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Yoon S, Bae HE, Hariharan P, Nygaard A, Lan B, Woubshete M, Sadaf A, Liu X, Loland CJ, Byrne B, Guan L, Chae PS. Rational Approach to Improve Detergent Efficacy for Membrane Protein Stabilization. Bioconjug Chem 2024; 35:223-231. [PMID: 38215010 DOI: 10.1021/acs.bioconjchem.3c00507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2024]
Abstract
Membrane protein structures are essential for the molecular understanding of diverse cellular processes and drug discovery. Detergents are not only widely used to extract membrane proteins from membranes but also utilized to preserve native protein structures in aqueous solution. However, micelles formed by conventional detergents are suboptimal for membrane protein stabilization, necessitating the development of novel amphiphilic molecules with enhanced protein stabilization efficacy. In this study, we prepared two sets of tandem malonate-derived glucoside (TMG) variants, both of which were designed to increase the alkyl chain density in micelle interiors. The alkyl chain density was modulated either by reducing the spacer length (TMG-Ms) or by introducing an additional alkyl chain between the two alkyl chains of the original TMGs (TMG-Ps). When evaluated with a few membrane proteins including a G protein-coupled receptor, TMG-P10,8 was found to be substantially more efficient at extracting membrane proteins and also effective at preserving protein integrity in the long term compared to the previously described TMG-A13. This result reveals that inserting an additional alkyl chain between the two existing alkyl chains is an effective way to optimize detergent properties for membrane protein study. This new biochemical tool and the design principle described have the potential to facilitate membrane protein structure determination.
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Affiliation(s)
- Soyoung Yoon
- Department of Bionano Engineering, Hanyang University ERICA, Ansan 155-88, South Korea
| | - Hyoung Eun Bae
- Department of Bionano Engineering, Hanyang University ERICA, Ansan 155-88, South Korea
| | - Parameswaran Hariharan
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, United States
| | - Andreas Nygaard
- Department of Neuroscience, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Baoliang Lan
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, School of Medicine, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Menebere Woubshete
- Department of Life Sciences, Imperial College London, London SW7 2AZ, U.K
| | - Aiman Sadaf
- Department of Bionano Engineering, Hanyang University ERICA, Ansan 155-88, South Korea
| | - Xiangyu Liu
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, School of Medicine, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Claus J Loland
- Department of Neuroscience, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Bernadette Byrne
- Department of Life Sciences, Imperial College London, London SW7 2AZ, U.K
| | - Lan Guan
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, United States
| | - Pil Seok Chae
- Department of Bionano Engineering, Hanyang University ERICA, Ansan 155-88, South Korea
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Sun M, Dai P, Cao Z, Dong J. Purine metabolism in plant pathogenic fungi. Front Microbiol 2024; 15:1352354. [PMID: 38384269 PMCID: PMC10879430 DOI: 10.3389/fmicb.2024.1352354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/29/2024] [Indexed: 02/23/2024] Open
Abstract
In eukaryotic cells, purine metabolism is the way to the production of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) and plays key roles in various biological processes. Purine metabolism mainly consists of de novo, salvage, and catabolic pathways, and some components of these pathways have been characterized in some plant pathogenic fungi, such as the rice blast fungus Magnaporthe oryzae and wheat head blight fungus Fusarium graminearum. The enzymatic steps of the de novo pathway are well-conserved in plant pathogenic fungi and play crucial roles in fungal growth and development. Blocking this pathway inhibits the formation of penetration structures and invasive growth, making it essential for plant infection by pathogenic fungi. The salvage pathway is likely indispensable but requires exogenous purines, implying that purine transporters are functional in these fungi. The catabolic pathway balances purine nucleotides and may have a conserved stage-specific role in pathogenic fungi. The significant difference of the catabolic pathway in planta and in vitro lead us to further explore and identify the key genes specifically regulating pathogenicity in purine metabolic pathway. In this review, we summarized recent advances in the studies of purine metabolism, focusing on the regulation of pathogenesis and growth in plant pathogenic fungi.
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Affiliation(s)
- Manli Sun
- State Key Laboratory of North China Crop Improvement and Regulation/Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology/College of Plant Protection, Hebei Agricultural University, Baoding, Hebei, China
| | | | | | - Jingao Dong
- State Key Laboratory of North China Crop Improvement and Regulation/Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology/College of Plant Protection, Hebei Agricultural University, Baoding, Hebei, China
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3
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Wang L, Hoang A, Gil-Iturbe E, Laganowsky A, Quick M, Zhou M. Mechanism of anion exchange and small-molecule inhibition of pendrin. Nat Commun 2024; 15:346. [PMID: 38184688 PMCID: PMC10771415 DOI: 10.1038/s41467-023-44612-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 12/21/2023] [Indexed: 01/08/2024] Open
Abstract
Pendrin (SLC26A4) is an anion exchanger that mediates bicarbonate (HCO3-) exchange for chloride (Cl-) and is crucial for maintaining pH and salt homeostasis in the kidney, lung, and cochlea. Pendrin also exports iodide (I-) in the thyroid gland. Pendrin mutations in humans lead to Pendred syndrome, causing hearing loss and goiter. Inhibition of pendrin is a validated approach for attenuating airway hyperresponsiveness in asthma and for treating hypertension. However, the mechanism of anion exchange and its inhibition by drugs remains poorly understood. We applied cryo-electron microscopy to determine structures of pendrin from Sus scrofa in the presence of either Cl-, I-, HCO3- or in the apo-state. The structures reveal two anion-binding sites in each protomer, and functional analyses show both sites are involved in anion exchange. The structures also show interactions between the Sulfate Transporter and Anti-Sigma factor antagonist (STAS) and transmembrane domains, and mutational studies suggest a regulatory role. We also determine the structure of pendrin in a complex with niflumic acid (NFA), which uncovers a mechanism of inhibition by competing with anion binding and impeding the structural changes necessary for anion exchange. These results reveal directions for understanding the mechanisms of anion selectivity and exchange and their regulations by the STAS domain. This work also establishes a foundation for analyzing the pathophysiology of mutations associated with Pendred syndrome.
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Affiliation(s)
- Lie Wang
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA
| | - Anthony Hoang
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA
| | - Eva Gil-Iturbe
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY, USA
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY, USA
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, TX, USA
| | - Matthias Quick
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY, USA.
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY, USA.
- Area Neuroscience - Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA.
| | - Ming Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA.
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Geertsma ER, Oliver D. SLC26 Anion Transporters. Handb Exp Pharmacol 2024; 283:319-360. [PMID: 37947907 DOI: 10.1007/164_2023_698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Solute carrier family 26 (SLC26) is a family of functionally diverse anion transporters found in all kingdoms of life. Anions transported by SLC26 proteins include chloride, bicarbonate, and sulfate, but also small organic dicarboxylates such as fumarate and oxalate. The human genome encodes ten functional homologs, several of which are causally associated with severe human diseases, highlighting their physiological importance. Here, we review novel insights into the structure and function of SLC26 proteins and summarize the physiological relevance of human members.
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Affiliation(s)
- Eric R Geertsma
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
| | - Dominik Oliver
- Department of Neurophysiology, Institute of Physiology and Pathophysiology, Philipps University Marburg, Marburg, Germany.
- Center for Mind, Brain and Behavior (CMBB), Universities of Marburg and Giessen, Marburg, Giessen, Germany.
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Xu L, Jia W, Tao X, Ye F, Zhang Y, Ding ZJ, Zheng SJ, Qiao S, Su N, Zhang Y, Wu S, Guo J. Structures and mechanisms of the Arabidopsis cytokinin transporter AZG1. NATURE PLANTS 2024; 10:180-191. [PMID: 38172575 DOI: 10.1038/s41477-023-01590-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 11/10/2023] [Indexed: 01/05/2024]
Abstract
Cytokinins are essential for plant growth and development, and their tissue distributions are regulated by transmembrane transport. Recent studies have revealed that members of the 'Aza-Guanine Resistant' (AZG) protein family from Arabidopsis thaliana can mediate cytokinin uptake in roots. Here we present 2.7 to 3.3 Å cryo-electron microscopy structures of Arabidopsis AZG1 in the apo state and in complex with its substrates trans-zeatin (tZ), 6-benzyleaminopurine (6-BAP) or kinetin. AZG1 forms a homodimer and each subunit shares a similar topology and domain arrangement with the proteins of the nucleobase/ascorbate transporter (NAT) family. These structures, along with functional analyses, reveal the molecular basis for cytokinin recognition. Comparison of the AZG1 structures determined in inward-facing conformations and predicted by AlphaFold2 in the occluded conformation allowed us to propose that AZG1 may carry cytokinins across the membrane through an elevator mechanism.
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Affiliation(s)
- Lingyi Xu
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
- Nanhu Brain-computer Interface Institute, Hangzhou, China.
| | - Wei Jia
- National Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang, China
- Calibra Lab at DIAN Diagnostics, Key Laboratory of Digital Technology in Medical Diagnostics of Zhejiang Provinces, Hangzhou, Zhejiang, China
| | - Xin Tao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Fan Ye
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Nanhu Brain-computer Interface Institute, Hangzhou, China
| | - Yan Zhang
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Nanhu Brain-computer Interface Institute, Hangzhou, China
| | - Zhong Jie Ding
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Shao Jian Zheng
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Shuai Qiao
- International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Nannan Su
- International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Yu Zhang
- National Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Shan Wu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, Hubei, China.
| | - Jiangtao Guo
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
- Nanhu Brain-computer Interface Institute, Hangzhou, China.
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Science and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
- Department of Cardiology, Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
- Cancer Center, Zhejiang University, Hangzhou, Zhejiang, China.
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, Zhejiang, China.
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6
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Georgiou X, Dimou S, Diallinas G, Samiotaki M. The interactome of the UapA transporter reveals putative new players in anterograde membrane cargo trafficking. Fungal Genet Biol 2023; 169:103840. [PMID: 37730157 DOI: 10.1016/j.fgb.2023.103840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/01/2023] [Accepted: 09/15/2023] [Indexed: 09/22/2023]
Abstract
Neosynthesized plasma membrane (PM) proteins co-translationally translocate to the ER, concentrate at regions called ER-exit sites (ERes) and pack into COPII secretory vesicles which are sorted to the early-Golgi through membrane fusion. Following Golgi maturation, membrane cargoes reach the late-Golgi, from where they exit in clathrin-coated vesicles destined to the PM, directly or through endosomes. Post-Golgi membrane cargo trafficking also involves the cytoskeleton and the exocyst. The Golgi-dependent secretory pathway is thought to be responsible for the trafficking of all major membrane proteins. However, our recent findings in Aspergillus nidulans showed that several plasma membrane cargoes, such as transporters and receptors, follow a sorting route that seems to bypass Golgi functioning. To gain insight on membrane trafficking and specifically Golgi-bypass, here we used proximity dependent biotinylation (PDB) coupled with data-independent acquisition mass spectrometry (DIA-MS) for identifying transient interactors of the UapA transporter. Our assays, which included proteomes of wild-type and mutant strains affecting ER-exit or endocytosis, identified both expected and novel interactions that might be physiologically relevant to UapA trafficking. Among those, we validated, using reverse genetics and fluorescence microscopy, that COPI coatomer is essential for ER-exit and anterograde trafficking of UapA and other membrane cargoes. We also showed that ArfAArf1 GTPase activating protein (GAP) Glo3 contributes to UapA trafficking at increased temperature. This is the first report addressing the identification of transient interactions during membrane cargo biogenesis using PDB and proteomics coupled with fungal genetics. Our work provides a basis for dissecting dynamic membrane cargo trafficking via PDB assays.
