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Agyemang E, Gonneville AN, Tiruvadi-Krishnan S, Lamichhane R. Exploring GPCR conformational dynamics using single-molecule fluorescence. Methods 2024; 226:35-48. [PMID: 38604413 PMCID: PMC11098685 DOI: 10.1016/j.ymeth.2024.03.011] [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: 12/06/2023] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 04/13/2024] Open
Abstract
G protein-coupled receptors (GPCRs) are membrane proteins that transmit specific external stimuli into cells by changing their conformation. This conformational change allows them to couple and activate G-proteins to initiate signal transduction. A critical challenge in studying and inferring these structural dynamics arises from the complexity of the cellular environment, including the presence of various endogenous factors. Due to the recent advances in cell-expression systems, membrane-protein purification techniques, and labeling approaches, it is now possible to study the structural dynamics of GPCRs at a single-molecule level both in vitro and in live cells. In this review, we discuss state-of-the-art techniques and strategies for expressing, purifying, and labeling GPCRs in the context of single-molecule research. We also highlight four recent studies that demonstrate the applications of single-molecule microscopy in revealing the dynamics of GPCRs. These techniques are also useful as complementary methods to verify the results obtained from other structural biology tools like cryo-electron microscopy and x-ray crystallography.
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Affiliation(s)
- Eugene Agyemang
- UT-ORNL Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN 37996, USA
| | - Alyssa N Gonneville
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Sriram Tiruvadi-Krishnan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Rajan Lamichhane
- UT-ORNL Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN 37996, USA; Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA.
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Wu Y, Jensen N, Rossner MJ, Wehr MC. Exploiting Cell-Based Assays to Accelerate Drug Development for G Protein-Coupled Receptors. Int J Mol Sci 2024; 25:5474. [PMID: 38791511 PMCID: PMC11121687 DOI: 10.3390/ijms25105474] [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: 04/22/2024] [Revised: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 05/26/2024] Open
Abstract
G protein-coupled receptors (GPCRs) are relevant targets for health and disease as they regulate various aspects of metabolism, proliferation, differentiation, and immune pathways. They are implicated in several disease areas, including cancer, diabetes, cardiovascular diseases, and mental disorders. It is worth noting that about a third of all marketed drugs target GPCRs, making them prime pharmacological targets for drug discovery. Numerous functional assays have been developed to assess GPCR activity and GPCR signaling in living cells. Here, we review the current literature of genetically encoded cell-based assays to measure GPCR activation and downstream signaling at different hierarchical levels of signaling, from the receptor to transcription, via transducers, effectors, and second messengers. Singleplex assay formats provide one data point per experimental condition. Typical examples are bioluminescence resonance energy transfer (BRET) assays and protease cleavage assays (e.g., Tango or split TEV). By contrast, multiplex assay formats allow for the parallel measurement of multiple receptors and pathways and typically use molecular barcodes as transcriptional reporters in barcoded assays. This enables the efficient identification of desired on-target and on-pathway effects as well as detrimental off-target and off-pathway effects. Multiplex assays are anticipated to accelerate drug discovery for GPCRs as they provide a comprehensive and broad identification of compound effects.
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Affiliation(s)
- Yuxin Wu
- Research Group Cell Signalling, Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, Nussbaumstr. 7, 80336 Munich, Germany
- Systasy Bioscience GmbH, Balanstr. 6, 81669 Munich, Germany
| | - Niels Jensen
- Systasy Bioscience GmbH, Balanstr. 6, 81669 Munich, Germany
- Section of Molecular Neurobiology, Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, Nussbaumstr. 7, 80336 Munich, Germany
| | - Moritz J. Rossner
- Systasy Bioscience GmbH, Balanstr. 6, 81669 Munich, Germany
- Section of Molecular Neurobiology, Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, Nussbaumstr. 7, 80336 Munich, Germany
| | - Michael C. Wehr
- Research Group Cell Signalling, Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, Nussbaumstr. 7, 80336 Munich, Germany
- Systasy Bioscience GmbH, Balanstr. 6, 81669 Munich, Germany
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Sakai K, Aoki K, Goto Y. Live-cell fluorescence imaging and optogenetic control of PKA kinase activity in fission yeast Schizosaccharomyces pombe. Yeast 2024; 41:349-363. [PMID: 38583078 DOI: 10.1002/yea.3937] [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: 01/16/2024] [Revised: 02/21/2024] [Accepted: 03/20/2024] [Indexed: 04/08/2024] Open
Abstract
The cAMP-PKA signaling pathway plays a crucial role in sensing and responding to nutrient availability in the fission yeast Schizosaccharomyces pombe. This pathway monitors external glucose levels to control cell growth and sexual differentiation. However, the temporal dynamics of the cAMP-PKA pathway in response to external stimuli remains unclear mainly due to the lack of tools to quantitatively visualize the activity of the pathway. Here, we report the development of the kinase translocation reporter (KTR)-based biosensor spPKA-KTR1.0, which allows us to measure the dynamics of PKA activity in fission yeast cells. The spPKA-KTR1.0 is derived from the transcription factor Rst2, which translocates from the nucleus to the cytoplasm upon PKA activation. We found that spPKA-KTR1.0 translocates between the nucleus and cytoplasm in a cAMP-PKA pathway-dependent manner, indicating that the spPKA-KTR1.0 is a reliable indicator of the PKA activity in fission yeast cells. In addition, we implemented a system that simultaneously visualizes and manipulates the cAMP-PKA signaling dynamics by introducing bPAC, a photoactivatable adenylate cyclase, in combination with spPKA-KTR1.0. This system offers an opportunity for investigating the role of the signaling dynamics of the cAMP-PKA pathway in fission yeast cells with higher temporal resolution.
