.4236/cellbio.2014.32006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
26
|
Tumulka F, Roos C, Löhr F, Bock C, Bernhard F, Dötsch V, Abele R. Conformational stabilization of the membrane embedded targeting domain of the lysosomal peptide transporter TAPL for solution NMR. JOURNAL OF BIOMOLECULAR NMR 2013; 57:141-154. [PMID: 24013930 DOI: 10.1007/s10858-013-9774-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 08/21/2013] [Indexed: 06/02/2023]
Abstract
The ATP binding cassette transporter TAPL translocates cytosolic peptides into the lumen of lysosomes driven by the hydrolysis of ATP. Functionally, this transporter can be divided into coreTAPL, comprising the transport function, and an additional N-terminal transmembrane domain called TMD0, which is essential for lysosomal targeting and mediates the interaction with the lysosomal associated membrane proteins LAMP-1 and LAMP-2. To elucidate the structure of this unique domain, we developed protocols for the production of high quantities of cell-free expressed TMD0 by screening different N-terminal expression tags. Independently of the amino acid sequence, high expression was detected for AU-rich sequences in the first seven codons, decreasing the free energy of RNA secondary structure formation at translation initiation. Furthermore, avoiding NGG codons in the region of translation initiation demonstrated a positive effect on expression. For NMR studies, conditions were optimized for high solubilization efficiency, long-term stability, and high quality spectra. A most critical step was the careful exchange of the detergent used for solubilization by the detergent dihexanoylphosphatidylcholine. Several constructs of different size were tested in order to stabilize the fold of TMD0 as well as to reduce the conformation exchange. NMR spectra with sufficient resolution and homogeneity were finally obtained with a TMD0 derivative only modified by a C-terminal His10-tag and containing a codon optimized AT-rich sequence.
Collapse
Affiliation(s)
- Franz Tumulka
- Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany
| | | | | | | | | | | | | |
Collapse
|
27
|
Co-operative function and mutual stabilization of the half ATP-binding cassette transporters HAF-4 and HAF-9 in Caenorhabditis elegans. Biochem J 2013; 452:467-75. [PMID: 23458156 DOI: 10.1042/bj20130115] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Caenorhabditis elegans HAF-4 and HAF-9 are half ABC (ATP-binding-cassette) transporters that are highly homologous to the human lysosomal peptide transporter TAPL [TAP (transporter associated with antigen processing)-like; ABCB9]. We reported previously that both HAF-4 and HAF-9 localize to the membrane of a subset of intestinal organelles, and are required for the formation of these organelles and other physiological aspects. In the present paper, we report the genetic and physical interactions between HAF-4 and HAF-9. Overexpression of HAF-4 and HAF-9 did not rescue the intestinal organelle defect of the haf-9 and haf-4 deletion mutants respectively, indicating that they cannot substitute for each other. Double haf-4 and haf-9 mutants do not exhibit more severe phenotypes than the single mutants, suggesting their co-operative function. Immunoprecipitation experiments demonstrated their physical interaction. The results of the present study suggest that HAF-4 and HAF-9 form a heterodimer. Furthermore, Western blot analysis of the deletion mutants and RNAi (RNA interference) knockdown experiments in GFP (green fluorescent protein)-tagged HAF-4 or HAF-9 transgenic worms suggest that HAF-4-HAF-9 heterodimer formation is required for their stabilization. The findings provide a clue as to how ABC transporters adopt a stable functional form.
Collapse
|
28
|
Demirel Ö, Jan I, Wolters D, Blanz J, Saftig P, Tampé R, Abele R. The lysosomal polypeptide transporter TAPL is stabilized by interaction with LAMP-1 and LAMP-2. J Cell Sci 2012; 125:4230-40. [PMID: 22641697 DOI: 10.1242/jcs.087346] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
TAPL (ABCB9) is a homodimeric polypeptide translocation machinery which transports cytosolic peptides into the lumen of lysosomes for degradation. Since the function of proteins is strongly dependent on the interaction network involved, we investigated the interactome of TAPL. A proteomic approach allowed identification of the lysosome-associated membrane proteins LAMP-1 and LAMP-2B as the most abundant interaction partners. Albeit with low frequency, major histocompatibility complex II subunits were also detected. The interaction interface with LAMP was mapped to the four-transmembrane helices constituting the N-terminal domain of TAPL (TMD0). The LAMP proteins bind independently to TAPL. This interaction has influence on neither subcellular localization nor peptide transport activity. However, in LAMP-deficient cells, the half-life of TAPL is decreased by a factor of five, whereas another lysosomal membrane protein, LIMP-2, is not affected. Reduced stability of TAPL is caused by increased lysosomal degradation, indicating that LAMP proteins retain TAPL on the limiting membrane of endosomes and prevent its sorting to intraluminal vesicles.
