1
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Yahiro T, Bayless-Edwards L, Jones JA, Ma L, Qin M, Mao T, Zhong H. A high-performance genetically encoded sensor for cellular imaging of PKC activity in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.19.604387. [PMID: 39091834 PMCID: PMC11291028 DOI: 10.1101/2024.07.19.604387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
We report a genetically encoded fluorescence lifetime sensor for protein kinase C (PKC) activity, named CKAR3, based on Förster resonance energy transfer. CKAR3 exhibits a 10-fold increased dynamic range compared to its parental sensors and enables in vivo imaging of PKC activity during animal behavior. Our results reveal robust PKC activity in a sparse neuronal subset in the motor cortex during locomotion, in part mediated by muscarinic acetylcholine receptors.
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Affiliation(s)
- Takaki Yahiro
- Vollum Institute, Oregon Health and Science University, Portland, OR, 97239
| | | | - James A Jones
- Vollum Institute, Oregon Health and Science University, Portland, OR, 97239
| | - Lei Ma
- Vollum Institute, Oregon Health and Science University, Portland, OR, 97239
| | - Maozhen Qin
- Vollum Institute, Oregon Health and Science University, Portland, OR, 97239
| | - Tianyi Mao
- Vollum Institute, Oregon Health and Science University, Portland, OR, 97239
| | - Haining Zhong
- Vollum Institute, Oregon Health and Science University, Portland, OR, 97239
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2
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Frei MS, Mehta S, Zhang J. Next-Generation Genetically Encoded Fluorescent Biosensors Illuminate Cell Signaling and Metabolism. Annu Rev Biophys 2024; 53:275-297. [PMID: 38346245 DOI: 10.1146/annurev-biophys-030722-021359] [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: 02/28/2024]
Abstract
Genetically encoded fluorescent biosensors have revolutionized the study of cell signaling and metabolism, as they allow for live-cell measurements with high spatiotemporal resolution. This success has spurred the development of tailor-made biosensors that enable the study of dynamic phenomena on different timescales and length scales. In this review, we discuss different approaches to enhancing and developing new biosensors. We summarize the technologies used to gain structural insights into biosensor design and comment on useful screening technologies. Furthermore, we give an overview of different applications where biosensors have led to key advances over recent years. Finally, we give our perspective on where future work is bound to make a large impact.
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Affiliation(s)
- Michelle S Frei
- Department of Pharmacology, University of California San Diego, La Jolla, California, USA; , ,
| | - Sohum Mehta
- Department of Pharmacology, University of California San Diego, La Jolla, California, USA; , ,
| | - Jin Zhang
- Department of Pharmacology, University of California San Diego, La Jolla, California, USA; , ,
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, California, USA
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, USA
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3
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Hodapp SJ, Gravel N, Kannan N, Newton AC. Cancer-associated mutations in protein kinase C theta are loss-of-function. Biochem J 2024; 481:759-775. [PMID: 38752473 PMCID: PMC11346454 DOI: 10.1042/bcj20240148] [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: 04/02/2024] [Revised: 05/14/2024] [Accepted: 05/16/2024] [Indexed: 06/11/2024]
Abstract
The Ca2+-independent, but diacylglycerol-regulated, novel protein kinase C (PKC) theta (θ) is highly expressed in hematopoietic cells where it participates in immune signaling and platelet function. Mounting evidence suggests that PKCθ may be involved in cancer, particularly blood cancers, breast cancer, and gastrointestinal stromal tumors, yet how to target this kinase (as an oncogene or as a tumor suppressor) has not been established. Here, we examine the effect of four cancer-associated mutations, R145H/C in the autoinhibitory pseudosubstrate, E161K in the regulatory C1A domain, and R635W in the regulatory C-terminal tail, on the cellular activity and stability of PKCθ. Live-cell imaging studies using the genetically-encoded fluorescence resonance energy transfer-based reporter for PKC activity, C kinase activity reporter 2 (CKAR2), revealed that the pseudosubstrate and C1A domain mutations impaired autoinhibition to increase basal signaling. This impaired autoinhibition resulted in decreased stability of the protein, consistent with the well-characterized behavior of Ca2+-regulated PKC isozymes wherein mutations that impair autoinhibition are paradoxically loss-of-function because the mutant protein is degraded. In marked contrast, the C-terminal tail mutation resulted in enhanced autoinhibition and enhanced stability. Thus, the examined mutations were loss-of-function by different mechanisms: mutations that impaired autoinhibition promoted the degradation of PKC, and those that enhanced autoinhibition stabilized an inactive PKC. Supporting a general loss-of-function of PKCθ in cancer, bioinformatics analysis revealed that protein levels of PKCθ are reduced in diverse cancers, including lung, renal, head and neck, and pancreatic. Our results reveal that PKCθ function is lost in cancer.
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Affiliation(s)
- Stefanie J. Hodapp
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, U.S.A
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, U.S.A
| | - Nathan Gravel
- Department of Biochemistry and Molecular Biology and Institute of Bioinformatics, University of Georgia, Athens, GA 30602, U.S.A
| | - Natarajan Kannan
- Department of Biochemistry and Molecular Biology and Institute of Bioinformatics, University of Georgia, Athens, GA 30602, U.S.A
| | - Alexandra C. Newton
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, U.S.A
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4
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Koveal D. Functional principles of genetically encoded fluorescent biosensors for metabolism and their quantitative use. J Neurochem 2024; 168:496-505. [PMID: 37314388 DOI: 10.1111/jnc.15878] [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: 04/18/2023] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 06/15/2023]
Abstract
Genetically encoded fluorescent biosensors provide an attractive means of measuring chemical changes in single cells on fast timescales (milliseconds to seconds). While their most prominent application has been in tracking neural activity and neurotransmitter release, there has been growing interest in developing and deploying new versions of these tools to study brain metabolism. However, the careful use of these tools and the interpretation of the data they provide remain challenging. Many biosensors are subject to interferences that can alter sensor responses within a single cell or between cells, producing ambiguous results. This presents a challenge for quantitation and for our ability to accurately interpret sensor responses. This review describes current methods of sensor quantitation, with a focus on cellular interferences that commonly affect sensor performance, ways to avoid false inferences, and recent advances in sensor optimization to make them more robust.
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Affiliation(s)
- Dorothy Koveal
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, Georgia, USA
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5
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Su Q, Zhang J, Lin W, Zhang JF, Newton AC, Mehta S, Yang J, Zhang J. Sensitive Fluorescent Biosensor Reveals Differential Subcellular Regulation of PKC. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.29.587373. [PMID: 38586003 PMCID: PMC10996667 DOI: 10.1101/2024.03.29.587373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
The protein kinase C (PKC) family of serine/threonine kinases, which consist of three distinctly regulated subfamilies, have long been established as critical for a variety of cellular functions. However, how PKC enzymes are regulated at different subcellular locations, particularly at emerging signaling hubs such as the ER, lysosome, and Par signaling complexes, is unclear. Here, we present a sensitive Excitation Ratiometric (ExRai) C Kinase Activity Reporter (ExRai-CKAR2) that enables the detection of minute changes in subcellular PKC activity. Using ExRai-CKAR2 in conjunction with an enhanced diacylglycerol (DAG) biosensor capable of detecting intracellular DAG dynamics, we uncover the differential regulation of PKC isoforms at distinct subcellular locations. We find that G-protein coupled receptor (GPCR) stimulation triggers sustained PKC activity at the ER and lysosomes, primarily mediated by Ca2+ sensitive conventional PKC (cPKC) and novel PKC (nPKC), respectively, with nPKC showing high basal activity due to elevated basal DAG levels on lysosome membranes. The high sensitivity of ExRai-CKAR2, targeted to either the cytosol or Par-complexes, further enabled us to detect previously inaccessible endogenous atypical PKC (aPKC) activity in 3D organoids. Taken together, ExRai-CKAR2 is a powerful tool for interrogating PKC regulation in response to physiological stimuli.
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Affiliation(s)
- Qi Su
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jing Zhang
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
| | - Wei Lin
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jin-Fan Zhang
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Alexandra C Newton
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
| | - Sohum Mehta
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jing Yang
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jin Zhang
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA
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6
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Jones AC, Kornev AP, Weng JH, Manning G, Taylor SS, Newton AC. Single-residue mutation in protein kinase C toggles between cancer and neurodegeneration. Biochem J 2023; 480:1299-1316. [PMID: 37551632 PMCID: PMC10586763 DOI: 10.1042/bcj20220397] [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: 03/16/2023] [Revised: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 08/09/2023]
Abstract
Conventional protein kinase C (cPKC) isozymes tune the signaling output of cells, with loss-of-function somatic mutations associated with cancer and gain-of-function germline mutations identified in neurodegeneration. PKC with impaired autoinhibition is removed from the cell by quality-control mechanisms to prevent the accumulation of aberrantly active enzyme. Here, we examine how a highly conserved residue in the C1A domain of cPKC isozymes permits quality-control degradation when mutated to histidine in cancer (PKCβ-R42H) and blocks down-regulation when mutated to proline in the neurodegenerative disease spinocerebellar ataxia (PKCγ-R41P). Using FRET-based biosensors, we determined that mutation of R42 to any residue, including lysine, resulted in reduced autoinhibition as indicated by higher basal activity and faster agonist-induced plasma membrane translocation. R42 is predicted to form a stabilizing salt bridge with E655 in the C-tail and mutation of E655, but not neighboring E657, also reduced autoinhibition. Western blot analysis revealed that whereas R42H had reduced stability, the R42P mutant was stable and insensitive to activator-induced ubiquitination and down-regulation, an effect previously observed by deletion of the entire C1A domain. Molecular dynamics (MD) simulations and analysis of stable regions of the domain using local spatial pattern (LSP) alignment suggested that P42 interacts with Q66 to impair mobility and conformation of one of the ligand-binding loops. Additional mutation of Q66 to the smaller asparagine (R42P/Q66N), to remove conformational constraints, restored degradation sensitivity. Our results unveil how disease-associated mutations of the same residue in the C1A domain can toggle between gain- or loss-of-function of PKC.