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Affiliation(s)
- Keiichiro Sakai
- Quantitative Biology Research Group, Department of Creative Research, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- Division of Quantitative Biology, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Aichi, Japan
| | - Kazuhiro Aoki
- Quantitative Biology Research Group, Department of Creative Research, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- Division of Quantitative Biology, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
- Center for Living Systems Information Science, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Division of Integrated Life Science, Department of Gene Mechanisms, Laboratory of Cell Cycle Regulation, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Yuhei Goto
- Quantitative Biology Research Group, Department of Creative Research, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- Division of Quantitative Biology, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
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4
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Ram A, Murphy D, DeCuzzi N, Patankar M, Hu J, Pargett M, Albeck JG. A guide to ERK dynamics, part 1: mechanisms and models. Biochem J 2023; 480:1887-1907. [PMID: 38038974 PMCID: PMC10754288 DOI: 10.1042/bcj20230276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 11/02/2023] [Accepted: 11/06/2023] [Indexed: 12/02/2023]
Abstract
Extracellular signal-regulated kinase (ERK) has long been studied as a key driver of both essential cellular processes and disease. A persistent question has been how this single pathway is able to direct multiple cell behaviors, including growth, proliferation, and death. Modern biosensor studies have revealed that the temporal pattern of ERK activity is highly variable and heterogeneous, and critically, that these dynamic differences modulate cell fate. This two-part review discusses the current understanding of dynamic activity in the ERK pathway, how it regulates cellular decisions, and how these cell fates lead to tissue regulation and pathology. In part 1, we cover the optogenetic and live-cell imaging technologies that first revealed the dynamic nature of ERK, as well as current challenges in biosensor data analysis. We also discuss advances in mathematical models for the mechanisms of ERK dynamics, including receptor-level regulation, negative feedback, cooperativity, and paracrine signaling. While hurdles still remain, it is clear that higher temporal and spatial resolution provide mechanistic insights into pathway circuitry. Exciting new algorithms and advanced computational tools enable quantitative measurements of single-cell ERK activation, which in turn inform better models of pathway behavior. However, the fact that current models still cannot fully recapitulate the diversity of ERK responses calls for a deeper understanding of network structure and signal transduction in general.