Collapse
Affiliation(s)
- Özlem Demirel
- Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | | | | | | | | | | | | |
Collapse
|
29
|
Kiss K, Brozik A, Kucsma N, Toth A, Gera M, Berry L, Vallentin A, Vial H, Vidal M, Szakacs G. Shifting the paradigm: the putative mitochondrial protein ABCB6 resides in the lysosomes of cells and in the plasma membrane of erythrocytes. PLoS One 2012; 7:e37378. [PMID: 22655043 PMCID: PMC3360040 DOI: 10.1371/journal.pone.0037378] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 04/18/2012] [Indexed: 11/19/2022] Open
Abstract
ABCB6, a member of the adenosine triphosphate–binding cassette (ABC) transporter family, has been proposed to be responsible for the mitochondrial uptake of porphyrins. Here we show that ABCB6 is a glycoprotein present in the membrane of mature erythrocytes and in exosomes released from reticulocytes during the final steps of erythroid maturation. Consistent with its presence in exosomes, endogenous ABCB6 is localized to the endo/lysosomal compartment, and is absent from the mitochondria of cells. Knock-down studies demonstrate that ABCB6 function is not required for de novo heme biosynthesis in differentiating K562 cells, excluding this ABC transporter as a key regulator of porphyrin synthesis. We confirm the mitochondrial localization of ABCB7, ABCB8 and ABCB10, suggesting that only three ABC transporters should be classified as mitochondrial proteins. Taken together, our results challenge the current paradigm linking the expression and function of ABCB6 to mitochondria.
Collapse
Affiliation(s)
- Katalin Kiss
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Anna Brozik
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Nora Kucsma
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Alexandra Toth
- 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
| | - Laurence Berry
- Unité Mixte de Recherche 5235 (Dynamique des Interactions Membranaires Normales et Pathologiques), Centre National de la Recherche Scientifique, Université Montpellier II, Montpellier, France
| | - Alice Vallentin
- Unité Mixte de Recherche 5235 (Dynamique des Interactions Membranaires Normales et Pathologiques), Centre National de la Recherche Scientifique, Université Montpellier II, Montpellier, France
| | - Henri Vial
- Unité Mixte de Recherche 5235 (Dynamique des Interactions Membranaires Normales et Pathologiques), Centre National de la Recherche Scientifique, Université Montpellier II, Montpellier, France
| | - Michel Vidal
- Unité Mixte de Recherche 5235 (Dynamique des Interactions Membranaires Normales et Pathologiques), Centre National de la Recherche Scientifique, Université Montpellier II, Montpellier, France
| | - Gergely Szakacs
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
- * E-mail:
| |
Collapse
|
30
|
Modulation of the expression of ABC transporters in murine (J774) macrophages exposed to large concentrations of the fluoroquinolone antibiotic moxifloxacin. Toxicology 2011; 290:178-86. [DOI: 10.1016/j.tox.2011.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 09/10/2011] [Accepted: 09/12/2011] [Indexed: 01/16/2023]
|
31
|
Bangert I, Tumulka F, Abele R. The lysosomal polypeptide transporter TAPL: more than a housekeeping factor? Biol Chem 2011; 392:61-6. [PMID: 21194361 DOI: 10.1515/bc.2011.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The transporter associated with antigen processing-like (TAPL) is a polypeptide transporter translocating cytosolic peptides into the lumen of lysosomes driven by ATP hydrolysis. TAPL belongs to the family of ABC transporters and forms a homodimer. This ABC transporter not only shows a broad tissue but also a wide phylogenetic distribution, because orthologs are still found in nematodes and insects. Here, we present the topology, substrate specificity, and distribution of this intracellular polypeptide transporter. Additionally, we will discuss its proposed physiological functions such as housekeeping together with a specialized factor for metabolite storage as well as for the adaptive immunity.
