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Masner M, Lujea N, Bisbal M, Acosta C, Kunda P. Linoleic and oleic acids enhance cell migration by altering the dynamics of microtubules and the remodeling of the actin cytoskeleton at the leading edge. Sci Rep 2021; 11:14984. [PMID: 34294745 PMCID: PMC8298526 DOI: 10.1038/s41598-021-94399-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/30/2021] [Indexed: 01/22/2023] Open
Abstract
Fatty acids (FA) have a multitude of biological actions on living cells. A target of their action is cell motility, a process of critical importance during cancer cell dissemination. Here, we studied the effect of unsaturated FA on ovarian cancer cell migration in vitro and its role in regulating cytoskeleton structures that are essential for cell motility. Scratch wound assays on human ovary cancer SKOV-3 cell monolayers revealed that low doses (16 μM) of linoleic acid (LA, 18:2 ω6) and oleic acid (OA; 18:1 ω9) promoted migration, while α-linolenic acid (ALA, 18:3 ω3), showed a migration rate similar to that of the control group. Single cell tracking demonstrated that LA and OA-treated cells migrated faster and were more orientated towards the wound closure than control. In vitro addition of those FA resulted in an increased number, length and protrusion speed of filopodia and also in a prominent and dynamic lamellipodia at the cell leading edge. Using time-lapse video-microscopy and FRAP we observed an increase in both the speed and frequency of actin waves associated with more mobile actin and augmented Rac1 activity. We also observed that FA induced microtubule-organizing center (MTOC)-orientation towards the cell front and affected the dynamics of microtubules (MT) in the direction of cell migration. We propose that environmental cues such as OA and LA present in ascitic fluid, should be taken into account as key factors for the regulation of cell migration.
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Affiliation(s)
- M Masner
- Centro de Investigación en Medicina Traslacional "Severo Amuchástegui" (CIMETSA), Instituto Universitario Ciencias Biomédicas Córdoba (IUCBC), Naciones Unidas 420, Córdoba, Argentina
| | - N Lujea
- Centro de Investigación en Medicina Traslacional "Severo Amuchástegui" (CIMETSA), Instituto Universitario Ciencias Biomédicas Córdoba (IUCBC), Naciones Unidas 420, Córdoba, Argentina
| | - M Bisbal
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - C Acosta
- Instituto de Histología y Embriología de Mendoza (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Patricia Kunda
- Centro de Investigación en Medicina Traslacional "Severo Amuchástegui" (CIMETSA), Instituto Universitario Ciencias Biomédicas Córdoba (IUCBC), Naciones Unidas 420, Córdoba, Argentina.
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2
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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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3
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Kim H, Ju J, Lee HN, Chun H, Seong J. Genetically Encoded Biosensors Based on Fluorescent Proteins. SENSORS (BASEL, SWITZERLAND) 2021; 21:795. [PMID: 33504068 PMCID: PMC7865379 DOI: 10.3390/s21030795] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 02/06/2023]
Abstract
Genetically encoded biosensors based on fluorescent proteins (FPs) allow for the real-time monitoring of molecular dynamics in space and time, which are crucial for the proper functioning and regulation of complex cellular processes. Depending on the types of molecular events to be monitored, different sensing strategies need to be applied for the best design of FP-based biosensors. Here, we review genetically encoded biosensors based on FPs with various sensing strategies, for example, translocation, fluorescence resonance energy transfer (FRET), reconstitution of split FP, pH sensitivity, maturation speed, and so on. We introduce general principles of each sensing strategy and discuss critical factors to be considered if available, then provide representative examples of these FP-based biosensors. These will help in designing the best sensing strategy for the successful development of new genetically encoded biosensors based on FPs.
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Affiliation(s)
- Hyunbin Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea; (H.K.); (J.J.); (H.N.L.); (H.C.)
- Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea
| | - Jeongmin Ju
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea; (H.K.); (J.J.); (H.N.L.); (H.C.)
- Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea
| | - Hae Nim Lee
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea; (H.K.); (J.J.); (H.N.L.); (H.C.)
- Department of Converging Science and Technology, Kyung Hee University, Seoul 02453, Korea
| | - Hyeyeon Chun
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea; (H.K.); (J.J.); (H.N.L.); (H.C.)
| | - Jihye Seong
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea; (H.K.); (J.J.); (H.N.L.); (H.C.)
- Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea
- Department of Converging Science and Technology, Kyung Hee University, Seoul 02453, Korea
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4
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In Vivo Quantification of Intramolecular FRET Using RacFRET Biosensors. Methods Mol Biol 2019. [PMID: 31432484 DOI: 10.1007/978-1-4939-9686-5_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Genetically encoded FRET biosensors are powerful tools to visualize protein activity and signaling events in vivo. Compared with a biochemical approach, FRET biosensors allow a noninvasive spatial-temporal detection of signaling processes in live cells and animal tissues. While the concept of this technique is relatively simple, the experimental procedure is complicated and consists of several steps: (1) biosensor optimization; (2) data acquisition; and (3) image processing with each step posing its own challenge. In this chapter, we discuss steps (2) and (3) with the emphasis on the intramolecular RacFRET biosensor. We describe the design principle of the biosensor, the experimental imaging setup for acquiring FRET data in zebrafish embryos expressing the RacFRET biosensor, and the step-by-step ratio image generation protocol using Fiji software. We discuss important considerations during FRET data acquisition and analysis. Finally, we provide a macro code for the automated ratio image generation.
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Bery N, Rabbitts TH. Bioluminescence Resonance Energy Transfer 2 (BRET2)-Based RAS Biosensors to Characterize RAS Inhibitors. ACTA ACUST UNITED AC 2019; 83:e83. [PMID: 30768855 DOI: 10.1002/cpcb.83] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Protein-protein interactions (PPIs) are principle biological processes that control normal cell growth, differentiation, and homeostasis but are also crucial in diseases such as malignancy, neuropathy, and infection. Despite the importance of PPIs in biology, this target class has been very challenging to convert to therapeutics. In the last decade, much progress has been made in the inhibition of PPIs involved in diseases, but many remain difficult such as RAS-effector interactions in cancers. We describe here a protocol for using Bioluminescence Resonance Energy Transfer 2 (BRET2)-based RAS biosensors to detect and characterize RAS PPI inhibition by macromolecules and small molecules. This method could be extended to any other small GTPases or any other PPIs of interest. © 2019 by John Wiley & Sons, Inc.
