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Abstract
Cell migration, a crucial step in numerous biological processes, is tightly regulated in space and time. Cells employ Rho GTPases, primarily Rho, Rac, and Cdc42, to regulate their motility. Like other small G proteins, Rho GTPases function as biomolecular switches in regulating cell migration by operating between GDP bound 'OFF' and GTP bound 'ON' states. Guanine nucleotide exchange factors (GEFs) catalyse the shuttling of GTPases from OFF to ON state. G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors that are involved in many signalling phenomena including cell survival and cell migration events. In this review, we summarize signalling mechanisms, involving GPCRs, leading to the activation of RhoGEFs. GPCRs exhibit diverse GEF activation modes that include the interaction of heterotrimeric G protein subunits with different domains of GEFs, phosphorylation, protein-protein interaction, protein-lipid interaction, and/or a combination of these processes.
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Affiliation(s)
- Aishwarya Omble
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Kiran Kulkarni
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India,CONTACT Kiran Kulkarni Academy of Scientific and Innovative Research (Acsir), Ghaziabad 201002, India
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Ras inhibitor CAPRI enables neutrophil-like cells to chemotax through a higher-concentration range of gradients. Proc Natl Acad Sci U S A 2021; 118:2002162118. [PMID: 34675073 DOI: 10.1073/pnas.2002162118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2021] [Indexed: 01/21/2023] Open
Abstract
Neutrophils sense and migrate through an enormous range of chemoattractant gradients through adaptation. Here, we reveal that in human neutrophils, calcium-promoted Ras inactivator (CAPRI) locally controls the GPCR-stimulated Ras adaptation. Human neutrophils lacking CAPRI (caprikd ) exhibit chemoattractant-induced, nonadaptive Ras activation; significantly increased phosphorylation of AKT, GSK-3α/3β, and cofilin; and excessive actin polymerization. caprikd cells display defective chemotaxis in response to high-concentration gradients but exhibit improved chemotaxis in low- or subsensitive-concentration gradients of various chemoattractants, as a result of their enhanced sensitivity. Taken together, our data reveal that CAPRI controls GPCR activation-mediated Ras adaptation and lowers the sensitivity of human neutrophils so that they are able to chemotax through a higher-concentration range of chemoattractant gradients.
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3
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Haji E, Mahri SA, Aloraij Y, Malik S, Mohammad S. Single-cell Analysis of β2-Adrenergic Receptor Dynamics by Quantitative Fluorescence Microscopy. Curr Mol Med 2021; 20:488-493. [PMID: 31840614 DOI: 10.2174/1566524020666191216125825] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/06/2019] [Accepted: 12/06/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND G protein-coupled receptors (GPCRs) represent the largest family of surface proteins and are involved in the regulation of key physiological processes. GPCRs are characterized by seven transmembrane domains, an extracellular N-terminus and an intracellular C-terminus. Cellular response of these receptors to their ligands is largely determined by their surface expression and postactivation behavior including expression, desensitization and resensitization. OBJECTIVE To develop a quantitative fluorescence Microscopy assay to study β2- Adrenergic receptor expression and desensitization. METHOD β2-Adrenergic receptor cDNA was engineered to put an HA tag at the extracellular N-terminus and GFP Tag at the intracellular C-terminus. GFP fluorescence serves as a measure of total cellular expression; whereas staining with CY3 conjugated anti-HA antibodies without permeabilizing the cells represents the surface expression of β2-AR. The images are quantified and amount of CY3 (surface) and GFP (total) fluorescence for each cell determined using image processing software. RESULTS The method is sensitive and allows for the simultaneous measurement of surface and total expression of β2-AR. CONCLUSION A highly accurate method is described for measuring β2-AR surface and total expression based on single-cell quantitative immunofluorescence. The method can be used to determine agonist-induced desensitization and resensitization process as well as receptor kinetics like endocytosis and exocytosis of β2-Adrenergic receptor and can be applied to essentially any other GPCR.
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Affiliation(s)
- Esraa Haji
- Experimental Medicine, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Saeed Al Mahri
- Experimental Medicine, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Yumna Aloraij
- Experimental Medicine, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Shuja Malik
- Experimental Medicine, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Sameer Mohammad
- Experimental Medicine, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
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4
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Lan Z, Lee MY, Chun E, Liu B, Liu W. Overview of Biochemical Assays in Lipidic Cubic Phase. Trends Biochem Sci 2018; 44:295-299. [PMID: 30243833 DOI: 10.1016/j.tibs.2018.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 07/25/2018] [Accepted: 08/22/2018] [Indexed: 11/15/2022]
Abstract
The development of novel biochemical methods to efficiently characterize membrane protein (MP) properties in lipidic cubic phase (LCP) is important for studying complicated MPs and their multimeric complexes. Here, we summarize recent LCP-related assays and provide an outlook on their applications in structure and function studies of MPs.