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Affiliation(s)
- Xenia Georgiou
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens 15784, Greece
| | - Sofia Dimou
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens 15784, Greece
| | - George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens 15784, Greece; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion 70013, Greece.
| | - Martina Samiotaki
- Biomedical Sciences Research Center "Alexander Fleming", Institute for Bioinnovation, Vari 16672, Greece.
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Li L, Zhou L, Jiang C, Liu Z, Meng D, Luo F, He Q, Yin H. AI-driven pan-proteome analyses reveal insights into the biohydrometallurgical properties of Acidithiobacillia. Front Microbiol 2023; 14:1243987. [PMID: 37744906 PMCID: PMC10512742 DOI: 10.3389/fmicb.2023.1243987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 08/21/2023] [Indexed: 09/26/2023] Open
Abstract
Microorganism-mediated biohydrometallurgy, a sustainable approach for metal recovery from ores, relies on the metabolic activity of acidophilic bacteria. Acidithiobacillia with sulfur/iron-oxidizing capacities are extensively studied and applied in biohydrometallurgy-related processes. However, only 14 distinct proteins from Acidithiobacillia have experimentally determined structures currently available. This significantly hampers in-depth investigations of Acidithiobacillia's structure-based biological mechanisms pertaining to its relevant biohydrometallurgical processes. To address this issue, we employed a state-of-the-art artificial intelligence (AI)-driven approach, with a median model confidence of 0.80, to perform high-quality full-chain structure predictions on the pan-proteome (10,458 proteins) of the type strain Acidithiobacillia. Additionally, we conducted various case studies on de novo protein structural prediction, including sulfate transporter and iron oxidase, to demonstrate how accurate structure predictions and gene co-occurrence networks can contribute to the development of mechanistic insights and hypotheses regarding sulfur and iron utilization proteins. Furthermore, for the unannotated proteins that constitute 35.8% of the Acidithiobacillia proteome, we employed the deep-learning algorithm DeepFRI to make structure-based functional predictions. As a result, we successfully obtained gene ontology (GO) terms for 93.6% of these previously unknown proteins. This study has a significant impact on improving protein structure and function predictions, as well as developing state-of-the-art techniques for high-throughput analysis of large proteomic data.
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Affiliation(s)
- Liangzhi Li
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China
| | - Lei Zhou
- Beijing Research Institute of Chemical Engineering and Metallurgy, Beijing, China
| | - Chengying Jiang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zhenghua Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China
| | - Delong Meng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China
| | - Feng Luo
- School of Computing, Clemson University, Clemson, SC, United States
| | - Qiang He
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Huaqun Yin
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China
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Weng J, Zhou X, Wiriyasermkul P, Ren Z, Chen K, Gil-Iturbe E, Zhou M, Quick M. Insight into the mechanism of H +-coupled nucleobase transport. Proc Natl Acad Sci U S A 2023; 120:e2302799120. [PMID: 37549264 PMCID: PMC10438392 DOI: 10.1073/pnas.2302799120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 07/07/2023] [Indexed: 08/09/2023] Open
Abstract
Members of the nucleobase/ascorbic acid transporter (NAT) gene family are found in all kingdoms of life. In mammals, the concentrative uptake of ascorbic acid (vitamin C) by members of the NAT family is driven by the Na+ gradient, while the uptake of nucleobases in bacteria is powered by the H+ gradient. Here, we report the structure and function of PurTCp, a NAT family member from Colwellia psychrerythraea. The structure of PurTCp was determined to 2.80 Å resolution by X-ray crystallography. PurTCp forms a homodimer, and each protomer has 14 transmembrane segments folded into a transport domain (core domain) and a scaffold domain (gate domain). A purine base is present in the structure and defines the location of the substrate binding site. Functional studies reveal that PurTCp transports purines but not pyrimidines and that purine binding and transport is dependent on the pH. Mutation of a conserved aspartate residue close to the substrate binding site reveals the critical role of this residue in H+-dependent transport of purines. Comparison of the PurTCp structure with transporters of the same structural fold suggests that rigid-body motions of the substrate-binding domain are central for substrate translocation across the membrane.
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Affiliation(s)
- Jun Weng
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY10032
| | - Xiaoming Zhou
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY10032
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY10032
| | - Pattama Wiriyasermkul
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY10032
| | - Zhenning Ren
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX77030
| | - Kehan Chen
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX77030
| | - Eva Gil-Iturbe
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY10032
| | - Ming Zhou
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY10032
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX77030
| | - Matthias Quick
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY10032
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY10032
- Area Neuroscience - Molecular Therapeutics, New York State Psychiatric Institute, New York, NY10032
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9
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Zhekova HR, Ramirez-Echemendía DP, Sejdiu BI, Pushkin A, Tieleman DP, Kurtz I. Coarse-grained molecular dynamics simulations of lipid-protein interactions in SLC4 proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.26.546592. [PMID: 37425774 PMCID: PMC10327080 DOI: 10.1101/2023.06.26.546592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The SLC4 family of secondary bicarbonate transporters is responsible for the transport of HCO 3 -, CO 3 2- , Cl - , Na + , K + , NH 3 and H + necessary for regulation of pH and ion homeostasis. They are widely expressed in numerous tissues throughout the body and function in different cell types with different membrane properties. Potential lipid roles in SLC4 function have been reported in experimental studies, focusing mostly on two members of the family: AE1 (Cl - /HCO 3 - exchanger) and NBCe1 (Na + -CO 3 2- cotransporter). Previous computational studies of the outward facing (OF) state of AE1 with model lipid membranes revealed enhanced protein-lipid interactions between cholesterol (CHOL) and phosphatidylinositol bisphosphate (PIP2). However, the protein-lipid interactions in other members of the family and other conformation states are still poorly understood and this precludes the detailed studies of a potential regulatory role for lipids in the SLC4 family. In this work, we performed multiple 50 µs coarse-grained molecular dynamics simulations on three members of the SLC4 family with different transport modes: AE1, NBCe1 and NDCBE (a Na + -CO 3 2- /Cl - exchanger), in model HEK293 membranes consisting of CHOL, PIP2, phosphatidylcholine (POPC), phosphatidylethanolamine (POPE), phosphatidylserine (POPS), and sphingomyelin (POSM). The recently resolved inward-facing (IF) state of AE1 was also included in the simulations. Lipid-protein contact analysis of the simulated trajectories was performed with the ProLint server, which provides a multitude of visualization tools for illustration of areas of enhanced lipid-protein contact and identification of putative lipid binding sites within the protein matrix. We observed enrichment of CHOL and PIP2 around all proteins with subtle differences in their distribution depending on the protein type and conformation state. Putative binding sites were identified for CHOL, PIP2, POPC, and POSM in the three studied proteins and their potential roles in the SLC4 transport function, conformational transition and protein dimerization were discussed. Statement of significance The SLC4 protein family is involved in critical physiological processes like pH and blood pressure regulation and maintenance of ion homeostasis. Its members can be found in various tissues. A number of studies suggest possible lipid regulation of the SLC4 function. However, the protein-lipid interactions in the SLC4 family are still poorly understood. Here we make use of long coarse-grained molecular dynamics simulations to assess the protein-lipid interactions in three SLC4 proteins with different transport modes, AE1, NBCe1, and NDCBE. We identify putative lipid binding sites for several lipid types of potential mechanistic importance, discuss them in the framework of the known experimental data and provide a necessary basis for further studies on lipid regulation of SLC4 function.
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Wang M, He J, Li S, Cai Q, Zhang K, She J. Structural basis of vitamin C recognition and transport by mammalian SVCT1 transporter. Nat Commun 2023; 14:1361. [PMID: 36914666 PMCID: PMC10011568 DOI: 10.1038/s41467-023-37037-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 02/28/2023] [Indexed: 03/15/2023] Open
Abstract
Vitamin C (L-ascorbic acid) is an essential nutrient for human health, and its deficiency has long been known to cause scurvy. Sodium-dependent vitamin C transporters (SVCTs) are responsible for vitamin C uptake and tissue distribution in mammals. Here, we present cryogenic electron microscopy structures of mouse SVCT1 in both the apo and substrate-bound states. Mouse SVCT1 forms a homodimer with each protomer containing a core domain and a gate domain. The tightly packed extracellular interfaces between the core domain and gate domain stabilize the protein in an inward-open conformation for both the apo and substrate-bound structures. Vitamin C binds at the core domain of each subunit, and two potential sodium ions are identified near the binding site. The coordination of sodium ions by vitamin C explains their coupling transport. SVCTs probably deliver substrate through an elevator mechanism in combination with local structural arrangements. Altogether, our results reveal the molecular mechanism by which SVCTs recognize vitamin C and lay a foundation for further mechanistic studies on SVCT substrate transport.
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Affiliation(s)
- Mingxing Wang
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, 230026, China
| | - Jin He
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, 230026, China
| | - Shanshan Li
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, 230026, China
| | - Qianwen Cai
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
| | - Kaiming Zhang
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, 230026, China.
| | - Ji She
- MOE Key Laboratory for Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
- Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, 230026, China.
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11
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Beltran JL, McGrath LG, Caruso S, Bain RK, Hendrix CE, Kamran H, Johnston HG, Collings RM, Henry MCN, Abera TAL, Donoso VA, Carriker EC, Thurtle-Schmidt BH. Borate Transporters and SLC4 Bicarbonate Transporters Share Key Functional Properties. MEMBRANES 2023; 13:membranes13020235. [PMID: 36837738 PMCID: PMC9959716 DOI: 10.3390/membranes13020235] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 06/03/2023]
Abstract
Borate transporters are membrane transport proteins that regulate intracellular borate levels. In plants, borate is a micronutrient essential for growth but is toxic in excess, while in yeast, borate is unnecessary for growth and borate export confers tolerance. Borate transporters share structural homology with human bicarbonate transporters in the SLC4 family despite low sequence identity and differences in transported solutes. Here, we characterize the S. cerevisiae borate transporter Bor1p and examine whether key biochemical features of SLC4 transporters extend to borate transporters. We show that borate transporters and SLC4 transporters share multiple properties, including lipid-promoted dimerization, sensitivity to stilbene disulfonate-derived inhibitors, and a requirement for an acidic residue at the solute binding site. We also identify several amino acids critical for Bor1p function and show that disease-causing mutations in human SLC4A1 will eliminate in vivo function when their homologous mutations are introduced in Bor1p. Our data help elucidate mechanistic features of Bor1p and reveal significant functional properties shared between borate transporters and SLC4 transporters.
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12
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CryoEM structures of anion exchanger 1 capture multiple states of inward- and outward-facing conformations. Commun Biol 2022; 5:1372. [PMID: 36517642 PMCID: PMC9751308 DOI: 10.1038/s42003-022-04306-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 11/28/2022] [Indexed: 12/15/2022] Open
Abstract
Anion exchanger 1 (AE1, band 3) is a major membrane protein of red blood cells and plays a key role in acid-base homeostasis, urine acidification, red blood cell shape regulation, and removal of carbon dioxide during respiration. Though structures of the transmembrane domain (TMD) of three SLC4 transporters, including AE1, have been resolved previously in their outward-facing (OF) state, no mammalian SLC4 structure has been reported in the inward-facing (IF) conformation. Here we present the cryoEM structures of full-length bovine AE1 with its TMD captured in both IF and OF conformations. Remarkably, both IF-IF homodimers and IF-OF heterodimers were detected. The IF structures feature downward movement in the core domain with significant unexpected elongation of TM11. Molecular modeling and structure guided mutagenesis confirmed the functional significance of residues involved in TM11 elongation. Our data provide direct evidence for an elevator-like mechanism of ion transport by an SLC4 family member.