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Affiliation(s)
- Abhineet Ram
- Department of Molecular and Cellular Biology, University of California, Davis, U.S.A
| | - Devan Murphy
- Department of Molecular and Cellular Biology, University of California, Davis, U.S.A
| | - Nicholaus DeCuzzi
- Department of Molecular and Cellular Biology, University of California, Davis, U.S.A
| | - Madhura Patankar
- Department of Molecular and Cellular Biology, University of California, Davis, U.S.A
| | - Jason Hu
- Department of Molecular and Cellular Biology, University of California, Davis, U.S.A
| | - Michael Pargett
- Department of Molecular and Cellular Biology, University of California, Davis, U.S.A
| | - John G. Albeck
- Department of Molecular and Cellular Biology, University of California, Davis, U.S.A
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Kamino K, Kadakia N, Avgidis F, Liu ZX, Aoki K, Shimizu T, Emonet T. Optimal inference of molecular interaction dynamics in FRET microscopy. Proc Natl Acad Sci U S A 2023; 120:e2211807120. [PMID: 37014867 PMCID: PMC10104582 DOI: 10.1073/pnas.2211807120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 02/10/2023] [Indexed: 04/05/2023] Open
Abstract
Intensity-based time-lapse fluorescence resonance energy transfer (FRET) microscopy has been a major tool for investigating cellular processes, converting otherwise unobservable molecular interactions into fluorescence time series. However, inferring the molecular interaction dynamics from the observables remains a challenging inverse problem, particularly when measurement noise and photobleaching are nonnegligible-a common situation in single-cell analysis. The conventional approach is to process the time-series data algebraically, but such methods inevitably accumulate the measurement noise and reduce the signal-to-noise ratio (SNR), limiting the scope of FRET microscopy. Here, we introduce an alternative probabilistic approach, B-FRET, generally applicable to standard 3-cube FRET-imaging data. Based on Bayesian filtering theory, B-FRET implements a statistically optimal way to infer molecular interactions and thus drastically improves the SNR. We validate B-FRET using simulated data and then apply it to real data, including the notoriously noisy in vivo FRET time series from individual bacterial cells to reveal signaling dynamics otherwise hidden in the noise.
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Affiliation(s)
- Keita Kamino
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT06511
- Quantitative Biology Institute, Yale University, New Haven, CT06511
- Institute of Molecular Biology, Academia Sinica, Taipei115, Taiwan
- PRESTO, Japan Science and Technology Agency, Kawaguchi-shi, Saitama332-0012, Japan
| | - Nirag Kadakia
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT06511
- Quantitative Biology Institute, Yale University, New Haven, CT06511
- Swartz Foundation for Theoretical Neuroscience, Yale University, New Haven, CT06511
| | | | - Zhe-Xuan Liu
- Institute of Physics, National Yang Ming Chiao Tung University, Hsinchu30010, Taiwan
| | - Kazuhiro Aoki
- Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi444-8787, Japan
- National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Aichi444-8585, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi240-0193, Japan
| | | | - Thierry Emonet
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT06511
- Quantitative Biology Institute, Yale University, New Haven, CT06511
- Department of Physics, Yale University, New Haven, CT06511
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6
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Tian M, Ma Y, Li T, Wu N, Li J, Jia H, Yan M, Wang W, Bian H, Tan X, Qi J. Functions of regulators of G protein signaling 16 in immunity, inflammation, and other diseases. Front Mol Biosci 2022; 9:962321. [PMID: 36120550 PMCID: PMC9478547 DOI: 10.3389/fmolb.2022.962321] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Regulators of G protein signaling (RGS) act as guanosine triphosphatase activating proteins to accelerate guanosine triphosphate hydrolysis of the G protein α subunit, leading to the termination of the G protein-coupled receptor (GPCR) downstream signaling pathway. RGS16, which is expressed in a number of cells and tissues, belongs to one of the small B/R4 subfamilies of RGS proteins and consists of a conserved RGS structural domain with short, disordered amino- and carboxy-terminal extensions and an α-helix that classically binds and de-activates heterotrimeric G proteins. However, with the deepening of research, it has been revealed that RGS16 protein not only regulates the classical GPCR pathway, but also affects immune, inflammatory, tumor and metabolic processes through other signaling pathways including the mitogen-activated protein kinase, phosphoinositide 3-kinase/protein kinase B, Ras homolog family member A and stromal cell-derived factor 1/C-X-C motif chemokine receptor 4 pathways. Additionally, the RGS16 protein may be involved in the Hepatitis B Virus -induced inflammatory response. Therefore, given the continuous expansion of knowledge regarding its role and mechanism, the structure, characteristics, regulatory mechanisms and known functions of the small RGS proteinRGS16 are reviewed in this paper to prepare for diagnosis, treatment, and prognostic evaluation of different diseases such as inflammation, tumor, and metabolic disorders and to better study its function in other diseases.
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Affiliation(s)
- Miaomiao Tian
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Yan Ma
- Zibo Central Hospital, Zibo, China
| | - Tao Li
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Nijin Wu
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Jiaqi Li
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Huimin Jia
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Meizhu Yan
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Wenwen Wang
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Hongjun Bian
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Xu Tan
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- *Correspondence: Jianni Qi, ; Xu Tan,
| | - Jianni Qi
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Provincial Engineering and Technological Research Center for Liver Diseases Prevention and Control, Jinan, China
- *Correspondence: Jianni Qi, ; Xu Tan,
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