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Affiliation(s)
- Alexander C. Jones
- Department of Pharmacology, University of California, La Jolla, CA 92093, U.S.A
- Biomedical Sciences Graduate Program, University of California, La Jolla, CA 92093, U.S.A
| | - Alexandr P. Kornev
- Department of Pharmacology, University of California, La Jolla, CA 92093, U.S.A
| | - Jui-Hung Weng
- Department of Pharmacology, University of California, La Jolla, CA 92093, U.S.A
| | | | - Susan S. Taylor
- Department of Pharmacology, University of California, La Jolla, CA 92093, U.S.A
| | - Alexandra C. Newton
- Department of Pharmacology, University of California, La Jolla, CA 92093, U.S.A
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7
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Jones AC, Kornev AP, Weng JH, Manning G, Taylor SS, Newton AC. Single-residue mutation in protein kinase C toggles between cancer and neurodegeneration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.16.532226. [PMID: 36993163 PMCID: PMC10055082 DOI: 10.1101/2023.03.16.532226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Conventional protein kinase C (PKC) isozymes tune the signaling output of cells, with loss-of-function somatic mutations associated with cancer and gain-of-function germline mutations identified in neurodegeneration. PKC with impaired autoinhibition is removed from the cell by quality-control mechanisms to prevent accumulation of aberrantly active enzyme. Here, we examine how a single residue in the C1A domain of PKCβ, arginine 42 (R42), permits quality-control degradation when mutated to histidine in cancer (R42H) and blocks downregulation when mutated to proline in the neurodegenerative disease spinocerebellar ataxia (R42P). Using FRET-based biosensors, we determined that mutation of R42 to any residue, including lysine, resulted in reduced autoinhibition as indicated by higher basal activity and faster agonist-induced plasma membrane translocation. R42 is predicted to form a stabilizing salt bridge with E655 in the C-tail and mutation of E655, but not neighboring E657, also reduced autoinhibition. Western blot analysis revealed that whereas R42H had reduced stability, the R42P mutant was stable and insensitive to activator-induced ubiquitination and downregulation, an effect previously observed by deletion of the entire C1A domain. Molecular dynamics (MD) simulations and analysis of stable regions of the domain using local spatial pattern (LSP) alignment suggested that P42 interacts with Q66 to impair mobility and conformation of one of the ligand-binding loops. Additional mutation of Q66 to the smaller asparagine (R42P/Q66N), to remove conformational constraints, restored degradation sensitivity to that of WT. Our results unveil how disease-associated mutations of the same residue in the C1A domain can toggle between gain- or loss-of-function of PKC.
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8
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Van Thillo T, Van Deuren V, Dedecker P. Smart genetically-encoded biosensors for the chemical monitoring of living systems. Chem Commun (Camb) 2023; 59:520-534. [PMID: 36519509 DOI: 10.1039/d2cc05363b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Genetically-encoded biosensors provide the all-optical and non-invasive visualization of dynamic biochemical events within living systems, which has allowed the discovery of profound new insights. Twenty-five years of biosensor development has steadily improved their performance and has provided us with an ever increasing biosensor repertoire. In this feature article, we present recent advances made in biosensor development and provide a perspective on the future direction of the field.
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Affiliation(s)
- Toon Van Thillo
- Department of Chemistry, KU Leuven, Celestijnenlaan 200G, 3001 Leuven, Belgium.
| | - Vincent Van Deuren
- Department of Chemistry, KU Leuven, Celestijnenlaan 200G, 3001 Leuven, Belgium.
| | - Peter Dedecker
- Department of Chemistry, KU Leuven, Celestijnenlaan 200G, 3001 Leuven, Belgium.
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9
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Prado LCDS, Giacchetto Felice A, Rodrigues TCV, Tiwari S, Andrade BS, Kato RB, Oliveira CJF, Silva MV, Barh D, Azevedo VADC, Jaiswal AK, Soares SDC. New putative therapeutic targets against Serratia marcescens using reverse vaccinology and subtractive genomics. J Biomol Struct Dyn 2022; 40:10106-10121. [PMID: 34192477 DOI: 10.1080/07391102.2021.1942211] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The Gram-negative bacillus Serratia marcescens, a member of Enterobacteriaceae family, is an opportunistic nosocomial pathogen commonly found in hospital outbreaks that can cause infections in the urinary tract, bloodstream, central nervous system and pneumonia. Because S. marcescens strains are resistant to several antibiotics, it is critical the need for effective treatments, including new drugs and vaccines. Here, we applied reverse vaccinology and subtractive genomic approaches for the in silico prediction of potential vaccine and drug targets against 59 strains of S. marcescens. We found 759 core non-host homologous proteins, of which 87 are putative surface-exposed proteins, 183 secreted proteins, and 80 membrane proteins. From these proteins, we predicted seven candidates vaccine targets: a sn-glycerol-3-phosphate-binding periplasmic protein UgpB, a vitamin B12 TonB-dependent receptor, a ferrichrome porin FhuA, a divisome-associated lipoprotein YraP, a membrane-bound lytic murein transglycosylase A, a peptidoglycan lytic exotransglycosylase, and a DUF481 domain-containing protein. We also predicted two drug targets: a N(4)-acetylcytidine amidohydrolase, and a DUF1428 family protein. Using the molecular docking approach for each drug target, we identified and selected ZINC04259491 and ZINC04235390 molecules as the most favorable interactions with the target active site residues. Our findings may contribute to the development of vaccines and new drug targets against S. marcescens. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Ligia Carolina da Silva Prado
- Inter-unit Post-Graduate Program in Bioinformatics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Andrei Giacchetto Felice
- Department of Microbiology, Immunology and Parasitology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil
| | - Thaís Cristina Vilela Rodrigues
- Inter-unit Post-Graduate Program in Bioinformatics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Sandeep Tiwari
- Inter-unit Post-Graduate Program in Bioinformatics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Bruno Silva Andrade
- Laboratory of Bioinformatics and Computational Chemistry, State University of Southwest of Bahia, Bahia, Brazil
| | - Rodrigo Bentes Kato
- Inter-unit Post-Graduate Program in Bioinformatics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Carlo José Freire Oliveira
- Department of Microbiology, Immunology and Parasitology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil
| | - Marcos Vinicius Silva
- Department of Microbiology, Immunology and Parasitology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil
| | - Debmalya Barh
- Centre for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology, Nonakuri, West Bengal, India
| | - Vasco Ariston de Carvalho Azevedo
- Inter-unit Post-Graduate Program in Bioinformatics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Arun Kumar Jaiswal
- Inter-unit Post-Graduate Program in Bioinformatics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Siomar de Castro Soares
- Department of Microbiology, Immunology and Parasitology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil
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10
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Kroning KE, Wang W. Genetically encoded tools for in vivo G-protein-coupled receptor agonist detection at cellular resolution. Clin Transl Med 2022; 12:e1124. [PMID: 36446954 PMCID: PMC9708909 DOI: 10.1002/ctm2.1124] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/10/2022] [Accepted: 11/11/2022] [Indexed: 12/03/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are the most abundant receptor type in the human body and are responsible for regulating many physiological processes, such as sensation, cognition, muscle contraction and metabolism. Further, GPCRs are widely expressed in the brain where their agonists make up a large number of neurotransmitters and neuromodulators. Due to the importance of GPCRs in human physiology, genetically encoded sensors have been engineered to detect GPCR agonists at cellular resolution in vivo. These sensors can be placed into two main categories: those that offer real-time information on the signalling dynamics of GPCR agonists and those that integrate the GPCR agonist signal into a permanent, quantifiable mark that can be used to detect GPCR agonist localisation in a large brain area. In this review, we discuss the various designs of real-time and integration sensors, their advantages and limitations, and some in vivo applications. We also discuss the potential of using real-time and integrator sensors together to identify neuronal circuits affected by endogenous GPCR agonists and perform detailed characterisations of the spatiotemporal dynamics of GPCR agonist release in those circuits. By using these sensors together, the overall knowledge of GPCR-mediated signalling can be expanded.
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Affiliation(s)
- Kayla E. Kroning
- Life Sciences Institute, University of MichiganAnn ArborMichiganUSA
- Department of ChemistryUniversity of MichiganAnn ArborMichiganUSA
| | - Wenjing Wang
- Life Sciences Institute, University of MichiganAnn ArborMichiganUSA
- Department of ChemistryUniversity of MichiganAnn ArborMichiganUSA
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11
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Chang H, Bennett AM, Cameron WD, Floro E, Au A, McFaul CM, Yip CM, Rocheleau JV. Targeting Apollo-NADP + to Image NADPH Generation in Pancreatic Beta-Cell Organelles. ACS Sens 2022; 7:3308-3317. [PMID: 36269889 PMCID: PMC9706804 DOI: 10.1021/acssensors.2c01174] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
NADPH/NADP+ redox state supports numerous reactions related to cell growth and survival; yet the full impact is difficult to appreciate due to organelle compartmentalization of NADPH and NADP+. To study glucose-stimulated NADPH production in pancreatic beta-cell organelles, we targeted the Apollo-NADP+ sensor by first selecting the most pH-stable version of the single-color sensor. We subsequently targeted mTurquoise2-Apollo-NADP+ to various organelles and confirmed activity in the cytoplasm, mitochondrial matrix, nucleus, and peroxisome. Finally, we measured the glucose- and glutamine-stimulated NADPH responses by single- and dual-color imaging of the targeted sensors. Overall, we developed multiple organelle-targeted Apollo-NADP+ sensors to reveal the prominent role of beta-cell mitochondria in determining NADPH production in the cytoplasm, nucleus, and peroxisome.
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Affiliation(s)
- Huntley
H. Chang
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada,Toronto
General Hospital Research Institute, University
Health Network, Toronto, Ontario M5G 2C4, Canada
| | - Alex M. Bennett
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada,Toronto
General Hospital Research Institute, University
Health Network, Toronto, Ontario M5G 2C4, Canada
| | - William D. Cameron
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada,Toronto
General Hospital Research Institute, University
Health Network, Toronto, Ontario M5G 2C4, Canada
| | - Eric Floro
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada,Toronto
General Hospital Research Institute, University
Health Network, Toronto, Ontario M5G 2C4, Canada
| | - Aaron Au
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Christopher M. McFaul
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Christopher M. Yip
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Jonathan V. Rocheleau
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada,Toronto
General Hospital Research Institute, University
Health Network, Toronto, Ontario M5G 2C4, Canada,Department
of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada,Banting
and Best Diabetes Centre, University of
Toronto, Toronto, Ontario M5G 2C4, Canada,
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12
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Vecchia MD, Conte-Daban A, Cappe B, Vandenberg W, Vandenabeele P, Riquet FB, Dedecker P. Spectrally Tunable Förster Resonance Energy Transfer-Based Biosensors Using Organic Dye Grafting. ACS Sens 2022; 7:2920-2927. [PMID: 36162130 DOI: 10.1021/acssensors.2c00066] [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: 01/31/2023]
Abstract
Biosensors based on Förster resonance energy transfer (FRET) have revolutionized cellular biology by allowing the direct measurement of biochemical processes in situ. Many genetically encoded sensors make use of fluorescent proteins that are limited in spectral versatility and that allow few ways to change the spectral properties once the construct has been created. In this work, we developed genetically encoded FRET biosensors based on the chemigenetic SNAP and HaloTag domains combined with matching organic fluorophores. We found that the resulting constructs can display comparable responses, kinetics, and reversibility compared to their fluorescent protein-based ancestors, but with the added advantage of spectral versatility, including the availability of red-shifted dye pairs. However, we also find that the introduction of these tags can alter the sensor readout, showing that careful validation is required before applying such constructs in practice. Overall, our approach delivers an innovative methodology that can readily expand the spectral variety and versatility of FRET-based biosensors.