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13
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Dimakis D, Pyrris Y, Diallinas G. Transmembrane helices 5 and 12 control transport dynamics, substrate affinity, and specificity in the elevator-type UapA transporter. Genetics 2022; 222:6650625. [PMID: 35894659 PMCID: PMC9434233 DOI: 10.1093/genetics/iyac107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 07/11/2022] [Indexed: 01/17/2023] Open
Abstract
An increasing number of solute transporters have been shown to function with the so-called sliding-elevator mechanism. Despite structural and functional differences, all elevator-type transporters use a common mechanism of substrate translocation via reversible movements of a mobile core domain (the elevator) hosting the substrate binding site along a rigid scaffold domain stably anchored in the plasma membrane via homodimerization. One of the best-studied elevator transporters is the UapA uric acid-xanthine/H+ symporter of the filamentous fungus Aspergillus nidulans. Here, we present a genetic analysis for deciphering the role of transmembrane segments (TMS) 5 and 12 in UapA transport function. We show that specific residues in both TMS5 and TMS12 control, negatively or positively, the dynamics of transport, but also substrate binding affinity and specificity. More specifically, mutations in TMS5 can lead not only to increased rate of transport but also to an inactive transporter due to high-affinity substrate-trapping, whereas mutations in TMS12 lead to apparently uncontrolled sliding and broadened specificity, leading in specific cases to UapA-mediated purine toxicity. Our findings shed new light on how elevator transporters function and how this knowledge can be applied to genetically modify their transport characteristics.
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Affiliation(s)
- Dimitris Dimakis
- Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
| | - Yiannis Pyrris
- Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
| | - George Diallinas
- Corresponding author: Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, 15784 Athens, Greece.
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14
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Wiuf A, Steffen JH, Becares ER, Grønberg C, Mahato DR, Rasmussen SGF, Andersson M, Croll T, Gotfryd K, Gourdon P. The two-domain elevator-type mechanism of zinc-transporting ZIP proteins. SCIENCE ADVANCES 2022; 8:eabn4331. [PMID: 35857505 PMCID: PMC9278863 DOI: 10.1126/sciadv.abn4331] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 05/27/2022] [Indexed: 05/13/2023]
Abstract
Zinc is essential for all organisms and yet detrimental at elevated levels. Hence, homeostasis of this metal is tightly regulated. The Zrt/Irt-like proteins (ZIPs) represent the only zinc importers in metazoans. Mutations in human ZIPs cause serious disorders, but the mechanism by which ZIPs transfer zinc remains elusive. Hitherto, structural information is only available for a model member, BbZIP, and as a single, ion-bound conformation, precluding mechanistic insights. Here, we elucidate an inward-open metal-free BbZIP structure, differing substantially in the relative positions of the two separate domains of ZIPs. With accompanying coevolutional analyses, mutagenesis, and uptake assays, the data point to an elevator-type transport mechanism, likely shared within the ZIP family, unifying earlier functional data. Moreover, the structure reveals a previously unknown ninth transmembrane segment that is important for activity in vivo. Our findings outline the mechanistic principles governing ZIP-protein transport and enhance the molecular understanding of ZIP-related disorders.
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Affiliation(s)
- Anders Wiuf
- Department of Biomedical Sciences, University of Copenhagen, Mærsk Tower 7-9, Nørre Allé 14, DK-2200 Copenhagen, Denmark
| | - Jonas Hyld Steffen
- Department of Biomedical Sciences, University of Copenhagen, Mærsk Tower 7-9, Nørre Allé 14, DK-2200 Copenhagen, Denmark
| | - Eva Ramos Becares
- Department of Biomedical Sciences, University of Copenhagen, Mærsk Tower 7-9, Nørre Allé 14, DK-2200 Copenhagen, Denmark
| | - Christina Grønberg
- Department of Biomedical Sciences, University of Copenhagen, Mærsk Tower 7-9, Nørre Allé 14, DK-2200 Copenhagen, Denmark
| | - Dhani Ram Mahato
- Department of Chemistry, Umeå University, Linnaeus Väg 10, SE-901 87 Umeå, Sweden
| | - Søren G. F. Rasmussen
- Department of Neuroscience, University of Copenhagen, Maersk Tower 7-5, Nørre Allé 14, DK-2200 Copenhagen, Denmark
| | - Magnus Andersson
- Department of Chemistry, Umeå University, Linnaeus Väg 10, SE-901 87 Umeå, Sweden
| | - Tristan Croll
- Cambridge Institute for Medical Research, Department of Haematology, University of Cambridge, Keith Peters Building, Hills Rd., Cambridge CB2 0XY, UK
| | - Kamil Gotfryd
- Department of Biomedical Sciences, University of Copenhagen, Mærsk Tower 7-9, Nørre Allé 14, DK-2200 Copenhagen, Denmark
| | - Pontus Gourdon
- Department of Biomedical Sciences, University of Copenhagen, Mærsk Tower 7-9, Nørre Allé 14, DK-2200 Copenhagen, Denmark
- Department of Experimental Medical Science, Lund University, Sölvegatan 19, SE-221 84 Lund, Sweden
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15
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Barata-Antunes C, Talaia G, Broutzakis G, Ribas D, De Beule P, Casal M, Stefan CJ, Diallinas G, Paiva S. Interactions of cytosolic tails in the Jen1 carboxylate transporter are critical for trafficking and transport activity. J Cell Sci 2022; 135:275079. [PMID: 35437607 DOI: 10.1242/jcs.260059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 04/05/2022] [Indexed: 12/26/2022] Open
Abstract
Plasma membrane (PM) transporters of the major facilitator superfamily (MFS) are essential for cell metabolism, growth and response to stress or drugs. In Saccharomyces cerevisiae, Jen1 is a monocarboxylate/H+ symporter that provides a model to dissect the molecular details underlying cellular expression, transport mechanism and turnover of MFS transporters. Here, we present evidence revealing novel roles of the cytosolic N- and C-termini of Jen1 in its biogenesis, PM stability and transport activity, using functional analyses of Jen1 truncations and chimeric constructs with UapA, an endocytosis-insensitive transporter of Aspergillus nidulans. Our results show that both N- and C-termini are critical for Jen1 trafficking to the PM, transport activity and endocytosis. Importantly, we provide evidence that Jen1 N- and C-termini undergo transport-dependent dynamic intramolecular interactions, which affect the transport activity and turnover of Jen1. Our results support an emerging concept where the cytoplasmic termini of PM transporters control transporter cell surface stability and function through flexible intramolecular interactions with each other. These findings might be extended to other MFS members to understand conserved and evolving mechanisms underlying transporter structure-function relationships. This article has an associated First Person interview with the first authors of the paper.
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Affiliation(s)
- Cláudia Barata-Antunes
- Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, 4710-057, Braga, Portugal.,Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, 4710-057, Braga, Portugal
| | - Gabriel Talaia
- Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, 4710-057, Braga, Portugal.,Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - George Broutzakis
- Department of Biology, National and Kapodistrian University of Athens, Panepistimiopolis 15784, Athens, Greece
| | - David Ribas
- Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, 4710-057, Braga, Portugal
| | - Pieter De Beule
- International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga s/n, Braga, Portugal
| | - Margarida Casal
- Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, 4710-057, Braga, Portugal.,Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, 4710-057, Braga, Portugal
| | - Christopher J Stefan
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, Panepistimiopolis 15784, Athens, Greece.,Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, 70013, Heraklion, Greece
| | - Sandra Paiva
- Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, 4710-057, Braga, Portugal.,Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, 4710-057, Braga, Portugal
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16
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Dimou S, Dionysopoulou M, Sagia GM, Diallinas G. Golgi-Bypass Is a Major Unconventional Route for Translocation to the Plasma Membrane of Non-Apical Membrane Cargoes in Aspergillus nidulans. Front Cell Dev Biol 2022; 10:852028. [PMID: 35465316 PMCID: PMC9021693 DOI: 10.3389/fcell.2022.852028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
Nutrient transporters have been shown to translocate to the plasma membrane (PM) of the filamentous fungus Aspergillus nidulans via an unconventional trafficking route that bypasses the Golgi. This finding strongly suggests the existence of distinct COPII vesicle subpopulations, one following Golgi-dependent conventional secretion and the other directed towards the PM. Here, we address whether Golgi-bypass concerns cargoes other than nutrient transporters and whether Golgi-bypass is related to cargo structure, size, abundance, physiological function, or polar vs. non-polar distribution in the PM. To address these questions, we followed the dynamic subcellular localization of two selected membrane cargoes differing in several of the aforementioned aspects. These are the proton-pump ATPase PmaA and the PalI pH signaling component. Our results show that neosynthesized PmaA and PalI are translocated to the PM via Golgi-bypass, similar to nutrient transporters. In addition, we showed that the COPII-dependent exit of PmaA from the ER requires the alternative COPII coat subunit LstA, rather than Sec24, whereas PalI requires the ER cargo adaptor Erv14. These findings strengthen the evidence of distinct cargo-specific COPII subpopulations and extend the concept of Golgi-independent biogenesis to essential transmembrane proteins, other than nutrient transporters. Overall, our findings point to the idea that Golgi-bypass might not constitute a fungal-specific peculiarity, but rather a novel major and cargo-specific sorting route in eukaryotic cells that has been largely ignored.
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Affiliation(s)
- Sofia Dimou
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens, Greece
| | - Mariangela Dionysopoulou
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens, Greece
| | - Georgia Maria Sagia
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens, Greece
| | - George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion, Greece
- *Correspondence: George Diallinas,
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17
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Kalli AC, Reithmeier RAF. Organization and Dynamics of the Red Blood Cell Band 3 Anion Exchanger SLC4A1: Insights From Molecular Dynamics Simulations. Front Physiol 2022; 13:817945. [PMID: 35283786 PMCID: PMC8914234 DOI: 10.3389/fphys.2022.817945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 01/27/2022] [Indexed: 01/16/2023] Open
Abstract
Molecular dynamics (MD) simulations have provided new insights into the organization and dynamics of the red blood cell Band 3 anion exchanger (AE1, SLC4A1). Band 3, like many solute carriers, works by an alternating access mode of transport where the protein rapidly (104/s) changes its conformation between outward and inward-facing states via a transient occluded anion-bound intermediate. While structural studies of membrane proteins usually reveal valuable structural information, these studies provide a static view often in the presence of detergents. Membrane transporters are embedded in a lipid bilayer and associated lipids play a role in their folding and function. In this review, we highlight MD simulations of Band 3 in realistic lipid bilayers that revealed specific lipid and protein interactions and were used to re-create a model of the Wright (Wr) blood group antigen complex of Band 3 and Glycophorin A. Current MD studies of Band 3 and related transporters are focused on describing the trajectory of substrate binding and translocation in real time. A structure of the intact Band 3 protein has yet to be achieved experimentally, but cryo-electron microscopy in combination with MD simulations holds promise to capture the conformational changes associated with anion transport in exquisite molecular detail.
