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Yan T, Weng F, Ming Y, Zhu S, Zhu M, Wang C, Guo C, Zhu K. Luminescence Probes in Bio-Applications: From Principle to Practice. BIOSENSORS 2024; 14:333. [PMID: 39056609 PMCID: PMC11274413 DOI: 10.3390/bios14070333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/03/2024] [Accepted: 07/04/2024] [Indexed: 07/28/2024]
Abstract
Bioanalysis based on optical imaging has gained significant progress in the last few decades. Luminescence probes are capable of detecting, monitoring, and tracing particular biomolecules in complex biological systems to figure out the roles of these molecules in organisms. Considering the rapid development of luminescence probes for bio-applications and their promising future, we have attempted to explore the working principles and recent advances in bio-applications of luminescence probes, in the hope of helping readers gain a detailed understanding of luminescence probes developed in recent years. In this review, we first focus on the current widely used luminescence probes, including fluorescence probes, bioluminescence probes, chemiluminescence probes, afterglow probes, photoacoustic probes, and Cerenkov luminescence probes. The working principles for each type of luminescence probe are concisely described and the bio-application of the luminescence probes is summarized by category, including metal ions detection, secretion detection, imaging, and therapy.
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Affiliation(s)
| | | | | | | | | | - Chunsheng Wang
- Department of Cardiovascular Surgery, Zhongshan Hospital Fudan University, Shanghai 200032, China; (T.Y.); (F.W.); (Y.M.); (S.Z.); (M.Z.)
| | - Changfa Guo
- Department of Cardiovascular Surgery, Zhongshan Hospital Fudan University, Shanghai 200032, China; (T.Y.); (F.W.); (Y.M.); (S.Z.); (M.Z.)
| | - Kai Zhu
- Department of Cardiovascular Surgery, Zhongshan Hospital Fudan University, Shanghai 200032, China; (T.Y.); (F.W.); (Y.M.); (S.Z.); (M.Z.)
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Jones Lipinski RA, Stancill JS, Nuñez R, Wynia-Smith SL, Sprague DJ, Nord JA, Bird A, Corbett JA, Smith BC. Zinc-chelating BET bromodomain inhibitors equally target islet endocrine cell types. Am J Physiol Regul Integr Comp Physiol 2024; 326:R515-R527. [PMID: 38618911 PMCID: PMC11381023 DOI: 10.1152/ajpregu.00259.2023] [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: 11/18/2023] [Revised: 03/19/2024] [Accepted: 04/07/2024] [Indexed: 04/16/2024]
Abstract
Inhibition of the bromodomain and extraterminal domain (BET) protein family is a potential strategy to prevent and treat diabetes; however, the clinical use of BET bromodomain inhibitors (BETis) is associated with adverse effects. Here, we explore a strategy for targeting BETis to β cells by exploiting the high-zinc (Zn2+) concentration in β cells relative to other cell types. We report the synthesis of a novel, Zn2+-chelating derivative of the pan-BETi (+)-JQ1, (+)-JQ1-DPA, in which (+)-JQ1 was conjugated to dipicolyl amine (DPA). As controls, we synthesized (+)-JQ1-DBA, a non-Zn2+-chelating derivative, and (-)-JQ1-DPA, an inactive enantiomer that chelates Zn2+. Molecular modeling and biophysical assays showed that (+)-JQ1-DPA and (+)-JQ1-DBA retain potent binding to BET bromodomains in vitro. Cellular assays demonstrated (+)-JQ1-DPA attenuated NF-ĸB target gene expression in β cells stimulated with the proinflammatory cytokine interleukin 1β. To assess β-cell selectivity, we isolated islets from a mouse model that expresses green fluorescent protein in insulin-positive β cells and mTomato in insulin-negative cells (non-β cells). Surprisingly, Zn2+ chelation did not confer β-cell selectivity as (+)-JQ1-DPA was equally effective in both β and α cells; however, (+)-JQ1-DPA was less effective in macrophages, a nonendocrine islet cell type. Intriguingly, the non-Zn2+-chelating derivative (+)-JQ1-DBA displayed the opposite selectivity, with greater effect in macrophages compared with (+)-JQ1-DPA, suggesting potential as a macrophage-targeting molecule. These findings suggest that Zn2+-chelating small molecules confer endocrine cell selectivity rather than β-cell selectivity in pancreatic islets and provide valuable insights and techniques to assess Zn2+ chelation as an approach to selectively target small molecules to pancreatic β cells.NEW & NOTEWORTHY Inhibition of BET bromodomains is a novel potential strategy to prevent and treat diabetes mellitus. However, BET inhibitors have negative side effects. We synthesized a BET inhibitor expected to exploit the high zinc concentration in β cells to accumulate in β cells. We show our inhibitor targeted pancreatic endocrine cells; however, it was less effective in immune cells. A control inhibitor showed the opposite effect. These findings help us understand how to target specific cells in diabetes treatment.
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Affiliation(s)
- Rachel A Jones Lipinski
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Program in Chemical Biology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Jennifer S Stancill
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Raymundo Nuñez
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Sarah L Wynia-Smith
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Daniel J Sprague
- Program in Chemical Biology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Joshua A Nord
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Amir Bird
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - John A Corbett
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Brian C Smith
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Program in Chemical Biology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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Jensen GC, Janis MK, Nguyen HN, David OW, Zastrow ML. Fluorescent Protein-Based Sensors for Detecting Essential Metal Ions across the Tree of Life. ACS Sens 2024; 9:1622-1643. [PMID: 38587931 PMCID: PMC11073808 DOI: 10.1021/acssensors.3c02695] [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] [Indexed: 04/10/2024]
Abstract
Genetically encoded fluorescent metal ion sensors are powerful tools for elucidating metal dynamics in living systems. Over the last 25 years since the first examples of genetically encoded fluorescent protein-based calcium indicators, this toolbox of probes has expanded to include other essential and non-essential metal ions. Collectively, these tools have illuminated fundamental aspects of metal homeostasis and trafficking that are crucial to fields ranging from neurobiology to human nutrition. Despite these advances, much of the application of metal ion sensors remains limited to mammalian cells and tissues and a limited number of essential metals. Applications beyond mammalian systems and in vivo applications in living organisms have primarily used genetically encoded calcium ion sensors. The aim of this Perspective is to provide, with the support of historical and recent literature, an updated and critical view of the design and use of fluorescent protein-based sensors for detecting essential metal ions in various organisms. We highlight the historical progress and achievements with calcium sensors and discuss more recent advances and opportunities for the detection of other essential metal ions. We also discuss outstanding challenges in the field and directions for future studies, including detecting a wider variety of metal ions, developing and implementing a broader spectral range of sensors for multiplexing experiments, and applying sensors to a wider range of single- and multi-species biological systems.
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Affiliation(s)
- Gary C Jensen
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
| | - Makena K Janis
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
| | - Hazel N Nguyen
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
| | - Ogonna W David
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
| | - Melissa L Zastrow
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
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Shukla AK, Mahale A, Choudhary S, Sharma P, Kulkarni OP, Bhattacharya A. Development and Validation of a Fluorogenic Probe for Lysosomal Zinc Release. Chembiochem 2024; 25:e202300783. [PMID: 38038368 DOI: 10.1002/cbic.202300783] [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: 11/20/2023] [Revised: 11/30/2023] [Accepted: 11/30/2023] [Indexed: 12/02/2023]
Abstract
Zinc homeostasis, which allows optimal zinc utilization in diverse life processes, is responsible for the general well-being of human beings. This paper describes developing and validating an easily accessible indole-containing zinc-specific probe in the cellular milieu. The probe was synthesized from readily available starting materials and was subjected to steady-state fluorescence studies. It showed selective sensing behavior towards Zn2+ with reversible binding. The suppression of PET (Photoinduced Electron Transfer) and ESIPT (Excited State Intramolecular Proton Transfer) elicited selectivity, and the detection limit was 0.63 μM (LOQ 6.8 μM). The zinc sensing capability of the probe was also screened in the presence of low molecular weight ligands [LMWLs] and showed interference only with GSH and ATP. It is non-toxic and can detect zinc in different cell lines under various stress conditions such as inflammation, hyperglycemia, and apoptosis. The probe could stain the early and late stages of apoptosis in PAN-2 cells by monitoring the zinc release. Most experiments were conducted without external zinc supplementation, showing its innate ability to detect zinc.
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Affiliation(s)
- Adarash Kumar Shukla
- Department of Chemistry, Birla Institute of Technology and Science-Pilani (Hyderabad Campus), Hyderabad, 500078, India
| | - Ashutosh Mahale
- Department of Pharmacy, Birla Institute of Technology and Science-Pilani (Hyderabad Campus), Hyderabad, 500078, India
| | - Savita Choudhary
- Department of Chemistry, Birla Institute of Technology and Science-Pilani (Hyderabad Campus), Hyderabad, 500078, India
| | - Pravesh Sharma
- Department of Pharmacy, Birla Institute of Technology and Science-Pilani (Hyderabad Campus), Hyderabad, 500078, India
| | - Onkar Prakash Kulkarni
- Department of Pharmacy, Birla Institute of Technology and Science-Pilani (Hyderabad Campus), Hyderabad, 500078, India
| | - Anupam Bhattacharya
- Department of Chemistry, Birla Institute of Technology and Science-Pilani (Hyderabad Campus), Hyderabad, 500078, India
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Chen B, Yu P, Chan WN, Xie F, Zhang Y, Liang L, Leung KT, Lo KW, Yu J, Tse GMK, Kang W, To KF. Cellular zinc metabolism and zinc signaling: from biological functions to diseases and therapeutic targets. Signal Transduct Target Ther 2024; 9:6. [PMID: 38169461 PMCID: PMC10761908 DOI: 10.1038/s41392-023-01679-y] [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: 05/27/2023] [Revised: 09/15/2023] [Accepted: 10/10/2023] [Indexed: 01/05/2024] Open
Abstract
Zinc metabolism at the cellular level is critical for many biological processes in the body. A key observation is the disruption of cellular homeostasis, often coinciding with disease progression. As an essential factor in maintaining cellular equilibrium, cellular zinc has been increasingly spotlighted in the context of disease development. Extensive research suggests zinc's involvement in promoting malignancy and invasion in cancer cells, despite its low tissue concentration. This has led to a growing body of literature investigating zinc's cellular metabolism, particularly the functions of zinc transporters and storage mechanisms during cancer progression. Zinc transportation is under the control of two major transporter families: SLC30 (ZnT) for the excretion of zinc and SLC39 (ZIP) for the zinc intake. Additionally, the storage of this essential element is predominantly mediated by metallothioneins (MTs). This review consolidates knowledge on the critical functions of cellular zinc signaling and underscores potential molecular pathways linking zinc metabolism to disease progression, with a special focus on cancer. We also compile a summary of clinical trials involving zinc ions. Given the main localization of zinc transporters at the cell membrane, the potential for targeted therapies, including small molecules and monoclonal antibodies, offers promising avenues for future exploration.