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Affiliation(s)
- Marco Dalla Vecchia
- Lab for NanoBiology, Department of Chemistry, 3001 Leuven, Belgium.,Molecular Signaling and Cell Death Unit, Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium.,Cell Death and Inflammation Unit, VIB-UGent Center for Inflammation Research (IRC), Technologiepark 71, Zwijnaarde, 9052 Ghent, Belgium
| | | | - Benjamin Cappe
- Molecular Signaling and Cell Death Unit, Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium.,Cell Death and Inflammation Unit, VIB-UGent Center for Inflammation Research (IRC), Technologiepark 71, Zwijnaarde, 9052 Ghent, Belgium
| | - Wim Vandenberg
- Lab for NanoBiology, Department of Chemistry, 3001 Leuven, Belgium
| | - Peter Vandenabeele
- Molecular Signaling and Cell Death Unit, Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium.,Cell Death and Inflammation Unit, VIB-UGent Center for Inflammation Research (IRC), Technologiepark 71, Zwijnaarde, 9052 Ghent, Belgium
| | - Franck B Riquet
- Molecular Signaling and Cell Death Unit, Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium.,Cell Death and Inflammation Unit, VIB-UGent Center for Inflammation Research (IRC), Technologiepark 71, Zwijnaarde, 9052 Ghent, Belgium.,Université de Lille, CNRS, UMR 8523-PhLAM-Physique des Lasers Atomes et Molécules, 59000 Lille, France
| | - Peter Dedecker
- Lab for NanoBiology, Department of Chemistry, 3001 Leuven, Belgium
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13
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Pilo CA, Baffi TR, Kornev AP, Kunkel MT, Malfavon M, Chen DH, Rossitto LA, Chen DX, Huang LC, Longman C, Kannan N, Raskind WH, Gonzalez DJ, Taylor SS, Gorrie G, Newton AC. Mutations in protein kinase Cγ promote spinocerebellar ataxia type 14 by impairing kinase autoinhibition. Sci Signal 2022; 15:eabk1147. [PMID: 36166510 PMCID: PMC9810342 DOI: 10.1126/scisignal.abk1147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Spinocerebellar ataxia type 14 (SCA14) is a neurodegenerative disease caused by germline variants in the diacylglycerol (DAG)/Ca2+-regulated protein kinase Cγ (PKCγ), leading to Purkinje cell degeneration and progressive cerebellar dysfunction. Most of the identified mutations cluster in the DAG-sensing C1 domains. Here, we found with a FRET-based activity reporter that SCA14-associated PKCγ mutations, including a previously undescribed variant, D115Y, enhanced the basal activity of the kinase by compromising its autoinhibition. Unlike other mutations in PKC that impair its autoinhibition but lead to its degradation, the C1 domain mutations protected PKCγ from such down-regulation. This enhanced basal signaling rewired the brain phosphoproteome, as revealed by phosphoproteomic analysis of cerebella from mice expressing a human SCA14-associated H101Y mutant PKCγ transgene. Mutations that induced a high basal activity in vitro were associated with earlier average age of onset in patients. Furthermore, the extent of disrupted autoinhibition, but not agonist-stimulated activity, correlated with disease severity. Molecular modeling indicated that almost all SCA14 variants not within the C1 domain were located at interfaces with the C1B domain, suggesting that mutations in and proximal to the C1B domain are a susceptibility for SCA14 because they uniquely enhance PKCγ basal activity while protecting the enzyme from down-regulation. These results provide insight into how PKCγ activation is modulated and how deregulation of the cerebellar phosphoproteome by SCA14-associated mutations affects disease progression.
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Affiliation(s)
- Caila A. Pilo
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
- Biomedical Sciences Graduate Program, University of California, La Jolla, CA 92037, USA
| | - Timothy R. Baffi
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - Alexandr P. Kornev
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - Maya T. Kunkel
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - Mario Malfavon
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - Dong-Hui Chen
- Department of Neurology, University of Washington Seattle, WA 98195, USA
| | - Leigh-Ana Rossitto
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
- Biomedical Sciences Graduate Program, University of California, La Jolla, CA 92037, USA
| | - Daniel X. Chen
- Department of Neurology, University of Washington Seattle, WA 98195, USA
| | - Liang-Chin Huang
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
| | - Cheryl Longman
- Queen Elizabeth University Hospital, Glasgow, Scotland G51 4TF, United Kingdom
| | - Natarajan Kannan
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Wendy H. Raskind
- Department of Medicine/Medical Genetics, University of Washington Seattle, WA 98195, USA
- Department of Psychiatry and Behavioral Sciences, University of Washington Seattle, WA 98195, USA
- Mental Illness Research, Education and Clinical Center, Department of Veterans Affairs, Seattle, WA 98108, USA
| | - David J. Gonzalez
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - Susan S. Taylor
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - George Gorrie
- Queen Elizabeth University Hospital, Glasgow, Scotland G51 4TF, United Kingdom
| | - Alexandra C. Newton
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
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14
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Real-time detection of response regulator phosphorylation dynamics in live bacteria. Proc Natl Acad Sci U S A 2022; 119:e2201204119. [PMID: 35994658 PMCID: PMC9436347 DOI: 10.1073/pnas.2201204119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bacteria utilize two-component system (TCS) signal transduction pathways to sense and adapt to changing environments. In a typical TCS, a stimulus induces a sensor histidine kinase (SHK) to phosphorylate a response regulator (RR), which then dimerizes and activates a transcriptional response. Here, we demonstrate that oligomerization-dependent depolarization of excitation light by fused mNeonGreen fluorescent protein probes enables real-time monitoring of RR dimerization dynamics in live bacteria. Using inducible promoters to independently express SHKs and RRs, we detect RR dimerization within seconds of stimulus addition in several model pathways. We go on to combine experiments with mathematical modeling to reveal that TCS phosphosignaling accelerates with SHK expression but decelerates with RR expression and SHK phosphatase activity. We further observe pulsatile activation of the SHK NarX in response to addition and depletion of the extracellular electron acceptor nitrate when the corresponding TCS is expressed from both inducible systems and the native chromosomal operon. Finally, we combine our method with polarized light microscopy to enable single-cell measurements of RR dimerization under changing stimulus conditions. Direct in vivo characterization of RR oligomerization dynamics should enable insights into the regulation of bacterial physiology.
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15
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A chemogenetic platform for controlling plasma membrane signaling and synthetic signal oscillation. Cell Chem Biol 2022; 29:1446-1464.e10. [PMID: 35835118 DOI: 10.1016/j.chembiol.2022.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/22/2022] [Accepted: 06/20/2022] [Indexed: 12/31/2022]
Abstract
Chemogenetic methods enabling the rapid translocation of specific proteins to the plasma membrane (PM) in a single protein-single ligand manner are useful tools in cell biology. We recently developed a technique, in which proteins fused to an Escherichia coli dihydrofolate reductase (eDHFR) variant carrying N-terminal hexalysine residues are recruited from the cytoplasm to the PM using the synthetic myristoyl-d-Cys-tethered trimethoprim (mDcTMP) ligand. However, this system achieved PM-specific translocation only when the eDHFR tag was fused to the N terminus of proteins, thereby limiting its application. In this report, we engineered a universal PM-targeting tag for mDcTMP-induced protein translocation by grafting the hexalysine motif into an intra-loop region of eDHFR. We demonstrate the broad applicability of the new loop-engineered eDHFR tag and mDcTMP pair for conditional PM recruitment and activation of various tag-fused signaling proteins with different fusion configurations and for reversibly and repeatedly controlling protein localization to generate synthetic signal oscillations.
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16
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Huang W, Guo C, Zhai J, Xie X. Fluorescence Anisotropy as a Self-Referencing Readout for Ion-Selective Sensing and Imaging Using Homo-FRET between Chromoionophores. Anal Chem 2022; 94:9793-9800. [PMID: 35772106 DOI: 10.1021/acs.analchem.2c01532] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Fluorescence anisotropy has been widely used in developing biosensors and immunoassays, by virtue of the self-reference and environment-sensitive properties. However, fluorescence anisotropic chemical sensors on inorganic ions are limited by the total anisotropy change. To this end, we demonstrate here fluorescence anisotropic ion-selective optodes based on the homo-FRET (Förster resonance energy transfer) of the crowded chromoionophores. The conventional fluorescence on-off mode is transformed into the anisotropic mode. Variation of the target ion concentration changes the inter-chromoionophore distance in the organic sensing phase, leading to different extents of homo-FRET and steady-state anisotropy. A theoretical model is developed by coupling homo-FRET and anisotropy. Anisotropic detections of pH, K+, and Na+ are demonstrated as examples based on the different ionophores for H+, K+, and Na+, respectively. Further, fluorescence imaging of the nano-optodes, plasticized poly(vinyl chloride) sensing films, and live cells are demonstrated using a homemade fluorescence anisotropic imaging platform. The results form the basis of an ion-selective analytical method operating in the fluorescence anisotropic mode, which could potentially be applied to other fluorescence on-off probes based on homo-FRET.
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Affiliation(s)
- Wenyu Huang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Chao Guo
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jingying Zhai
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xiaojiang Xie
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
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17
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Absolute measurement of cellular activities using photochromic single-fluorophore biosensors and intermittent quantification. Nat Commun 2022; 13:1850. [PMID: 35387971 PMCID: PMC8986857 DOI: 10.1038/s41467-022-29508-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 03/18/2022] [Indexed: 11/20/2022] Open
Abstract
Genetically-encoded biosensors based on a single fluorescent protein are widely used to visualize analyte levels or enzymatic activities in cells, though usually to monitor relative changes rather than absolute values. We report photochromism-enabled absolute quantification (PEAQ) biosensing, a method that leverages the photochromic properties of biosensors to provide an absolute measure of the analyte concentration or activity. We develop proof-of-concept photochromic variants of the popular GCaMP family of Ca2+ biosensors, and show that these can be used to resolve dynamic changes in the absolute Ca2+ concentration in live cells. We also develop intermittent quantification, a technique that combines absolute aquisitions with fast fluorescence acquisitions to deliver fast but fully quantitative measurements. We also show how the photochromism-based measurements can be expanded to situations where the absolute illumination intensities are unknown. In principle, PEAQ biosensing can be applied to other biosensors with photochromic properties, thereby expanding the possibilities for fully quantitative measurements in complex and dynamic systems. Biosensors often report relative rather than absolute values. Here the authors report a method that utilises the photochromic properties of biosensors to provide an absolute measure of the analyte concentration or activity: photochromism-enabled absolute quantification (PEAQ) biosensing.