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Affiliation(s)
- Antreas C. Kalli
- Leeds Institute of Cardiovascular and Metabolic Medicine and Astbury Center for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Reinhart A. F. Reithmeier
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- *Correspondence: Reinhart A. F. Reithmeier,
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18
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Wu H, Liu S, Su P, Xie Z, Gui T, Zhao L, Liu Y, Chen L. Molecular insight into coordination sites for substrates and their coupling kinetics in Na
+
/HCO
3
−
cotransporter NBCe1. J Physiol 2022; 600:3083-3111. [DOI: 10.1113/jp282034] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 02/03/2022] [Indexed: 11/08/2022] Open
Affiliation(s)
- Han Wu
- Key Laboratory of Molecular Biophysics of Ministry of Education School of Life Science & Technology Huazhong University of Science & Technology Wuhan 430074 China
| | - Shiyong Liu
- School of Physics Huazhong University of Science and Technology Wuhan 430074 China
| | - Pan Su
- Key Laboratory of Molecular Biophysics of Ministry of Education School of Life Science & Technology Huazhong University of Science & Technology Wuhan 430074 China
| | - Zhang‐Dong Xie
- Key Laboratory of Molecular Biophysics of Ministry of Education School of Life Science & Technology Huazhong University of Science & Technology Wuhan 430074 China
| | - Tian‐Xiang Gui
- Key Laboratory of Molecular Biophysics of Ministry of Education School of Life Science & Technology Huazhong University of Science & Technology Wuhan 430074 China
| | - Lei Zhao
- Department of Obstetrics Maternal and Child Health Hospital of Hubei Province Wuhan 430070 China
| | - Ying Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education School of Life Science & Technology Huazhong University of Science & Technology Wuhan 430074 China
| | - Li‐Ming Chen
- Key Laboratory of Molecular Biophysics of Ministry of Education School of Life Science & Technology Huazhong University of Science & Technology Wuhan 430074 China
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19
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Holzhüter K, Geertsma ER. Uniport, Not Proton-Symport, in a Non-Mammalian SLC23 Transporter. J Mol Biol 2021; 434:167393. [PMID: 34896363 DOI: 10.1016/j.jmb.2021.167393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/17/2021] [Accepted: 12/01/2021] [Indexed: 10/25/2022]
Abstract
SLC23 family members are transporters of either nucleobases or ascorbate. While the mammalian SLC23 ascorbate transporters are sodium-coupled, the non-mammalian nucleobase transporters have been proposed, but not formally shown, to be proton-coupled symporters. This assignment is exclusively based on in vivo transport assays using protonophores. Here, by establishing the first in vitro transport assay for this protein family, we demonstrate that a representative member of the SLC23 nucleobase transporters operates as a uniporter instead. We explain these conflicting assignments by identifying a critical role of uracil phosphoribosyltransferase, the enzyme converting uracil to UMP, in driving uracil uptake in vivo. Detailed characterization of uracil phosphoribosyltransferase reveals that the sharp reduction of uracil uptake in whole cells in presence of protonophores is caused by acidification-induced enzyme inactivation. The SLC23 family therefore consists of both uniporters and symporters in line with the structurally related SLC4 and SLC26 families that have previously been demonstrated to accommodate both transport modes as well.
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Affiliation(s)
- Katharina Holzhüter
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany
| | - Eric R Geertsma
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany; Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany.
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20
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Tatsaki E, Anagnostopoulou E, Zantza I, Lazou P, Mikros E, Frillingos S. Identification of New Specificity Determinants in Bacterial Purine Nucleobase Transporters based on an Ancestral Sequence Reconstruction Approach. J Mol Biol 2021; 433:167329. [PMID: 34710398 DOI: 10.1016/j.jmb.2021.167329] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 10/05/2021] [Accepted: 10/19/2021] [Indexed: 11/28/2022]
Abstract
The relation of sequence with specificity in membrane transporters is challenging to explore. Most relevant studies until now rely on comparisons of present-day homologs. In this work, we study a set of closely related transporters by employing an evolutionary, ancestral-reconstruction approach and reveal unexpected new specificity determinants. We analyze a monophyletic group represented by the xanthine-specific XanQ of Escherichia coli in the Nucleobase-Ascorbate Transporter/Nucleobase-Cation Symporter-2 (NAT/NCS2) family. We reconstructed AncXanQ, the putative common ancestor of this clade, expressed it in E. coli K-12, and found that, in contrast to XanQ, it encodes a high-affinity permease for both xanthine and guanine, which also recognizes adenine, hypoxanthine, and a range of analogs. AncXanQ conserves all binding-site residues of XanQ and differs substantially in only five intramembrane residues outside the binding site. We subjected both homologs to rationally designed mutagenesis and present evidence that these five residues are linked with the specificity change. In particular, we reveal Ser377 of XanQ (Gly in AncXanQ) as a major determinant. Replacement of this Ser with Gly enlarges the specificity of XanQ towards an AncXanQ-phenotype. The ortholog from Neisseria meningitidis retaining Gly at this position is also a xanthine/guanine transporter with extended substrate profile like AncXanQ. Molecular Dynamics shows that the S377G replacement tilts transmembrane helix 12 resulting in rearrangement of Phe376 relative to Phe94 in the XanQ binding pocket. This effect may rationalize the enlarged specificity. On the other hand, the specificity effect of S377G can be masked by G27S or other mutations through epistatic interactions.
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Affiliation(s)
- Ekaterini Tatsaki
- Laboratory of Biological Chemistry, Department of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Eleni Anagnostopoulou
- Laboratory of Biological Chemistry, Department of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece. https://twitter.com/EleniAnagn
| | - Iliana Zantza
- Division of Pharmaceutical Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Panayiota Lazou
- Laboratory of Biological Chemistry, Department of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Emmanuel Mikros
- Division of Pharmaceutical Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Stathis Frillingos
- Laboratory of Biological Chemistry, Department of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece; Institute of Biosciences, University Research Center of Ioannina, Ioannina, Greece.
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21
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Wang W, Tsirulnikov K, Zhekova HR, Kayık G, Khan HM, Azimov R, Abuladze N, Kao L, Newman D, Noskov SY, Zhou ZH, Pushkin A, Kurtz I. Cryo-EM structure of the sodium-driven chloride/bicarbonate exchanger NDCBE. Nat Commun 2021; 12:5690. [PMID: 34584093 PMCID: PMC8478935 DOI: 10.1038/s41467-021-25998-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 09/08/2021] [Indexed: 02/08/2023] Open
Abstract
SLC4 transporters play significant roles in pH regulation and cellular sodium transport. The previously solved structures of the outward facing (OF) conformation for AE1 (SLC4A1) and NBCe1 (SLC4A4) transporters revealed an identical overall fold despite their different transport modes (chloride/bicarbonate exchange versus sodium-carbonate cotransport). However, the exact mechanism determining the different transport modes in the SLC4 family remains unknown. In this work, we report the cryo-EM 3.4 Å structure of the OF conformation of NDCBE (SLC4A8), which shares transport properties with both AE1 and NBCe1 by mediating the electroneutral exchange of sodium-carbonate with chloride. This structure features a fully resolved extracellular loop 3 and well-defined densities corresponding to sodium and carbonate ions in the tentative substrate binding pocket. Further, we combine computational modeling with functional studies to unravel the molecular determinants involved in NDCBE and SLC4 transport.
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Affiliation(s)
- Weiguang Wang
- grid.19006.3e0000 0000 9632 6718Department of Medicine, Division of Nephrology, David Geffen School of Medicine, University of California, Los Angeles, CA USA ,grid.509979.b0000 0004 7666 6191Electron Imaging Center for Nanomachines, California NanoSystems Institute, University of California, Los Angeles, CA USA
| | - Kirill Tsirulnikov
- grid.19006.3e0000 0000 9632 6718Department of Medicine, Division of Nephrology, David Geffen School of Medicine, University of California, Los Angeles, CA USA
| | - Hristina R. Zhekova
- grid.22072.350000 0004 1936 7697Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Gülru Kayık
- grid.22072.350000 0004 1936 7697Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Hanif Muhammad Khan
- grid.22072.350000 0004 1936 7697Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Rustam Azimov
- grid.19006.3e0000 0000 9632 6718Department of Medicine, Division of Nephrology, David Geffen School of Medicine, University of California, Los Angeles, CA USA
| | - Natalia Abuladze
- grid.19006.3e0000 0000 9632 6718Department of Medicine, Division of Nephrology, David Geffen School of Medicine, University of California, Los Angeles, CA USA
| | - Liyo Kao
- grid.19006.3e0000 0000 9632 6718Department of Medicine, Division of Nephrology, David Geffen School of Medicine, University of California, Los Angeles, CA USA
| | - Debbie Newman
- grid.19006.3e0000 0000 9632 6718Department of Medicine, Division of Nephrology, David Geffen School of Medicine, University of California, Los Angeles, CA USA
| | - Sergei Yu. Noskov
- grid.22072.350000 0004 1936 7697Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Z. Hong Zhou
- grid.509979.b0000 0004 7666 6191Electron Imaging Center for Nanomachines, California NanoSystems Institute, University of California, Los Angeles, CA USA ,grid.19006.3e0000 0000 9632 6718Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA USA
| | - Alexander Pushkin
- grid.19006.3e0000 0000 9632 6718Department of Medicine, Division of Nephrology, David Geffen School of Medicine, University of California, Los Angeles, CA USA
| | - Ira Kurtz
- grid.19006.3e0000 0000 9632 6718Department of Medicine, Division of Nephrology, David Geffen School of Medicine, University of California, Los Angeles, CA USA ,grid.19006.3e0000 0000 9632 6718Brain Research Institute, University of California, Los Angeles, CA USA
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22
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Molecular mechanism of prestin electromotive signal amplification. Cell 2021; 184:4669-4679.e13. [PMID: 34390643 PMCID: PMC8674105 DOI: 10.1016/j.cell.2021.07.034] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/26/2021] [Accepted: 07/23/2021] [Indexed: 11/21/2022]
Abstract
Hearing involves two fundamental processes: mechano-electrical transduction and signal amplification. Despite decades of studies, the molecular bases for both remain elusive. Here, we show how prestin, the electromotive molecule of outer hair cells (OHCs) that senses both voltage and membrane tension, mediates signal amplification by coupling conformational changes to alterations in membrane surface area. Cryoelectron microscopy (cryo-EM) structures of human prestin bound with chloride or salicylate at a common "anion site" adopt contracted or expanded states, respectively. Prestin is ensconced within a perimeter of well-ordered lipids, through which it induces dramatic deformation in the membrane and couples protein conformational changes to the bulk membrane. Together with computational studies, we illustrate how the anion site is allosterically coupled to changes in the transmembrane domain cross-sectional area and the surrounding membrane. These studies provide insight into OHC electromotility by providing a structure-based mechanism of the membrane motor prestin.
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23
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Diallinas G. Transporter Specificity: A Tale of Loosened Elevator-Sliding. Trends Biochem Sci 2021; 46:708-717. [PMID: 33903007 DOI: 10.1016/j.tibs.2021.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/13/2021] [Accepted: 03/26/2021] [Indexed: 12/14/2022]
Abstract
Elevator-type transporters are a group of proteins translocating nutrients and metabolites across cell membranes. Despite structural and functional differences, elevator-type transporters use a common mechanism of substrate translocation via reversible movements of a mobile core domain (the elevator), which includes the substrate binding site, along a rigid scaffold domain, stably anchored in the plasma membrane. How substrate specificity is determined in elevator transporters remains elusive. Here, I discuss how a recent report on the sliding elevator mechanism, seen under the context of genetic analysis of a prototype fungal transporter, sheds light on how specificity might be genetically modified. I propose that flexible specificity alterations might occur by 'loosening' of the sliding mechanism from tight coupling to substrate binding.
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Affiliation(s)
- George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, 15784, Athens, Greece; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion, Greece.