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Affiliation(s)
- Bonan Chen
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China
- CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Peiyao Yu
- Department of Pathology, Nanfang Hospital and Basic Medical College, Southern Medical University, Guangdong Province Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Wai Nok Chan
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China
- CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Fuda Xie
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China
- CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Yigan Zhang
- Institute of Biomedical Research, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Li Liang
- Department of Pathology, Nanfang Hospital and Basic Medical College, Southern Medical University, Guangdong Province Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Kam Tong Leung
- Department of Pediatrics, The Chinese University of Hong Kong, Hong Kong, China
| | - Kwok Wai Lo
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Jun Yu
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China
| | - Gary M K Tse
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Wei Kang
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China.
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China.
- CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
| | - Ka Fai To
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China.
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China.
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6
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Kambe T, Wagatsuma T. Metalation and activation of Zn 2+ enzymes via early secretory pathway-resident ZNT proteins. BIOPHYSICS REVIEWS 2023; 4:041302. [PMID: 38510844 PMCID: PMC10903440 DOI: 10.1063/5.0176048] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 11/21/2023] [Indexed: 03/22/2024]
Abstract
Zinc (Zn2+), an essential trace element, binds to various proteins, including enzymes, transcription factors, channels, and signaling molecules and their receptors, to regulate their activities in a wide range of physiological functions. Zn2+ proteome analyses have indicated that approximately 10% of the proteins encoded by the human genome have potential Zn2+ binding sites. Zn2+ binding to the functional site of a protein (for enzymes, the active site) is termed Zn2+ metalation. In eukaryotic cells, approximately one-third of proteins are targeted to the endoplasmic reticulum; therefore, a considerable number of proteins mature by Zn2+ metalation in the early secretory pathway compartments. Failure to capture Zn2+ in these compartments results in not only the inactivation of enzymes (apo-Zn2+ enzymes), but also their elimination via degradation. This process deserves attention because many Zn2+ enzymes that mature during the secretory process are associated with disease pathogenesis. However, how Zn2+ is mobilized via Zn2+ transporters, particularly ZNTs, and incorporated in enzymes has not been fully elucidated from the cellular perspective and much less from the biophysical perspective. This review focuses on Zn2+ enzymes that are activated by Zn2+ metalation via Zn2+ transporters during the secretory process. Further, we describe the importance of Zn2+ metalation from the physiopathological perspective, helping to reveal the importance of understanding Zn2+ enzymes from a biophysical perspective.
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Affiliation(s)
- Taiho Kambe
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Takumi Wagatsuma
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
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Chen Y, Pang S, Li J, Lu Y, Gao C, Xiao Y, Chen M, Wang M, Ren X. Genetically encoded protein sensors for metal ion detection in biological systems: a review and bibliometric analysis. Analyst 2023; 148:5564-5581. [PMID: 37872814 DOI: 10.1039/d3an01412f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Metal ions are indispensable elements in living organisms and are associated with regulating various biological processes. An imbalance in metal ion content can lead to disorders in normal physiological functions of the human body and cause various diseases. Genetically encoded fluorescent protein sensors have the advantages of low biotoxicity, high specificity, and a long imaging time in vivo and have become a powerful tool to visualize or quantify the concentration level of biomolecules in vivo and in vitro, temporal and spatial distribution, and life activity process. This review analyzes the development status and current research hotspots in the field of genetically encoded fluorescent protein sensors by bibliometric analysis. Based on the results of bibliometric analysis, the research progress of genetically encoded fluorescent protein sensors for metal ion detection is reviewed, and the construction strategies, physicochemical properties, and applications of such sensors in biological imaging are summarized.
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Affiliation(s)
- Yuxueyuan Chen
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300381, China
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - ShuChao Pang
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300381, China
| | - Jingya Li
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Yun Lu
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Chenxia Gao
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Yanyu Xiao
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Meiling Chen
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
- Tianjin Key Laboratory of Therapeutic Substance of Traditional Chinese Medicine, Tianjin 301617, China.
| | - Meng Wang
- State Key Laboratory of Component-based Chinese Medicine, Tianjin 301617, China
| | - Xiaoliang Ren
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
- Tianjin Key Laboratory of Therapeutic Substance of Traditional Chinese Medicine, Tianjin 301617, China.
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Fang H, Li Y, Yang X, Chen Y, Guo Z, He W. Recent advances in Zn 2+ imaging: From organelles to in vivo applications. Curr Opin Chem Biol 2023; 76:102378. [PMID: 37633062 DOI: 10.1016/j.cbpa.2023.102378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 07/15/2023] [Accepted: 07/24/2023] [Indexed: 08/28/2023]
Abstract
Zn2+ is involved in various physiological and pathological processes in living systems. Monitoring the dynamic spatiotemporal changes of Zn2+ levels in organelles, cells, and in vivo is of great importance for the investigation of the physiological and pathological functions of Zn2+. However, this task is quite challenging since Zn2+ in living systems is present at low concentrations and undergoes rapid dynamic changes. In this review, we summarize the design and application of fluorescent probes for Zn2+ imaging in organelles, cells, and live organisms reported over the past two years. We aim to provide inspiration for the design of novel Zn2+ probes for multi-level monitoring and deepen the understanding of Zn2+ biology.
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Affiliation(s)
- Hongbao Fang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China.
| | - Yaheng Li
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China
| | - Xiuzhi Yang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China
| | - Yuncong Chen
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China; Nanchuang (Jiangsu) Institute of Chemistry and Health, Nanjing 210000, China.
| | - Zijian Guo
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China; Nanchuang (Jiangsu) Institute of Chemistry and Health, Nanjing 210000, China
| | - Weijiang He
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China; Nanchuang (Jiangsu) Institute of Chemistry and Health, Nanjing 210000, China.
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9
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Wu Y, Lewis W, Wai JL, Xiong M, Zheng J, Yang Z, Gordon C, Lu Y, New SY, Zhang XB, Lu Y. Ratiometric Detection of Zn 2+ Using DNAzyme-Based Bioluminescence Resonance Energy Transfer Sensors. CHEMISTRY (BASEL, SWITZERLAND) 2023; 5:1745-1759. [PMID: 38371491 PMCID: PMC10874629 DOI: 10.3390/chemistry5030119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
While fluorescent sensors have been developed for monitoring metal ions in health and diseases, they are limited by the requirement of an excitation light source that can lead to photobleaching and a high autofluorescence background. To address these issues, bioluminescence resonance energy transfer (BRET)-based protein or small molecule sensors have been developed; however, most of them are not highly selective nor generalizable to different metal ions. Taking advantage of the high selectivity and generalizability of DNAzymes, we report herein DNAzyme-based ratiometric sensors for Zn2+ based on BRET. The 8-17 DNAzyme was labeled with luciferase and Cy3. The proximity between luciferase and Cy3 permiQed BRET when coelenterazine, the substrate for luciferase, was introduced. Adding samples containing Zn2+ resulted in a cleavage of the substrate strand, causing dehybridization of the DNAzyme construct, thus increasing the distance between Cy3 and luciferase and changing the BRET signals. Using these sensors, we detected Zn2+ in serum samples and achieved Zn2+ detection with a smartphone camera. Moreover, since the BRET pair is not the component that determines the selectivity of the sensors, this sensing platform has the potential to be adapted for the detection of other metal ions with other metal-dependent DNAzymes.
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Affiliation(s)
- Yuting Wu
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Whitney Lewis
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Jing Luen Wai
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801
- School of Pharmacy, Faculty of Science and Engineering, University of No0ingham Malaysia, Semenyih, Selangor 43500, Malaysia
| | - Mengyi Xiong
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Jiao Zheng
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Zhenglin Yang
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Chloe Gordon
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
| | - Ying Lu
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
| | - Siu Yee New
- School of Pharmacy, Faculty of Science and Engineering, University of No0ingham Malaysia, Semenyih, Selangor 43500, Malaysia
| | - Xiao-Bing Zhang
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Yi Lu
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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10
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Wang D, Wei L, Tan J, Yan Y, Wei M, Song T, Li S, Zhao L, Wu W, Li Z, Liu Q. A novel strategy of engineering genetically encoded probe for ultrasensitive sensing Hg 2+ with unusual planar trigonometric coordination configuration. Anal Chim Acta 2023; 1252:341049. [PMID: 36935153 DOI: 10.1016/j.aca.2023.341049] [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: 01/07/2023] [Revised: 02/13/2023] [Accepted: 03/03/2023] [Indexed: 03/07/2023]
Abstract
At present, few genetically encoded fluorescent probes are currently available for the analysis of toxic heavy metal ions, and most have poor performance that cannot meet the requirements of sensitive and dynamic detection in living cells. In this study, we designed a single fluorescent protein-based probe sfGFP-MerBD, which can specifically response to Hg2+ with high binding affinity and wide dynamic range. More importantly, the developing probe can timely and reversibly monitor changes of Hg2+ concentration in living mammalian cells. The excellent performance of this probe is largely due to the recognition element of the probe, MerBD, which adopts an unusual planar trigonometric coordination configuration with Hg2+, and the coordination can cause enough conformational change to influence the fluorescence of skeleton protein sfGFP coupled with it. The small peptide MerBD was delicately designed based on the three-dimensional structure of metalloprotein MerR. This novel design strategy solves the challenging problems that there are few natural functional proteins in the process of constructing fluorescent probes for toxic metal ions and some functional proteins cannot be directly used as recognition elements. Based on the new strategy, more genetically encoded fluorescent probes of toxic heavy metal ions can be efficiently constructed and applied in the future.