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18
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Jena S, Parker LL. Fluorescence Lifetime Imaging Probes for Cell-Based Measurements of Enzyme Activity. Methods Mol Biol 2022; 2394:133-162. [PMID: 35094326 PMCID: PMC10041689 DOI: 10.1007/978-1-0716-1811-0_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Posttranslational modification (PTM) enzymes are important modulators of protein structure and function. They typically act by chemically modifying amino acids, often on side chain functional groups, to change the physiochemical landscape of the protein and thus its biophysical behavior. In particular, protein kinases are enzymes that transfer phosphate from ATP to serine, threonine, or tyrosine in protein substrates. They are key regulators of vital cellular pathways such as survival, proliferation, and apoptosis, and their dysregulation in the context of cancer has been widely investigated for the purpose of development of anticancer drugs. However, several critical questions pertaining to their physiology, such as heterogeneity of kinase signaling within and between cells, and other factors that may play into the mechanisms of drug resistance, remain unanswered. Many of the current strategies to measure kinase activity lack the scope, subcellular resolution, and real-time monitoring ability needed to obtain the type of information needed about their dynamics and localization in cells. While FRET-based biosensors are capable of dynamic single cell imaging, their applications can be limited by difficulties in multiplexing and the inherent inadequacies of steady state measurements. In this chapter, we describe our fluorescence lifetime imaging microscopy (FLIM) probe technology in which peptide kinase substrates, linked to cell-penetrating peptides and labeled with small molecule fluorophores, are used to report kinase activity through time-resolved fluorescence imaging to visualize and quantify changes to the probe's fluorescence lifetime. These can be multiplexed for more than one kinase at a time, and interpretation is not affected by differences in local intensity due to probe uptake and distribution or photobleaching. With careful choice of peptide substrate(s), fluorophore label, and imaging set-up, high specificity and spatiotemporal resolution can be achieved. Due to the mechanism by which the lifetime change occurs, this approach is compatible with other PTMs (such as acetylation, methylation), and so the considerations for kinase FLIM probe design described in this chapter should be broadly applicable for other PTMs as well.
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19
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Chen M, Sun T, Zhong Y, Zhou X, Zhang J. A Highly Sensitive Fluorescent Akt Biosensor Reveals Lysosome-Selective Regulation of Lipid Second Messengers and Kinase Activity. ACS CENTRAL SCIENCE 2021; 7:2009-2020. [PMID: 34963894 PMCID: PMC8704034 DOI: 10.1021/acscentsci.1c00919] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Indexed: 06/14/2023]
Abstract
The serine/threonine protein kinase Akt regulates a wide range of cellular functions via phosphorylation of various substrates distributed throughout the cell, including at the plasma membrane and endomembrane compartments. Disruption of compartmentalized Akt signaling underlies the pathology of many diseases such as cancer and diabetes. However, the specific spatial organization of Akt activity and the underlying regulatory mechanisms, particularly the mechanism controlling its activity at the lysosome, are not clearly understood. We developed a highly sensitive excitation-ratiometric Akt activity reporter (ExRai-AktAR2), enabling the capture of minute changes in Akt activity dynamics at subcellular compartments. In conjunction with super-resolution expansion microscopy, we found that growth factor stimulation leads to increased colocalization of Akt with lysosomes and accumulation of lysosomal Akt activity. We further showed that 3-phosphoinositides (3-PIs) accumulate on the lysosomal surface, in a manner dependent on dynamin-mediated endocytosis. Importantly, lysosomal 3-PIs are needed for growth-factor-induced activities of Akt and mechanistic target of rapamycin complex 1 (mTORC1) on the lysosomal surface, as targeted depletion of 3-PIs has detrimental effects. Thus, 3-PIs, a class of critical lipid second messengers that are typically found in the plasma membrane, unexpectedly accumulate on the lysosomal membrane in response to growth factor stimulation, to direct the multifaceted kinase Akt to organize lysosome-specific signaling.
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Affiliation(s)
- Mingyuan Chen
- Department
of Bioengineering, University of California,
San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
| | - Tengqian Sun
- Department
of Pharmacology, University of California,
San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
| | - Yanghao Zhong
- Department
of Pharmacology, University of California,
San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
- Biomedical
Sciences Graduate Program, University of
California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Xin Zhou
- Department
of Pharmacology, University of California,
San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
| | - Jin Zhang
- Department
of Bioengineering, University of California,
San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
- Department
of Pharmacology, University of California,
San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
- Department
of Chemistry & Biochemistry, University
of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
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20
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Díaz-García C, Renart ML, Poveda JA, Giudici AM, González-Ros JM, Prieto M, Coutinho A. Probing the Structural Dynamics of the Activation Gate of KcsA Using Homo-FRET Measurements. Int J Mol Sci 2021; 22:ijms222111954. [PMID: 34769384 PMCID: PMC8584343 DOI: 10.3390/ijms222111954] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/18/2021] [Accepted: 10/29/2021] [Indexed: 12/16/2022] Open
Abstract
The allosteric coupling between activation and inactivation processes is a common feature observed in K+ channels. Particularly, in the prokaryotic KcsA channel the K+ conduction process is controlled by the inner gate, which is activated by acidic pH, and by the selectivity filter (SF) or outer gate, which can adopt non-conductive or conductive states. In a previous study, a single tryptophan mutant channel (W67 KcsA) enabled us to investigate the SF dynamics using time-resolved homo-Förster Resonance Energy Transfer (homo-FRET) measurements. Here, the conformational changes of both gates were simultaneously monitored after labelling the G116C position with tetramethylrhodamine (TMR) within a W67 KcsA background. At a high degree of protein labeling, fluorescence anisotropy measurements showed that the pH-induced KcsA gating elicited a variation in the homo-FRET efficiency among the conjugated TMR dyes (TMR homo-FRET), while the conformation of the SF was simultaneously tracked (W67 homo-FRET). The dependence of the activation pKa of the inner gate with the ion occupancy of the SF unequivocally confirmed the allosteric communication between the two gates of KcsA. This simple TMR homo-FRET based ratiometric assay can be easily extended to study the conformational dynamics associated with the gating of other ion channels and their modulation.
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Affiliation(s)
- Clara Díaz-García
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (M.P.)
- Associate Laboratory i4HB, Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Maria Lourdes Renart
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
- Correspondence: (M.L.R.); (A.C.)
| | - José Antonio Poveda
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
| | - Ana Marcela Giudici
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
| | - José M. González-Ros
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
| | - Manuel Prieto
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (M.P.)
- Associate Laboratory i4HB, Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Ana Coutinho
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (M.P.)
- Associate Laboratory i4HB, Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
- Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Correspondence: (M.L.R.); (A.C.)
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21
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Ratiometric two-photon fluorescence probes for sensing, imaging and biomedicine applications at living cell and small animal levels. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.214114] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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22
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Zhang JF, Mehta S, Zhang J. Signaling Microdomains in the Spotlight: Visualizing Compartmentalized Signaling Using Genetically Encoded Fluorescent Biosensors. Annu Rev Pharmacol Toxicol 2021; 61:587-608. [PMID: 33411579 DOI: 10.1146/annurev-pharmtox-010617-053137] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
How cells muster a network of interlinking signaling pathways to faithfully convert diverse external cues to specific functional outcomes remains a central question in biology. Through their ability to convert dynamic biochemical activities to rapid and precise optical readouts, genetically encoded fluorescent biosensors have become instrumental in unraveling the molecular logic controlling the specificity of intracellular signaling. In this review, we discuss how the use of genetically encoded fluorescent biosensors to visualize dynamic signaling events within their native cellular context is elucidating the different strategies employed by cells to organize signaling activities into discrete compartments, or signaling microdomains, to ensure functional specificity.
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Affiliation(s)
- Jin-Fan Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093, USA; .,Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, USA
| | - Sohum Mehta
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093, USA;
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093, USA; .,Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, USA.,Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA
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23
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Plante AE, Rao VP, Rizzo MA, Meredith AL. Comparative Ca 2+ channel contributions to intracellular Ca 2+ levels in the circadian clock. BIOPHYSICAL REPORTS 2021; 1:100005. [PMID: 35330949 PMCID: PMC8942421 DOI: 10.1016/j.bpr.2021.100005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/08/2021] [Indexed: 11/22/2022]
Abstract
Circadian rhythms in mammals are coordinated by the central clock in the brain, located in the suprachiasmatic nucleus (SCN). Multiple molecular and cellular signals display a circadian variation within SCN neurons, including intracellular Ca2+, but the mechanisms are not definitively established. SCN cytosolic Ca2+ levels exhibit a peak during the day, when both action potential firing and Ca2+ channel activity are increased, and are decreased at night, correlating with a reduction in firing rate. In this study, we employ a single-color fluorescence anisotropy reporter (FLARE), Venus FLARE-Cameleon, and polarization inverted selective-plane illumination microscopy to measure rhythmic changes in cytosolic Ca2+ in SCN neurons. Using this technique, the Ca2+ channel subtypes contributing to intracellular Ca2+ at the peak and trough of the circadian cycle were assessed using a pharmacological approach with Ca2+ channel inhibitors. Peak (218 ± 16 nM) and trough (172 ± 13 nM) Ca2+ levels were quantified, indicating a 1.3-fold circadian variance in Ca2+ concentration. Inhibition of ryanodine-receptor-mediated Ca2+ release produced a larger relative decrease in cytosolic Ca2+ at both time points compared to voltage-gated Ca2+channels. These results support the hypothesis that circadian Ca2+ rhythms in SCN neurons are predominantly driven by intracellular Ca2+ channels, although not exclusively so. The study provides a foundation for future experiments to probe Ca2+ signaling in a dynamic biological context using FLAREs.
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Affiliation(s)
- Amber E. Plante
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Vishnu P. Rao
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Megan A. Rizzo
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea L. Meredith
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
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24
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Murphy KJ, Reed DA, Trpceski M, Herrmann D, Timpson P. Quantifying and visualising the nuances of cellular dynamics in vivo using intravital imaging. Curr Opin Cell Biol 2021; 72:41-53. [PMID: 34091131 DOI: 10.1016/j.ceb.2021.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/23/2021] [Accepted: 04/28/2021] [Indexed: 12/14/2022]
Abstract
Intravital imaging is a powerful technology used to quantify and track dynamic changes in live cells and tissues within an intact environment. The ability to watch cell biology in real-time 'as it happens' has provided novel insight into tissue homeostasis, as well as disease initiation, progression and response to treatment. In this minireview, we highlight recent advances in the field of intravital microscopy, touching upon advances in awake versus anaesthesia-based approaches, as well as the integration of biosensors into intravital imaging. We also discuss current challenges that, in our opinion, need to be overcome to further advance the field of intravital imaging at the single-cell, subcellular and molecular resolution to reveal nuances of cell behaviour that can be targeted in complex disease settings.