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Affiliation(s)
- Zhu Lan
- School of Molecular Sciences, and Biodesign Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, AZ 85287-1604, USA
| | - Ming-Yue Lee
- School of Molecular Sciences, and Biodesign Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, AZ 85287-1604, USA
| | - Eugene Chun
- School of Molecular Sciences, and Biodesign Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, AZ 85287-1604, USA
| | - Bin Liu
- School of Molecular Sciences, and Biodesign Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, AZ 85287-1604, USA
| | - Wei Liu
- School of Molecular Sciences, and Biodesign Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, AZ 85287-1604, USA.
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5
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Abstract
Receptor activation upon ligand binding induces activation of multiple signaling pathways. To fully understand how these signaling pathways coordinate, it is essential to determine the dynamic nature of the spatiotemporal activation profile of signaling components at the level of single living cells. Here, we outline a detailed methodology for visualizing and quantitatively measuring the spatiotemporal activation of Ras and PKD1 by applying advanced fluorescence imaging techniques, including multichannel, simultaneous imaging and Förster resonance energy transfer (FRET).
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Islam AFMT, Stepanski BM, Charest PG. Studying Chemoattractant Signal Transduction Dynamics in Dictyostelium by BRET. Methods Mol Biol 2017; 1407:63-77. [PMID: 27271894 DOI: 10.1007/978-1-4939-3480-5_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Understanding the dynamics of chemoattractant signaling is key to our understanding of the mechanisms underlying the directed migration of cells, including that of neutrophils to sites of infections and of cancer cells during metastasis. A model frequently used for deciphering chemoattractant signal transduction is the social amoeba Dictyostelium discoideum. However, the methods available to quantitatively measure chemotactic signaling are limited. Here, we describe a protocol to quantitatively study chemoattractant signal transduction in Dictyostelium by monitoring protein-protein interactions and conformational changes using Bioluminescence Resonance Energy Transfer (BRET).
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Affiliation(s)
- A F M Tariqul Islam
- Department of Chemistry and Biochemistry, University of Arizona, 1041 E. Lowell Street, Tucson, 85721-0088, AZ, USA
| | - Branden M Stepanski
- Department of Chemistry and Biochemistry, University of Arizona, 1041 E. Lowell Street, Tucson, 85721-0088, AZ, USA
| | - Pascale G Charest
- Department of Chemistry and Biochemistry, University of Arizona, 1041 E. Lowell Street, Tucson, 85721-0088, AZ, USA.
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Song Y, Ge B, Lao J, Wang Z, Yang B, Wang X, He H, Li J, Huang F. Regulation of the Oligomeric Status of CCR3 with Binding Ligands Revealed by Single-Molecule Fluorescence Imaging. Biochemistry 2017; 57:852-860. [PMID: 28994588 DOI: 10.1021/acs.biochem.7b00676] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The relationship between the oligomeric status and functions of chemokine receptor CCR3 is still controversial. We use total internal reflection fluorescence microscopy at the single-molecule level to visualize the oligomeric status of CCR3 and its regulation of the membrane of stably transfected T-REx-293 cells. We find that the population of the dimers and oligomers of CCR3 can be modulated by the binding of ligands. Natural agonists can induce an increase in the level of dimers and oligomers at high concentrations, whereas antagonists do not have a significant influence on the oligomeric status. Moreover, monomeric CCR3 exhibits a stronger chemotactic response in the migration assay of stably transfected CCR3 cells. Together, these data support the notion that CCR3 exists as a mixture of monomers and dimers under nearly physiological conditions and the monomeric CCR3 receptor is the minimal functional unit in cellular signaling transduction. To the best of our knowledge, these results constitute the first report of the oligomeric status of CCR3 and its regulation.