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Affiliation(s)
- Nicolas Bery
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, John Radcliffe Hospital, Headington, Oxford, United Kingdom
| | - Terence H Rabbitts
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, John Radcliffe Hospital, Headington, Oxford, United Kingdom
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6
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Wong HL, Akamatsu A, Wang Q, Higuchi M, Matsuda T, Okuda J, Kosami KI, Inada N, Kawasaki T, Kaneko-Kawano T, Nagawa S, Tan L, Kawano Y, Shimamoto K. In vivo monitoring of plant small GTPase activation using a Förster resonance energy transfer biosensor. PLANT METHODS 2018; 14:56. [PMID: 30002723 PMCID: PMC6035793 DOI: 10.1186/s13007-018-0325-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 06/29/2018] [Indexed: 05/05/2023]
Abstract
BACKGROUND Small GTPases act as molecular switches that regulate various plant responses such as disease resistance, pollen tube growth, root hair development, cell wall patterning and hormone responses. Thus, to monitor their activation status within plant cells is believed to be the key step in understanding their roles. RESULTS We have established a plant version of a Förster resonance energy transfer (FRET) probe called Ras and interacting protein chimeric unit (Raichu) that can successfully monitor activation of the rice small GTPase OsRac1 during various defence responses in cells. Here, we describe the protocol for visualizing spatiotemporal activity of plant Rac/ROP GTPase in living plant cells, transfection of rice protoplasts with Raichu-OsRac1 and acquisition of FRET images. CONCLUSIONS Our protocol should be adaptable for monitoring activation for other plant small GTPases and protein-protein interactions for other FRET sensors in various plant cells.
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Affiliation(s)
- Hann Ling Wong
- Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, 630-0192 Japan
- Present Address: Department of Biological Science, University Tunku Abdul Rahman, Jalan Universiti, Bandar Barat, 31900 Kampar, Perak Malaysia
| | - Akira Akamatsu
- Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, 630-0192 Japan
- Present Address: Department of Bioscience, Kwansei Gakuin University, 2-1 Gakuen, Sanda, 669-1337 Japan
| | - Qiong Wang
- Present Address: Signal Transduction and Immunity Group, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, No. 3888 Chenhua Road, Shanghai, 201602 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Masayuki Higuchi
- Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, 630-0192 Japan
| | - Tomonori Matsuda
- Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, 630-0192 Japan
| | - Jun Okuda
- Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, 630-0192 Japan
| | - Ken-ichi Kosami
- Present Address: Signal Transduction and Immunity Group, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, No. 3888 Chenhua Road, Shanghai, 201602 China
| | - Noriko Inada
- College of Life, Environment, and Advanced, Osaka Prefecture University Sciences, Sakai, Osaka 599-8531 Japan
| | - Tsutomu Kawasaki
- Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, 630-0192 Japan
- Present Address: Department of Advanced Bioscience, Kindai University, 3327-204 Nakamachi, Nara, 631-8505 Japan
| | | | - Shingo Nagawa
- Core Facility of Cell Biology, Shanghai Center for Plant Stress Biology, No. 3888 Chenhua Road, Shanghai, 201602 China
- Present Address: FAFU-UCR Joint Center and Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian China
| | - Li Tan
- Core Facility of Cell Biology, Shanghai Center for Plant Stress Biology, No. 3888 Chenhua Road, Shanghai, 201602 China
| | - Yoji Kawano
- Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, 630-0192 Japan
- Present Address: Signal Transduction and Immunity Group, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, No. 3888 Chenhua Road, Shanghai, 201602 China
- Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka, Totsuka, Yokohama, Kanagawa 244-0813 Japan
| | - Ko Shimamoto
- Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, 630-0192 Japan
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7
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Zhao Y, Sivaji S, Chiang MC, Ali H, Zukowski M, Ali S, Kennedy B, Sklyar A, Cheng A, Guo Z, Reed AK, Kodali R, Borowski J, Frost G, Beukema P, Wills ZP. Amyloid Beta Peptides Block New Synapse Assembly by Nogo Receptor-Mediated Inhibition of T-Type Calcium Channels. Neuron 2017; 96:355-372.e6. [PMID: 29024660 DOI: 10.1016/j.neuron.2017.09.041] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 07/27/2017] [Accepted: 09/22/2017] [Indexed: 01/07/2023]
Abstract
Compelling evidence links amyloid beta (Aβ) peptide accumulation in the brains of Alzheimer's disease (AD) patients with the emergence of learning and memory deficits, yet a clear understanding of the events that drive this synaptic pathology are lacking. We present evidence that neurons exposed to Aβ are unable to form new synapses, resulting in learning deficits in vivo. We demonstrate the Nogo receptor family (NgR1-3) acts as Aβ receptors mediating an inhibition of synapse assembly, plasticity, and learning. Live imaging studies reveal Aβ activates NgRs on the dendritic shaft of neurons, triggering an inhibition of calcium signaling. We define T-type calcium channels as a target of Aβ-NgR signaling, mediating Aβ's inhibitory effects on calcium, synapse assembly, plasticity, and learning. These studies highlight deficits in new synapse assembly as a potential initiator of cognitive pathology in AD, and pinpoint calcium dysregulation mediated by NgRs and T-type channels as key components. VIDEO ABSTRACT.
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Affiliation(s)
- Yanjun Zhao
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Sivaprakash Sivaji
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Michael C Chiang
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Haadi Ali
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Monica Zukowski
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Sareen Ali
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Bryan Kennedy
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Alex Sklyar
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Alice Cheng
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Zihan Guo
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Alexander K Reed
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Ravindra Kodali
- Department of Structural Biology and Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Jennifer Borowski
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Georgia Frost
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Patrick Beukema
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, PA 15213, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Zachary P Wills
- Department of Neurobiology, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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8
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Impairment of PDGF-induced chemotaxis by extracellular α-synuclein through selective inhibition of Rac1 activation. Sci Rep 2016; 6:37810. [PMID: 27886249 PMCID: PMC5122898 DOI: 10.1038/srep37810] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 11/02/2016] [Indexed: 01/10/2023] Open
Abstract
Parkinson’s disease (PD) is characterized by α-synuclein (α-Syn)-positive intracytoplasmic inclusions, known as Lewy bodies. Although it is known that extracellular α-Syn is detected in the plasma and cerebrospinal fluid, its physiological significance remains unclear. Here, we show that extracellular α-Syn suppresses platelet-derived growth factor (PDGF)-induced chemotaxis in human neuroblastoma SH-SY5Y cells. The inhibitory effect was stronger in the mutant α-Syn(A53T), found in hereditary PD, and the degree of inhibition was time-dependent, presumably because of the oligomerization of α-Syn. PDGF-induced activation of Akt or Erk was not influenced by α-Syn(A53T). Further studies revealed that α-Syn(A53T) inhibited PDGF-induced Rac1 activation, whereas Cdc42 activation remained unaffected, resulting in unbalanced actin filament remodeling. These results shed light on the understanding of pathological as well as physiological functions of extracellular α-Syn in neuronal cells.