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Affiliation(s)
- Kendelle J Murphy
- Garvan Institute of Medical Research & The Kinghorn Cancer Centre, Cancer Theme, Sydney, NSW, 2010, Australia; St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, NSW, 2010, Australia
| | - Daniel A Reed
- Garvan Institute of Medical Research & The Kinghorn Cancer Centre, Cancer Theme, Sydney, NSW, 2010, Australia; St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, NSW, 2010, Australia
| | - Michael Trpceski
- Garvan Institute of Medical Research & The Kinghorn Cancer Centre, Cancer Theme, Sydney, NSW, 2010, Australia
| | - David Herrmann
- Garvan Institute of Medical Research & The Kinghorn Cancer Centre, Cancer Theme, Sydney, NSW, 2010, Australia; St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, NSW, 2010, Australia.
| | - Paul Timpson
- Garvan Institute of Medical Research & The Kinghorn Cancer Centre, Cancer Theme, Sydney, NSW, 2010, Australia; St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, NSW, 2010, Australia.
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25
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Lauri A, Fasano G, Venditti M, Dallapiccola B, Tartaglia M. In vivo Functional Genomics for Undiagnosed Patients: The Impact of Small GTPases Signaling Dysregulation at Pan-Embryo Developmental Scale. Front Cell Dev Biol 2021; 9:642235. [PMID: 34124035 PMCID: PMC8194860 DOI: 10.3389/fcell.2021.642235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/12/2021] [Indexed: 12/24/2022] Open
Abstract
While individually rare, disorders affecting development collectively represent a substantial clinical, psychological, and socioeconomic burden to patients, families, and society. Insights into the molecular mechanisms underlying these disorders are required to speed up diagnosis, improve counseling, and optimize management toward targeted therapies. Genome sequencing is now unveiling previously unexplored genetic variations in undiagnosed patients, which require functional validation and mechanistic understanding, particularly when dealing with novel nosologic entities. Functional perturbations of key regulators acting on signals' intersections of evolutionarily conserved pathways in these pathological conditions hinder the fine balance between various developmental inputs governing morphogenesis and homeostasis. However, the distinct mechanisms by which these hubs orchestrate pathways to ensure the developmental coordinates are poorly understood. Integrative functional genomics implementing quantitative in vivo models of embryogenesis with subcellular precision in whole organisms contribute to answering these questions. Here, we review the current knowledge on genes and mechanisms critically involved in developmental syndromes and pediatric cancers, revealed by genomic sequencing and in vivo models such as insects, worms and fish. We focus on the monomeric GTPases of the RAS superfamily and their influence on crucial developmental signals and processes. We next discuss the effectiveness of exponentially growing functional assays employing tractable models to identify regulatory crossroads. Unprecedented sophistications are now possible in zebrafish, i.e., genome editing with single-nucleotide precision, nanoimaging, highly resolved recording of multiple small molecules activity, and simultaneous monitoring of brain circuits and complex behavioral response. These assets permit accurate real-time reporting of dynamic small GTPases-controlled processes in entire organisms, owning the potential to tackle rare disease mechanisms.
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Affiliation(s)
- Antonella Lauri
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | | | | | | | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
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26
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Laskaratou D, Fernández GS, Coucke Q, Fron E, Rocha S, Hofkens J, Hendrix J, Mizuno H. Quantification of FRET-induced angular displacement by monitoring sensitized acceptor anisotropy using a dim fluorescent donor. Nat Commun 2021; 12:2541. [PMID: 33953187 PMCID: PMC8099864 DOI: 10.1038/s41467-021-22816-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 03/23/2021] [Indexed: 02/03/2023] Open
Abstract
Förster resonance energy transfer (FRET) between fluorescent proteins has become a common platform for designing genetically encoded biosensors. For live cell imaging, the acceptor-to-donor intensity ratio is most commonly used to readout FRET efficiency, which largely depends on the proximity between donor and acceptor. Here, we introduce an anisotropy-based mode of FRET detection (FADED: FRET-induced Angular Displacement Evaluation via Dim donor), which probes for relative orientation rather than proximity alteration. A key element in this technique is suppression of donor bleed-through, which allows measuring purer sensitized acceptor anisotropy. This is achieved by developing Geuda Sapphire, a low-quantum-yield FRET-competent fluorescent protein donor. As a proof of principle, Ca2+ sensors were designed using calmodulin as a sensing domain, showing sigmoidal dose response to Ca2+. By monitoring the anisotropy, a Ca2+ rise in living HeLa cells is observed upon histamine challenging. We conclude that FADED provides a method for quantifying the angular displacement via FRET.
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Affiliation(s)
- Danai Laskaratou
- Laboratory for Biomolecular Network Dynamics, Biochemistry, Molecular and Structural Biology Section, Department of Chemistry, KU Leuven, Heverlee, Belgium
| | | | - Quinten Coucke
- Chem & Tech-Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Heverlee, Belgium
| | - Eduard Fron
- Chem & Tech-Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Heverlee, Belgium
- KU Leuven Core Facility for Advanced Spectroscopy, KU Leuven, Heverlee, Belgium
| | - Susana Rocha
- Chem & Tech-Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Heverlee, Belgium
| | - Johan Hofkens
- Chem & Tech-Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Heverlee, Belgium
| | - Jelle Hendrix
- Chem & Tech-Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Heverlee, Belgium
- Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre and Biomedical Research Institute, Hasselt University, Agoralaan C (BIOMED), Diepenbeek, Belgium
| | - Hideaki Mizuno
- Laboratory for Biomolecular Network Dynamics, Biochemistry, Molecular and Structural Biology Section, Department of Chemistry, KU Leuven, Heverlee, Belgium.
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Baffi TR, Lordén G, Wozniak JM, Feichtner A, Yeung W, Kornev AP, King CC, Del Rio JC, Limaye AJ, Bogomolovas J, Gould CM, Chen J, Kennedy EJ, Kannan N, Gonzalez DJ, Stefan E, Taylor SS, Newton AC. mTORC2 controls the activity of PKC and Akt by phosphorylating a conserved TOR interaction motif. Sci Signal 2021; 14:eabe4509. [PMID: 33850054 PMCID: PMC8208635 DOI: 10.1126/scisignal.abe4509] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The complex mTORC2 is accepted to be the kinase that controls the phosphorylation of the hydrophobic motif, a key regulatory switch for AGC kinases, although whether mTOR directly phosphorylates this motif remains controversial. Here, we identified an mTOR-mediated phosphorylation site that we termed the TOR interaction motif (TIM; F-x3-F-pT), which controls the phosphorylation of the hydrophobic motif of PKC and Akt and the activity of these kinases. The TIM is invariant in mTORC2-dependent AGC kinases, is evolutionarily conserved, and coevolved with mTORC2 components. Mutation of this motif in Akt1 and PKCβII abolished cellular kinase activity by impairing activation loop and hydrophobic motif phosphorylation. mTORC2 directly phosphorylated the PKC TIM in vitro, and this phosphorylation event was detected in mouse brain. Overexpression of PDK1 in mTORC2-deficient cells rescued hydrophobic motif phosphorylation of PKC and Akt by a mechanism dependent on their intrinsic catalytic activity, revealing that mTORC2 facilitates the PDK1 phosphorylation step, which, in turn, enables autophosphorylation. Structural analysis revealed that PKC homodimerization is driven by a TIM-containing helix, and biophysical proximity assays showed that newly synthesized, unphosphorylated PKC dimerizes in cells. Furthermore, disruption of the dimer interface by stapled peptides promoted hydrophobic motif phosphorylation. Our data support a model in which mTORC2 relieves nascent PKC dimerization through TIM phosphorylation, recruiting PDK1 to phosphorylate the activation loop and triggering intramolecular hydrophobic motif autophosphorylation. Identification of TIM phosphorylation and its role in the regulation of PKC provides the basis for AGC kinase regulation by mTORC2.
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Affiliation(s)
- Timothy R Baffi
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
- Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, CA 92093, USA
| | - Gema Lordén
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
| | - Jacob M Wozniak
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
- Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, CA 92093, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093, USA
| | - Andreas Feichtner
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, Innsbruck A-6020, Austria
| | - Wayland Yeung
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Alexandr P Kornev
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
| | - Charles C King
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
| | - Jason C Del Rio
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
- Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, CA 92093, USA
| | - Ameya J Limaye
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, USA
| | - Julius Bogomolovas
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093, USA
| | - Christine M Gould
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
- Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, CA 92093, USA
| | - Ju Chen
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093, USA
| | - Eileen J Kennedy
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, USA
| | - Natarajan Kannan
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - David J Gonzalez
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093, USA
| | - Eduard Stefan
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, Innsbruck A-6020, Austria
| | - Susan S Taylor
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA 92093, USA
| | - Alexandra C Newton
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA.
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Simultaneous readout of multiple FRET pairs using photochromism. Nat Commun 2021; 12:2005. [PMID: 33790271 PMCID: PMC8012603 DOI: 10.1038/s41467-021-22043-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 02/17/2021] [Indexed: 01/11/2023] Open
Abstract
Förster resonant energy transfer (FRET) is a powerful mechanism to probe associations in situ. Simultaneously performing more than one FRET measurement can be challenging due to the spectral bandwidth required for the donor and acceptor fluorophores. We present an approach to distinguish overlapping FRET pairs based on the photochromism of the donor fluorophores, even if the involved fluorophores display essentially identical absorption and emission spectra. We develop the theory underlying this method and validate our approach using numerical simulations. To apply our system, we develop rsAKARev, a photochromic biosensor for cAMP-dependent protein kinase (PKA), and combine it with the spectrally-identical biosensor EKARev, a reporter for extracellular signal-regulated kinase (ERK) activity, to deliver simultaneous readout of both activities in the same cell. We further perform multiplexed PKA, ERK, and calcium measurements by including a third, spectrally-shifted biosensor. Our work demonstrates that exploiting donor photochromism in FRET can be a powerful approach to simultaneously read out multiple associations within living cells. Performing multiple FRET measurements at once can be challenging. Here the authors report a method to discriminate between overlapping FRET pairs, even if the fluorophores display almost identical absorption and emission spectra, based on the photochromism of the donor fluorophores.