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Affiliation(s)
- Yanzhuo Song
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Baosheng Ge
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Jun Lao
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Zhencai Wang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Bin Yang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Xiaojuan Wang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Hua He
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Jiqiang Li
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
| | - Fang Huang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China) , Qingdao 266580, P. R. China
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Naganathan S, Ray-Saha S, Park M, Tian H, Sakmar TP, Huber T. Multiplex detection of functional G protein-coupled receptors harboring site-specifically modified unnatural amino acids. Biochemistry 2015; 54:776-86. [PMID: 25524496 PMCID: PMC4310623 DOI: 10.1021/bi501267x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
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We developed a strategy for identifying
positions in G protein-coupled
receptors that are amenable to bioorthogonal modification with a peptide
epitope tag under cell culturing conditions. We introduced the unnatural
amino acid p-azido-l-phenylalanine (azF)
into human CC chemokine receptor 5 (CCR5) at site-specific amber codon
mutations. We then used strain-promoted azide–alkyne [3+2]
cycloaddition to label the azF-CCR5 variants with a FLAG peptide epitope-conjugated
aza-dibenzocyclooctyne (DBCO) reagent. A microtiter plate-based sandwich
fluorophore-linked immunosorbent assay was used to probe simultaneously
the FLAG epitope and the receptor using infrared dye-conjugated antibodies
so that the extent of DBCO incorporation, corresponding nominally
to labeling efficiency, could be quantified ratiometrically. The extent
of incorporation of DBCO at the various sites was evaluated in the
context of a recent crystal structure of maraviroc-bound CCR5. We
observed that labeling efficiency varied dramatically depending on
the topological location of the azF in CCR5. Interestingly, position
109 in transmembrane helix 3, located in a hydrophobic cavity on the
extracellular side of the receptor, was labeled most efficiently.
Because the bioorthogonal labeling and detection strategy described
might be used to introduce a variety of different peptide epitopes
or fluorophores into engineered expressed receptors, it might prove
to be useful for a wide range of applications, including single-molecule
detection studies of receptor trafficking and signaling mechanism.
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Affiliation(s)
- Saranga Naganathan
- Laboratory of Chemical Biology & Signal Transduction, The Rockefeller University , New York, New York 10065, United States
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Park M, Tian H, Naganathan S, Sakmar TP, Huber T. Quantitative Multi-color Detection Strategies for Bioorthogonally Labeled GPCRs. Methods Mol Biol 2015; 1335:67-93. [PMID: 26260595 DOI: 10.1007/978-1-4939-2914-6_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We describe multiple bioorthogonal approaches to label G protein-coupled receptors (GPCRs) heterologously expressed in mammalian cells. The use of genetically encoded unnatural amino acids as bioorthogonal tags results in receptors that are expressed at lower levels than even their low abundance wild-type counterparts. Therefore, reproducible and sensitive quantification of the labeled GPCRs is extremely important and conventional methods are simply not sufficiently accurate and precise. Silver stains lack reproducibility, spectroscopic methods using fluorescent ligands are limited to quantifying only functional receptor molecules, and immunoassays using epitope tags derived from rhodopsin are particularly variable for low-abundance GPCRs. To avoid these shortcomings, we employ near infrared (NIR) imaging-based methods that enable simultaneous multi-color detection of two different antigens, thus facilitating the ratiometric analysis of bioorthogonally modified GPCRs. We anticipate that these multi-color detection strategies will provide new tools for quantitatively assessing stoichiometrically labeled GPCRs for studies of signalosomes and for structure-function relationships at a single molecule level.
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Affiliation(s)
- Minyoung Park
- Laboratory of Chemical Biology & Signal Transduction, The Rockefeller University, New York, NY, 10065, USA
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Ren A, Moon C, Zhang W, Sinha C, Yarlagadda S, Arora K, Wang X, Yue J, Parthasarathi K, Heil-Chapdelaine R, Tigyi G, Naren AP. Asymmetrical macromolecular complex formation of lysophosphatidic acid receptor 2 (LPA2) mediates gradient sensing in fibroblasts. J Biol Chem 2014; 289:35757-69. [PMID: 25542932 DOI: 10.1074/jbc.m114.595512] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chemotactic migration of fibroblasts toward growth factors relies on their capacity to sense minute extracellular gradients and respond to spatially confined receptor-mediated signals. Currently, mechanisms underlying the gradient sensing of fibroblasts remain poorly understood. Using single-particle tracking methodology, we determined that a lysophosphatidic acid (LPA) gradient induces a spatiotemporally restricted decrease in the mobility of LPA receptor 2 (LPA2) on chemotactic fibroblasts. The onset of decreased LPA2 mobility correlates to the spatial recruitment and coupling to LPA2-interacting proteins that anchor the complex to the cytoskeleton. These localized PDZ motif-mediated macromolecular complexes of LPA2 trigger a Ca(2+) puff gradient that governs gradient sensing and directional migration in response to LPA. Disruption of the PDZ motif-mediated assembly of the macromolecular complex of LPA2 disorganizes the gradient of Ca(2+) puffs, disrupts gradient sensing, and reduces the directional migration of fibroblasts toward LPA. Our findings illustrate that the asymmetric macromolecular complex formation of chemoattractant receptors mediates gradient sensing and provides a new mechanistic basis for models to describe gradient sensing of fibroblasts.