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Affiliation(s)
- Dan Wang
- College of Chemistry and Materials, Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, 530001, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, 530004, China; Nanning New Technology Entrepreneur Center, Nanning, 530006, China.
| | - Liudan Wei
- College of Chemistry and Materials, Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, 530001, China; Guangxi Academy of Sciences, Nanning, 530007, China
| | - Jiaxin Tan
- College of Chemistry and Materials, Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, 530001, China
| | - Yiyu Yan
- College of Chemistry and Materials, Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, 530001, China
| | - Min Wei
- College of Chemistry and Materials, Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, 530001, China
| | - Tianyu Song
- College of Chemistry and Materials, Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, 530001, China
| | - Sihang Li
- College of Chemistry and Materials, Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, 530001, China
| | - Liu Zhao
- College of Chemistry and Materials, Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, 530001, China
| | - Weibo Wu
- College of Chemistry and Materials, Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, 530001, China
| | - Zhipeng Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, 530004, China.
| | - Qingyou Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, 530004, China.
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11
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Effects of Marginal Zn Excess and Thiamine Deficiency on Microglial N9 Cell Metabolism and Their Interactions with Septal SN56 Cholinergic Cells. Int J Mol Sci 2023; 24:ijms24054465. [PMID: 36901896 PMCID: PMC10002586 DOI: 10.3390/ijms24054465] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/10/2023] [Accepted: 02/21/2023] [Indexed: 03/12/2023] Open
Abstract
Mild thiamine deficiency aggravates Zn accumulation in cholinergic neurons. It leads to the augmentation of Zn toxicity by its interaction with the enzymes of energy metabolism. Within this study, we tested the effect of Zn on microglial cells cultivated in a thiamine-deficient medium, containing 0.003 mmol/L of thiamine vs. 0.009 mmol/L in a control medium. In such conditions, a subtoxic 0.10 mmol/L Zn concentration caused non-significant alterations in the survival and energy metabolism of N9 microglial cells. Both activities of the tricarboxylic acid cycle and the acetyl-CoA level were not decreased in these culture conditions. Amprolium augmented thiamine pyrophosphate deficits in N9 cells. This led to an increase in the intracellular accumulation of free Zn and partially aggravated its toxicity. There was differential sensitivity of neuronal and glial cells to thiamine-deficiency-Zn-evoked toxicity. The co-culture of neuronal SN56 with microglial N9 cells reduced the thiamine-deficiency-Zn-evoked inhibition of acetyl-CoA metabolism and restored the viability of the former. The differential sensitivity of SN56 and N9 cells to borderline thiamine deficiency combined with marginal Zn excess may result from the strong inhibition of pyruvate dehydrogenase in neuronal cells and no inhibition of this enzyme in the glial ones. Therefore, ThDP supplementation can make any brain cell more resistant to Zn excess.
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12
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Abstract
The genetically encoded fluorescent sensors convert chemical and physical signals into light. They are powerful tools for the visualisation of physiological processes in living cells and freely moving animals. The fluorescent protein is the reporter module of a genetically encoded biosensor. In this study, we first review the history of the fluorescent protein in full emission spectra on a structural basis. Then, we discuss the design of the genetically encoded biosensor. Finally, we briefly review several major types of genetically encoded biosensors that are currently widely used based on their design and molecular targets, which may be useful for the future design of fluorescent biosensors.
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Affiliation(s)
- Minji Wang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, No. 3663 Zhong Shan Road North, Shanghai, 200062, China
| | - Yifan Da
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, No. 3663 Zhong Shan Road North, Shanghai, 200062, China
| | - Yang Tian
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, No. 3663 Zhong Shan Road North, Shanghai, 200062, China
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13
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Dischler AM, Maslar D, Zhang C, Qin Y. Development and Characterization of a Red Fluorescent Protein-Based Sensor RZnP1 for the Detection of Cytosolic Zn 2. ACS Sens 2022; 7:3838-3845. [PMID: 36508266 DOI: 10.1021/acssensors.2c01774] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Fluorescent sensors have been developed to record Zn2+ dynamics and measure Zn2+ concentrations within the cell. Most previous efforts on developing single-wavelength sensors are focused on green sensors. Here, we engineer a genetically encoded, single red fluorescent protein-based Zn2+ sensor, Red Zinc Probe (RZnP1), which can detect intracellular concentrations of Zn2+. RZnP1 demonstrates a sensitive response to cytosolic Zn2+ (Kd = 438 pM), decent brightness (quantum yield (QY) = 0.15), good in situ dynamic range (Fmax/Fmin = 4.0), and specificity for Zn2+ over other biologically relevant metal cations. RZnP1 offers a way to image Zn2+ with multiple intracellular ions in tandem. We demonstrate the simultaneous recording of Zn2+ and Ca2+ using RZnP1 alongside the Ca2+ sensor GCaMP5G in HeLa cells. We also use RZnP1 with mito-GZnP2, a green fluorescent protein (GFP)-based mitochondrial Zn2+ sensor, to track Zn2+ dynamics in the cytosol and mitochondria concurrently in rat primary neuron culture. Our work not only expands the toolbox of Zn2+ sensors but also demonstrates techniques for imaging Zn2+ dynamics along with other cations and between multiple subcellular compartments simultaneously.
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Affiliation(s)
- Anna M Dischler
- Department of Biological Sciences, University of Denver, Denver, Colorado80210, United States
| | - Drew Maslar
- Department of Biological Sciences, University of Denver, Denver, Colorado80210, United States
| | - Chen Zhang
- Department of Biological Sciences, University of Denver, Denver, Colorado80210, United States
| | - Yan Qin
- Department of Biological Sciences, University of Denver, Denver, Colorado80210, United States
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14
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Zou W, Nguyen HN, Zastrow ML. Mutant Flavin-Based Fluorescent Protein Sensors for Detecting Intracellular Zinc and Copper in Escherichia coli. ACS Sens 2022; 7:3369-3378. [PMID: 36282086 PMCID: PMC9888404 DOI: 10.1021/acssensors.2c01376] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Flavin-based fluorescent proteins (FbFPs) are a class of fluorescent reporters that undergo oxygen-independent fluorophore incorporation, which is an important advantage over green fluorescent proteins (GFPs) and mFruits. A FbFP derived from Chlamydomonas reinhardtii (CreiLOV) is a promising platform for designing new metal sensors. Some FbFPs are intrinsically quenched by metal ions, but the question of where metals bind and how to tune metal affinity has not been addressed. We used site-directed mutagenesis of CreiLOV to probe a hypothesized copper(II) binding site that led to fluorescence quenching. Most mutations changed the fluorescence quenching level, supporting the proposed site. One key mutation introducing a second cysteine residue in place of asparagine (CreiLOVN41C) significantly altered metal affinity and selectivity, yielding a zinc sensor. The fluorescence intensity and lifetime of CreiLOVN41C were reversibly quenched by Zn2+ ions with a biologically relevant affinity (apparent dissociation constant, Kd, of 1 nM). Copper quenching of CreiLOVN41C was retained but with several orders of magnitude higher affinity than CreiLOV (Kd = 0.066 fM for Cu2+, 5.4 fM for Cu+) and partial reversibility. We also show that CreiLOVN41C is an excellent intensity- and lifetime-based zinc sensor in aerobic and anaerobic live bacterial cells. Zn2+-induced fluorescence quenching is reversible over several cycles in Escherichia coli cell suspensions and can be imaged by fluorescence microscopy. CreiLOVN41C is a novel oxygen-independent metal sensor that significantly expands the current fluorescent protein-based toolbox of metal sensors and will allow for studies of anaerobic and low oxygen systems previously precluded by the use of oxygen-dependent GFPs.
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Affiliation(s)
- Wenping Zou
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
| | - Hazel N Nguyen
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
| | - Melissa L Zastrow
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
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15
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Xia Z, Yang X, Bi X, Tong X, Min J, Wang F. Zinc transporter Slc30a1 regulates melanocyte development by interacting with mt2 in zebrafish. Eur J Cell Biol 2022; 101:151272. [PMID: 36063588 DOI: 10.1016/j.ejcb.2022.151272] [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: 02/04/2022] [Revised: 08/24/2022] [Accepted: 08/27/2022] [Indexed: 12/14/2022] Open
Abstract
The essential trace element zinc is involved in multiple biological processes including development and metabolism, while its role in melanocyte formation is still unclear. Slc30a1a and Slc30a1b are zinc exporters in zebrafish. Here, we found that melanocytes were increased in slc30a1a and slc30a1b double mutant zebrafish. SMART-seq data revealed that genes involved in the melanoma pathway and the gene mt2, which encodes zinc-binding protein, were significantly upregulated in the mutants. In addition, the expression of mt2 was specifically increased in mutant melanocytes, as detected by in situ hybridization, suggesting an essential role of this gene in the tissue. Mechanistically, we demonstrated that elevated zinc levels resulting from Slc30a1 deficiency promoted melanocyte proliferation and that mt2 played a protective role in the process of Slc30a1/zinc-mediated melanocyte hyperplasia. This study uncovered the critical function of Slc30a1-mediated zinc homeostasis in melanocyte development and suggests that accumulated zinc in melanocytes would be a risk for inducing melanoma and that mt2 is a potential target for controlling diseases related to abnormal melanocyte development.
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Affiliation(s)
- Zhidan Xia
- The Fourth Affiliated Hospital, School of Public Health, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.
| | - Xiu Yang
- The Fourth Affiliated Hospital, School of Public Health, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Xinying Bi
- The Fourth Affiliated Hospital, School of Public Health, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Xiujuan Tong
- The Fourth Affiliated Hospital, School of Public Health, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Junxia Min
- The Fourth Affiliated Hospital, School of Public Health, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Fudi Wang
- The Fourth Affiliated Hospital, School of Public Health, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.