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24
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Insights into the Role of Membrane Lipids in the Structure, Function and Regulation of Integral Membrane Proteins. Int J Mol Sci 2021; 22:ijms22169026. [PMID: 34445730 PMCID: PMC8396450 DOI: 10.3390/ijms22169026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/15/2021] [Accepted: 08/17/2021] [Indexed: 02/07/2023] Open
Abstract
Membrane proteins exist within the highly hydrophobic membranes surrounding cells and organelles, playing key roles in cellular function. It is becoming increasingly clear that the membrane does not just act as an appropriate environment for these proteins, but that the lipids that make up these membranes are essential for membrane protein structure and function. Recent technological advances in cryogenic electron microscopy and in advanced mass spectrometry methods, as well as the development of alternative membrane mimetic systems, have allowed experimental study of membrane protein–lipid complexes. These have been complemented by computational approaches, exploiting the ability of Molecular Dynamics simulations to allow exploration of membrane protein conformational changes in membranes with a defined lipid content. These studies have revealed the importance of lipids in stabilising the oligomeric forms of membrane proteins, mediating protein–protein interactions, maintaining a specific conformational state of a membrane protein and activity. Here we review some of the key recent advances in the field of membrane protein–lipid studies, with major emphasis on respiratory complexes, transporters, channels and G-protein coupled receptors.
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25
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Structure and function of an Arabidopsis thaliana sulfate transporter. Nat Commun 2021; 12:4455. [PMID: 34294705 PMCID: PMC8298490 DOI: 10.1038/s41467-021-24778-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 07/01/2021] [Indexed: 02/06/2023] Open
Abstract
Plant sulfate transporters (SULTR) mediate absorption and distribution of sulfate (SO42-) and are essential for plant growth; however, our understanding of their structures and functions remains inadequate. Here we present the structure of a SULTR from Arabidopsis thaliana, AtSULTR4;1, in complex with SO42- at an overall resolution of 2.8 Å. AtSULTR4;1 forms a homodimer and has a structural fold typical of the SLC26 family of anion transporters. The bound SO42- is coordinated by side-chain hydroxyls and backbone amides, and further stabilized electrostatically by the conserved Arg393 and two helix dipoles. Proton and SO42- are co-transported by AtSULTR4;1 and a proton gradient significantly enhances SO42- transport. Glu347, which is ~7 Å from the bound SO42-, is required for H+-driven transport. The cytosolic STAS domain interacts with transmembrane domains, and deletion of the STAS domain or mutations to the interface compromises dimer formation and reduces SO42- transport, suggesting a regulatory function of the STAS domain.
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26
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Alexander CR, Huntley RB, Schultes NP, Mourad GS. Functional characterization of the adenine transporter EaAdeP from the fire blight pathogen Erwinia amylovora and its effect on disease establishment in apples and pears. FEMS Microbiol Lett 2021; 367:5932216. [PMID: 33152083 DOI: 10.1093/femsle/fnaa173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 10/18/2020] [Indexed: 11/13/2022] Open
Abstract
Erwinia amylovora is the causal agent of fire blight, an economically important disease of apples and pears. As part of the infection process, Er. amylovora propagates on different plant tissues each with distinct nutrient environments. Here, the biochemical properties of the Er. amylovora adenine permease (EaAdeP) are investigated. Heterologous expression of EaAdeP in nucleobase transporter-deficient Escherichia coli strains, coupled with radiolabel uptake studies, revealed that EaAdeP is a high affinity adenine transporter with a Km of 0.43 ± 0.09 μM. Both Es. coli and Er. amylovora carrying extra copies of EaAdeP are sensitive to growth on the toxic analog 8-azaadenine. EaAdeP is expressed during immature pear fruit infection. Immature pear and apple fruit virulence assays reveal that an E. amylovora ΔadeP::Camr mutant is still able to cause disease symptoms, however, with growth at a lower level, indicating that external adenine is utilized in disease establishment.
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Affiliation(s)
- Candace R Alexander
- Department of Biology, Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN 46805, USA
| | - Regan B Huntley
- Department of Plant Pathology & Ecology, The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT 06511, USA
| | - Neil P Schultes
- Department of Plant Pathology & Ecology, The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT 06511, USA
| | - George S Mourad
- Department of Biology, Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN 46805, USA
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27
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Cecchetti C, Strauss J, Stohrer C, Naylor C, Pryor E, Hobbs J, Tanley S, Goldman A, Byrne B. A novel high-throughput screen for identifying lipids that stabilise membrane proteins in detergent based solution. PLoS One 2021; 16:e0254118. [PMID: 34252116 PMCID: PMC8274869 DOI: 10.1371/journal.pone.0254118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/20/2021] [Indexed: 12/29/2022] Open
Abstract
Membrane proteins have a range of crucial biological functions and are the target of about 60% of all prescribed drugs. For most studies, they need to be extracted out of the lipid-bilayer, e.g. by detergent solubilisation, leading to the loss of native lipids, which may disturb important protein-lipid/bilayer interactions and thus functional and structural integrity. Relipidation of membrane proteins has proven extremely successful for studying challenging targets, but the identification of suitable lipids can be expensive and laborious. Therefore, we developed a screen to aid the high-throughput identification of beneficial lipids. The screen covers a large lipid space and was designed to be suitable for a range of stability assessment methods. Here, we demonstrate its use as a tool for identifying stabilising lipids for three membrane proteins: a bacterial pyrophosphatase (Tm-PPase), a fungal purine transporter (UapA) and a human GPCR (A2AR). A2AR is stabilised by cholesteryl hemisuccinate, a lipid well known to stabilise GPCRs, validating the approach. Additionally, our screen also identified a range of new lipids which stabilised our test proteins, providing a starting point for further investigation and demonstrating its value as a novel tool for membrane protein research. The pre-dispensed screen will be made commercially available to the scientific community in future and has a number of potential applications in the field.
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Affiliation(s)
- Cristina Cecchetti
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Jannik Strauss
- Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Claudia Stohrer
- Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, United Kingdom
| | | | - Edward Pryor
- Anatrace, Maumee, Ohio, United States of America
| | | | | | - Adrian Goldman
- Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, United Kingdom
- MIBS, Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- * E-mail: (AG); (BB)
| | - Bernadette Byrne
- Department of Life Sciences, Imperial College London, London, United Kingdom
- * E-mail: (AG); (BB)
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28
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Impact of Membrane Lipids on UapA and AzgA Transporter Subcellular Localization and Activity in Aspergillus nidulans. J Fungi (Basel) 2021; 7:jof7070514. [PMID: 34203131 PMCID: PMC8304608 DOI: 10.3390/jof7070514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 12/21/2022] Open
Abstract
Recent biochemical and biophysical evidence have established that membrane lipids, namely phospholipids, sphingolipids and sterols, are critical for the function of eukaryotic plasma membrane transporters. Here, we study the effect of selected membrane lipid biosynthesis mutations and of the ergosterol-related antifungal itraconazole on the subcellular localization, stability and transport kinetics of two well-studied purine transporters, UapA and AzgA, in Aspergillus nidulans. We show that genetic reduction in biosynthesis of ergosterol, sphingolipids or phosphoinositides arrest A. nidulans growth after germling formation, but solely blocks in early steps of ergosterol (Erg11) or sphingolipid (BasA) synthesis have a negative effect on plasma membrane (PM) localization and stability of transporters before growth arrest. Surprisingly, the fraction of UapA or AzgA that reaches the PM in lipid biosynthesis mutants is shown to conserve normal apparent transport kinetics. We further show that turnover of UapA, which is the transporter mostly sensitive to membrane lipid content modification, occurs during its trafficking and by enhanced endocytosis, and is partly dependent on autophagy and Hect-type HulARsp5 ubiquitination. Our results point out that the role of specific membrane lipids on transporter biogenesis and function in vivo is complex, combinatorial and transporter-dependent.
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29
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Srinivasan P, Smolke CD. Engineering cellular metabolite transport for biosynthesis of computationally predicted tropane alkaloid derivatives in yeast. Proc Natl Acad Sci U S A 2021; 118:e2104460118. [PMID: 34140414 PMCID: PMC8237673 DOI: 10.1073/pnas.2104460118] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Microbial biosynthesis of plant natural products (PNPs) can facilitate access to valuable medicinal compounds and derivatives. Such efforts are challenged by metabolite transport limitations, which arise when complex plant pathways distributed across organelles and tissues are reconstructed in unicellular hosts without concomitant transport machinery. We recently reported an engineered yeast platform for production of the tropane alkaloid (TA) drugs hyoscyamine and scopolamine, in which product accumulation is limited by vacuolar transport. Here, we demonstrate that alleviation of transport limitations at multiple steps in an engineered pathway enables increased production of TAs and screening of useful derivatives. We first show that supervised classifier models trained on a tissue-delineated transcriptome from the TA-producing plant Atropa belladonna can predict TA transporters with greater efficacy than conventional regression- and clustering-based approaches. We demonstrate that two of the identified transporters, AbPUP1 and AbLP1, increase TA production in engineered yeast by facilitating vacuolar export and cellular reuptake of littorine and hyoscyamine. We incorporate four different plant transporters, cofactor regeneration mechanisms, and optimized growth conditions into our yeast platform to achieve improvements in de novo hyoscyamine and scopolamine production of over 100-fold (480 μg/L) and 7-fold (172 μg/L). Finally, we leverage computational tools for biosynthetic pathway prediction to produce two different classes of TA derivatives, nortropane alkaloids and tropane N-oxides, from simple precursors. Our work highlights the importance of cellular transport optimization in recapitulating complex PNP biosyntheses in microbial hosts and illustrates the utility of computational methods for gene discovery and expansion of heterologous biosynthetic diversity.
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Affiliation(s)
| | - Christina D Smolke
- Department of Bioengineering, Stanford University, Stanford, CA 94305;
- Chan Zuckerberg Biohub, San Francisco, CA 94158
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30
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Structural and functional insights into the mechanism of action of plant borate transporters. Sci Rep 2021; 11:12328. [PMID: 34112901 PMCID: PMC8192573 DOI: 10.1038/s41598-021-91763-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 05/28/2021] [Indexed: 02/05/2023] Open
Abstract
Boron has essential roles in plant growth and development. BOR proteins are key in the active uptake and distribution of boron, and regulation of intracellular boron concentrations. However, their mechanism of action remains poorly studied. BOR proteins are homologues of the human SLC4 family of transporters, which includes well studied mammalian transporters such as the human Anion Exchanger 1 (hAE1). Here we generated Arabidopsis thaliana BOR1 (AtBOR1) variants based (i) on known disease causing mutations of hAE1 (S466R, A500R) and (ii) a loss of function mutation (D311A) identified in the yeast BOR protein, ScBOR1p. The AtBOR1 variants express in yeast and localise to the plasma membrane, although both S466R and A500R exhibit lower expression than the WT AtBOR1 and D311A. The D311A, S466R and A500R mutations result in a loss of borate efflux activity in a yeast bor1p knockout strain. A. thaliana plants containing these three individual mutations exhibit substantially decreased growth phenotypes in soil under conditions of low boron. These data confirm an important role for D311 in the function of the protein and show that mutations equivalent to disease-causing mutations in hAE1 have major effects in AtBOR1. We also obtained a low resolution cryo-EM structure of a BOR protein from Oryza sativa, OsBOR3, lacking the 30 C-terminal amino acid residues. This structure confirms the gate and core domain organisation previously observed for related proteins, and is strongly suggestive of an inward facing conformation.