Collapse
Affiliation(s)
- Irina Bangert
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Strasse 9, Frankfurt/Main, Germany
| | | | | |
Collapse
|
32
|
Fujimoto Y, Kamakura A, Motohashi Y, Ohashi-Kobayashi A, Maeda M. Transporter Associated with Antigen Processing-Like (ABCB9) Stably Expressed in Chinese Hamster Ovary-K1 Cells Is Sorted to the Microdomains of Lysosomal Membranes. Biol Pharm Bull 2011; 34:36-40. [DOI: 10.1248/bpb.34.36] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yasuyuki Fujimoto
- Department of Molecular Biology, School of Pharmacy, Iwate Medical University
| | - Aya Kamakura
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University
| | - Yu Motohashi
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University
| | - Ayako Ohashi-Kobayashi
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University
| | - Masatomo Maeda
- Department of Molecular Biology, School of Pharmacy, Iwate Medical University
| |
Collapse
|
33
|
Demirel O, Bangert I, Tampé R, Abele R. Tuning the cellular trafficking of the lysosomal peptide transporter TAPL by its N-terminal domain. Traffic 2010; 11:383-93. [PMID: 20377823 DOI: 10.1111/j.1600-0854.2009.01021.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The homodimeric ATP-binding cassette (ABC) transport complex TAPL (transporter associated with antigen processing-like, ABCB9) translocates a broad spectrum of peptides from the cytosol into the lumen of lysosomes. The presence of an extra N-terminal transmembrane domain (TMD0) lacking any sequence homology to known proteins distinguishes TAPL from most other ABC transporters of its subfamily. By dissecting TAPL, we could assign distinct functions to the core complex and TMD0. The core-TAPL complex, composed of six predicted transmembrane helices and a nucleotide-binding domain, is sufficient for peptide transport, showing that the core transport complex is correctly targeted to and assembled in the membrane. Strikingly, in contrast to the full-length transporter, the core translocation complex is targeted preferentially to the plasma membrane. However, TMD0 alone, comprising a putative four transmembrane helix bundle, traffics to lysosomes. Upon coexpression, TMD0 forms a stable non-covalently linked complex with the core translocation machinery and guides core-TAPL into lysosomal compartments. Therefore, TMD0 represents a unique domain, which folds independently and encodes the information for lysosomal targeting. These outcomes are discussed in respect of trafficking, folding and function of TAPL.
Collapse
Affiliation(s)
- Ozlem Demirel
- Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt am Main, Germany
| | | | | | | |
Collapse
|
34
|
Abstract
The blood-brain barrier (BBB) is a dynamic physical and biological barrier between blood circulation and the central nervous system (CNS). This unique feature of the BBB lies in the structure of the neurovascular unit and its cerebral micro-vascular endothelial cells. The BBB restricts the passage of blood-borne drugs, neurotoxic substances and peripheral immune cells from entering the brain, while selectively facilitating the transport of nutrients across the BBB into the brain. Thus, the integrity and proper function of the BBB is crucial to homeostasis and physiological function of the CNS. A number of transport and carrier systems are expressed and polarized on the luminal or abluminal surface of the BBB to realize these discrete functions. Among these systems, ABC transporters play a critical role in keeping drugs and neurotoxic substances from entering the brain and in transporting toxic metabolites out of the brain. A number of studies have demonstrated that ABCB1 and ABCG2 are critical to drug efflux at the BBB and that ABCC1 is essential for the blood-cerebral spinal fluid (CSF) barrier. The presence of these efflux ABC transporters also creates a major obstacle for drug delivery into the brain. We have comprehensively reviewed the literature on ABC transporters and drug efflux at the BBB. Understanding the molecular mechanisms of these transporters is important in the development of new drugs and new strategies for drug delivery into the brain.
Collapse
Affiliation(s)
- Shanshan Shen
- Neurobiology Program, Institute for Biological Sciences, National Research Council of Canada, Ottawa, Canada K1A 0R6
| | | |
Collapse
|
35
|
The ABC of dendritic cell development and function. Trends Immunol 2009; 30:421-9. [PMID: 19699682 DOI: 10.1016/j.it.2009.06.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 06/24/2009] [Accepted: 06/25/2009] [Indexed: 12/14/2022]
Abstract
ATP-binding cassette (ABC) transporters are known for their involvement in clinical multidrug resistance (MDR) and their physiological defensive functions in barrier organs. More recently, attention has been focused on their possible involvement in the regulation of immune responses following the identification of their substrates as known immunomodulating agents (e.g. prostaglandins, leukotrienes and cyclic nucleotides) and their functional expression in various immune effector cells, most notably in dendritic cells (DCs). This review addresses the possible roles of ABC transporters in DC development and function, as well as the putative immunostimulatory potential of their cytostatic substrates and how this knowledge might benefit DC-based chemo-immunotherapies.