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Affiliation(s)
- Aixia Ren
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - Changsuk Moon
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, the Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Weiqiang Zhang
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, the Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee 38103
| | - Chandrima Sinha
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - Sunitha Yarlagadda
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, the Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Kavisha Arora
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, the Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Xusheng Wang
- the Department of Structural Biology and Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, and
| | - Junming Yue
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - Kaushik Parthasarathi
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | | | - Gabor Tigyi
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - Anjaparavanda P Naren
- From the Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, the Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229,
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Lohse MJ, Nuber S, Hoffmann C. Fluorescence/bioluminescence resonance energy transfer techniques to study G-protein-coupled receptor activation and signaling. Pharmacol Rev 2012; 64:299-336. [PMID: 22407612 DOI: 10.1124/pr.110.004309] [Citation(s) in RCA: 251] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Fluorescence and bioluminescence resonance energy transfer (FRET and BRET) techniques allow the sensitive monitoring of distances between two labels at the nanometer scale. Depending on the placement of the labels, this permits the analysis of conformational changes within a single protein (for example of a receptor) or the monitoring of protein-protein interactions (for example, between receptors and G-protein subunits). Over the past decade, numerous such techniques have been developed to monitor the activation and signaling of G-protein-coupled receptors (GPCRs) in both the purified, reconstituted state and in intact cells. These techniques span the entire spectrum from ligand binding to the receptors down to intracellular second messengers. They allow the determination and the visualization of signaling processes with high temporal and spatial resolution. With these techniques, it has been demonstrated that GPCR signals may show spatial and temporal patterning. In particular, evidence has been provided for spatial compartmentalization of GPCRs and their signals in intact cells and for distinct physiological consequences of such spatial patterning. We review here the FRET and BRET technologies that have been developed for G-protein-coupled receptors and their signaling proteins (G-proteins, effectors) and the concepts that result from such experiments.
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Affiliation(s)
- Martin J Lohse
- Institute of Pharmacology and Toxicology, Versbacher Str. 9, 97078 Würzburg, Germany.
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Xu X, Meckel T, Brzostowski JA, Yan J, Meier-Schellersheim M, Jin T. Coupling mechanism of a GPCR and a heterotrimeric G protein during chemoattractant gradient sensing in Dictyostelium. Sci Signal 2010; 3:ra71. [PMID: 20876874 DOI: 10.1126/scisignal.2000980] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The coupling of heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) with G proteins is fundamental for GPCR signaling; however, the mechanism of coupling is still debated. Moreover, how the proposed mechanisms affect the dynamics of downstream signaling remains unclear. Here, through experiments involving fluorescence recovery after photobleaching and single-molecule imaging, we directly measured the mobilities of cyclic adenosine monophosphate (cAMP) receptor 1 (cAR1), a chemoattractant receptor, and a G protein βγ subunit in live cells. We found that cAR1 diffused more slowly in the plasma membrane than did Gβγ. Upon binding of ligand to the receptor, the mobility of cAR1 was unchanged, whereas the speed of a fraction of the faster-moving Gβγ subunits decreased. Our measurements showed that cAR1 was relatively immobile and Gβγ diffused freely, suggesting that chemoattractant-bound cAR1 transiently interacted with G proteins. Using models of possible coupling mechanisms, we computed the temporal kinetics of G protein activation. Our fluorescence resonance energy transfer imaging data showed that fully activated cAR1 induced the sustained dissociation of G protein α and βγ subunits, which indicated that ligand-bound cAR1 activated G proteins continuously. Finally, simulations indicated that a high-affinity coupling of ligand-bound receptors and G proteins was essential for cAR1 to translate extracellular gradient signals into directional cellular responses. We suggest that chemoattractant receptors use a ligand-induced coupling rather than a precoupled mechanism to control the activation of G proteins during chemotaxis.
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Affiliation(s)
- Xuehua Xu
- Chemotaxis Signal Section, National Institutes of Health, Rockville, MD 20852, USA
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