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16
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Zhang C, Dischler A, Glover K, Qin Y. Neuronal signalling of zinc: from detection and modulation to function. Open Biol 2022; 12:220188. [PMID: 36067793 PMCID: PMC9448499 DOI: 10.1098/rsob.220188] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Zinc is an essential trace element that stabilizes protein structures and allosterically modulates a plethora of enzymes, ion channels and neurotransmitter receptors. Labile zinc (Zn2+) acts as an intracellular and intercellular signalling molecule in response to various stimuli, which is especially important in the central nervous system. Zincergic neurons, characterized by Zn2+ deposits in synaptic vesicles and presynaptic Zn2+ release, are found in the cortex, hippocampus, amygdala, olfactory bulb and spinal cord. To provide an overview of synaptic Zn2+ and intracellular Zn2+ signalling in neurons, the present paper summarizes the fluorescent sensors used to detect Zn2+ signals, the cellular mechanisms regulating the generation and buffering of Zn2+ signals, as well as the current perspectives on their pleiotropic effects on phosphorylation signalling, synapse formation, synaptic plasticity, as well as sensory and cognitive function.
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Affiliation(s)
- Chen Zhang
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
| | - Anna Dischler
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
| | - Kaitlyn Glover
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
| | - Yan Qin
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
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17
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Michielsen CMS, van Aalen EA, Merkx M. Ratiometric Bioluminescent Zinc Sensor Proteins to Quantify Serum and Intracellular Free Zn 2. ACS Chem Biol 2022; 17:1567-1576. [PMID: 35611686 PMCID: PMC9207811 DOI: 10.1021/acschembio.2c00227] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
![]()
Fluorescent Zn2+ sensors play a pivotal role in zinc
biology, but their application in complex media such as blood serum
or plate reader-based cellular assays is hampered by autofluorescence
and light scattering. Bioluminescent sensor proteins provide an attractive
alternative to fluorescent sensors for these applications, but the
only bioluminescent sensor protein developed so far, BLZinCh, has
a limited sensor response and a suboptimal Zn2+ affinity.
In this work, we expanded the toolbox of bioluminescent Zn2+ sensors by developing two new sensor families that show a large
change in the emission ratio and cover a range of physiologically
relevant Zn2+ affinities. The LuZi platform relies on competitive
complementation of split NanoLuc luciferase and displays a robust,
2-fold change in red-to-blue emission, allowing quantification of
free Zn2+ between 2 pM and 1 nM. The second platform was
developed by replacing the long flexible GGS linker in the original
BLZinCh sensor by rigid polyproline linkers, yielding a series of
BLZinCh-Pro sensors with a 3–4-fold improved ratiometric response
and physiologically relevant Zn2+ affinities between 0.5
and 1 nM. Both the LuZi and BLZinCh-Pro sensors allowed the direct
determination of low nM concentrations of free Zn2+ in
serum, providing an attractive alternative to more laborious and/or
indirect approaches to measure serum zinc levels. Furthermore, the
genetic encoding of the BLZinCh-Pro sensors allowed their use as intracellular
sensors, where the sensor occupancy of 40–50% makes them ideally
suited to monitor both increases and decreases in intracellular free
Zn2+ concentration in simple, plate reader-based measurements,
without the need for fluorescence microscopy.
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18
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Wu SY, Shen Y, Shkolnikov I, Campbell RE. Fluorescent Indicators For Biological Imaging of Monatomic Ions. Front Cell Dev Biol 2022; 10:885440. [PMID: 35573682 PMCID: PMC9093666 DOI: 10.3389/fcell.2022.885440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/04/2022] [Indexed: 11/13/2022] Open
Abstract
Monatomic ions play critical biological roles including maintaining the cellular osmotic pressure, transmitting signals, and catalyzing redox reactions as cofactors in enzymes. The ability to visualize monatomic ion concentration, and dynamic changes in the concentration, is essential to understanding their many biological functions. A growing number of genetically encodable and synthetic indicators enable the visualization and detection of monatomic ions in biological systems. With this review, we aim to provide a survey of the current landscape of reported indicators. We hope this review will be a useful guide to researchers who are interested in using indicators for biological applications and to tool developers seeking opportunities to create new and improved indicators.
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Affiliation(s)
- Sheng-Yi Wu
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Yi Shen
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Irene Shkolnikov
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
- Department of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Robert E. Campbell
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
- Department of Chemistry, The University of Tokyo, Tokyo, Japan
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19
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Liu R, Kowada T, Du Y, Amagai Y, Matsui T, Inaba K, Mizukami S. Organelle-Level Labile Zn 2+ Mapping Based on Targetable Fluorescent Sensors. ACS Sens 2022; 7:748-757. [PMID: 35238552 PMCID: PMC8963189 DOI: 10.1021/acssensors.1c02153] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Although many Zn2+ fluorescent probes have been developed, there remains a lack of consensus on the labile Zn2+ concentrations ([Zn2+]) in several cellular compartments, as the fluorescence properties and zinc affinity of the fluorescent probes are greatly affected by the pH and redox environments specific to organelles. In this study, we developed two turn-on-type Zn2+ fluorescent probes, namely, ZnDA-2H and ZnDA-3H, with low pH sensitivity and suitable affinity (Kd = 5.0 and 0.16 nM) for detecting physiological labile Zn2+ in various cellular compartments, such as the cytosol, nucleus, ER, and mitochondria. Due to their sufficient membrane permeability, both probes were precisely localized to the target organelles in HeLa cells using HaloTag labeling technology. Using an in situ standard quantification method, we identified the [Zn2+] in the tested organelles, resulting in the subcellular [Zn2+] distribution as [Zn2+]ER < [Zn2+]mito < [Zn2+]cyto ∼ [Zn2+]nuc.
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Affiliation(s)
- Rong Liu
- Graduate
School of Life Sciences, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Toshiyuki Kowada
- Graduate
School of Life Sciences, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai, Miyagi 980-8577, Japan,Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan,Department
of Chemistry, Faculty of Science, Tohoku
University, 6-3 Aramaki-aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Yuyin Du
- Department
of Chemistry, Faculty of Science, Tohoku
University, 6-3 Aramaki-aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Yuta Amagai
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Toshitaka Matsui
- Graduate
School of Life Sciences, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai, Miyagi 980-8577, Japan,Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan,Department
of Chemistry, Faculty of Science, Tohoku
University, 6-3 Aramaki-aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Kenji Inaba
- Graduate
School of Life Sciences, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai, Miyagi 980-8577, Japan,Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan,Department
of Chemistry, Faculty of Science, Tohoku
University, 6-3 Aramaki-aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan,AMED-CREST,
Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo, 100-0004, Japan
| | - Shin Mizukami
- Graduate
School of Life Sciences, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai, Miyagi 980-8577, Japan,Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan,Department
of Chemistry, Faculty of Science, Tohoku
University, 6-3 Aramaki-aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan,AMED-CREST,
Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo, 100-0004, Japan,
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20
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Zhao H, Zastrow ML. Transition Metals Induce Quenching of Monomeric Near-Infrared Fluorescent Proteins. Biochemistry 2022; 61:494-504. [PMID: 35289592 DOI: 10.1021/acs.biochem.1c00705] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Transition metals such as zinc and copper are essential in numerous life processes, and both deficiency and toxic overload of these metals are associated with various diseases. Fluorescent metal sensors are powerful tools for studying the roles of metal ions in the physiology and pathology of biological systems. Green fluorescent protein (GFP) and its derivatives are highly utilized for protein-based sensor design, but application to anaerobic systems is limited because these proteins require oxygen to become fluorescent. Bacteriophytochrome-based monomeric near-infrared fluorescent proteins (miRFPs) covalently bind a bilin cofactor, which can be added exogenously for anaerobic cells. miRFPs can also have emission wavelengths extending to >700 nm, which is valuable for imaging applications. Here, we evaluated the suitability of miRFP670 and miRFP709 as platforms for single fluorescent protein metal ion sensors. We found that divalent metal ions like Zn2+, Co2+, Ni2+, and Cu2+ can quench from ∼6-20% (Zn2+, Co2+, and Ni2+) and up to nearly 90% (Cu2+) of the fluorescence intensity of pure miRFPs and have similar impacts in live Escherichia coli cells expressing miRFPs. The presence of a 6× histidine tag for purification influences metal quenching, but significant Cu2+-induced quenching and a picomolar binding affinity are retained in the absence of the His6 tag in both cuvettes and live bacterial cells. By comparing the Cu2+ and Cu+-induced quenching results for miRFP670 and miRFP709 and through examining absorption spectra and previously reported crystal structures, we propose a surface metal binding site near the biliverdin IXα chromophore.
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Affiliation(s)
- Haowen Zhao
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
| | - Melissa L Zastrow
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
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21
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Kowada T, Mizukami S. Fluorescent Probes for the Quantification of Labile Metal Ions in Living Cells. J SYN ORG CHEM JPN 2021. [DOI: 10.5059/yukigoseikyokaishi.79.1020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Shin Mizukami
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University
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22
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Abstract
Zinc (Zn2+) is an essential metal in biology, and its bioavailability is highly regulated. Many cell types exhibit fluctuations in Zn2+ that appear to play an important role in cellular function. However, the detailed molecular mechanisms by which Zn2+ dynamics influence cell physiology remain enigmatic. Here, we use a combination of fluorescent biosensors and cell perturbations to define how changes in intracellular Zn2+ impact kinase signaling pathways. By simultaneously monitoring Zn2+ dynamics and kinase activity in individual cells, we quantify changes in labile Zn2+ and directly correlate changes in Zn2+ with ERK and Akt activity. Under our experimental conditions, Zn2+ fluctuations are not toxic and do not activate stress-dependent kinase signaling. We demonstrate that while Zn2+ can nonspecifically inhibit phosphatases leading to sustained kinase activation, ERK and Akt are predominantly activated via upstream signaling and through a common node via Ras. We provide a framework for quantification of Zn2+ fluctuations and correlate these fluctuations with signaling events in single cells to shed light on the role that Zn2+ dynamics play in healthy cell signaling.