Collapse
|
36
|
Kawai H, Tanji T, Shiraishi H, Yamada M, Iijima R, Inoue T, Kezuka Y, Ohashi K, Yoshida Y, Tohyama K, Gengyo-Ando K, Mitani S, Arai H, Ohashi-Kobayashi A, Maeda M. Normal formation of a subset of intestinal granules in Caenorhabditis elegans requires ATP-binding cassette transporters HAF-4 and HAF-9, which are highly homologous to human lysosomal peptide transporter TAP-like. Mol Biol Cell 2009; 20:2979-90. [PMID: 19403699 PMCID: PMC2695804 DOI: 10.1091/mbc.e08-09-0912] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 04/10/2009] [Accepted: 04/17/2009] [Indexed: 11/11/2022] Open
Abstract
TAP-like (TAPL; ABCB9) is a half-type ATP-binding cassette (ABC) transporter that localizes in lysosome and putatively conveys peptides from cytosol to lysosome. However, the physiological role of this transporter remains to be elucidated. Comparison of genome databases reveals that TAPL is conserved in various species from a simple model organism, Caenorhabditis elegans, to mammals. C. elegans possesses homologous TAPL genes: haf-4 and haf-9. In this study, we examined the tissue-specific expression of these two genes and analyzed the phenotypes of the loss-of-function mutants for haf-4 and haf-9 to elucidate the in vivo function of these genes. Both HAF-4 and HAF-9 tagged with green fluorescent protein (GFP) were mainly localized on the membrane of nonacidic but lysosome-associated membrane protein homologue (LMP-1)-positive intestinal granules from larval to adult stage. The mutants for haf-4 and haf-9 exhibited granular defects in late larval and young adult intestinal cells, associated with decreased brood size, prolonged defecation cycle, and slow growth. The intestinal granular phenotype was rescued by the overexpression of the GFP-tagged wild-type protein, but not by the ATP-unbound form of HAF-4. These results demonstrate that two ABC transporters, HAF-4 and HAF-9, are related to intestinal granular formation and some other physiological aspects.
Collapse
Affiliation(s)
- Hiromi Kawai
- *Department of Molecular Biology and Biochemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Takahiro Tanji
- Department of Immunobiology, School of Pharmacy, Iwate Medical University, Yahaba, Shiwa-gun, Iwate 028-3694, Japan
| | - Hirohisa Shiraishi
- Department of Immunobiology, School of Pharmacy, Iwate Medical University, Yahaba, Shiwa-gun, Iwate 028-3694, Japan
| | - Mitsuo Yamada
- *Department of Molecular Biology and Biochemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Ryoko Iijima
- *Department of Molecular Biology and Biochemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Takao Inoue
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yasuko Kezuka
- *Department of Molecular Biology and Biochemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Kazuaki Ohashi
- *Department of Molecular Biology and Biochemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Yasuo Yoshida
- The Center for Electron Microscopy and Bio-Imaging Research, Iwate Medical University, Morioka, Iwate 020-8505, Japan; and
| | - Koujiro Tohyama
- The Center for Electron Microscopy and Bio-Imaging Research, Iwate Medical University, Morioka, Iwate 020-8505, Japan; and
| | - Keiko Gengyo-Ando
- Department of Physiology, School of Medicine, Tokyo Women's Medical University, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Shohei Mitani
- Department of Physiology, School of Medicine, Tokyo Women's Medical University, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Hiroyuki Arai
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ayako Ohashi-Kobayashi
- *Department of Molecular Biology and Biochemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
- Department of Immunobiology, School of Pharmacy, Iwate Medical University, Yahaba, Shiwa-gun, Iwate 028-3694, Japan
| | - Masatomo Maeda
- *Department of Molecular Biology and Biochemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| |
Collapse
|
37
|
Abele R, Tampé R. Peptide trafficking and translocation across membranes in cellular signaling and self-defense strategies. Curr Opin Cell Biol 2009; 21:508-15. [PMID: 19443191 DOI: 10.1016/j.ceb.2009.04.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 04/11/2009] [Accepted: 04/14/2009] [Indexed: 01/03/2023]
Abstract
Cells are metastable per se and a fine-tuned balance of de novo protein synthesis and degradation shapes their proteome. The primary function of peptides is to supply amino acids for de novo protein synthesis or as an energy source during starvation. Peptides are intrinsically short-lived and steadily trimmed by an armada of intra and extracellular peptidases. However, peptides acquired additional, more sophisticated tasks already early in evolution. Here, we summarize current knowledge on intracellular peptide trafficking and translocation mediated by ATP-binding cassette (ABC) transport machineries with a focus on the functions of protein degradation products as important signaling molecules in self-defense mechanisms.