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29
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Gauron MC, Newton AC, Colombo MI. PKCα Is Recruited to Staphylococcus aureus-Containing Phagosomes and Impairs Bacterial Replication by Inhibition of Autophagy. Front Immunol 2021; 12:662987. [PMID: 33815423 PMCID: PMC8013776 DOI: 10.3389/fimmu.2021.662987] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/03/2021] [Indexed: 11/24/2022] Open
Abstract
Hijacking the autophagic machinery is a key mechanism through which invasive pathogens such as Staphylococcus aureus replicate in their host cells. We have previously demonstrated that the bacteria replicate in phagosomes labeled with the autophagic protein LC3, before escaping to the cytoplasm. Here, we show that the Ca2+-dependent PKCα binds to S. aureus-containing phagosomes and that α-hemolysin, secreted by S. aureus, promotes this recruitment of PKCα to phagosomal membranes. Interestingly, the presence of PKCα prevents the association of the autophagic protein LC3. Live cell imaging experiments using the PKC activity reporter CKAR reveal that treatment of cells with S. aureus culture supernatants containing staphylococcal secreted factors transiently activates PKC. Functional studies reveal that overexpression of PKCα causes a marked inhibition of bacterial replication. Taken together, our data identify enhancing PKCα activity as a potential approach to inhibit S. aureus replication in mammalian cells.
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Affiliation(s)
- Maria Celeste Gauron
- Laboratorio de Mecanismos Moleculares Implicados en el Tráfico Vesicular y la Autofagia-Instituto de Histología y Embriología (IHEM)- Universidad Nacional de Cuyo, CONICET- Facultad de Ciencias Médicas, Mendoza, Argentina.,Department of Pharmacology, University of California San Diego, La Jolla, CA, United States
| | - Alexandra C Newton
- Department of Pharmacology, University of California San Diego, La Jolla, CA, United States
| | - María Isabel Colombo
- Laboratorio de Mecanismos Moleculares Implicados en el Tráfico Vesicular y la Autofagia-Instituto de Histología y Embriología (IHEM)- Universidad Nacional de Cuyo, CONICET- Facultad de Ciencias Médicas, Mendoza, Argentina
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30
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Keyes J, Mehta S, Zhang J. Strategies for Multiplexed Biosensor Imaging to Study Intracellular Signaling Networks. Methods Mol Biol 2021; 2350:1-20. [PMID: 34331275 PMCID: PMC8580745 DOI: 10.1007/978-1-0716-1593-5_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Signal transduction processes are a necessary component of multicellular life, and their dysregulation is the basis for a host of syndromes and diseases. Thus, it is imperative that we discover the complex details of how signal transduction processes result in specific cellular outcomes. One of the primary mechanisms of regulation over signaling pathways is through spatiotemporal control. However, traditional methods are limited in their ability to reveal such details. To overcome these limitations, researchers have developed a variety of genetically encodable, fluorescent protein-based biosensors to study these dynamic processes in real time in living cells. Due to the complexities and interconnectedness of signaling pathways, it is thus desirable to use multiple biosensors in individual cells to better elucidate the relationships between signaling pathways. However, multiplexed imaging with such biosensors has been historically difficult. Nevertheless, recent developments in designs and multiplexing strategies have led to vast improvements in our capabilities. In this review, we provide perspectives on the recently developed biosensor designs and multiplexing strategies that are available for multiplexed imaging of signal transduction pathways.
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Affiliation(s)
- Jeremiah Keyes
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Sohum Mehta
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA.
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31
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Van AAN, Kunkel MT, Baffi TR, Lordén G, Antal CE, Banerjee S, Newton AC. Protein kinase C fusion proteins are paradoxically loss of function in cancer. J Biol Chem 2021; 296:100445. [PMID: 33617877 PMCID: PMC8008189 DOI: 10.1016/j.jbc.2021.100445] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 02/11/2021] [Accepted: 02/18/2021] [Indexed: 12/02/2022] Open
Abstract
Within the AGC kinase superfamily, gene fusions resulting from chromosomal rearrangements have been most frequently described for protein kinase C (PKC), with gene fragments encoding either the C-terminal catalytic domain or the N-terminal regulatory moiety fused to other genes. Kinase fusions that eliminate regulatory domains are typically gain of function and often oncogenic. However, several quality control pathways prevent accumulation of aberrant PKC, suggesting that PKC fusions may paradoxically be loss of function. To explore this topic, we used biochemical, cellular, and genome editing approaches to investigate the function of fusions that retain the portion of the gene encoding either the catalytic domain or regulatory domain of PKC. Overexpression studies revealed that PKC catalytic domain fusions were constitutively active but vulnerable to degradation. Genome editing of endogenous genes to generate a cancer-associated PKC fusion resulted in cells with detectable levels of fusion transcript but no detectable protein. Hence, PKC catalytic domain fusions are paradoxically loss of function as a result of their instability, preventing appreciable accumulation of protein in cells. Overexpression of a PKC regulatory domain fusion suppressed both basal and agonist-induced endogenous PKC activity, acting in a dominant-negative manner by competing for diacylglycerol. For both catalytic and regulatory domain fusions, the PKC component of the fusion proteins mediated the effects of the full-length fusions on the parameters examined, suggesting that the partner protein is dispensable in these contexts. Taken together, our findings reveal that PKC gene fusions are distinct from oncogenic fusions and present a mechanism by which loss of PKC function occurs in cancer.
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Affiliation(s)
- An-Angela N Van
- Department of Pharmacology, University of California at San Diego, La Jolla, California, USA; Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, California, USA
| | - Maya T Kunkel
- Department of Pharmacology, University of California at San Diego, La Jolla, California, USA
| | - Timothy R Baffi
- Department of Pharmacology, University of California at San Diego, La Jolla, California, USA; Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, California, USA
| | - Gema Lordén
- Department of Pharmacology, University of California at San Diego, La Jolla, California, USA
| | - Corina E Antal
- Department of Pharmacology, University of California at San Diego, La Jolla, California, USA; Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, California, USA
| | - Sourav Banerjee
- Department of Pharmacology, University of California at San Diego, La Jolla, California, USA
| | - Alexandra C Newton
- Department of Pharmacology, University of California at San Diego, La Jolla, California, USA.
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32
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Liput DJ, Nguyen TA, Augustin SM, Lee JO, Vogel SS. A Guide to Fluorescence Lifetime Microscopy and Förster's Resonance Energy Transfer in Neuroscience. CURRENT PROTOCOLS IN NEUROSCIENCE 2020; 94:e108. [PMID: 33232577 PMCID: PMC8274369 DOI: 10.1002/cpns.108] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Fluorescence lifetime microscopy (FLIM) and Förster's resonance energy transfer (FRET) are advanced optical tools that neuroscientists can employ to interrogate the structure and function of complex biological systems in vitro and in vivo using light. In neurobiology they are primarily used to study protein-protein interactions, to study conformational changes in protein complexes, and to monitor genetically encoded FRET-based biosensors. These methods are ideally suited to optically monitor changes in neurons that are triggered optogenetically. Utilization of this technique by neuroscientists has been limited, since a broad understanding of FLIM and FRET requires familiarity with the interactions of light and matter on a quantum mechanical level, and because the ultra-fast instrumentation used to measure fluorescent lifetimes and resonance energy transfer are more at home in a physics lab than in a biology lab. In this overview, we aim to help neuroscientists overcome these obstacles and thus feel more comfortable with the FLIM-FRET method. Our goal is to aid researchers in the neuroscience community to achieve a better understanding of the fundamentals of FLIM-FRET and encourage them to fully leverage its powerful ability as a research tool. Published 2020. U.S. Government.
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Affiliation(s)
- Daniel J. Liput
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
- Laboratory of Molecular Physiology, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
| | - Tuan A. Nguyen
- Laboratory of Biophotonics and Quantum Biology, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
| | - Shana M. Augustin
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
| | - Jeong Oen Lee
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
| | - Steven S. Vogel
- Laboratory of Biophotonics and Quantum Biology, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
- Corresponding author:
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33
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Zhou X, Mehta S, Zhang J. Genetically Encodable Fluorescent and Bioluminescent Biosensors Light Up Signaling Networks. Trends Biochem Sci 2020; 45:889-905. [PMID: 32660810 PMCID: PMC7502535 DOI: 10.1016/j.tibs.2020.06.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 05/25/2020] [Accepted: 06/01/2020] [Indexed: 12/12/2022]
Abstract
Cell signaling networks are intricately regulated in time and space to determine the responses and fates of cells to different cues. Genetically encodable fluorescent and bioluminescent biosensors enable the direct visualization of these spatiotemporal signaling dynamics within the native biological context, and have therefore become powerful molecular tools whose unique benefits are being used to address challenging biological questions. We first review the basis of biosensor design and remark on recent technologies that are accelerating biosensor development. We then discuss a few of the latest advances in the development and application of genetically encodable fluorescent and bioluminescent biosensors that have led to scientific or technological breakthroughs.
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Affiliation(s)
- Xin Zhou
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Sohum Mehta
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA.
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34
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Abstract
Peroxiredoxins are most central to the cellular adaptation against oxidative stress. They act as oxidant scavengers, stress sensors, transmitters of signals, and chaperones, and they possess a unique quaternary switch that is intimately related to these functions. However, so far it has not been possible to monitor peroxiredoxin structural changes in the intact cellular environment. This study presents genetically encoded probes, based on homo-FRET (Förster resonance energy transfer between identical fluorophores) fluorescence polarization, that allow following these quaternary changes in real time, in living cells. We envisage that these probes can be used to address a broad range of questions related to the function of peroxiredoxins. Peroxiredoxins are central to cellular redox homeostasis and signaling. They serve as peroxide scavengers, sensors, signal transducers, and chaperones, depending on conditions and context. Typical 2-Cys peroxiredoxins are known to switch between different oligomeric states, depending on redox state, pH, posttranslational modifications, and other factors. Quaternary states and their changes are closely connected to peroxiredoxin activity and function but so far have been studied, almost exclusively, outside the context of the living cell. Here we introduce the use of homo-FRET (Förster resonance energy transfer between identical fluorophores) fluorescence polarization to monitor dynamic changes in peroxiredoxin quaternary structure inside the crowded environment of living cells. Using the approach, we confirm peroxide- and thioredoxin-related quaternary transitions to take place in cellulo and observe that the relationship between dimer–decamer transitions and intersubunit disulfide bond formation is more complex than previously thought. Furthermore, we demonstrate the use of the approach to compare different peroxiredoxin isoforms and to identify mutations and small molecules affecting the oligomeric state inside cells. Mutagenesis experiments reveal that the dimer–decamer equilibrium is delicately balanced and can be shifted by single-atom structural changes. We show how to use this insight to improve the design of peroxiredoxin-based redox biosensors.
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35
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Rational Design of a Protein Kinase A Nuclear-cytosol Translocation Reporter. Sci Rep 2020; 10:9365. [PMID: 32518322 PMCID: PMC7283302 DOI: 10.1038/s41598-020-66349-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 05/11/2020] [Indexed: 12/14/2022] Open
Abstract
Protein Kinase A (PKA) exists as a tetrameric holoenzyme which activates with increase of cAMP and plays an important role in many physiological processes including cardiac physiology, neuronal development, and adipocyte function. Although this kinase has been the subject of numerous biosensor designs, a single-fluorophore reporter that performs comparably to Förster resonance energy transfer (FRET) has not yet been reported. Here, we have used basic observations of electrostatic interactions in PKA substrate recognition mechanism and nucleus localization sequence motif to design a phosphorylation switch that shuttles between the cytosol and the nucleus, a strategy that should be generalizable to all basophilic kinases. The resulting reporter yielded comparable kinetics and dynamic range to the PKA FRET reporter, AKAR3EV. We also performed basic characterization and demonstrated its potential use in monitoring multiple signaling molecules inside cells using basic fluorescence microscopy. Due to the single-fluorophore nature of this reporter, we envision that this could find broad applications in studies involving single cell analysis of PKA activity.