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9
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Marinović M, Šoštar M, Filić V, Antolović V, Weber I. Quantitative imaging of Rac1 activity in Dictyostelium cells with a fluorescently labelled GTPase-binding domain from DPAKa kinase. Histochem Cell Biol 2016; 146:267-79. [DOI: 10.1007/s00418-016-1440-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/19/2016] [Indexed: 02/06/2023]
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10
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Abstract
Since their discovery, G protein-coupled receptors (GPCRs) constitute one of the most studied proteins leading to important discoveries and perspectives in terms of their biology and implication in physiology and pathophysiology. This is mostly linked to the remarkable advances in the development and application of the biophysical resonance energy transfer (RET)-based approaches, including bioluminescence and fluorescence resonance energy transfer (BRET and FRET, respectively). Indeed, BRET and FRET have been extensively applied to study different aspects of GPCR functioning such as their activation and regulation either statically or dynamically, in real-time and intact cells. Consequently, our view on GPCRs has considerably changed opening new challenges for the study of GPCRs in their native tissues in the aim to get more knowledge on how these receptors control the biological responses. Moreover, the technological aspect of this field of research promises further developments for robust and reliable new RET-based assays that may be compatible with high-throughput screening as well as drug discovery programs.
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Affiliation(s)
- Mohammed Akli Ayoub
- Biologie et Bioinformatique des Systèmes de Signalisation, Institut National de la Recherche Agronomique, UMR85, Unité Physiologie de la Reproduction et des Comportements; CNRS, UMR7247, Nouzilly, France; LE STUDIUM(®) Loire Valley Institute for Advanced Studies, Orléans, France.
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11
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Eller-Borges R, Batista WL, da Costa PE, Tokikawa R, Curcio MF, Strumillo ST, Sartori A, Moraes MS, de Oliveira GA, Taha MO, Fonseca FV, Stern A, Monteiro HP. Ras, Rac1, and phosphatidylinositol-3-kinase (PI3K) signaling in nitric oxide induced endothelial cell migration. Nitric Oxide 2015; 47:40-51. [PMID: 25819133 DOI: 10.1016/j.niox.2015.03.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 03/13/2015] [Accepted: 03/18/2015] [Indexed: 10/23/2022]
Abstract
The small GTP-binding proteins Ras and Rac1 are molecular switches exchanging GDP for GTP and converting external signals in response to a variety of stimuli. Ras and Rac1 play an important role in cell proliferation, cell differentiation, and cell migration. Rac1 is directly involved in the reorganization and changes in the cytoskeleton during cell motility. Nitric oxide (NO) stimulates the Ras - ERK1/2 MAP kinases signaling pathway and is involved in the interaction between Ras and the phosphatidyl-inositol-3 Kinase (PI3K) signaling pathway and cell migration. This study utilizes bradykinin (BK), which promotes endogenous production of NO, in an investigation of the role of NO in the activation of Rac1 in rabbit aortic endothelial cells (RAEC). NO-derived from BK stimulation of RAEC and incubation of the cells with the s-nitrosothiol S-nitrosoglutathione (GSNO) activated Rac1. NO-derived from BK stimulation promoted RAEC migration over a period of 12 h. The use of RAEC permanently transfected with the dominant negative mutant of Ras (Ras(N17)) or with the non-nitrosatable mutant of Ras (Ras(C118S)); and the use of specific inhibitors of: Ras, PI3K, and Rac1 resulted in inhibition of NO-mediated Rac1 activation. BK-stimulated s-nitrosylation of Ras in RAEC mediates Rac1 activation and cell migration. Inhibition of NO-mediated Rac1 activation resulted in inhibition of endothelial cell migration. In conclusion, the NO indirect activation of Rac1 involves the direct participation of Ras and PI3K in the migration of endothelial cells stimulated with BK.
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Affiliation(s)
- Roberta Eller-Borges
- Department of Biochemistry, Center for Cellular and Molecular Therapy-CTCMOL, Escola Paulista de Medicina /Universidade Federal de São Paulo, SP, Brazil
| | - Wagner L Batista
- Department of Biological Sciences, Universidade Federal de São Paulo/Campus Diadema, SP, Brazil
| | - Paulo E da Costa
- Department of Biochemistry, Center for Cellular and Molecular Therapy-CTCMOL, Escola Paulista de Medicina /Universidade Federal de São Paulo, SP, Brazil
| | - Rita Tokikawa
- Department of Biochemistry, Center for Cellular and Molecular Therapy-CTCMOL, Escola Paulista de Medicina /Universidade Federal de São Paulo, SP, Brazil
| | - Marli F Curcio
- Department of Biochemistry, Center for Cellular and Molecular Therapy-CTCMOL, Escola Paulista de Medicina /Universidade Federal de São Paulo, SP, Brazil
| | - Scheilla T Strumillo
- Department of Biochemistry, Center for Cellular and Molecular Therapy-CTCMOL, Escola Paulista de Medicina /Universidade Federal de São Paulo, SP, Brazil
| | - Adriano Sartori
- Department of Biochemistry, Center for Cellular and Molecular Therapy-CTCMOL, Escola Paulista de Medicina /Universidade Federal de São Paulo, SP, Brazil
| | - Miriam S Moraes
- Department of Biochemistry, Center for Cellular and Molecular Therapy-CTCMOL, Escola Paulista de Medicina /Universidade Federal de São Paulo, SP, Brazil
| | - Graciele A de Oliveira
- Department of Biochemistry, Center for Cellular and Molecular Therapy-CTCMOL, Escola Paulista de Medicina /Universidade Federal de São Paulo, SP, Brazil
| | - Murched O Taha
- Department of Surgery, Escola Paulista de Medicina/Universidade Federal de São Paulo, SP, Brazil
| | - Fábio V Fonseca
- Department of Medicine, Institute for Transformative Molecular Medicine, Case Western University, Cleveland, OH, USA
| | - Arnold Stern
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA; Escuela de Medicina, Universidad Espíritu Santo, Guayaquil, Ecuador.
| | - Hugo P Monteiro
- Department of Biochemistry, Center for Cellular and Molecular Therapy-CTCMOL, Escola Paulista de Medicina /Universidade Federal de São Paulo, SP, Brazil.