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31
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Plant transporters involved in combating boron toxicity: beyond 3D structures. Biochem Soc Trans 2021; 48:1683-1696. [PMID: 32779723 PMCID: PMC7458394 DOI: 10.1042/bst20200164] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/15/2020] [Accepted: 07/17/2020] [Indexed: 12/12/2022]
Abstract
Membrane transporters control the movement and distribution of solutes, including the disposal or compartmentation of toxic substances that accumulate in plants under adverse environmental conditions. In this minireview, in the light of the approaching 100th anniversary of unveiling the significance of boron to plants (K. Warington, 1923; Ann. Bot.37, 629) we discuss the current state of the knowledge on boron transport systems that plants utilise to combat boron toxicity. These transport proteins include: (i) nodulin-26-like intrinsic protein-types of aquaporins, and (ii) anionic efflux (borate) solute carriers. We describe the recent progress made on the structure–function relationships of these transport proteins and point out that this progress is integral to quantitative considerations of the transporter's roles in tissue boron homeostasis. Newly acquired knowledge at the molecular level has informed on the transport mechanics and conformational states of boron transport systems that can explain their impact on cell biology and whole plant physiology. We expect that this information will form the basis for engineering transporters with optimised features to alleviate boron toxicity tolerance in plants exposed to suboptimal soil conditions for sustained food production.
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32
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Cecchetti C, Scull NJ, Mohan TC, Alguel Y, Jones AMC, Cameron AD, Byrne B. Transfer of stabilising mutations between different secondary active transporter families. FEBS Open Bio 2021; 11:1685-1694. [PMID: 33932145 PMCID: PMC8167854 DOI: 10.1002/2211-5463.13168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/25/2021] [Accepted: 04/15/2021] [Indexed: 11/24/2022] Open
Abstract
Integral membrane transporters play essential roles in the movement of substrates across biological membranes. One approach to produce transporters suitable for structural studies is to introduce mutations that reduce conformational flexibility and increase stability. However, it can be difficult to predict which mutations will result in a more stable protein. Previously, we stabilised the uric acid‐xanthine transporter, UapA, a member of the SLC23 family, through introduction of a single‐point mutation, G411V, trapping the protein in the inward‐facing conformation. Here, we attempted to stabilise the structurally related BOR1 transporter from Arabidopsis thaliana, a member of the SLC4 family, by introducing the equivalent substitution. We identified possible residues, P362 and M363, in AtBOR1, likely to be equivalent to the G411 of UapA, and generated four mutants, P362V or L and M363F or Y. Stability analysis using heated Fluorescent Size Exclusion Chromatography indicated that the M363F/Y mutants were more stable than the WT AtBOR1 and P362V/L mutants. Furthermore, functional complementation analysis revealed that the M363F/Y mutants exhibited reduced transport activity compared to the P362V/L and WT proteins. Purification and crystallisation of the M363F/Y proteins yielded crystals that diffracted better than WT (5.5 vs 7 Å). We hypothesise that the increased bulk of the F and Y substitutions limits the ability of the protein to undergo the conformational rearrangements associated with transport. These proteins represent a basis for future studies on AtBOR1.
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Affiliation(s)
| | - Nicola J Scull
- Department of Life Sciences, Imperial College London, UK
| | | | - Yilmaz Alguel
- Department of Life Sciences, Imperial College London, UK
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33
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Identification of multiple substrate binding sites in SLC4 transporters in the outward-facing conformation: Insights into the transport mechanism. J Biol Chem 2021; 296:100724. [PMID: 33932403 PMCID: PMC8191340 DOI: 10.1016/j.jbc.2021.100724] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 04/21/2021] [Accepted: 04/27/2021] [Indexed: 01/17/2023] Open
Abstract
Solute carrier family 4 (SLC4) transporters mediate the transmembrane transport of HCO3-, CO32-, and Cl- necessary for pH regulation, transepithelial H+/base transport, and ion homeostasis. Substrate transport with varying stoichiometry and specificity is achieved through an exchange mechanism and/or through coupling of the uptake of anionic substrates to typically co-transported Na+. Recently solved outward-facing structures of two SLC4 members (human anion exchanger 1 [hAE1] and human electrogenic sodium bicarbonate cotransporter 1 [hNBCe1]) with different transport modes (Cl-/HCO3- exchange versus Na+-CO32- symport) revealed highly conserved three-dimensional organization of their transmembrane domains. However, the exact location of the ion binding sites and their protein-ion coordination motifs are still unclear. In the present work, we combined site identification by ligand competitive saturation mapping and extensive molecular dynamics sampling with functional mutagenesis studies which led to the identification of two substrate binding sites (entry and central) in the outward-facing states of hAE1 and hNBCe1. Mutation of residues in the identified binding sites led to impaired transport in both proteins. We also showed that R730 in hAE1 is crucial for anion binding in both entry and central sites, whereas in hNBCe1, a Na+ acts as an anchor for CO32- binding to the central site. Additionally, protonation of the central acidic residues (E681 in hAE1 and D754 in hNBCe1) alters the ion dynamics in the permeation cavity and may contribute to the transport mode differences in SLC4 proteins. These results provide a basis for understanding the functional differences between hAE1 and hNBCe1 and may facilitate potential drug development for diseases such as proximal and distal renal tubular acidosis.
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34
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Pizzagalli MD, Bensimon A, Superti‐Furga G. A guide to plasma membrane solute carrier proteins. FEBS J 2021; 288:2784-2835. [PMID: 32810346 PMCID: PMC8246967 DOI: 10.1111/febs.15531] [Citation(s) in RCA: 137] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/07/2020] [Accepted: 08/17/2020] [Indexed: 12/13/2022]
Abstract
This review aims to serve as an introduction to the solute carrier proteins (SLC) superfamily of transporter proteins and their roles in human cells. The SLC superfamily currently includes 458 transport proteins in 65 families that carry a wide variety of substances across cellular membranes. While members of this superfamily are found throughout cellular organelles, this review focuses on transporters expressed at the plasma membrane. At the cell surface, SLC proteins may be viewed as gatekeepers of the cellular milieu, dynamically responding to different metabolic states. With altered metabolism being one of the hallmarks of cancer, we also briefly review the roles that surface SLC proteins play in the development and progression of cancer through their influence on regulating metabolism and environmental conditions.
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Affiliation(s)
- Mattia D. Pizzagalli
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Ariel Bensimon
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Giulio Superti‐Furga
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
- Center for Physiology and PharmacologyMedical University of ViennaAustria
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35
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Endocytosis of nutrient transporters in fungi: The ART of connecting signaling and trafficking. Comput Struct Biotechnol J 2021; 19:1713-1737. [PMID: 33897977 PMCID: PMC8050425 DOI: 10.1016/j.csbj.2021.03.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 03/14/2021] [Accepted: 03/14/2021] [Indexed: 12/11/2022] Open
Abstract
Plasma membrane transporters play pivotal roles in the import of nutrients, including sugars, amino acids, nucleobases, carboxylic acids, and metal ions, that surround fungal cells. The selective removal of these transporters by endocytosis is one of the most important regulatory mechanisms that ensures a rapid adaptation of cells to the changing environment (e.g., nutrient fluctuations or different stresses). At the heart of this mechanism lies a network of proteins that includes the arrestin‐related trafficking adaptors (ARTs) which link the ubiquitin ligase Rsp5 to nutrient transporters and endocytic factors. Transporter conformational changes, as well as dynamic interactions between its cytosolic termini/loops and with lipids of the plasma membrane, are also critical during the endocytic process. Here, we review the current knowledge and recent findings on the molecular mechanisms involved in nutrient transporter endocytosis, both in the budding yeast Saccharomyces cerevisiae and in some species of the filamentous fungus Aspergillus. We elaborate on the physiological importance of tightly regulated endocytosis for cellular fitness under dynamic conditions found in nature and highlight how further understanding and engineering of this process is essential to maximize titer, rate and yield (TRY)-values of engineered cell factories in industrial biotechnological processes.
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Key Words
- AAs, amino acids
- ACT, amino Acid/Choline Transporter
- AP, adaptor protein
- APC, amino acid-polyamine-organocation
- Arg, arginine
- Arrestins
- Arts, arrestin‐related trafficking adaptors
- Asp, aspartic acid
- Aspergilli
- Biotechnology
- C, carbon
- C-terminus, carboxyl-terminus
- Cell factories
- Conformational changes
- Cu, copper
- DUBs, deubiquitinating enzymes
- EMCs, eisosome membrane compartments
- ER, endoplasmic reticulum
- ESCRT, endosomal sorting complex required for transport
- Endocytic signals
- Endocytosis
- Fe, iron
- Fungi
- GAAC, general amino acid control
- Glu, glutamic acid
- H+, proton
- IF, inward-facing
- LAT, L-type Amino acid Transporter
- LID, loop Interaction Domain
- Lys, lysine
- MCCs, membrane compartments containing the arginine permease Can1
- MCCs/eisosomes
- MCPs, membrane compartments of Pma1
- MFS, major facilitator superfamily
- MVB, multi vesicular bodies
- Met, methionine
- Metabolism
- Mn, manganese
- N, nitrogen
- N-terminus, amino-terminus
- NAT, nucleobase Ascorbate Transporter
- NCS1, nucleobase/Cation Symporter 1
- NCS2, nucleobase cation symporter family 2
- NH4+, ammonium
- Nutrient transporters
- OF, outward-facing
- PEST, proline (P), glutamic acid (E), serine (S), and threonine (T)
- PM, plasma membrane
- PVE, prevacuolar endosome
- Saccharomyces cerevisiae
- Signaling pathways
- Structure-function
- TGN, trans-Golgi network
- TMSs, transmembrane segments
- TORC1, target of rapamycin complex 1
- TRY, titer, rate and yield
- Trp, tryptophan
- Tyr, tyrosine
- Ub, ubiquitin
- Ubiquitylation
- VPS, vacuolar protein sorting
- W/V, weight per volume
- YAT, yeast Amino acid Transporter
- Zn, Zinc
- fAATs, fungal AA transporters
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36
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Elevator-type mechanisms of membrane transport. Biochem Soc Trans 2021; 48:1227-1241. [PMID: 32369548 PMCID: PMC7329351 DOI: 10.1042/bst20200290] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 03/29/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022]
Abstract
Membrane transporters are integral membrane proteins that mediate the passage of solutes across lipid bilayers. These proteins undergo conformational transitions between outward- and inward-facing states, which lead to alternating access of the substrate-binding site to the aqueous environment on either side of the membrane. Dozens of different transporter families have evolved, providing a wide variety of structural solutions to achieve alternating access. A sub-set of structurally diverse transporters operate by mechanisms that are collectively named 'elevator-type'. These transporters have one common characteristic: they contain a distinct protein domain that slides across the membrane as a rigid body, and in doing so it 'drags" the transported substrate along. Analysis of the global conformational changes that take place in membrane transporters using elevator-type mechanisms reveals that elevator-type movements can be achieved in more than one way. Molecular dynamics simulations and experimental data help to understand how lipid bilayer properties may affect elevator movements and vice versa.
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37
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Context-dependent Cryptic Roles of Specific Residues in Substrate Selectivity of the UapA Purine Transporter. J Mol Biol 2021; 433:166814. [PMID: 33497644 DOI: 10.1016/j.jmb.2021.166814] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/29/2020] [Accepted: 01/04/2021] [Indexed: 12/22/2022]
Abstract
Members of the ubiquitous Nucleobase Ascorbate Transporter (NAT) family are H+ or Na+ symporters specific for the cellular uptake of either purines and pyrimidines or L-ascorbic acid. Despite the fact that several bacterial and fungal members have been extensively characterised at a genetic, biochemical or cellular level, and crystal structures of NAT members from Escherichia coli and Aspergillus nidulans have been determined pointing to a mechanism of transport, we have little insight on how substrate selectivity is determined. Here, we present systematic mutational analyses, rational combination of mutations, and novel genetic screens that reveal cryptic context-dependent roles of partially conserved residues in the so-called NAT signature motif in determining the specificity of the UapA transporter of A. nidulans. We show that specific NAT signature motif substitutions, alone and in combinations with each other or with distant mutations in residues known to affect substrate selectivity, lead to novel UapA versions possessing variable transport capacities and specificities for nucleobases. In particular, we show that a UapA version including the quadruple mutation T405S/F406Y/A407S/Q408E in the NAT signature motif (UapA-SYSE) becomes incapable of purine transport, but gains a novel pyrimidine-related profile, which can be further altered to a more promiscuous purine/pyrimidine profile when combined with replacements at distantly located residues, especially at F528. Our results reveal that UapA specificity is genetically highly modifiable and allow us to speculate on how the elevator-type mechanism of transport might account for this flexibility.