Collapse
Affiliation(s)
- Rupert Abele
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt aM, Germany
| | | |
Collapse
|
38
|
Sturm A, Cunningham P, Dean M. The ABC transporter gene family of Daphnia pulex. BMC Genomics 2009; 10:170. [PMID: 19383151 PMCID: PMC2680897 DOI: 10.1186/1471-2164-10-170] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Accepted: 04/21/2009] [Indexed: 11/24/2022] Open
Abstract
Background The large gene superfamily of ABC (ATP-binding cassette) transporters encodes membrane proteins involved in trafficking processes across biological membranes and further essential cell biological functions. ABC transporters are evolutionary ancient and involved in the biochemical defence against toxicants. We report here a genome-wide survey of ABC proteins of Daphnia pulex, providing for the first time information on ABC proteins in crustacea, a primarily aquatic arthropod subphylum of high ecological and economical importance. Results We identified 64 ABC proteins in the Daphnia genome, which possesses members of all current ABC subfamilies A to H. To unravel phylogenetic relationships, ABC proteins of Daphnia were compared to those from yeast, worm, fruit fly and human. A high conservation of Daphnia of ABC transporters was observed for proteins involved in fundamental cellular processes, including the mitochondrial half transporters of the ABCB subfamily, which function in iron metabolism and transport of Fe/S protein precursors, and the members of subfamilies ABCD, ABCE and ABCF, which have roles in very long chain fatty acid transport, initiation of gene transcription and protein translation, respectively. A number of Daphnia proteins showed one-to-one orthologous relationships to Drosophila ABC proteins including the sulfonyl urea receptor (SUR), the ecdysone transporter ET23, and the eye pigment precursor transporter scarlet. As the fruit fly, Daphnia lacked homologues to the TAP protein, which plays a role in antigene processing, and the cystic fibrosis transmembrane conductance regulator (CFTR), which functions as a chloride channel. Daphnia showed two proteins homologous to MDR (multidrug resistance) P-glycoproteins (ABCB subfamily) and six proteins homologous to MRPs (multidrug resistance-associated proteins) (ABCC subfamily). However, lineage specific gene duplications in the ABCB and ABCC subfamilies complicated the inference of function. A particularly high number of gene duplications were observed in the ABCG and ABCH subfamilies, which have 23 and 15 members, respectively. Conclusion The in silico characterisation of ABC transporters in the Daphnia pulex genome revealed that the complement of ABC transporters is as complex in crustaceans as that other metazoans. Not surprisingly, among currently available genomes, Daphnia ABC transporters most closely resemble those of the fruit fly, another arthropod.
Collapse
Affiliation(s)
- Armin Sturm
- Institute of Aquaculture, University of Stirling, Stirling, UK.
| | | | | |
Collapse
|
39
|
Kamakura A, Fujimoto Y, Motohashi Y, Ohashi K, Ohashi-Kobayashi A, Maeda M. Functional dissection of transmembrane domains of human TAP-like (ABCB9). Biochem Biophys Res Commun 2008; 377:847-51. [DOI: 10.1016/j.bbrc.2008.10.078] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Accepted: 10/15/2008] [Indexed: 11/24/2022]
|
40
|
Zhao C, Haase W, Tampé R, Abele R. Peptide Specificity and Lipid Activation of the Lysosomal Transport Complex ABCB9 (TAPL). J Biol Chem 2008; 283:17083-91. [DOI: 10.1074/jbc.m801794200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
41
|
Ohara T, Ohashi-Kobayashi A, Maeda M. Biochemical characterization of transporter associated with antigen processing (TAP)-like (ABCB9) expressed in insect cells. Biol Pharm Bull 2008; 31:1-5. [PMID: 18175933 DOI: 10.1248/bpb.31.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ATP-binding cassette (ABC) transporter, transporter associated with antigen processing (TAP)-like (TAPL) tagged with a histidine cluster was overexpressed, amounting to as much as 1-2% of total membrane proteins in Drosophila cell line S2. TAPL was effectively solubilized from membranes by Triton X-100, NP-40 and n-dodecyl-beta-D-maltoside. Solubilized TAPL bound ATP-agarose and adenosine 5'-diphosphate (ADP)-agarose but not adenosine 5'-monophosphate (AMP)-agarose. The binding was competed for by excess free ATP, ADP, guanosine 5'-triphosphate (GTP) and dATP but not by AMP. Pyrimidine nucleotides such as uridine 5'-triphosphate (UTP) and cytidine 5'-triphosphate (CTP) were less effective competitors, suggesting that purine nucleotide triphosphates are substrates for TAPL. The ATP-binding of TAPL required Mg(2+), and was observed at neutral pH. Chemical cross-linking experiments suggested that TAPL forms a homodimer in the membrane and under the solubilized conditions.