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36
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Moeyaert B, Dedecker P. Genetically encoded biosensors based on innovative scaffolds. Int J Biochem Cell Biol 2020; 125:105761. [PMID: 32504671 DOI: 10.1016/j.biocel.2020.105761] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/27/2020] [Accepted: 04/29/2020] [Indexed: 12/12/2022]
Abstract
Genetically encoded biosensors are indispensable tools for visualizing the spatiotemporal dynamics of analytes or processes in living cells in vitro and in vivo. Their widespread adaptation has gone hand in hand with the development of sensors for new analytes or processes and improved functionality and robustness. In this review, we highlight some of the recent advances in genetically encoded biosensor development, with a special focus on novel and innovative scaffolds that will lead to new possibilities in the future.
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Affiliation(s)
- Benjamien Moeyaert
- Laboratory for Nanobiology, Department of Chemistry, KU Leuven, Celestijnenlaan 200G, 3001 Heverlee, Belgium
| | - Peter Dedecker
- Laboratory for Nanobiology, Department of Chemistry, KU Leuven, Celestijnenlaan 200G, 3001 Heverlee, Belgium.
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37
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Ghilardi SJ, O'Reilly BM, Sgro AE. Intracellular signaling dynamics and their role in coordinating tissue repair. WILEY INTERDISCIPLINARY REVIEWS. SYSTEMS BIOLOGY AND MEDICINE 2020; 12:e1479. [PMID: 32035001 PMCID: PMC7187325 DOI: 10.1002/wsbm.1479] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/20/2019] [Accepted: 12/31/2019] [Indexed: 12/11/2022]
Abstract
Tissue repair is a complex process that requires effective communication and coordination between cells across multiple tissues and organ systems. Two of the initial intracellular signals that encode injury signals and initiate tissue repair responses are calcium and extracellular signal-regulated kinase (ERK). However, calcium and ERK signaling control a variety of cellular behaviors important for injury repair including cellular motility, contractility, and proliferation, as well as the activity of several different transcription factors, making it challenging to relate specific injury signals to their respective repair programs. This knowledge gap ultimately hinders the development of new wound healing therapies that could take advantage of native cellular signaling programs to more effectively repair tissue damage. The objective of this review is to highlight the roles of calcium and ERK signaling dynamics as mechanisms that link specific injury signals to specific cellular repair programs during epithelial and stromal injury repair. We detail how the signaling networks controlling calcium and ERK can now also be dissected using classical signal processing techniques with the advent of new biosensors and optogenetic signal controllers. Finally, we advocate the importance of recognizing calcium and ERK dynamics as key links between injury detection and injury repair programs that both organize and execute a coordinated tissue repair response between cells across different tissues and organs. This article is categorized under: Models of Systems Properties and Processes > Mechanistic Models Biological Mechanisms > Cell Signaling Laboratory Methods and Technologies > Imaging Models of Systems Properties and Processes > Organ, Tissue, and Physiological Models.
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Affiliation(s)
- Samuel J. Ghilardi
- Department of Biomedical Engineering and the Biological Design CenterBoston UniversityBostonMassachusetts
| | - Breanna M. O'Reilly
- Department of Biomedical Engineering and the Biological Design CenterBoston UniversityBostonMassachusetts
| | - Allyson E. Sgro
- Department of Biomedical Engineering and the Biological Design CenterBoston UniversityBostonMassachusetts
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38
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Reissaus CA, Day KH, Mirmira RG, Dunn KW, Pavalko FM, Day RN. PIE-FLIM Measurements of Two Different FRET-Based Biosensor Activities in the Same Living Cells. Biophys J 2020; 118:1820-1829. [PMID: 32191861 DOI: 10.1016/j.bpj.2020.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 02/27/2020] [Accepted: 03/02/2020] [Indexed: 12/14/2022] Open
Abstract
We report the use of pulsed interleaved excitation (PIE)-fluorescence lifetime imaging microscopy (FLIM) to measure the activities of two different biosensor probes simultaneously in single living cells. Many genetically encoded biosensors rely on the measurement of Förster resonance energy transfer (FRET) to detect changes in biosensor conformation that accompany the targeted cell signaling event. One of the most robust ways of quantifying FRET is to measure changes in the fluorescence lifetime of the donor fluorophore using FLIM. The study of complex signaling networks in living cells demands the ability to track more than one of these cellular events at the same time. Here, we demonstrate how PIE-FLIM can separate and quantify the signals from different FRET-based biosensors to simultaneously measure changes in the activity of two cell signaling pathways in the same living cells in tissues. The imaging system described here uses selectable laser wavelengths and synchronized detection gating that can be tailored and optimized for each FRET pair. Proof-of-principle studies showing simultaneous measurement of cytosolic calcium and protein kinase A activity are shown, but the PIE-FLIM approach is broadly applicable to other signaling pathways.
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Affiliation(s)
- Christopher A Reissaus
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana; The Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kathleen H Day
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Raghavendra G Mirmira
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana; The Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kenneth W Dunn
- The Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana; Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Fredrick M Pavalko
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, Indiana; The Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, Indiana
| | - Richard N Day
- The Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana; Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, Indiana.
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39
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Mo GCH, Posner C, Rodriguez EA, Sun T, Zhang J. A rationally enhanced red fluorescent protein expands the utility of FRET biosensors. Nat Commun 2020; 11:1848. [PMID: 32296061 PMCID: PMC7160135 DOI: 10.1038/s41467-020-15687-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 03/20/2020] [Indexed: 11/30/2022] Open
Abstract
Genetically encoded Förster Resonance Energy Transfer (FRET)-based biosensors are powerful tools to illuminate spatiotemporal regulation of cell signaling in living cells, but the utility of the red spectrum for biosensing was limited due to a lack of bright and stable red fluorescent proteins. Here, we rationally improve the photophysical characteristics of the coral-derived fluorescent protein TagRFP-T. We show that a new single-residue mutant, super-TagRFP (stagRFP) has nearly twice the molecular brightness of TagRFP-T and negligible photoactivation. stagRFP facilitates significant improvements on multiple green-red biosensors as a FRET acceptor and is an efficient FRET donor that supports red/far-red FRET biosensing. Capitalizing on the ability of stagRFP to couple with multiple FRET partners, we develop a novel multiplex method to examine the confluence of signaling activities from three kinases simultaneously in single living cells, providing evidence for a role of Src family kinases in regulating growth factor induced Akt and ERK activities.
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Affiliation(s)
- Gary C H Mo
- Department of Pharmacology, University of California San Diego, La Jolla, CA, 92093, USA
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Clara Posner
- Department of Pharmacology, University of California San Diego, La Jolla, CA, 92093, USA
- Department of Bioengineering, University of California San Diego, La Jolla, CA, 92093, USA
| | - Erik A Rodriguez
- Department of Chemistry, The George Washington University, Washington, DC, 20052, USA
| | - Tengqian Sun
- Department of Pharmacology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Jin Zhang
- Department of Pharmacology, University of California San Diego, La Jolla, CA, 92093, USA.
- Department of Bioengineering, University of California San Diego, La Jolla, CA, 92093, USA.
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA.
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40
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Bertolin G, Tramier M. Insights into the non-mitotic functions of Aurora kinase A: more than just cell division. Cell Mol Life Sci 2020; 77:1031-1047. [PMID: 31562563 PMCID: PMC11104877 DOI: 10.1007/s00018-019-03310-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 09/13/2019] [Accepted: 09/18/2019] [Indexed: 02/02/2023]
Abstract
AURKA is a serine/threonine kinase overexpressed in several cancers. Originally identified as a protein with multifaceted roles during mitosis, improvements in quantitative microscopy uncovered several non-mitotic roles as well. In physiological conditions, AURKA regulates cilia disassembly, neurite extension, cell motility, DNA replication and senescence programs. In cancer-like contexts, AURKA actively promotes DNA repair, it acts as a transcription factor, promotes cell migration and invasion, and it localises at mitochondria to regulate mitochondrial dynamics and ATP production. Here we review the non-mitotic roles of AURKA, and its partners outside of cell division. In addition, we give an insight into how structural data and quantitative fluorescence microscopy allowed to understand AURKA activation and its interaction with new substrates, highlighting future developments in fluorescence microscopy needed to better understand AURKA functions in vivo. Last, we will recapitulate the most significant AURKA inhibitors currently in clinical trials, and we will explore how the non-mitotic roles of the kinase may provide new insights to ameliorate current pharmacological strategies against AURKA overexpression.
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Affiliation(s)
- Giulia Bertolin
- Univ Rennes, CNRS, IGDR (Genetics and Development Institute of Rennes), UMR 6290, F-35000, Rennes, France.
| | - Marc Tramier
- Univ Rennes, CNRS, IGDR (Genetics and Development Institute of Rennes), UMR 6290, F-35000, Rennes, France.
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41
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42
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Shu X. Imaging dynamic cell signaling in vivo with new classes of fluorescent reporters. Curr Opin Chem Biol 2019; 54:1-9. [PMID: 31678813 DOI: 10.1016/j.cbpa.2019.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/08/2019] [Accepted: 09/19/2019] [Indexed: 12/27/2022]
Abstract
Dynamical features of cell signaling are the essence of living organisms. To understand animal development, it is fundamental to investigate signaling dynamics in vivo. Robust reporters are required to visualize spatial and temporal dynamics of enzyme activities and protein-protein interactions involved in signaling pathways. In this review, we summarize recent development in the design of new classes of fluorescent reporters for imaging dynamic activities of proteases, kinases, and protein-protein interactions. These reporters operate on new physical and/or chemical principles; achieve large dynamic range, high brightness, and fast kinetics; and reveal spatiotemporal dynamics of signaling that is correlated with developmental events such as embryonic morphogenesis in live animals including Drosophila and zebrafish. Therefore, many of these reporters are great tools for biological discovery and mechanistic understanding of animal development and disease progression.
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Affiliation(s)
- Xiaokun Shu
- Department of Pharmaceutical Chemistry, University of California - San Francisco, San Francisco, CA, United States; Cardiovascular Research Institute, University of California - San Francisco, San Francisco, CA, United States.