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23
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Kumar A, Sardhalia V, Sahoo PR, Kumar A, Kumar S. Structure analysis and evaluation of two probes for the colorimetric detection of Hg2+ and turn-on fluorescence-based detection of Cd2+ ions in an aqueous solution. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.130233] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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24
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Ghazvini Zadeh EH, Huang Z, Xia J, Li D, Davidson HW, Li WH. ZIGIR, a Granule-Specific Zn 2+ Indicator, Reveals Human Islet α Cell Heterogeneity. Cell Rep 2021; 32:107904. [PMID: 32668245 DOI: 10.1016/j.celrep.2020.107904] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 05/04/2020] [Accepted: 06/23/2020] [Indexed: 02/07/2023] Open
Abstract
Numerous mammalian cells contain abundant Zn2+ in their secretory granules, yet available Zn2+ sensors lack the desired specificity and sensitivity for imaging granular Zn2+. We developed a fluorescent zinc granule indicator, ZIGIR, that possesses numerous desired properties for live cell imaging, including >100-fold fluorescence enhancement, membrane permeability, and selective enrichment to acidic granules. The combined advantages endow ZIGIR with superior sensitivity and specificity for imaging granular Zn2+. ZIGIR enables separation of heterogenous β cells based on their insulin content and sorting of mouse islets into pure α cells and β cells. In human islets, ZIGIR facilitates sorting of endocrine cells into highly enriched α cells and β cells, reveals unexpectedly high Zn2+ activity in the somatostatin granule of some δ cells, and uncovers variation in the glucagon content among human α cells. We expect broad applications of ZIGIR for studying Zn2+ biology and Zn2+-rich secretory granules and for engineering β cells with high insulin content for treating diabetes.
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Affiliation(s)
- Ebrahim H Ghazvini Zadeh
- Departments of Cell Biology and Biochemistry, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX 75390-9039, USA
| | - ZhiJiang Huang
- Departments of Cell Biology and Biochemistry, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX 75390-9039, USA
| | - Jing Xia
- Departments of Cell Biology and Biochemistry, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX 75390-9039, USA; Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Daliang Li
- Departments of Cell Biology and Biochemistry, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX 75390-9039, USA
| | - Howard W Davidson
- Barbara Davis Center for Diabetes, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Wen-Hong Li
- Departments of Cell Biology and Biochemistry, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX 75390-9039, USA.
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25
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Sala D, Giachetti A, Rosato A. Insights into the Dynamics of the Human Zinc Transporter ZnT8 by MD Simulations. J Chem Inf Model 2021; 61:901-912. [PMID: 33508935 PMCID: PMC8023586 DOI: 10.1021/acs.jcim.0c01139] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Indexed: 02/07/2023]
Abstract
ZnT8 is a human zinc(II) transporter expressed at the membrane of secretory granules where it contributes to insulin storage importing zinc ions from the cytosol. In the human population, the two most common ZnT8 variants carry an arginine (R325) or a tryptophan (W325) in position 325. The former variant has the most efficient kinetics in zinc transport and has been correlated to a higher risk of developing insulin resistance. On the contrary, the W325 variant is less active and protects against type-2-diabetes. Here, we used molecular dynamics (MD) simulations to investigate the main differences between the R325 and W325 variants in the interaction with zinc(II) ions. Our simulations suggested that the position of the metal ion within the transport site was not the same for the two variants, underlying a different rearrangement of the transmembrane (TM) helices in the channel. The W325 variant featured a peculiar zinc environment not detected in the experimental structures. With respect to conformational dynamics, we observed that the R325 variant was significantly more flexible than W325, with the main role played by the transmembrane domain (TMD) and the C-terminal domain (CTD). This dynamics affected the packing of the TM helices and thus the channel accessibility from the cytosol. The dimer interface that keeps the two TM channels in contact became looser in both variants upon zinc binding to the transport site, suggesting that this may be an important step toward the switch from the inward- to the outward-facing state of the protein.
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Affiliation(s)
- Davide Sala
- Magnetic
Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Andrea Giachetti
- Consorzio
Interuniversitario di Risonanze Magnetiche di Metallo Proteine, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Antonio Rosato
- Magnetic
Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
- Department
of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
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26
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Pratt EP, Anson KJ, Tapper JK, Simpson DM, Palmer AE. Systematic Comparison of Vesicular Targeting Signals Leads to the Development of Genetically Encoded Vesicular Fluorescent Zn 2+ and pH Sensors. ACS Sens 2020; 5:3879-3891. [PMID: 33305939 DOI: 10.1021/acssensors.0c01231] [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] [Indexed: 11/28/2022]
Abstract
Genetically encoded fluorescent sensors have been widely used to illuminate secretory vesicle dynamics and the vesicular lumen, including Zn2+ and pH, in living cells. However, vesicular sensors have a tendency to mislocalize and are susceptible to the acidic intraluminal pH. In this study, we performed a systematic comparison of five different vesicular proteins to target the fluorescent protein mCherry and a Zn2+ Förster resonance energy transfer (FRET) sensor to secretory vesicles. We found that motifs derived from vesicular cargo proteins, including chromogranin A (CgA), target vesicular puncta with greater efficacy than transmembrane proteins. To characterize vesicular Zn2+ levels, we developed CgA-Zn2+ FRET sensor fusions with existing sensors ZapCY1 and eCALWY-4 and characterized subcellular localization and the influence of pH on sensor performance. We simultaneously monitored Zn2+ and pH in individual secretory vesicles by leveraging the acceptor fluorescent protein as a pH sensor and found that pH influenced FRET measurements in situ. While unable to characterize vesicular Zn2+ at the single-vesicle level, we were able to monitor Zn2+ dynamics in populations of vesicles and detected high vesicular Zn2+ in MIN6 cells compared to lower levels in the prostate cancer cell line LnCaP. The combination of CgA-ZapCY1 and CgA-eCALWY-4 allows for measurement of Zn2+ from pM to nM ranges.
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Affiliation(s)
- Evan P.S. Pratt
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - Kelsie J. Anson
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - Justin K. Tapper
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - David M. Simpson
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - Amy E. Palmer
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
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Kowada T, Watanabe T, Amagai Y, Liu R, Yamada M, Takahashi H, Matsui T, Inaba K, Mizukami S. Quantitative Imaging of Labile Zn 2+ in the Golgi Apparatus Using a Localizable Small-Molecule Fluorescent Probe. Cell Chem Biol 2020; 27:1521-1531.e8. [PMID: 32997976 DOI: 10.1016/j.chembiol.2020.09.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 06/16/2020] [Accepted: 09/08/2020] [Indexed: 12/15/2022]
Abstract
Fluorescent Zn2+ probes used for the quantitative analysis of labile Zn2+ concentration ([Zn2+]) in target organelles are crucial for understanding the role of Zn2+ in biological processes. Although several fluorescent Zn2+ probes have been developed to date, there is still a lack of consensus concerning the [Zn2+] in intracellular organelles. In this study, we describe the development of ZnDA-1H, a small-molecule fluorescent probe for Zn2+, which exhibits less pH sensitivity, high Zn2+ selectivity, and large fluorescence enhancement upon binding to Zn2+. Through protein labeling technology, ZnDA-1H was precisely targeted in various intracellular organelles, such as the nucleus, mitochondria, endoplasmic reticulum, and Golgi apparatus. ZnDA-1H exhibited a reversible fluorescence response toward labile Zn2+ in these organelles in live cells. Using this probe, the [Zn2+] in the Golgi apparatus was estimated to be 25 ± 1 nM, suggesting that labile Zn2+ plays a physiological role in the secretory pathway.
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Affiliation(s)
- Toshiyuki Kowada
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan; Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan; Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Tomomi Watanabe
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Yuta Amagai
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Rong Liu
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Momo Yamada
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Hiroto Takahashi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Toshitaka Matsui
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan; Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan; Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Kenji Inaba
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan; Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan; Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Shin Mizukami
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan; Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan; Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan.
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28
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Pratt EPS, Damon LJ, Anson KJ, Palmer AE. Tools and techniques for illuminating the cell biology of zinc. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118865. [PMID: 32980354 DOI: 10.1016/j.bbamcr.2020.118865] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 09/13/2020] [Accepted: 09/15/2020] [Indexed: 12/19/2022]
Abstract
Zinc (Zn2+) is an essential micronutrient that is required for a wide variety of cellular processes. Tools and methods have been instrumental in revealing the myriad roles of Zn2+ in cells. This review highlights recent developments fluorescent sensors to measure the labile Zn2+ pool, chelators to manipulate Zn2+ availability, and fluorescent tools and proteomics approaches for monitoring Zn2+-binding proteins in cells. Finally, we close with some highlights on the role of Zn2+ in regulating cell function and in cell signaling.
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Affiliation(s)
- Evan P S Pratt
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, Boulder, CO 80303, United States of America
| | - Leah J Damon
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, Boulder, CO 80303, United States of America
| | - Kelsie J Anson
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, Boulder, CO 80303, United States of America
| | - Amy E Palmer
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, Boulder, CO 80303, United States of America.
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29
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Soleja N, Irfan, Mohsin M. Ratiometric imaging of flux dynamics of cobalt with an optical sensor. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2020.112699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Xue J, Xie T, Zeng W, Jiang Y, Bai XC. Cryo-EM structures of human ZnT8 in both outward- and inward-facing conformations. eLife 2020; 9:e58823. [PMID: 32723473 PMCID: PMC7428307 DOI: 10.7554/elife.58823] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/28/2020] [Indexed: 01/02/2023] Open
Abstract
ZnT8 is a Zn2+/H+ antiporter that belongs to SLC30 family and plays an essential role in regulating Zn2+ accumulation in the insulin secretory granules of pancreatic β cells. However, the Zn2+/H+ exchange mechanism of ZnT8 remains unclear due to the lack of high-resolution structures. Here, we report the cryo-EM structures of human ZnT8 (HsZnT8) in both outward- and inward-facing conformations. HsZnT8 forms a dimeric structure with four Zn2+ binding sites within each subunit: a highly conserved primary site in transmembrane domain (TMD) housing the Zn2+ substrate; an interfacial site between TMD and C-terminal domain (CTD) that modulates the Zn2+ transport activity of HsZnT8; and two adjacent sites buried in the cytosolic domain and chelated by conserved residues from CTD and the His-Cys-His (HCH) motif from the N-terminal segment of the neighboring subunit. A comparison of the outward- and inward-facing structures reveals that the TMD of each HsZnT8 subunit undergoes a large structural rearrangement, allowing for alternating access to the primary Zn2+ site during the transport cycle. Collectively, our studies provide the structural insights into the Zn2+/H+ exchange mechanism of HsZnT8.