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38
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Dissecting the Conformational Dynamics of the Bile Acid Transporter Homologue ASBT NM. J Mol Biol 2021; 433:166764. [PMID: 33359100 DOI: 10.1016/j.jmb.2020.166764] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 12/11/2020] [Accepted: 12/11/2020] [Indexed: 11/21/2022]
Abstract
Apical sodium-dependent bile acid transporter (ASBT) catalyses uphill transport of bile acids using the electrochemical gradient of Na+ as the driving force. The crystal structures of two bacterial homologues ASBTNM and ASBTYf have previously been determined, with the former showing an inward-facing conformation, and the latter adopting an outward-facing conformation accomplished by the substitution of the critical Na+-binding residue glutamate-254 with an alanine residue. While the two crystal structures suggested an elevator-like movement to afford alternating access to the substrate binding site, the mechanistic role of Na+ and substrate in the conformational isomerization remains unclear. In this study, we utilized site-directed alkylation monitored by in-gel fluorescence (SDAF) to probe the solvent accessibility of the residues lining the substrate permeation pathway of ASBTNM under different Na+ and substrate conditions, and interpreted the conformational states inferred from the crystal structures. Unexpectedly, the crosslinking experiments demonstrated that ASBTNM is a monomer protein, unlike the other elevator-type transporters, usually forming a homodimer or a homotrimer. The conformational dynamics observed by the biochemical experiments were further validated using DEER measuring the distance between the spin-labelled pairs. Our results revealed that Na+ ions shift the conformational equilibrium of ASBTNM toward the inward-facing state thereby facilitating cytoplasmic uptake of substrate. The current findings provide a novel perspective on the conformational equilibrium of secondary active transporters.
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39
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Sampson CDD, Stewart MJ, Mindell JA, Mulligan C. Solvent accessibility changes in a Na +-dependent C 4-dicarboxylate transporter suggest differential substrate effects in a multistep mechanism. J Biol Chem 2020; 295:18524-18538. [PMID: 33087444 PMCID: PMC7939474 DOI: 10.1074/jbc.ra120.013894] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 10/06/2020] [Indexed: 11/06/2022] Open
Abstract
The divalent anion sodium symporter (DASS) family (SLC13) plays critical roles in metabolic homeostasis, influencing many processes, including fatty acid synthesis, insulin resistance, and adiposity. DASS transporters catalyze the Na+-driven concentrative uptake of Krebs cycle intermediates and sulfate into cells; disrupting their function can protect against age-related metabolic diseases and can extend lifespan. An inward-facing crystal structure and an outward-facing model of a bacterial DASS family member, VcINDY from Vibrio cholerae, predict an elevator-like transport mechanism involving a large rigid body movement of the substrate-binding site. How substrate binding influences the conformational state of VcINDY is currently unknown. Here, we probe the interaction between substrate binding and protein conformation by monitoring substrate-induced solvent accessibility changes of broadly distributed positions in VcINDY using a site-specific alkylation strategy. Our findings reveal that accessibility to all positions tested is modulated by the presence of substrates, with the majority becoming less accessible in the presence of saturating concentrations of both Na+ and succinate. We also observe separable effects of Na+ and succinate binding at several positions suggesting distinct effects of the two substrates. Furthermore, accessibility changes to a solely succinate-sensitive position suggests that substrate binding is a low-affinity, ordered process. Mapping these accessibility changes onto the structures of VcINDY suggests that Na+ binding drives the transporter into an as-yet-unidentified conformational state, involving rearrangement of the substrate-binding site-associated re-entrant hairpin loops. These findings provide insight into the mechanism of VcINDY, which is currently the only structurally characterized representative of the entire DASS family.
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Affiliation(s)
- Connor D D Sampson
- School of Biosciences, University of Kent, Canterbury, Kent, United Kingdom
| | - Matthew J Stewart
- School of Biosciences, University of Kent, Canterbury, Kent, United Kingdom
| | - Joseph A Mindell
- Membrane Transport Biophysics Section, Porter Neuroscience Research Center, NINDS, National Institutes of Health, Bethesda, Maryland, USA
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40
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Akiyama T, Kunishima N, Nemoto S, Kazama K, Hirose M, Sudo Y, Matsuura Y, Naitow H, Murata T. Further thermo-stabilization of thermophilic rhodopsin from Thermus thermophilus JL-18 through engineering in extramembrane regions. Proteins 2020; 89:301-310. [PMID: 33064333 PMCID: PMC7894484 DOI: 10.1002/prot.26015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 09/26/2020] [Accepted: 10/12/2020] [Indexed: 11/11/2022]
Abstract
It is known that a hyperthermostable protein tolerable at temperatures over 100°C can be designed from a soluble globular protein by introducing mutations. To expand the applicability of this technology to membrane proteins, here we report a further thermo-stabilization of the thermophilic rhodopsin from Thermus thermophilus JL-18 as a model membrane protein. Ten single mutations in the extramembrane regions were designed based on a computational prediction of folding free-energy differences upon mutation. Experimental characterizations using the UV-visible spectroscopy and the differential scanning calorimetry revealed that four of ten mutations were thermo-stabilizing: V79K, T114D, A115P, and A116E. The mutation-structure relationship of the TR constructs was analyzed using molecular dynamics simulations at 300 K and at 1800 K that aimed simulating structures in the native and in the random-coil states, respectively. The native-state simulation exhibited an ion-pair formation of the stabilizing V79K mutant as it was designed, and suggested a mutation-induced structural change of the most stabilizing T114D mutant. On the other hand, the random-coil-state simulation revealed a higher structural fluctuation of the destabilizing mutant S8D when compared to the wild type, suggesting that the higher entropy in the random-coil state deteriorated the thermal stability. The present thermo-stabilization design in the extramembrane regions based on the free-energy calculation and the subsequent evaluation by the molecular dynamics may be useful to improve the production of membrane proteins for structural studies.
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Affiliation(s)
- Tomoki Akiyama
- Department of Chemistry, Graduate School of Science, and Molecular Chirality Research, Chiba University, Chiba, Japan
| | - Naoki Kunishima
- RIKEN RSC-Rigaku Collaboration Center, RIKEN SPring-8 Center, Sayo-gun, Hyogo, Japan.,RIKEN SPring-8 Center, Sayo-gun, Hyogo, Japan
| | - Sayaka Nemoto
- Department of Chemistry, Graduate School of Science, and Molecular Chirality Research, Chiba University, Chiba, Japan
| | - Kazuki Kazama
- Department of Chemistry, Graduate School of Science, and Molecular Chirality Research, Chiba University, Chiba, Japan
| | - Masako Hirose
- Malvern Panalytical division of Spectris Co., Ltd, Tokyo, Japan
| | - Yuki Sudo
- Division of Pharmaceutical Sciences, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | | | | | - Takeshi Murata
- Department of Chemistry, Graduate School of Science, and Molecular Chirality Research, Chiba University, Chiba, Japan
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41
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Chi X, Jin X, Chen Y, Lu X, Tu X, Li X, Zhang Y, Lei J, Huang J, Huang Z, Zhou Q, Pan X. Structural insights into the gating mechanism of human SLC26A9 mediated by its C-terminal sequence. Cell Discov 2020; 6:55. [PMID: 32818062 PMCID: PMC7417587 DOI: 10.1038/s41421-020-00193-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 07/07/2020] [Indexed: 11/25/2022] Open
Abstract
The human SLC26 transporter family exhibits various transport characteristics, and family member SLC26A9 performs multiple roles, including acting as Cl-/HCO3- exchangers, Cl- channels, and Na+ transporters. Some mutations of SLC26A9 are correlated with abnormalities in respiration and digestion systems. As a potential target colocalizing with CFTR in cystic fibrosis patients, SLC26A9 is of great value in drug development. Here, we present a cryo-EM structure of the human SLC26A9 dimer at 2.6 Å resolution. A segment at the C-terminal end is bound to the entry of the intracellular vestibule of the putative transport pathway, which has been proven by electrophysiological experiments to be a gating modulator. Multiple chloride and sodium ions are resolved in the high-resolution structure, identifying novel ion-binding pockets for the first time. Together, our structure takes important steps in elucidating the structural features and regulatory mechanism of SLC26A9, with potential significance in the treatment of cystic fibrosis.
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Affiliation(s)
- Ximin Chi
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Xueqin Jin
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Yun Chen
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Xiaoli Lu
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Xinyu Tu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191 China
| | - Xiaorong Li
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Yuanyuan Zhang
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Jianlin Lei
- Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Jing Huang
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Zhuo Huang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191 China
- Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, 100191 China
| | - Qiang Zhou
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Xiaojing Pan
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084 China
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42
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Functional (un)cooperativity in elevator transport proteins. Biochem Soc Trans 2020; 48:1047-1055. [PMID: 32573703 DOI: 10.1042/bst20190970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 11/17/2022]
Abstract
The activity of enzymes is subject to regulation at multiple levels. Cooperativity, the interconnected behavior of active sites within a protein complex, directly affects protein activity. Cooperativity is a mode of regulation that requires neither extrinsic factors nor protein modifications. Instead, it allows enzymes themselves to modulate reaction rates. Cooperativity is an important regulatory mechanism in soluble proteins, but also examples of cooperative membrane proteins have been described. In this review, we summarize the current knowledge on interprotomer cooperativity in elevator-type proteins, a class of membrane transporters characterized by large rigid-body movements perpendicular to the membrane, and highlight well-studied examples and experimental approaches.
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43
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van 't Klooster JS, Cheng TY, Sikkema HR, Jeucken A, Moody DB, Poolman B. Membrane Lipid Requirements of the Lysine Transporter Lyp1 from Saccharomyces cerevisiae. J Mol Biol 2020; 432:4023-4031. [PMID: 32413406 PMCID: PMC8005870 DOI: 10.1016/j.jmb.2020.04.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 04/28/2020] [Accepted: 04/30/2020] [Indexed: 11/25/2022]
Abstract
Membrane lipids act as solvents and functional cofactors for integral membrane proteins. The yeast plasma membrane is unusual in that it may have a high lipid order, which coincides with low passive permeability for small molecules and a slow lateral diffusion of proteins. Yet, membrane proteins whose functions require altered conformation must have flexibility within membranes. We have determined the molecular composition of yeast plasma membrane lipids located within a defined diameter of model proteins, including the APC-superfamily lysine transporter Lyp1. We now use the composition of lipids that naturally surround Lyp1 to guide testing of lipids that support the normal functioning of the transporter, when reconstituted in vesicles of defined lipid composition. We find that phosphatidylserine and ergosterol are essential for Lyp1 function, and the transport activity displays a sigmoidal relationship with the concentration of these lipids. Non-bilayer lipids stimulate transport activity, but different types are interchangeable. Remarkably, Lyp1 requires a relatively high fraction of lipids with one or more unsaturated acyl chains. The transport data and predictions of the periprotein lipidome of Lyp1 support a new model in which a narrow band of lipids immediately surrounding the transmembrane stalk of a model protein allows conformational changes in the protein.