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12
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Gomez GA, McLachlan RW, Wu SK, Caldwell BJ, Moussa E, Verma S, Bastiani M, Priya R, Parton RG, Gaus K, Sap J, Yap AS. An RPTPα/Src family kinase/Rap1 signaling module recruits myosin IIB to support contractile tension at apical E-cadherin junctions. Mol Biol Cell 2015; 26:1249-62. [PMID: 25631816 PMCID: PMC4454173 DOI: 10.1091/mbc.e14-07-1223] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Cell-cell adhesion couples the contractile cortices of epithelial cells together, generating tension to support a range of morphogenetic processes. E-cadherin adhesion plays an active role in generating junctional tension by promoting actin assembly and cortical signaling pathways that regulate myosin II. Multiple myosin II paralogues accumulate at mammalian epithelial cell-cell junctions. Earlier, we found that myosin IIA responds to Rho-ROCK signaling to support junctional tension in MCF-7 cells. Although myosin IIB is also found at the zonula adherens (ZA) in these cells, its role in junctional contractility and its mode of regulation are less well understood. We now demonstrate that myosin IIB contributes to tension at the epithelial ZA. Further, we identify a receptor type-protein tyrosine phosphatase alpha-Src family kinase-Rap1 pathway as responsible for recruiting myosin IIB to the ZA and supporting contractile tension. Overall these findings reinforce the concept that orthogonal E-cadherin-based signaling pathways recruit distinct myosin II paralogues to generate the contractile apparatus at apical epithelial junctions.
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Affiliation(s)
- Guillermo A Gomez
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Robert W McLachlan
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Selwin K Wu
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Benjamin J Caldwell
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Elliott Moussa
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Suzie Verma
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Michele Bastiani
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Rashmi Priya
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Robert G Parton
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
| | - Katharina Gaus
- UNSW Australia, ARC Centre of Excellence in Advanced Molecular Imaging and Australian Centre for Nanomedicine, Sydney 2052, Australia
| | - Jan Sap
- Université Paris Diderot, Sorbonne Paris Cité, Epigenetics and Cell Fate, UMR 7216 CNRS Bâtiment Lamarck, F-75205 Paris Cedex 13, France
| | - Alpha S Yap
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
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13
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Devauges V, Matthews DR, Aluko J, Nedbal J, Levitt JA, Poland SP, Coban O, Weitsman G, Monypenny J, Ng T, Ameer-Beg SM. Steady-state acceptor fluorescence anisotropy imaging under evanescent excitation for visualisation of FRET at the plasma membrane. PLoS One 2014; 9:e110695. [PMID: 25360776 PMCID: PMC4215982 DOI: 10.1371/journal.pone.0110695] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 09/15/2014] [Indexed: 11/22/2022] Open
Abstract
We present a novel imaging system combining total internal reflection fluorescence (TIRF) microscopy with measurement of steady-state acceptor fluorescence anisotropy in order to perform live cell Förster Resonance Energy Transfer (FRET) imaging at the plasma membrane. We compare directly the imaging performance of fluorescence anisotropy resolved TIRF with epifluorescence illumination. The use of high numerical aperture objective for TIRF required correction for induced depolarization factors. This arrangement enabled visualisation of conformational changes of a Raichu-Cdc42 FRET biosensor by measurement of intramolecular FRET between eGFP and mRFP1. Higher activity of the probe was found at the cell plasma membrane compared to intracellularly. Imaging fluorescence anisotropy in TIRF allowed clear differentiation of the Raichu-Cdc42 biosensor from negative control mutants. Finally, inhibition of Cdc42 was imaged dynamically in live cells, where we show temporal changes of the activity of the Raichu-Cdc42 biosensor.
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Affiliation(s)
- Viviane Devauges
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Daniel R. Matthews
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Justin Aluko
- Department of Physics, King's College London, London, United Kingdom
| | - Jakub Nedbal
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - James A. Levitt
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Simon P. Poland
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Oana Coban
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Gregory Weitsman
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - James Monypenny
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Tony Ng
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Simon M. Ameer-Beg
- Richard Dimbleby Cancer Research Laboratory, Division of Cancer Studies and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
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14
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Sands B, Jenkins P, Peria WJ, Naivar M, Houston JP, Brent R. Measuring and sorting cell populations expressing isospectral fluorescent proteins with different fluorescence lifetimes. PLoS One 2014; 9:e109940. [PMID: 25302964 PMCID: PMC4193854 DOI: 10.1371/journal.pone.0109940] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 09/04/2014] [Indexed: 01/03/2023] Open
Abstract
Study of signal transduction in live cells benefits from the ability to visualize and quantify light emitted by fluorescent proteins (XFPs) fused to different signaling proteins. However, because cell signaling proteins are often present in small numbers, and because the XFPs themselves are poor fluorophores, the amount of emitted light, and the observable signal in these studies, is often small. An XFP's fluorescence lifetime contains additional information about the immediate environment of the fluorophore that can augment the information from its weak light signal. Here, we constructed and expressed in Saccharomyces cerevisiae variants of Teal Fluorescent Protein (TFP) and Citrine that were isospectral but had shorter fluorescence lifetimes, ∼1.5 ns vs ∼3 ns. We modified microscopic and flow cytometric instruments to measure fluorescence lifetimes in live cells. We developed digital hardware and a measure of lifetime called a “pseudophasor” that we could compute quickly enough to permit sorting by lifetime in flow. We used these abilities to sort mixtures of cells expressing TFP and the short-lifetime TFP variant into subpopulations that were respectively 97% and 94% pure. This work demonstrates the feasibility of using information about fluorescence lifetime to help quantify cell signaling in living cells at the high throughput provided by flow cytometry. Moreover, it demonstrates the feasibility of isolating and recovering subpopulations of cells with different XFP lifetimes for subsequent experimentation.