Collapse
Affiliation(s)
- Tomomi Ohara
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | | | | |
Collapse
|
42
|
Jalil YA, Ritz V, Jakimenko A, Schmitz-Salue C, Siebert H, Awuah D, Kotthaus A, Kietzmann T, Ziemann C, Hirsch-Ernst KI. Vesicular localization of the rat ATP-binding cassette half-transporter rAbcb6. Am J Physiol Cell Physiol 2008; 294:C579-90. [PMID: 18160489 DOI: 10.1152/ajpcell.00612.2006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The clarification of subcellular localization represents an important basis toward characterization of ATP-binding cassette (ABC) transporters and resolution of their roles in cellular physiology. Rat Abcb6 (rAbcb6) is a membrane-situated half-transporter belonging to the ABC protein superfamily. To investigate rAbcb6 subcellular distribution, the human colon adenocarcinoma line LoVo, which we found to be devoid of endogenous human ABCB6 mRNA, was employed for heterologous expression of rAbcb6 bearing a COOH-terminal epitope tag (rAbcb6-V5). Following subcellular fractionation, rAbcb6-V5 was observed as an N-glycosylated protein in fractions enriched with lysosomal/endosomal membrane proteins. Indirect immunofluorescence analyses of rAbcb6-V5 using antibodies against a rAbcb6-specific peptide or against the V5-tag revealed a punctate pattern that was colocalized with lysosome-associated membrane protein 1 (LAMP1), a marker of lysosomes/late endosomes. Substantial colocalization of tagged rAbcb6 with lysosomal/late endosomal marker was confirmed with living, unfixed LoVo cells coexpressing rAbcb6 fused to enhanced green fluorescent protein. Vesicular distribution in LoVo cells was consistent with localization of endogenous rAbcb6 expressed in rat primary hepatocyte cultures or in liver sections, as revealed by overlap of rat Lamp1 with rAbcb6 in double immunofluorescence analyses. Since several Abcb6-related half-transporters confer heavy metal tolerance, we investigated whether rAbcb6 expression in LoVo cells might affect sensitivity toward transition metal toxicity. Applying MTT viability assays, we found that expression of either rAbcb6-V5 or untagged rAbcb6 conferred tolerance toward copper, but not to cobalt or zinc. In summary, these results demonstrate that rAbcb6 is a glycosylated protein targeted to intracellular vesicular membranes and suggest involvement of rAbcb6 in transition metal homeostasis.
Collapse
Affiliation(s)
- Youssef Abdul Jalil
- Institute of Pharmacology and Toxicology, University of Göttingen, Robert-Koch-Str. 40, D-37075 Göttingen, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Demirel Ö, Waibler Z, Kalinke U, Grünebach F, Appel S, Brossart P, Hasilik A, Tampé R, Abele R. Identification of a Lysosomal Peptide Transport System Induced during Dendritic Cell Development. J Biol Chem 2007; 282:37836-43. [DOI: 10.1074/jbc.m708139200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
44
|
Schroeder LK, Kremer S, Kramer MJ, Currie E, Kwan E, Watts JL, Lawrenson AL, Hermann GJ. Function of the Caenorhabditis elegans ABC transporter PGP-2 in the biogenesis of a lysosome-related fat storage organelle. Mol Biol Cell 2007; 18:995-1008. [PMID: 17202409 PMCID: PMC1805080 DOI: 10.1091/mbc.e06-08-0685] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Caenorhabditis elegans gut granules are intestine specific lysosome-related organelles with birefringent and autofluorescent contents. We identified pgp-2, which encodes an ABC transporter, in screens for genes required for the proper formation of gut granules. pgp-2(-) embryos mislocalize birefringent material into the intestinal lumen and are lacking in acidified intestinal V-ATPase-containing compartments. Adults without pgp-2(+) function similarly lack organelles with gut granule characteristics. These cellular phenotypes indicate that pgp-2(-) animals are defective in gut granule biogenesis. Double mutant analysis suggests that pgp-2(+) functions in parallel with the AP-3 adaptor complex during gut granule formation. We find that pgp-2 is expressed in the intestine where it functions in gut granule biogenesis and that PGP-2 localizes to the gut granule membrane. These results support a direct role of an ABC transporter in regulating lysosome biogenesis. Previously, pgp-2(+) activity has been shown to be necessary for the accumulation of Nile Red-stained fat in C. elegans. We show that gut granules are sites of fat storage in C. elegans embryos and adults. Notably, levels of triacylglycerides are relatively normal in animals defective in the formation of gut granules. Our results provide an explanation for the loss of Nile Red-stained fat in pgp-2(-) animals as well as insight into the specialized function of this lysosome-related organelle.