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Affiliation(s)
- Jing Xue
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
| | - Tian Xie
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Cell Biology, University of Texas Southwestern Medical CenterDallasUnited States
| | - Weizhong Zeng
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
| | - Youxing Jiang
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
| | - Xiao-chen Bai
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Cell Biology, University of Texas Southwestern Medical CenterDallasUnited States
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Maares M, Haase H. A Guide to Human Zinc Absorption: General Overview and Recent Advances of In Vitro Intestinal Models. Nutrients 2020; 12:E762. [PMID: 32183116 PMCID: PMC7146416 DOI: 10.3390/nu12030762] [Citation(s) in RCA: 146] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 02/23/2020] [Accepted: 03/09/2020] [Indexed: 12/17/2022] Open
Abstract
Zinc absorption in the small intestine is one of the main mechanisms regulating the systemic homeostasis of this essential trace element. This review summarizes the key aspects of human zinc homeostasis and distribution. In particular, current knowledge on human intestinal zinc absorption and the influence of diet-derived factors on bioaccessibility and bioavailability as well as intrinsic luminal and basolateral factors with an impact on zinc uptake are discussed. Their investigation is increasingly performed using in vitro cellular intestinal models, which are continually being refined and keep gaining importance for studying zinc uptake and transport via the human intestinal epithelium. The vast majority of these models is based on the human intestinal cell line Caco-2 in combination with other relevant components of the intestinal epithelium, such as mucin-secreting goblet cells and in vitro digestion models, and applying improved compositions of apical and basolateral media to mimic the in vivo situation as closely as possible. Particular emphasis is placed on summarizing previous applications as well as key results of these models, comparing their results to data obtained in humans, and discussing their advantages and limitations.
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Affiliation(s)
- Maria Maares
- Technische Universität Berlin, Chair of Food Chemistry and Toxicology, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Hajo Haase
- Technische Universität Berlin, Chair of Food Chemistry and Toxicology, Straße des 17. Juni 135, 10623 Berlin, Germany
- TraceAge-DFG Research Unit on Interactions of Essential Trace Elements in Healthy and Diseased Elderly, D-13353 Potsdam-Berlin-Jena, Germany
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32
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Mikata Y, Nozaki K, Tanaka M, Konno H, Matsumoto A, Kawamura M, Sato SI. Switching of Fluorescent Zn/Cd Selectivity in N, N, N', N'-Tetrakis(6-methoxy-2-quinolylmethyl)-1,2-diphenylethylenediamine by One Asymmetric Carbon Atom Inversion. Inorg Chem 2020; 59:5313-5324. [PMID: 32048842 DOI: 10.1021/acs.inorgchem.9b03304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A quinoline-based hexadentate ligand, (S,S)-N,N,N',N'-tetrakis(6-methoxy-2-quinolylmethyl)-1,2-diphenylethylenediamine ((S,S)-6-MeOTQPh2EN), exhibits fluorescence enhancement at 498 nm upon addition of 1 equiv of Zn2+ (IZn/I0 = 12, φZn = 0.047) in aqueous DMF solution (DMF/H2O = 2:1). Addition of 1 equiv of Cd2+ affords a much smaller fluorescence increase at the same wavelength (ICd/I0 = 2.5, ICd/IZn = 21%). The trivalent metal ions such as Al3+, Cr3+, and Fe3+ also exhibit fluorescence enhancement at 395 nm (IAl/I0 = 22, ICr/I0 = 6 and IFe3+/I0 = 13). In contrast, meso-6-MeOTQPh2EN exhibits a Cd2+-selective fluorescence increase at 405 nm in the presence of 1 equiv of metal ion (ICd/I0 = 11.5, φCd = 0.022), while Zn2+ induces a smaller fluorescent response under the same experimental conditions (IZn/I0 = 3.3, IZn/ICd = 29%). In this case, the fluorescence intensities of meso-6-MeOTQPh2EN in the presence of a large amount of Zn2+ and Cd2+ become similar. This diastereomer-dependent, fluorescent metal ion specificity is derived from the Zn2+-specific intramolecular excimer formation in (S,S)-6-MeOTQPh2EN-Zn2+ complex and higher binding affinity of meso-6-MeOTQPh2EN with Cd2+ in comparison to Zn2+. The more conformationally restricted diastereomeric pair, namely, cis- and trans-TQDACHs (cis- and trans-N,N,N',N'-tetrakis(2-quinolylmethyl)-1,2-diaminocyclohexanes), both exhibit Zn2+-specific fluorescence enhancement because of the high metal binding affinity and intramolecular excimer forming property derived from the rigid DACH backbone.
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Affiliation(s)
- Yuji Mikata
- Department of Chemistry, Biology, and Environmental Science, Faculty of Science, Nara Women's University, Nara 630-8506, Japan.,KYOUSEI Science Center, Nara Women's University, Nara 630-8506, Japan.,Department of Chemistry, Faculty of Science, Nara Women's University, Nara 630-8506, Japan
| | - Kana Nozaki
- Department of Chemistry, Faculty of Science, Nara Women's University, Nara 630-8506, Japan
| | - Marin Tanaka
- Department of Chemistry, Biology, and Environmental Science, Faculty of Science, Nara Women's University, Nara 630-8506, Japan
| | - Hideo Konno
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Arimasa Matsumoto
- Department of Chemistry, Biology, and Environmental Science, Faculty of Science, Nara Women's University, Nara 630-8506, Japan
| | - Masaya Kawamura
- Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Shin-Ichiro Sato
- Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan
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34
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Xian Y, Zhou M, Han S, Yang R, Wang Y. A FRET biosensor reveals free zinc deficiency in diabetic beta-cell vesicles. CHINESE CHEM LETT 2020. [DOI: 10.1016/j.cclet.2019.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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35
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Real-time monitoring of glutathione in living cells using genetically encoded FRET-based ratiometric nanosensor. Sci Rep 2020; 10:992. [PMID: 31969596 PMCID: PMC6976633 DOI: 10.1038/s41598-020-57654-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 01/02/2020] [Indexed: 01/11/2023] Open
Abstract
Reduced glutathione (GSH) level inside the cell is a critical determinant for cell viability. The level of GSH varies across the cells, tissues and environmental conditions. However, our current understanding of physiological and pathological GSH changes at high spatial and temporal resolution is limited due to non-availability of practicable GSH-detection methods. In order to measure GSH at real-time, a ratiometric genetically encoded nanosensor was developed using fluorescent proteins and fluorescence resonance energy transfer (FRET) approach. The construction of the sensor involved the introduction of GSH binding protein (YliB) as a sensory domain between cyan fluorescent protein (CFP; FRET donor) and yellow fluorescent protein (YFP; FRET acceptor). The developed sensor, named as FLIP-G (Fluorescence Indicator Protein for Glutathione) was able to measure the GSH level under in vitro and in vivo conditions. When the purified FLIP-G was titrated with different concentrations of GSH, the FRET ratio increased with increase in GSH-concentration. The sensor was found to be specific for GSH and also stable to changes in pH. Moreover, in live bacterial cells, the constructed sensor enabled the real-time quantification of cytosolic GSH that is controlled by the oxidative stress level. When expressed in yeast cells, FRET ratio increased with the external supply of GSH to living cells. Therefore, as a valuable tool, the developed FLIP-G can monitor GSH level in living cells and also help in gaining new insights into GSH metabolism.
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36
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Jiang A, Liu Y, Chen G, Li Y, Tang B. The cross-talk modulation of excited state electron transfer to reduce the false negative background for high fidelity imaging in vivo. Chem Sci 2020; 11:1964-1974. [PMID: 34123291 PMCID: PMC8148380 DOI: 10.1039/c9sc05765j] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 12/20/2019] [Indexed: 12/12/2022] Open
Abstract
In practice, high fidelity fluorescence imaging in vivo faces many issues, for example: (1) the fluorescence background of the probe is bleached by the wide intensity scale of fluorescence microscopy, displaying an inherent false negative background (FNB); and (2) the dosage of the probe has to be increased to achieve sufficient intensity for in vivo imaging, causing a vicious cycle that exacerbates the FNB. Herein, we constructed a fluorophore (F)-electron donor (D)-electron regulator (R) system, and thereby developed a dual modulation strategy for the de novo design of high fidelity probes. Using cross-talk modulation, the probe allows: (1) enhanced ESET (excited state electron transfer) from F to D, which minimizes the inherent FNB based on synergistic PET (photo induced electron transfer); and (2) the inhibition of PET and weakening of ESET from F to D to maximize the reporting intensity to further reduce the FNB, which is additionally enhanced by an overdose of the probe. To test the implementation, we constructed a 7-hydroxy-2-oxo-2H-chromene-3-carbaldehyde (HPC) series of probes, with HPC (F) as the fluorophore, 2-hydrazinylpyridine, which was screened as an electronically adjustable donor (D), and electronic regulators (R). In particular, HPC-7 and HPC-8 provided cell/zebrafish imaging with negligible background even using the rather low fluorescence scale of microscopy (a region for revealing hidden background). Interestingly, with the specificity of HPC for reporting zinc, we achieved probe HPC-5, which possesses both an ultralow inherent FNB and optimal reporting intensity for tissue and in vivo imaging, enabling the in vivo imaging of zinc in mice for the first time. Under this high-fidelity mode, the fluorescence monitoring of zinc ions during the development of liver cancer in mice was successfully performed. We envision that the dual modulation strategy with the F-D-R system could provide a useful concept for the de novo design of practical probes.