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Affiliation(s)
- Bryan Sands
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Patrick Jenkins
- Department of Chemical Engineering, New Mexico State University, Las Cruces, New Mexico, United States of America
| | - William J. Peria
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Mark Naivar
- Darkling X, LLC, Los Alamos, New Mexico, United States of America
| | - Jessica P. Houston
- Department of Chemical Engineering, New Mexico State University, Las Cruces, New Mexico, United States of America
| | - Roger Brent
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- * E-mail:
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15
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Sample V, Mehta S, Zhang J. Genetically encoded molecular probes to visualize and perturb signaling dynamics in living biological systems. J Cell Sci 2014; 127:1151-60. [PMID: 24634506 PMCID: PMC3953811 DOI: 10.1242/jcs.099994] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 01/22/2013] [Indexed: 01/05/2023] Open
Abstract
In this Commentary, we discuss two sets of genetically encoded molecular tools that have significantly enhanced our ability to observe and manipulate complex biochemical processes in their native context and that have been essential in deepening our molecular understanding of how intracellular signaling networks function. In particular, genetically encoded biosensors are widely used to directly visualize signaling events in living cells, and we highlight several examples of basic biosensor designs that have enabled researchers to capture the spatial and temporal dynamics of numerous signaling molecules, including second messengers and signaling enzymes, with remarkable detail. Similarly, we discuss a number of genetically encoded biochemical perturbation techniques that are being used to manipulate the activity of various signaling molecules with far greater spatial and temporal selectivity than can be achieved using standard pharmacological or genetic techniques, focusing specifically on examples of chemically driven and light-inducible perturbation strategies. We then describe recent efforts to combine these diverse and powerful molecular tools into a unified platform that can be used to elucidate the molecular details of biological processes that may potentially extend well beyond the realm of signal transduction.
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Affiliation(s)
- Vedangi Sample
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA
| | - Sohum Mehta
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA
| | - Jin Zhang
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA
- Department of Oncology, The Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA
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16
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Akamatsu A, Wong HL, Fujiwara M, Okuda J, Nishide K, Uno K, Imai K, Umemura K, Kawasaki T, Kawano Y, Shimamoto K. An OsCEBiP/OsCERK1-OsRacGEF1-OsRac1 module is an essential early component of chitin-induced rice immunity. Cell Host Microbe 2014; 13:465-76. [PMID: 23601108 DOI: 10.1016/j.chom.2013.03.007] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 01/17/2013] [Accepted: 03/04/2013] [Indexed: 11/30/2022]
Abstract
OsCEBiP, a chitin-binding protein, and OsCERK1, a receptor-like kinase, are plasma membrane (PM) proteins that form a receptor complex essential for fungal chitin-driven immune responses in rice. The signaling events immediately following chitin perception are unclear. Investigating the spatiotemporal regulation of the rice small GTPase OsRac1, we find that chitin induces rapid activation of OsRac1 at the PM. Searching for OsRac1 interactors, we identified OsRacGEF1 as a guanine nucleotide exchange factor for OsRac1. OsRacGEF1 interacts with OsCERK1 and is activated when its C-terminal S549 is phosphorylated by the cytoplasmic domain of OsCERK1 in response to chitin. Activated OsRacGEF1 is required for chitin-driven immune responses and resistance to rice blast fungus infection. Further, a protein complex including OsCERK1 and OsRacGEF1 is transported from the endoplasmic reticulum to the PM. Collectively, our results suggest that OsCEBiP, OsCERK1, OsRacGEF1, and OsRac1 function as key components of a "defensome" critically engaged early during chitin-induced immunity.
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Affiliation(s)
- Akira Akamatsu
- Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
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17
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Azzarelli R, Pacary E, Garg R, Garcez P, van den Berg D, Riou P, Ridley AJ, Friedel RH, Parsons M, Guillemot F. An antagonistic interaction between PlexinB2 and Rnd3 controls RhoA activity and cortical neuron migration. Nat Commun 2014; 5:3405. [PMID: 24572910 PMCID: PMC3939360 DOI: 10.1038/ncomms4405] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 02/06/2014] [Indexed: 02/06/2023] Open
Abstract
A transcriptional programme initiated by the proneural factors Neurog2 and Ascl1 controls successive steps of neurogenesis in the embryonic cerebral cortex. Previous work has shown that proneural factors also confer a migratory behaviour to cortical neurons by inducing the expression of the small GTP-binding proteins such as Rnd2 and Rnd3. However, the directionality of radial migration suggests that migrating neurons also respond to extracellular signal-regulated pathways. Here we show that the Plexin B2 receptor interacts physically and functionally with Rnd3 and stimulates RhoA activity in migrating cortical neurons. Plexin B2 competes with p190RhoGAP for binding to Rnd3, thus blocking the Rnd3-mediated inhibition of RhoA and also recruits RhoGEFs to directly stimulate RhoA activity. Thus, an interaction between the cell-extrinsic Plexin signalling pathway and the cell-intrinsic Ascl1-Rnd3 pathway determines the level of RhoA activity appropriate for cortical neuron migration.