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43
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Bertolin G, Sizaire F, Déméautis C, Chapuis C, Mérola F, Erard M, Tramier M. Optimized FRET Pairs and Quantification Approaches To Detect the Activation of Aurora Kinase A at Mitosis. ACS Sens 2019; 4:2018-2027. [PMID: 31317736 DOI: 10.1021/acssensors.9b00486] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Genetically encoded Förster's Resonance Energy Transfer (FRET) biosensors are indispensable tools to sense the spatiotemporal dynamics of signal transduction pathways. Investigating the crosstalk between different signaling pathways is becoming increasingly important to follow cell development and fate programs. To this end, FRET biosensors must be optimized to monitor multiple biochemical activities simultaneously and in single cells. In addition, their sensitivity must be increased to follow their activation even when the abundance of the biosensor is low. We describe here the development of a second generation of Aurora kinase A/AURKA biosensors. First, we adapt the original AURKA biosensor-GFP-AURKA-mCherry-to multiplex FRET by using dark acceptors as ShadowG or ShadowY. Then, we use the novel superYFP acceptor protein to measure FRET by 2-color Fluorescence Cross-Correlation Spectroscopy, in cytosolic regions where the abundance of AURKA is extremely low and undetectable with the original AURKA biosensor. These results pave the way to the use of FRET biosensors to follow AURKA activation in conjunction with substrate-based activity biosensors. In addition, they open up the possibility of tracking the activation of small pools of AURKA and its interaction with novel substrates, which would otherwise remain undetectable with classical biochemical approaches.
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Affiliation(s)
- Giulia Bertolin
- Univ Rennes, CNRS, IGDR (Genetics and Development Institute of Rennes), UMR 6290, F-35000 Rennes, France
| | - Florian Sizaire
- Univ Rennes, CNRS, IGDR (Genetics and Development Institute of Rennes), UMR 6290, F-35000 Rennes, France
| | - Claire Déméautis
- Univ Rennes, CNRS, IGDR (Genetics and Development Institute of Rennes), UMR 6290, F-35000 Rennes, France
| | - Catherine Chapuis
- Univ Rennes, CNRS, IGDR (Genetics and Development Institute of Rennes), UMR 6290, F-35000 Rennes, France
| | - Fabienne Mérola
- Univ Paris Sud, CNRS, LCP (Laboratoire de Chimie Physique), UMR 800, F-91400 Orsay, France
| | - Marie Erard
- Univ Paris Sud, CNRS, LCP (Laboratoire de Chimie Physique), UMR 800, F-91400 Orsay, France
| | - Marc Tramier
- Univ Rennes, CNRS, IGDR (Genetics and Development Institute of Rennes), UMR 6290, F-35000 Rennes, France
- Univ Rennes, BIOSIT, UMS CNRS 3480, US INSERM
018, F-35000 Rennes, France
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44
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Metzbower SR, Joo Y, Benavides DR, Blanpied TA. Properties of Individual Hippocampal Synapses Influencing NMDA-Receptor Activation by Spontaneous Neurotransmission. eNeuro 2019; 6:ENEURO.0419-18.2019. [PMID: 31110134 PMCID: PMC6541874 DOI: 10.1523/eneuro.0419-18.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 05/05/2019] [Accepted: 05/12/2019] [Indexed: 12/14/2022] Open
Abstract
NMDA receptor (NMDAR) activation is critical for maintenance and modification of synapse strength. Specifically, NMDAR activation by spontaneous glutamate release has been shown to mediate some forms of synaptic plasticity as well as synaptic development. Interestingly, there is evidence that within individual synapses each release mode may be segregated such that postsynaptically there are distinct pools of responsive receptors. To examine potential regulators of NMDAR activation because of spontaneous glutamate release in cultured hippocampal neurons, we used GCaMP6f imaging at single synapses in concert with confocal and super-resolution imaging. Using these single-spine approaches, we found that Ca2+ entry activated by spontaneous release tends to be carried by GluN2B-NMDARs. Additionally, the amount of NMDAR activation varies greatly both between synapses and within synapses, and is unrelated to spine and synapse size, but does correlate loosely with synapse distance from the soma. Despite the critical role of spontaneous activation of NMDARs in maintaining synaptic function, their activation seems to be controlled factors other than synapse size or synapse distance from the soma. It is most likely that NMDAR activation by spontaneous release influenced variability in subsynaptic receptor position, release site position, vesicle content, and channel properties. Therefore, spontaneous activation of NMDARs appears to be regulated distinctly from other receptor types, notably AMPARs, within individual synapses.
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Affiliation(s)
| | - Yuyoung Joo
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland, 21201
| | - David R Benavides
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland, 21201
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45
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Ross B, Wong SH, Snell NE, Zhang J, Rizzo MA. Triple Fluorescence Anisotropy Reporter Imaging in Living Cells. Bio Protoc 2019; 9:ew3226. [PMID: 31423459 DOI: 10.21769/bioprotoc.3226] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
FRET-based genetically encoded biosensors incorporate two fluorescent proteins into their design to enable ratiometric biosensing of signaling activities in live cells. While emission ratios are generally useful for quantitative studies, they leave little room in the optical spectrum for additional sensors and optogenetic tools. Homotransfer-based reporters, such as the FLuorescence Anisotropy REporters (FLAREs), incorporate two fluorescent proteins of the same color into their design. Conversion to a single color opens the visible spectrum for the use of complementary sensors. Here, we present a protocol for measuring three independent intracellular signals in living cells. We describe the configuration and calibration of a widefield microscope for multicolor FLARE imaging. Three FLARE sensors for intracellular calcium, MAPK activity, and PKA phosphorylation are co-transfected into HEK293 cells, and triple FRET imaging is performed. Compared to heterotransfer FRET biosensors, the polarization-based multiplex imaging can track multiple signaling activities concurrently in a targeted cell population.
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Affiliation(s)
- Brian Ross
- Department of Pharmacology, University of California, San Diego, La Jolla, California, United States.,Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, Maryland, United States
| | - Shenq Huey Wong
- Department of Physiology, University of Maryland Baltimore, Maryland, United States
| | - Nicole E Snell
- Department of Physiology, University of Maryland Baltimore, Maryland, United States
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, California, United States.,Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - M A Rizzo
- Department of Physiology, University of Maryland Baltimore, Maryland, United States
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46
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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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47
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Combining Optical Approaches with Human Inducible Pluripotent Stem Cells in G Protein-Coupled Receptor Drug Screening and Development. Biomolecules 2018; 8:biom8040180. [PMID: 30567417 PMCID: PMC6315445 DOI: 10.3390/biom8040180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/07/2018] [Accepted: 12/14/2018] [Indexed: 12/11/2022] Open
Abstract
Drug discovery for G protein-coupled receptors (GPCRs) stands at an interesting juncture. Screening programs are slowly moving away from model heterologous cell systems such as human embryonic kidney (HEK) 293 cells to more relevant cellular, tissue and whole animal platforms. Investigators are now developing analytical approaches as means to undertake different aspects of drug discovery by scaling into increasingly more relevant models all the way down to the single cell level. Such approaches include cellular, tissue slice and whole animal models where biosensors that track signaling events and receptor conformational profiles can be used. Here, we review aspects of biosensor-based imaging approaches that might be used in inducible pluripotent stem cell (iPSC) and organoid models, and focus on how such models must be characterized in order to apply them in drug screening.
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48
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Snell NE, Rao VP, Seckinger KM, Liang J, Leser J, Mancini AE, Rizzo MA. Homotransfer of FRET Reporters for Live Cell Imaging. BIOSENSORS-BASEL 2018; 8:bios8040089. [PMID: 30314323 PMCID: PMC6316388 DOI: 10.3390/bios8040089] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 09/27/2018] [Accepted: 10/10/2018] [Indexed: 01/01/2023]
Abstract
Förster resonance energy transfer (FRET) between fluorophores of the same species was recognized in the early to mid-1900s, well before modern heterotransfer applications. Recently, homotransfer FRET principles have re-emerged in biosensors that incorporate genetically encoded fluorescent proteins. Homotransfer offers distinct advantages over the standard heterotransfer FRET method, some of which are related to the use of fluorescence polarization microscopy to quantify FRET between two fluorophores of identical color. These include enhanced signal-to-noise, greater compatibility with other optical sensors and modulators, and new design strategies based upon the clustering or dimerization of singly-labeled sensors. Here, we discuss the theoretical basis for measuring homotransfer using polarization microscopy, procedures for data collection and processing, and we review the existing genetically-encoded homotransfer biosensors.
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Affiliation(s)
- Nicole E Snell
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - Vishnu P Rao
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - Kendra M Seckinger
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - Junyi Liang
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - Jenna Leser
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - Allison E Mancini
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
| | - M A Rizzo
- Department of Physiology, University of Maryland School of Medicine, 660 W Redwood St/HH525B, Baltimore, MD 21201, USA.
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49
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Seckinger KM, Rao VP, Snell NE, Mancini AE, Markwardt ML, Rizzo MA. Nitric Oxide Activates β-Cell Glucokinase by Promoting Formation of the "Glucose-Activated" State. Biochemistry 2018; 57:5136-5144. [PMID: 30053375 PMCID: PMC6338087 DOI: 10.1021/acs.biochem.8b00333] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The release of insulin from the pancreas is tightly controlled by glucokinase (GCK) activity that couples β-cell metabolism to changes in blood sugar. Despite having only a single glucose-binding site, GCK displays positive glucose cooperativity. Ex vivo structural studies have identified several potential protein conformations with varying levels of enzymatic activity, yet it is unclear how living cells regulate GCK cooperativity. To better understand the cellular regulation of GCK activation, we developed a homotransfer Förster resonance energy transfer (FRET) GCK biosensor and used polarization microscopy to eliminate fluorescence crosstalk from FRET quantification and improve the signal-to-noise ratio. This approach enhanced sensor contrast compared to that seen with the heterotransfer FRET GCK reporter and allowed observation of individual GCK states using an automated method to analyze FRET data at the pixel level. Mutations known to activate and inhibit GCK activity produced distinct anisotropy distributions, suggesting that at least two conformational states exist in living cells. A high glucose level activated the biosensor in a manner consistent with GCK's enzymology. Interestingly, glucose-free conditions did not affect GCK biosensor FRET, indicating that there is a single low-activity state, which is counter to proposed structural models of GCK cooperativity. Under low-glucose conditions, application of chemical NO donors efficiently shifted GCK to the more active conformation. Notably, GCK activation by mutation, a high glucose level, a pharmacological GCK activator, or S-nitrosylation all shared the same FRET distribution. These data suggest a simplified model for GCK activation in living cells, where post-translational modification of GCK by S-nitrosylation facilitates a single conformational transition that enhances GCK enzymatic activity.
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Affiliation(s)
- Kendra M. Seckinger
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Vishnu P. Rao
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Nicole E. Snell
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Allison E. Mancini
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Michele L. Markwardt
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - M. A. Rizzo
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
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