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Affiliation(s)
- Ao Jiang
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University Jinan 250014 P. R. China
- The Key Laboratory of Life-Organic Analysis; Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, College of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Yuxia Liu
- The Key Laboratory of Life-Organic Analysis; Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, College of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Guang Chen
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University Jinan 250014 P. R. China
- The Key Laboratory of Life-Organic Analysis; Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, College of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Yong Li
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University Jinan 250014 P. R. China
| | - Bo Tang
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University Jinan 250014 P. R. China
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37
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Sub-nanomolar sensitive GZnP3 reveals TRPML1-mediated neuronal Zn 2+ signals. Nat Commun 2019; 10:4806. [PMID: 31641116 PMCID: PMC6805855 DOI: 10.1038/s41467-019-12761-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 09/27/2019] [Indexed: 02/07/2023] Open
Abstract
Although numerous fluorescent Zn2+ sensors have been reported, it is unclear whether and how Zn2+ can be released from the intracellular compartments into the cytosol due to a lack of probes that can detect physiological dynamics of cytosolic Zn2+. Here, we create a genetically encoded sensor, GZnP3, which demonstrates unprecedented sensitivity for Zn2+ at sub-nanomolar concentrations. Using GZnP3 as well as GZnP3-derived vesicular targeted probes, we provide the first direct evidence that Zn2+ can be released from endolysosomal vesicles to the cytosol in primary hippocampal neurons through the TRPML1 channel. Such TRPML1-mediated Zn2+ signals are distinct from Ca2+ in that they are selectively present in neurons, sustain longer, and are significantly higher in neurites as compared to the soma. Together, our work not only creates highly sensitive probes for investigating sub-nanomolar Zn2+ dynamics, but also reveals new pools of Zn2+ signals that can play critical roles in neuronal function. Numerous fluorescent Zn2+ sensors are available but most are unsuitable to detect physiological dynamics of cytosolic Zn2+. In this study, the authors present a genetically encoded sensor with sub-nanomolar sensitivity and show that Zn2 + is released from endolysosomal vesicles via TRPML1 in neurons.
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Chen M, Zhang S, Xing Y, Li X, He Y, Wang Y, Oberholzer J, Ai HW. Genetically Encoded, Photostable Indicators to Image Dynamic Zn 2+ Secretion of Pancreatic Islets. Anal Chem 2019; 91:12212-12219. [PMID: 31475537 PMCID: PMC6773511 DOI: 10.1021/acs.analchem.9b01802] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
As an essential element for living organisms, zinc (Zn2+) exerts its biological functions both intracellularly and extracellularly. Previous studies have reported a number of genetically encoded Zn2+ indicators (GEZIs), which have been widely used to monitor Zn2+ in the cytosol and intracellular organelles. However, it is challenging to localize existing GEZIs to the extracellular space to detect secreted Zn2+. Herein, we report two photostable, green fluorescent protein (GFP) based indicators, ZIBG1 and ZIBG2, which respond to Zn2+ selectively and have affinities suited for detecting Zn2+ secretion from intracellular vesicles. In particular, ZIBG2 can be effectively targeted to the extracellular side of plasma membrane. We applied cell surface-localized ZIBG2 to monitor glucose-induced dynamic Zn2+ secretion from mouse insulinoma MIN6 cells and primary mouse and human pancreatic islets. Because Zn2+ is co-released with insulin from β-cells, the fluorescence of cell surface-localized ZIBG2 was shown to be a strong indicator for the functional potency of islets. Our work here has thus expanded the use of GEZIs to image dynamic Zn2+ secretion in live tissue. Because it is convenient to use genetically encoded indicators for expression over extended periods and for in vivo delivery, we envision future applications of ZIBG2 in development of induced β-cells or islets to advance cell replacement therapies for diabetes and in direct imaging of Zn2+ secretion dynamics in vivo.
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Affiliation(s)
- Minghai Chen
- Center for Membrane and Cell Physiology, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
- Department of Molecular Physiology and Biological Physics, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
| | - Shen Zhang
- Center for Membrane and Cell Physiology, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
- Department of Chemistry, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
| | - Yuan Xing
- Department of Surgery, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
| | - Xinyu Li
- Center for Membrane and Cell Physiology, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
- Department of Molecular Physiology and Biological Physics, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
| | - Yi He
- Department of Surgery, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
| | - Yong Wang
- Department of Surgery, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
| | - José Oberholzer
- Department of Surgery, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
- Department of Bioengineering, and , University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
| | - Hui-wang Ai
- Center for Membrane and Cell Physiology, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
- Department of Molecular Physiology and Biological Physics, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
- Department of Chemistry, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
- Department of Bioengineering, and , University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
- UVA Cancer Center, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia 22908, United States
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Two plant-hosted whole-cell bacterial biosensors for detection of bioavailable Cr(VI). World J Microbiol Biotechnol 2019; 35:129. [DOI: 10.1007/s11274-019-2703-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 07/26/2019] [Indexed: 10/26/2022]
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Yeh HW, Ai HW. Development and Applications of Bioluminescent and Chemiluminescent Reporters and Biosensors. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2019; 12:129-150. [PMID: 30786216 PMCID: PMC6565457 DOI: 10.1146/annurev-anchem-061318-115027] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Although fluorescent reporters and biosensors have become indispensable tools in biological and biomedical fields, fluorescence measurements require external excitation light, thereby limiting their use in thick tissues and live animals. Bioluminescent reporters and biosensors may potentially overcome this hurdle because they use enzyme-catalyzed exothermic biochemical reactions to generate excited-state emitters. This review first introduces the development of bioluminescent reporters, and next, their applications in sensing biological changes in vitro and in vivo as biosensors. Lastly, we discuss chemiluminescent sensors that produce photons in the absence of luciferases. This review aims to explore fundamentals and experimental insights and to emphasize the yet-to-be-reached potential of next-generation luminescent reporters and biosensors.
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Affiliation(s)
- Hsien-Wei Yeh
- Center for Membrane and Cell Physiology, Department of Molecular Physiology and Biological Physics, and Department of Chemistry, University of Virginia, Charlottesville, Virginia 22908, USA;
| | - Hui-Wang Ai
- Center for Membrane and Cell Physiology, Department of Molecular Physiology and Biological Physics, and Department of Chemistry, University of Virginia, Charlottesville, Virginia 22908, USA;
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Manzoor O, Soleja N, Khan P, Imtaiyaz Hassan M, Mohsin M. Visualization of thiamine in living cells using genetically encoded fluorescent nanosensor. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.03.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Gao P, Pan W, Li N, Tang B. Fluorescent probes for organelle-targeted bioactive species imaging. Chem Sci 2019; 10:6035-6071. [PMID: 31360411 PMCID: PMC6585876 DOI: 10.1039/c9sc01652j] [Citation(s) in RCA: 366] [Impact Index Per Article: 73.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 05/23/2019] [Indexed: 12/12/2022] Open
Abstract
The dynamic fluctuations of bioactive species in living cells are associated with numerous physiological and pathological phenomena. The emergence of organelle-targeted fluorescent probes has significantly facilitated our understanding on the biological functions of these species. This review describes the design, applications, challenges and potential directions of organelle-targeted bioactive species probes.
Bioactive species, including reactive oxygen species (ROS, including O2˙–, H2O2, HOCl, 1O2, ˙OH, HOBr, etc.), reactive nitrogen species (RNS, including ONOO–, NO, NO2, HNO, etc.), reactive sulfur species (RSS, including GSH, Hcy, Cys, H2S, H2Sn, SO2 derivatives, etc.), ATP, HCHO, CO and so on, are a highly important category of molecules in living cells. The dynamic fluctuations of these molecules in subcellular microenvironments determine cellular homeostasis, signal conduction, immunity and metabolism. However, their abnormal expressions can cause disorders which are associated with diverse major diseases. Monitoring bioactive molecules in subcellular structures is therefore critical for bioanalysis and related drug discovery. With the emergence of organelle-targeted fluorescent probes, significant progress has been made in subcellular imaging. Among the developed subcellular localization fluorescent tools, ROS, RNS and RSS (RONSS) probes are highly attractive, owing to their potential for revealing the physiological and pathological functions of these highly reactive, interactive and interconvertible molecules during diverse biological events, which are rather significant for advancing our understanding of different life phenomena and exploring new technologies for life regulation. This review mainly illustrates the design principles, detection mechanisms, current challenges, and potential future directions of organelle-targeted fluorescent probes toward RONSS.
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Affiliation(s)
- Peng Gao
- College of Chemistry, Chemical Engineering and Materials Science , Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong , Key Laboratory of Molecular and Nano Probes , Ministry of Education , Institute of Molecular and Nano Science , Shandong Normal University , Jinan 250014 , P. R. China . ;
| | - Wei Pan
- College of Chemistry, Chemical Engineering and Materials Science , Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong , Key Laboratory of Molecular and Nano Probes , Ministry of Education , Institute of Molecular and Nano Science , Shandong Normal University , Jinan 250014 , P. R. China . ;
| | - Na Li
- College of Chemistry, Chemical Engineering and Materials Science , Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong , Key Laboratory of Molecular and Nano Probes , Ministry of Education , Institute of Molecular and Nano Science , Shandong Normal University , Jinan 250014 , P. R. China . ;
| | - Bo Tang
- College of Chemistry, Chemical Engineering and Materials Science , Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong , Key Laboratory of Molecular and Nano Probes , Ministry of Education , Institute of Molecular and Nano Science , Shandong Normal University , Jinan 250014 , P. R. China . ;
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Live-Cell Imaging of Physiologically Relevant Metal Ions Using Genetically Encoded FRET-Based Probes. Cells 2019; 8:cells8050492. [PMID: 31121936 PMCID: PMC6562680 DOI: 10.3390/cells8050492] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/17/2019] [Accepted: 05/21/2019] [Indexed: 01/02/2023] Open
Abstract
Essential biochemical reactions and processes within living organisms are coupled to subcellular fluctuations of metal ions. Disturbances in cellular metal ion homeostasis are frequently associated with pathological alterations, including neurotoxicity causing neurodegeneration, as well as metabolic disorders or cancer. Considering these important aspects of the cellular metal ion homeostasis in health and disease, measurements of subcellular ion signals are of broad scientific interest. The investigation of the cellular ion homeostasis using classical biochemical methods is quite difficult, often even not feasible or requires large cell numbers. Here, we report of genetically encoded fluorescent probes that enable the visualization of metal ion dynamics within individual living cells and their organelles with high temporal and spatial resolution. Generally, these probes consist of specific ion binding domains fused to fluorescent protein(s), altering their fluorescent properties upon ion binding. This review focuses on the functionality and potential of these genetically encoded fluorescent tools which enable monitoring (sub)cellular concentrations of alkali metals such as K+, alkaline earth metals including Mg2+ and Ca2+, and transition metals including Cu+/Cu2+ and Zn2+. Moreover, we discuss possible approaches for the development and application of novel metal ion biosensors for Fe2+/Fe3+, Mn2+ and Na+.