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Affiliation(s)
- Roberta Azzarelli
- Division of Molecular Neurobiology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
- Present address: Hutchison/MRC Research Centre, University of Cambridge, Box 197, Biomedical Campus, Cambridge CB2 0XZ, UK
| | - Emilie Pacary
- Division of Molecular Neurobiology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
- Present address: INSERM, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U862, Bordeaux F-33000, France or University Bordeaux, Neurocentre Magendie, Physiopathologie de la plasticité neuronale, U862, Bordeaux F-33000, France
| | - Ritu Garg
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Patricia Garcez
- Division of Molecular Neurobiology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
| | - Debbie van den Berg
- Division of Molecular Neurobiology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
| | - Philippe Riou
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
- Present address: Protein Phosphorylation Laboratory, Cancer Research UK, London Research Institute, Lincoln's Inn Fields Laboratories, London WC2A 3LY, UK
| | - Anne J. Ridley
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Roland H. Friedel
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, New York 10029, USA
| | - Maddy Parsons
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - François Guillemot
- Division of Molecular Neurobiology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
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18
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Leptin activates RhoA/ROCK pathway to induce cytoskeleton remodeling in nucleus pulposus cells. Int J Mol Sci 2014; 15:1176-88. [PMID: 24441571 PMCID: PMC3907862 DOI: 10.3390/ijms15011176] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 01/03/2014] [Accepted: 01/08/2014] [Indexed: 01/01/2023] Open
Abstract
Hyperleptinemia is implicated in obesity-associated lumbar disc degeneration. Nevertheless, the effect of leptin on the intracellular signaling of nucleus pulposus cells is not clear. The current study sought to delineate the possible involvement of the RhoA/ROCK pathway in leptin-mediated cytoskeleton reorganization in nucleus pulposus cells. Nucleus pulposus cells isolated from scoliosis patients were treated with 10 ng/mL of leptin. Fluorescent resonance energy transfer analysis was used to determine the activation of RhoA signaling in nucleus pulposus cells. The protein expression of LIMK1 and cofilin-2 were analyzed by western blot analysis. F-actin cytoskeletal reorganization was assessed by rhodamine-conjugated phalloidin immunoprecipitation. Leptin induced F-actin reorganization and stress fiber formation in nucleus pulposus cells, accompanied by localized RhoA activation and phosphorylation of LIMK1 and cofilin. The RhoA inhibitor C3 exoenzyme or the ROCK inhibitor Y-27632 potently attenuated the effects of leptin on F-actin reorganization and stress fiber formation. Both inhibitors also prevented leptin-induced phosphorylation of LIMK1 and cofilin-2. Our study demonstrated that leptin activated the RhoA/ROCK/LIMK/cofilin-2 cascade to induce cytoskeleton reorganization in nucleus pulposus cells. These findings may provide novel insights into the pathogenic mechanism of obesity-associated lumbar disc degeneration.
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19
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Oliveira AF, Yasuda R. Imaging the activity of Ras superfamily GTPase proteins in small subcellular compartments in neurons. Methods Mol Biol 2014; 1071:109-28. [PMID: 24052384 DOI: 10.1007/978-1-62703-622-1_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Resolving the spatiotemporal dynamics of intracellular signaling is important for understanding the molecular mechanisms of various cellular processes induced by extracellular signals. Two-photon fluorescence lifetime imaging microscopy (2pFLIM) in combination with a fluorescence resonance energy transfer (FRET)-based signaling sensors allows one to image signaling within small subcellular compartments, such as dendritic spines of neurons, with high sensitivity and spatiotemporal resolution. In this protocol, we describe the procedures and equipment required for imaging intracellular signaling activity, with a particular focus on signaling mediated by the Ras superfamily of small GTPase proteins.
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Affiliation(s)
- Ana F Oliveira
- Department of Neurobiology, Duke University Medical Center, Durham, NC, USA
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20
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Novel split-luciferase-based genetically encoded biosensors for noninvasive visualization of Rho GTPases. PLoS One 2013; 8:e62230. [PMID: 23614039 PMCID: PMC3627919 DOI: 10.1371/journal.pone.0062230] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 03/19/2013] [Indexed: 02/05/2023] Open
Abstract
Rho family GTPases are critical regulators of many important cellular processes and the dysregulation of their activities is implicated in a variety of human diseases including oncogenesis and propagation of malignancy. The traditional methods, such as “pull-down” or two-hybrid procedures, are poorly suited to dynamically evaluate the activity of Rho GTPases, especially in living mammalian cells. To provide a novel alternative approach to analyzing Rho GTPase-associated signaling pathways in vivo, we developed a series of bioluminescent biosensors based on the genetically engineered firefly luciferase. These split-luciferase-based biosensors enable non-invasive visualization and quantification of the activity of Rho GTPases in living subjects. The strategy is to reasonably split the gene of firefly luciferase protein into two inactive fragments and then respectively fuse the two fragments to Rho GTPase and the GTPase-binding domain (GBD) of the specific effector. Upon Rho GTPase interacting with the binding domain in a GTP-dependent manner, these two luciferase fragments are brought into close proximity, leading to luciferase reconstitution and photon production in the presence of the substrate. Using these bimolecular luminescence complementation (BiLC) biosensors, we successfully visualized and quantified the activities of the three best characterized Rho GTPases by measuring the luminescence in living cells. We also experimentally investigated the sensitivity of these Rho GTPase biosensors to upstream regulatory proteins and extracellular ligands without lysing cells and doing labor-intensive works. By virtue of the unique functional characteristics of bioluminescence imaging, the BiLC-based biosensors provide an enormous potential for in vivo imaging of Rho GTPase signaling pathways and high-throughput screening of therapeutic drugs targeted to Rho GTPases and (or) upstream molecules in the near future.
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21
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Aoki K, Kamioka Y, Matsuda M. Fluorescence resonance energy transfer imaging of cell signaling from in vitro to in vivo: basis of biosensor construction, live imaging, and image processing. Dev Growth Differ 2013; 55:515-22. [PMID: 23387795 DOI: 10.1111/dgd.12039] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/27/2012] [Accepted: 12/27/2012] [Indexed: 12/14/2022]
Abstract
The progress in imaging technology with fluorescent proteins has uncovered a wide range of biological processes in developmental biology. In particular, genetically-encoded biosensors based on the principle of fluorescence resonance energy transfer (FRET) have been used to visualize spatial and temporal dynamics of intracellular signaling in living cells. However, development of sensitive FRET biosensors and their application to developmental biology remain challenging tasks, which has prevented their widespread use in developmental biology. In this review, we first overview general procedures and tips of imaging with FRET biosensors. We then describe recent advances in FRET imaging - namely, the use of optimized backbones for intramolecular FRET biosensors and transposon-mediated gene transfer to generate stable cell lines and transgenic mice expressing FRET biosensors. Finally, we discuss future perspectives of FRET imaging in developmental biology.
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Affiliation(s)
- Kazuhiro Aoki
- Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan.