Collapse
Affiliation(s)
| | - Susan Kremer
- Program in Biochemistry and Molecular Biology, Lewis and Clark College, Portland, OR 97219; and
| | - Maxwell J. Kramer
- Program in Biochemistry and Molecular Biology, Lewis and Clark College, Portland, OR 97219; and
| | - Erin Currie
- *Department of Biology and
- Program in Biochemistry and Molecular Biology, Lewis and Clark College, Portland, OR 97219; and
| | - Elizabeth Kwan
- Program in Biochemistry and Molecular Biology, Lewis and Clark College, Portland, OR 97219; and
| | - Jennifer L. Watts
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164
| | | | - Greg J. Hermann
- *Department of Biology and
- Program in Biochemistry and Molecular Biology, Lewis and Clark College, Portland, OR 97219; and
| |
Collapse
|
45
|
Palti Y, Rodriguez MF, Gahr SA, Hansen JD. Evolutionary history of the ABCB2 genomic region in teleosts. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2007; 31:483-98. [PMID: 17055577 DOI: 10.1016/j.dci.2006.07.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Revised: 07/21/2006] [Accepted: 07/23/2006] [Indexed: 05/12/2023]
Abstract
Gene duplication, silencing and translocation have all been implicated in shaping the unique genomic architecture of the teleost MH regions. Previously, we demonstrated that trout possess five unlinked regions encoding MH genes. One of these regions harbors ABCB2 which in all other vertebrate classes is found in the MHC class II region. In this study, we sequenced a BAC contig for the trout ABCB2 region. Analysis of this region revealed the presence of genes homologous to those located in the human class II (ABCB2, BRD2, psiDAA), extended class II (RGL2, PHF1, SYGP1) and class III (PBX2, Notch-L) regions. The organization and syntenic relationships of this region were then compared to similar regions in humans, Tetraodon and zebrafish to learn more about the evolutionary history of this region. Our analysis indicates that this region was generated during the teleost-specific duplication event while also providing insight about potential MH paralogous regions in teleosts.
Collapse
Affiliation(s)
- Y Palti
- National Center for Cool and Cold Water Aquaculture USDA/ARS, 11861 Leetown Road, Kearneysville, WV 25430, USA.
| | | | | | | |
Collapse
|
46
|
Schaheen L, Patton G, Fares H. Suppression of thecup-5mucolipidosis type IV-related lysosomal dysfunction by the inactivation of an ABC transporter inC. elegans. Development 2006; 133:3939-48. [PMID: 16943270 DOI: 10.1242/dev.02575] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mutations in MCOLN1, which encodes the protein mucolipin 1, result in the lysosomal storage disease mucolipidosis Type IV. Studies on human mucolipin 1 and on CUP-5, the Caenorhabditis elegans ortholog of mucolipin 1, have shown that these proteins are required for lysosome biogenesis/function. Loss of CUP-5 results in a defect in lysosomal degradation, leading to embryonic lethality. We have identified a mutation in the ABC transporter MRP-4 that rescues the degradation defect and the corresponding lethality, owing to the absence of CUP-5. MRP-4 localizes to endocytic compartments and its levels are elevated in the absence of CUP-5. These results indicate that the lysosomal degradation defect is exacerbated in some cells because of the accumulation of MRP-4 in lysosomes rather than the loss of CUP-5 per se. We also show that under some conditions, loss of MRP-4 rescues the embryonic lethality caused by the loss of the cathepsin L protease, indicating that the accumulation of ABC transporters may be a more general mechanism whereby an initial lysosomal dysfunction is more severely compromised.
Collapse
Affiliation(s)
- Lara Schaheen
- Department of Molecular and Cellular Biology, Life Sciences South Room 531, University of Arizona, Tucson, AZ 85721, USA
| | | | | |
Collapse
|
47
|
Sundaram P, Echalier B, Han W, Hull D, Timmons L. ATP-binding cassette transporters are required for efficient RNA interference in Caenorhabditis elegans. Mol Biol Cell 2006; 17:3678-88. [PMID: 16723499 PMCID: PMC1525249 DOI: 10.1091/mbc.e06-03-0192] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
RNA interference (RNAi) is a conserved gene-silencing phenomenon that can be triggered by delivery of double-stranded RNA (dsRNA) to cells and is a widely exploited technology in analyses of gene function. Although a number of proteins that facilitate RNAi have been identified, current descriptions of RNAi and interrelated mechanisms are far from complete. Here, we report that the Caenorhabditis elegans gene haf-6 is required for efficient RNAi. HAF-6 is a member of the ATP-binding cassette (ABC) transporter gene superfamily. ABC transporters use ATP to translocate small molecule substrates across the membranes in which they reside, often against a steep concentration gradient. Collectively, ABC transporters are involved in a variety of activities, including protective or barrier mechanisms that export drugs or toxins from cells, organellar biogenesis, and mechanisms that protect against viral infection. HAF-6 is expressed predominantly in the intestine and germline and is localized to intracellular reticular organelles. We further demonstrate that eight additional ABC genes from diverse subfamilies are each required for efficient RNAi in C. elegans. Thus, the ability to mount a robust RNAi response to dsRNA depends upon the deployment of two ancient systems that respond to environmental assaults: RNAi mechanisms and membrane transport systems that use ABC proteins.