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Slocum JD, Palmer AE, Jimenez R. Intramolecular Fluorescent Protein Association in a Class of Zinc FRET Sensors Leads to Increased Dynamic Range. J Phys Chem B 2019; 123:3079-3085. [PMID: 30942588 DOI: 10.1021/acs.jpcb.9b02479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Genetically encoded Förster resonance energy transfer (FRET) sensors enable the visualization of ions, molecules, and processes in live cells. However, despite their widespread use, the molecular states that determine sensor performance are usually poorly understood, which limits efforts to improve them. We used dynamic light scattering (DLS) and time-resolved fluorescence anisotropy to uncover the sensing mechanism of ZifCV1.173, a Zn2+ FRET sensor. We found that the dynamic range (DR) of ZifCV1.173 was dominated by the high FRET efficiency of the Zn2+-free state, in which the donor and acceptor fluorescent proteins were closely associated. Mutating the donor-acceptor interface revealed that the DR of ZifCV1.173 could be increased or decreased by promoting or disrupting the donor-acceptor interaction, respectively. Adapting the same mutations to a related sensor showed the same pattern of DR tuning, supporting our sensing mechanism and suggesting that DLS and time-resolved fluorescence anisotropy might be generally useful in the biophysical characterization of other FRET sensors.
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Zinc regulates ERp44-dependent protein quality control in the early secretory pathway. Nat Commun 2019; 10:603. [PMID: 30723194 PMCID: PMC6363758 DOI: 10.1038/s41467-019-08429-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 01/09/2019] [Indexed: 01/14/2023] Open
Abstract
Zinc ions (Zn2+) are imported into the early secretory pathway by Golgi-resident transporters, but their handling and functions are not fully understood. Here, we show that Zn2+ binds with high affinity to the pH-sensitive chaperone ERp44, modulating its localization and ability to retrieve clients like Ero1α and ERAP1 to the endoplasmic reticulum (ER). Silencing the Zn2+ transporters that uptake Zn2+ into the Golgi led to ERp44 dysfunction and increased secretion of Ero1α and ERAP1. High-resolution crystal structures of Zn2+-bound ERp44 reveal that Zn2+ binds to a conserved histidine-cluster. The consequent large displacements of the regulatory C-terminal tail expose the substrate-binding surface and RDEL motif, ensuring client capture and retrieval. ERp44 also forms Zn2+-bridged homodimers, which dissociate upon client binding. Histidine mutations in the Zn2+-binding sites compromise ERp44 activity and localization. Our findings reveal a role of Zn2+ as a key regulator of protein quality control at the ER-Golgi interface. Zinc ions (Zn2+) are imported by Golgi-resident transporters but the function of zinc in the early secretory pathway has remained unknown. Here the authors find that Zn2+ regulates protein quality control in the early secretory pathway by demonstrating that the pH-sensitive chaperone ERp44 binds Zn2+ and solving the Zn2+-bound ERp44 structure.
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Chabosseau P, Woodier J, Cheung R, Rutter GA. Sensors for measuring subcellular zinc pools. Metallomics 2019; 10:229-239. [PMID: 29431830 DOI: 10.1039/c7mt00336f] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Zinc homeostasis is essential for normal cellular function, and defects in this process are associated with a number of diseases including type 2 diabetes (T2D), neurological disorders and cardiovascular disease. Thus, variants in the SLC30A8 gene, encoding the vesicular/granular zinc transporter ZnT8, are associated with altered insulin release and increased T2D risk while the zinc importer ZIP12 is implicated in pulmonary hypertension. In light of these, and findings in other diseases, recent efforts have focused on the development of refined sensors for intracellular free zinc ions that can be targeted to subcellular regions including the cytosol, endoplasmic reticulum (ER), secretory granules, Golgi apparatus, nucleus and the mitochondria. Here, we discuss recent advances in Zn2+ probe engineering and their applications to the measurement of labile subcellular zinc pools in different cell types.
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Affiliation(s)
- Pauline Chabosseau
- Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK.
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Terai K, Imanishi A, Li C, Matsuda M. Two Decades of Genetically Encoded Biosensors Based on Förster Resonance Energy Transfer. Cell Struct Funct 2019; 44:153-169. [DOI: 10.1247/csf.18035] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Kenta Terai
- Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University
- Research Center for Dynamic Living Systems, Graduate School of Biostudies, Kyoto University
| | - Ayako Imanishi
- Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University
| | - Chunjie Li
- Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University
| | - Michiyuki Matsuda
- Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University
- Research Center for Dynamic Living Systems, Graduate School of Biostudies, Kyoto University
- Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University
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Greenwald EC, Mehta S, Zhang J. Genetically Encoded Fluorescent Biosensors Illuminate the Spatiotemporal Regulation of Signaling Networks. Chem Rev 2018; 118:11707-11794. [PMID: 30550275 PMCID: PMC7462118 DOI: 10.1021/acs.chemrev.8b00333] [Citation(s) in RCA: 302] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cellular signaling networks are the foundation which determines the fate and function of cells as they respond to various cues and stimuli. The discovery of fluorescent proteins over 25 years ago enabled the development of a diverse array of genetically encodable fluorescent biosensors that are capable of measuring the spatiotemporal dynamics of signal transduction pathways in live cells. In an effort to encapsulate the breadth over which fluorescent biosensors have expanded, we endeavored to assemble a comprehensive list of published engineered biosensors, and we discuss many of the molecular designs utilized in their development. Then, we review how the high temporal and spatial resolution afforded by fluorescent biosensors has aided our understanding of the spatiotemporal regulation of signaling networks at the cellular and subcellular level. Finally, we highlight some emerging areas of research in both biosensor design and applications that are on the forefront of biosensor development.
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Affiliation(s)
- Eric C Greenwald
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Sohum Mehta
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Jin Zhang
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
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Superiority of SpiroZin2 Versus FluoZin-3 for monitoring vesicular Zn 2+ allows tracking of lysosomal Zn 2+ pools. Sci Rep 2018; 8:15034. [PMID: 30302024 PMCID: PMC6177427 DOI: 10.1038/s41598-018-33102-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 09/17/2018] [Indexed: 12/28/2022] Open
Abstract
Small-molecule fluorescent probes are powerful and ubiquitous tools for measuring the concentration and distribution of analytes in living cells. However, accurate characterization of these analytes requires rigorous evaluation of cell-to-cell heterogeneity in fluorescence intensities and intracellular distribution of probes. In this study, we perform a parallel and systematic comparison of two small-molecule fluorescent vesicular Zn2+ probes, FluoZin-3 AM and SpiroZin2, to evaluate each probe for measurement of vesicular Zn2+ pools. Our results reveal that SpiroZin2 is a specific lysosomal vesicular Zn2+ probe and affords uniform measurement of resting Zn2+ levels at the single cell level with proper calibration. In contrast, FluoZin-3 AM produces highly variable fluorescence intensities and non-specifically localizes in the cytosol and multiple vesicular compartments. We further applied SpiroZin2 to lactating mouse mammary epithelial cells and detected a transient increase of lysosomal free Zn2+ at 24-hour after lactation hormone treatment, which implies that lysosomes play a role in the regulation of Zn2+ homeostasis during lactation. This study demonstrates the need for critical characterization of small-molecule fluorescent probes to define the concentration and localization of analytes in different cell populations, and reveals SpiroZin2 to be capable of reporting diverse perturbations to lysosomal Zn2+.
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50
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Holliday MJ, Ferrao R, de Leon Boenig G, Estevez A, Helgason E, Rohou A, Dueber EC, Fairbrother WJ. Picomolar zinc binding modulates formation of Bcl10-nucleating assemblies of the caspase recruitment domain (CARD) of CARD9. J Biol Chem 2018; 293:16803-16817. [PMID: 30206119 DOI: 10.1074/jbc.ra118.004821] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 09/04/2018] [Indexed: 12/28/2022] Open
Abstract
The caspase recruitment domain-containing protein 9 (CARD9)-B-cell lymphoma/leukemia 10 (Bcl10) signaling axis is activated in myeloid cells during the innate immune response to a variety of diverse pathogens. This signaling pathway requires a critical caspase recruitment domain (CARD)-CARD interaction between CARD9 and Bcl10 that promotes downstream activation of factors, including NF-κB and the mitogen-activated protein kinase (MAPK) p38. Despite these insights, CARD9 remains structurally uncharacterized, and little mechanistic understanding of its regulation exists. We unexpectedly found here that the CARD in CARD9 binds to Zn2+ with picomolar affinity-a concentration comparable with the levels of readily accessible Zn2+ in the cytosol. NMR solution structures of the CARD9-CARD in the apo and Zn2+-bound states revealed that Zn2+ has little effect on the ground-state structure of the CARD; yet the stability of the domain increased considerably upon Zn2+ binding, with a concomitant reduction in conformational flexibility. Moreover, Zn2+ binding inhibited polymerization of the CARD9-CARD into helical assemblies. Here, we also present a 20-Å resolution negative-stain EM (NS-EM) structure of these filamentous assemblies and show that they adopt a similar helical symmetry as reported previously for filaments of the Bcl10 CARD. Using both bulk assays and direct NS-EM visualization, we further show that the CARD9-CARD assemblies can directly template and thereby nucleate Bcl10 polymerization, a capacity considered critical to propagation of the CARD9-Bcl10 signaling cascade. Our findings indicate that CARD9 is a potential target of Zn2+-mediated signaling that affects Bcl10 polymerization in innate immune responses.
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Affiliation(s)
| | - Ryan Ferrao
- Structural Biology Department, Genentech, South San Francisco, California 94080
| | | | - Alberto Estevez
- Structural Biology Department, Genentech, South San Francisco, California 94080
| | | | - Alexis Rohou
- Structural Biology Department, Genentech, South San Francisco, California 94080
| | - Erin C Dueber
- From the Early Discovery Biochemistry Department and
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