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22
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Burdisso JE, González Á, Arregui CO. PTP1B promotes focal complex maturation, lamellar persistence and directional migration. J Cell Sci 2013; 126:1820-31. [DOI: 10.1242/jcs.118828] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Previous findings established that ER-bound PTP1B targets peripheral cell-matrix adhesions and regulates positively cell adhesion to fibronectin. Here we show that PTP1B enhances focal complex lifetime at the lamellipodium base, delaying their turnover and facilitating α-actinin incorporation. We demonstrate the presence of catalytic PTP1BD181A-α-actinin complexes at focal complexes. Kymograph analysis reveals that PTP1B contributes to lamellar protrusion persistence and directional cell migration. Pull down and FRET analysis also shows that PTP1B is required for efficient integrin-dependent downregulation of RhoA and upregulation of Rac1 during spreading. A substrate trap strategy revealed that FAK/Src recruitment and Src activity were essential for the generation of PTP1B substrates in adhesions. PTP1B targets the negative regulatory site of Src (phosphotyrosine 529), paxillin and p130Cas at peripheral cell-matrix adhesions. We postulate that PTP1B modulates more than one pathway required for focal complex maturation and membrane protrusion, including α-actinin-mediated cytoskeletal anchorage, integrin-dependent activation of the FAK/Src signaling pathway, and RhoA and Rac1 GTPase activity. By doing so, PTP1B contributes to coordinate adhesion turnover, lamellar stability and directional cell migration.
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23
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Cheadle L, Biederer T. The novel synaptogenic protein Farp1 links postsynaptic cytoskeletal dynamics and transsynaptic organization. ACTA ACUST UNITED AC 2012; 199:985-1001. [PMID: 23209303 PMCID: PMC3518221 DOI: 10.1083/jcb.201205041] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Synaptic adhesion organizes synapses, yet the signaling pathways that drive and integrate synapse development remain incompletely understood. We screened for regulators of these processes by proteomically analyzing synaptic membranes lacking the synaptogenic adhesion molecule SynCAM 1. This identified FERM, Rho/ArhGEF, and Pleckstrin domain protein 1 (Farp1) as strongly reduced in SynCAM 1 knockout mice. Farp1 regulates dendritic filopodial dynamics in immature neurons, indicating roles in synapse formation. Later in development, Farp1 is postsynaptic and its 4.1 protein/ezrin/radixin/moesin (FERM) domain binds SynCAM 1, assembling a synaptic complex. Farp1 increases synapse number and modulates spine morphology, and SynCAM 1 requires Farp1 for promoting spines. In turn, SynCAM 1 loss reduces the ability of Farp1 to elevate spine density. Mechanistically, Farp1 activates the GTPase Rac1 in spines downstream of SynCAM 1 clustering, and promotes F-actin assembly. Farp1 furthermore triggers a retrograde signal regulating active zone composition via SynCAM 1. These results reveal a postsynaptic signaling pathway that engages transsynaptic interactions to coordinate synapse development.
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Affiliation(s)
- Lucas Cheadle
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
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24
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Lam AJ, St-Pierre F, Gong Y, Marshall JD, Cranfill PJ, Baird MA, McKeown MR, Wiedenmann J, Davidson MW, Schnitzer MJ, Tsien RY, Lin MZ. Improving FRET dynamic range with bright green and red fluorescent proteins. Nat Methods 2012; 9:1005-12. [PMID: 22961245 PMCID: PMC3461113 DOI: 10.1038/nmeth.2171] [Citation(s) in RCA: 561] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 08/10/2012] [Indexed: 11/18/2022]
Abstract
A variety of genetically encoded reporters use changes in fluorescence (or Förster) resonance energy transfer (FRET) to report on biochemical processes in living cells. The standard genetically encoded FRET pair consists of CFPs and YFPs, but many CFP-YFP reporters suffer from low FRET dynamic range, phototoxicity from the CFP excitation light and complex photokinetic events such as reversible photobleaching and photoconversion. We engineered two fluorescent proteins, Clover and mRuby2, which are the brightest green and red fluorescent proteins to date and have the highest Förster radius of any ratiometric FRET pair yet described. Replacement of CFP and YFP with these two proteins in reporters of kinase activity, small GTPase activity and transmembrane voltage significantly improves photostability, FRET dynamic range and emission ratio changes. These improvements enhance detection of transient biochemical events such as neuronal action-potential firing and RhoA activation in growth cones.
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Affiliation(s)
- Amy J Lam
- Department of Bioengineering, Stanford University, Stanford, California, USA
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25
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Zhu L, Fu Y. Analysis of in vivo ROP GTPase activity at the subcellular level by fluorescence resonance energy transfer microscopy. Methods Mol Biol 2012; 876:145-52. [PMID: 22576092 DOI: 10.1007/978-1-61779-809-2_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Proteins generally interact with some other proteins to achieve their cellular functions. Fluorescence resonance energy transfer (FRET) microscopy provides a powerful technique to elucidate such interactions in vivo. FRET occurs when two properly chosen fluorophores are sufficiently close (less than 10 nm). Aided by multiple colored fluorescent proteins (FPs), FRET microscopy has been widely used in live cells for detection of protein-protein interaction and in some cases protein activity in a real-time in vivo manner, which contributes to the understanding of the mechanisms for the regulation of many cellular activities, such as signal transduction pathways. Here, we describe a convenient and fast FRET imaging microscopy involving transiently expressed proteins fused with an FRET pair of fluorescent proteins (e.g., cyn fluorescent protein and yellow fluorescent protein). We describe an example of the FRET-based assay used to analyze ROP GTPase activity in live plant cells.