Collapse
Affiliation(s)
- Prema Sundaram
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045
| | - Benjamin Echalier
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045
| | - Wang Han
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045
| | - Dawn Hull
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045
| | - Lisa Timmons
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045
| |
Collapse
|
48
|
Herget M, Tampé R. Intracellular peptide transporters in human--compartmentalization of the "peptidome". Pflugers Arch 2006; 453:591-600. [PMID: 16710701 DOI: 10.1007/s00424-006-0083-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2006] [Accepted: 03/27/2006] [Indexed: 01/09/2023]
Abstract
In the human genome, the five adenosine triphosphate (ATP)-binding cassette (ABC) half transporters ABCB2 (TAP1), ABCB3 (TAP2), ABCB9 (TAP-like), and in part, also ABCB8 and ABCB10 are closely related with regard to their structural and functional properties. Although targeted to different cellular compartments such as the endoplasmic reticulum (ER), lysosomes, and mitochondria, they are involved in intracellular peptide trafficking across membranes. The transporter associated with antigen processing (TAP1 and TAP2) constitute a key machinery in the major histocompatibility complex (MHC) class I-mediated cellular immune defense against infected or malignantly transformed cells. TAP translocates the cellular "peptidome" derived primarily from cytosolic proteasomal degradation into the ER lumen for presentation by MHC class I molecules. The homodimeric ABCB9 (TAP-like) complex located in lysosomal compartments shares structural and functional similarities to TAP; however, its biological role seems to be different from the MHC I antigen processing. ABCB8 and ABCB10 are targeted to the inner mitochondrial membrane. MDL1, the yeast homologue of ABCB10, is involved in the export of peptides derived from proteolysis of inner-membrane proteins into the intermembrane space. As such peptides are presented as minor histocompatibility antigens on the surface of mammalian cells, a physiological role of ABCB10 in the antigen processing can be accounted.
Collapse
Affiliation(s)
- Meike Herget
- Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Frankfurt, Germany
| | | |
Collapse
|
49
|
Ohashi-Kobayashi A, Ohashi K, Du WB, Omote H, Nakamoto R, Al-Shawi M, Maeda M. Examination of drug resistance activity of human TAP-like (ABCB9) expressed in yeast. Biochem Biophys Res Commun 2006; 343:597-601. [PMID: 16554024 DOI: 10.1016/j.bbrc.2006.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Accepted: 03/02/2006] [Indexed: 11/29/2022]
Abstract
A half-type ABC transporter, human TAP-like (hTAPL) tagged with histidine cluster, was expressed in budding yeast protease-deficient strain BJ5457, and the effect of expression for resistance to peptide compounds including antibiotics and proteinase inhibitor was examined. Among these compounds, the yeast expressing hTAPL exhibits high sensitivity to valinomycin, a monovalent cation ionophore. A mutation in Walker A motif, which lost ATP-binding activity of hTAPL, eliminated the enhanced sensitivity to valinomycin. These findings suggest that the transport activity of hTAPL is important for conferring high valinomycin-sensitive phenotype to yeast.
Collapse
Affiliation(s)
- Ayako Ohashi-Kobayashi
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | | | | | | | | | | | | |
Collapse
|
50
|
Zhao C, Tampé R, Abele R. TAP and TAP-like--brothers in arms? Naunyn Schmiedebergs Arch Pharmacol 2006; 372:444-50. [PMID: 16525794 DOI: 10.1007/s00210-005-0028-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Accepted: 12/07/2005] [Indexed: 10/24/2022]
Abstract
The transporter associated with antigen processing like (TAPL, ABCB9) is a member of the ATP-binding cassette (ABC) transporter family. Moreover, TAPL belongs to the TAP family due to its high sequence homology to TAP1 and TAP2. TAPL forms a homodimer which is localized in lysosomes with a minor fraction in the ER. It functions as an ATP-dependent peptide transporter which shows a broad peptide specificity ranging from 6-mer up to 59-mer peptides. In contrast to TAP, TAPL transports peptides with low affinity but high efficiency. This review will briefly summarize current knowledge about the structural organization and possible physiological function of TAPL in antigen processing and presentation.
Collapse
Affiliation(s)
- Chenguang Zhao
- Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Marie-Curie-Str. 9, 60439, Frankfurt am Main, Germany
| | | | | |
Collapse
|