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Affiliation(s)
- Joury S van 't Klooster
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands
| | - Tan-Yun Cheng
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women's Hospital, Harvard Medical School, 60 Fenwood Road, Boston, MA 02115, USA
| | - Hendrik R Sikkema
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands
| | - Aike Jeucken
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands
| | - D Branch Moody
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women's Hospital, Harvard Medical School, 60 Fenwood Road, Boston, MA 02115, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Bert Poolman
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
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44
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Botou M, Yalelis V, Lazou P, Zantza I, Papakostas K, Charalambous V, Mikros E, Flemetakis E, Frillingos S. Specificity profile of NAT/NCS2 purine transporters in
Sinorhizobium
(
Ensifer
)
meliloti. Mol Microbiol 2020; 114:151-171. [DOI: 10.1111/mmi.14503] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 03/16/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Maria Botou
- Laboratory of Biological Chemistry Department of Medicine School of Health Sciences University of Ioannina Ioannina Greece
| | - Vassilis Yalelis
- Laboratory of Biological Chemistry Department of Medicine School of Health Sciences University of Ioannina Ioannina Greece
| | - Panayiota Lazou
- Laboratory of Biological Chemistry Department of Medicine School of Health Sciences University of Ioannina Ioannina Greece
| | - Iliana Zantza
- Division of Pharmaceutical Chemistry Department of Pharmacy School of Health Sciences National and Kapodistrian University of Athens Athens Greece
| | - Konstantinos Papakostas
- Laboratory of Biological Chemistry Department of Medicine School of Health Sciences University of Ioannina Ioannina Greece
| | - Vassiliki Charalambous
- Laboratory of Biological Chemistry Department of Medicine School of Health Sciences University of Ioannina Ioannina Greece
| | - Emmanuel Mikros
- Division of Pharmaceutical Chemistry Department of Pharmacy School of Health Sciences National and Kapodistrian University of Athens Athens Greece
| | - Emmanouil Flemetakis
- Laboratory of Molecular Biology Department of Biotechnology Agricultural University of Athens Athens Greece
| | - Stathis Frillingos
- Laboratory of Biological Chemistry Department of Medicine School of Health Sciences University of Ioannina Ioannina Greece
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45
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Campagnaro GD, de Koning HP. Purine and pyrimidine transporters of pathogenic protozoa - conduits for therapeutic agents. Med Res Rev 2020; 40:1679-1714. [PMID: 32144812 DOI: 10.1002/med.21667] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/12/2020] [Accepted: 02/18/2020] [Indexed: 02/06/2023]
Abstract
Purines and pyrimidines are essential nutrients for any cell. Most organisms are able to synthesize their own purines and pyrimidines, but this ability was lost in protozoans that adapted to parasitism, leading to a great diversification in transporter activities in these organisms, especially for the acquisition of amino acids and nucleosides from their hosts throughout their life cycles. Many of these transporters have been shown to have sufficiently different substrate affinities from mammalian transporters, making them good carriers for therapeutic agents. In this review, we summarize the knowledge obtained on purine and pyrimidine activities identified in protozoan parasites to date and discuss their importance for the survival of these parasites and as drug carriers, as well as the perspectives of developments in the field.
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Affiliation(s)
- Gustavo D Campagnaro
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 120 University Place, Glasgow, UK
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 120 University Place, Glasgow, UK
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46
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Kourkoulou A, Grevias P, Lambrinidis G, Pyle E, Dionysopoulou M, Politis A, Mikros E, Byrne B, Diallinas G. Specific Residues in a Purine Transporter Are Critical for Dimerization, ER Exit, and Function. Genetics 2019; 213:1357-1372. [PMID: 31611232 PMCID: PMC6893392 DOI: 10.1534/genetics.119.302566] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 10/02/2019] [Indexed: 12/11/2022] Open
Abstract
Transporters are transmembrane proteins that mediate the selective translocation of solutes across biological membranes. Recently, we have shown that specific interactions with plasma membrane phospholipids are essential for the formation and/or stability of functional dimers of the purine transporter UapA, a prototypic eukaryotic member of the ubiquitous nucleobase ascorbate transporter (NAT) family. Here, we provide strong evidence that distinct interactions of UapA with membrane lipids are essential for ab initio formation of functional dimers in the ER, or ER exit and further subcellular trafficking. Through genetic screens, we identify mutations that restore defects in dimer formation and/or trafficking. Suppressors of defective dimerization restore ab initio formation of UapA dimers in the ER. Most of these suppressors are located in the movable core domain, but also in the core-dimerization interface and in residues of the dimerization domain exposed to lipids. Molecular dynamics suggest that the majority of suppressors stabilize interhelical interactions in the core domain and thus assist the formation of functional UapA dimers. Among suppressors restoring dimerization, a specific mutation, T401P, was also isolated independently as a suppressor restoring trafficking, suggesting that stabilization of the core domain restores function by sustaining structural defects caused by the abolishment of essential interactions with specific lipids. Importantly, the introduction of mutations topologically equivalent to T401P into a rat homolog of UapA, namely rSNBT1, permitted the functional expression of a mammalian NAT in Aspergillus nidulans Thus, our results provide a potential route for the functional expression and manipulation of mammalian transporters in the model Aspergillus system.
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Affiliation(s)
- Anezia Kourkoulou
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, 15784, Greece
| | - Pothos Grevias
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, 15784, Greece
| | - George Lambrinidis
- Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimioupolis, 15771, Greece
| | - Euan Pyle
- Department of Life Sciences, Imperial College London, SW7 2AZ, UK
- Department of Chemistry, King's College London, SE1 1DB, UK
| | - Mariangela Dionysopoulou
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, 15784, Greece
| | | | - Emmanuel Mikros
- Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimioupolis, 15771, Greece
| | - Bernadette Byrne
- Department of Life Sciences, Imperial College London, SW7 2AZ, UK
| | - George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, 15784, Greece
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47
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Wang C, Sun B, Zhang X, Huang X, Zhang M, Guo H, Chen X, Huang F, Chen T, Mi H, Yu F, Liu LN, Zhang P. Structural mechanism of the active bicarbonate transporter from cyanobacteria. NATURE PLANTS 2019; 5:1184-1193. [PMID: 31712753 DOI: 10.1038/s41477-019-0538-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 09/27/2019] [Indexed: 05/11/2023]
Abstract
Bicarbonate transporters play essential roles in pH homeostasis in mammals and photosynthesis in aquatic photoautotrophs. A number of bicarbonate transporters have been characterized, among which is BicA-a low-affinity, high-flux SLC26-family bicarbonate transporter involved in cyanobacterial CO2-concentrating mechanisms (CCMs) that accumulate CO2 and improve photosynthetic carbon fixation. Here, we report the three-dimensional structure of BicA from Synechocystis sp. PCC6803. Crystal structures of the transmembrane domain (BicATM) and the cytoplasmic STAS domain (BicASTAS) of BicA were solved. BicATM was captured in an inward-facing HCO3--bound conformation and adopts a '7+7' fold monomer. HCO3- binds to a cytoplasm-facing hydrophilic pocket within the membrane. BicASTAS is assembled as a compact homodimer structure and is required for the dimerization of BicA. The dimeric structure of BicA was further analysed using cryo-electron microscopy and physiological analysis of the full-length BicA, and may represent the physiological unit of SLC26-family transporters. Comparing the BicATM structure with the outward-facing transmembrane domain structures of other bicarbonate transporters suggests an elevator transport mechanism that is applicable to the SLC26/4 family of sodium-dependent bicarbonate transporters. This study advances our knowledge of the structures and functions of cyanobacterial bicarbonate transporters, and will inform strategies for bioengineering functional BicA in heterologous organisms to increase assimilation of CO2.
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Affiliation(s)
- Chengcheng Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bo Sun
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China
| | - Xue Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiaowei Huang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Minhua Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Hui Guo
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Xin Chen
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Fang Huang
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Taiyu Chen
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Hualing Mi
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Fang Yu
- Shanghai Key Laboratory of Plant Molecualr Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Lu-Ning Liu
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Peng Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
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48
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Saouros S, Cecchetti C, Jones A, Cameron AD, Byrne B. Strategies for successful isolation of a eukaryotic transporter. Protein Expr Purif 2019; 166:105522. [PMID: 31654736 DOI: 10.1016/j.pep.2019.105522] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 10/18/2019] [Accepted: 10/20/2019] [Indexed: 11/24/2022]
Abstract
The isolation of integral membrane proteins for structural analysis remains challenging and this is particularly the case for eukaryotic membrane proteins. Here we describe our efforts to isolate OsBOR3, a boron transporter from Oryza sativa. OsBOR3 was expressed as both full length and a C-terminally truncated form lacking residues 643-672 (OsBOR3Δ1-642). While both express well as C-terminal GFP fusion proteins in Saccharomyces cerevisiae, the full length protein isolates poorly in the detergent dodecyl-β-d-maltoside (DDM). The OsBOR3Δ1-642 isolated in DDM in large quantities but was contaminated with GFP tagged protein, indicated incomplete protease removal of the tag. Addition of the reducing agent dithiothreitol (DTT) had no effect on isolation. Detergent screening indicated that the neopentyl glycol detergents, LMNG, UDMNG and DMNG conferred greater stability on the OsBOR3Δ1-642 than DDM. Isolation of OsBOR3Δ1-642 in LMNG both in the presence and absence of DTT produced large quantities of protein but contaminated with GFP tagged protein. Isolation of OsBOR3Δ1-642 in DMNG + DTT resulted in protein sample that does not contain any detectable GFP but elutes at a higher retention volume than that seen for protein isolated in either DDM or LMNG. Mass spectrometry confirmed that the LMNG and DMNG purified protein is OsBOR3Δ1-642 indicating that the DMNG isolated protein is monomer compared to the dimer isolated using LMNG. This was further supported by single particle electron microscopic analysis revealing that the DMNG protein particles are roughly half the size of the LMNG protein particles.
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Affiliation(s)
- Savvas Saouros
- Department of Life Sciences, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - Cristina Cecchetti
- Department of Life Sciences, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - Alex Jones
- School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
| | - Alexander D Cameron
- School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
| | - Bernadette Byrne
- Department of Life Sciences, Imperial College London, Exhibition Road, London, SW7 2AZ, UK.
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Diallinas G, Martzoukou O. Transporter membrane traffic and function: lessons from a mould. FEBS J 2019; 286:4861-4875. [DOI: 10.1111/febs.15078] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/26/2019] [Accepted: 09/30/2019] [Indexed: 12/16/2022]
Affiliation(s)
- George Diallinas
- Department of Biology National and Kapodistrian University of Athens Greece
| | - Olga Martzoukou
- Department of Biology National and Kapodistrian University of Athens Greece
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50
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Pyle E, Guo C, Hofmann T, Schmidt C, Ribiero O, Politis A, Byrne B. Protein–Lipid Interactions Stabilize the Oligomeric State of BOR1p from Saccharomyces cerevisiae. Anal Chem 2019; 91:13071-13079. [DOI: 10.1021/acs.analchem.9b03271] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Euan Pyle
- Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, U.K
- Department of Chemistry, Kings College London, 7 Trinity Street, London SE1 1DB, U.K
| | - Chengzhi Guo
- Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, U.K
| | - Tommy Hofmann
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Centre, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str 3a, D-06120 Halle, Germany
| | - Carla Schmidt
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Centre, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str 3a, D-06120 Halle, Germany
| | - Orquidea Ribiero
- Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, U.K
| | - Argyris Politis
- Department of Chemistry, Kings College London, 7 Trinity Street, London SE1 1DB, U.K
| | - Bernadette Byrne
- Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, U.K
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