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Affiliation(s)
- Lei Zhu
- State Key Laboratory of Plant Physiology and Biochemistry, Department of Plant Sciences, College of Biological Sciences, China Agricultural University, Beijing, China
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26
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Marshall CB, Meiri D, Smith MJ, Mazhab-Jafari MT, Gasmi-Seabrook GMC, Rottapel R, Stambolic V, Ikura M. Probing the GTPase cycle with real-time NMR: GAP and GEF activities in cell extracts. Methods 2012; 57:473-85. [PMID: 22750304 DOI: 10.1016/j.ymeth.2012.06.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 06/19/2012] [Accepted: 06/21/2012] [Indexed: 01/18/2023] Open
Abstract
The Ras superfamily of small GTPases is a large family of switch-like proteins that control diverse cellular functions, and their deregulation is associated with multiple disease processes. When bound to GTP they adopt a conformation that interacts with effector proteins, whereas the GDP-bound state is generally biologically inactive. GTPase activating proteins (GAPs) promote hydrolysis of GTP, thus impeding the biological activity of GTPases, whereas guanine nucleotide exchange factors (GEFs) promote exchange of GDP for GTP and activate GTPase proteins. A number of methods have been developed to assay GTPase nucleotide hydrolysis and exchange, as well as the activity of GAPs and GEFs. The kinetics of these reactions are often studied with purified proteins and fluorescent nucleotide analogs, which have been shown to non-specifically impact hydrolysis and exchange. Most GAPs and GEFs are large multidomain proteins subject to complex regulation that is challenging to reconstitute in vitro. In cells, the activities of full-length GAPs or GEFs are typically assayed indirectly on the basis of nucleotide loading of the cognate GTPase, or by exploiting their interaction with effector proteins. Here, we describe a recently developed real-time NMR method to assay kinetics of nucleotide exchange and hydrolysis reactions by direct monitoring of nucleotide-dependent structural changes in an isotopically labeled GTPase. The unambiguous readout of this method makes it possible to precisely measure GAP and GEF activities from extracts of mammalian cells, enabling studies of their catalytic and regulatory mechanisms. We present examples of NMR-based assays of full-length GAPs and GEFs overexpressed in mammalian cells.
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Affiliation(s)
- Christopher B Marshall
- Ontario Cancer Institute and The Campbell Family Cancer Research Institute, University Health Network, 101 College Street, Rm 4-804 Toronto Medical Discovery Tower, MaRS Building, Toronto, ON, Canada M5G 1L7
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Abstract
A neuron is able to seamlessly respond to a number of signals, in a timely and specific manner. This process, of integrating multiple inputs, relays on the orchestration of intracellular events by signaling networks. The inherent complexity of signaling networks has made computational modeling a useful approach to understand their underlying regulatory principles. Recent advances in imaging techniques have highlighted the nonhomogeneous nature of intracellular signaling and its significant contribution to the maintenance of signal specificity. Computational modeling can provide mechanistic insight into the origins of these inhomogeneous distributions of signaling components and their role in the integrative capabilities of the neuron.
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Affiliation(s)
- Wendy C Wenderski
- Department of Pharmacology and System Therapeutics, Friedman Brain Institute, Systems Biology Center of New York, Mount Sinai School of Medicine, New York, New York, USA
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29
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Carlin LM, Evans R, Milewicz H, Fernandes L, Matthews DR, Perani M, Levitt J, Keppler MD, Monypenny J, Coolen T, Barber PR, Vojnovic B, Suhling K, Fraternali F, Ameer-Beg S, Parker PJ, Thomas NSB, Ng T. A targeted siRNA screen identifies regulators of Cdc42 activity at the natural killer cell immunological synapse. Sci Signal 2011; 4:ra81. [PMID: 22126964 DOI: 10.1126/scisignal.2001729] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Natural killer (NK) cells kill tumor cells and virally infected cells, and an effective NK cell response requires processes, such as motility, recognition, and directional secretion, that rely on cytoskeletal rearrangement. The Rho guanosine triphosphatase (GTPase) Cdc42 coordinates cytoskeletal reorganization downstream of many receptors. The Rho-related GTPase from plants 1 (ROP1) exhibits oscillatory activation behavior at the apical plasma membrane of growing pollen tubes; however, a similar oscillation in Rho GTPase activity has so far not been demonstrated in mammalian cells. We hypothesized that oscillations in Cdc42 activity might occur within NK cells as they interact with target cells. Through fluorescence lifetime imaging of a Cdc42 biosensor, we observed that in live NK cells forming immunological synapses with target cells, Cdc42 activity oscillated after exhibiting an initial increase. We used protein-protein interaction networks and structural databases to identify candidate proteins that controlled Cdc42 activity, leading to the design of a targeted short interfering RNA screen. The guanine nucleotide exchange factors RhoGEF6 and RhoGEF7 were necessary for Cdc42 activation within the NK cell immunological synapse. In addition, the kinase Akt and the p85α subunit of phosphoinositide 3-kinase (PI3K) were required for Cdc42 activation, the periodicity of the oscillation in Cdc42 activity, and the subsequent polarization of cytotoxic vesicles toward target cells. Given that PI3Ks are targets of tumor therapies, our findings suggest the need to monitor innate immune function during the course of targeted therapy against these enzymes.
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Affiliation(s)
- Leo M Carlin
- Richard Dimbleby Department of Cancer Research, King's College London, London SE1 1UL, UK
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Kardash E, Bandemer J, Raz E. Imaging protein activity in live embryos using fluorescence resonance energy transfer biosensors. Nat Protoc 2011; 6:1835-46. [DOI: 10.1038/nprot.2011.395] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Pacary E, Heng J, Azzarelli R, Riou P, Castro D, Lebel-Potter M, Parras C, Bell DM, Ridley AJ, Parsons M, Guillemot F. Proneural transcription factors regulate different steps of cortical neuron migration through Rnd-mediated inhibition of RhoA signaling. Neuron 2011; 69:1069-84. [PMID: 21435554 PMCID: PMC3383999 DOI: 10.1016/j.neuron.2011.02.018] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2011] [Indexed: 12/12/2022]
Abstract
Little is known of the intracellular machinery that controls the motility of newborn neurons. We have previously shown that the proneural protein Neurog2 promotes the migration of nascent cortical neurons by inducing the expression of the atypical Rho GTPase Rnd2. Here, we show that another proneural factor, Ascl1, promotes neuronal migration in the cortex through direct regulation of a second Rnd family member, Rnd3. Both Rnd2 and Rnd3 promote neuronal migration by inhibiting RhoA signaling, but they control distinct steps of the migratory process, multipolar to bipolar transition in the intermediate zone and locomotion in the cortical plate, respectively. Interestingly, these divergent functions directly result from the distinct subcellular distributions of the two Rnd proteins. Because Rnd proteins also regulate progenitor divisions and neurite outgrowth, we propose that proneural factors, through spatiotemporal regulation of Rnd proteins, integrate the process of neuronal migration with other events in the neurogenic program.
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Affiliation(s)
- Emilie Pacary
- Division of Molecular Neurobiology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
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32
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Tkachenko E, Sabouri-Ghomi M, Pertz O, Kim C, Gutierrez E, Machacek M, Groisman A, Danuser G, Ginsberg MH. Protein kinase A governs a RhoA-RhoGDI protrusion-retraction pacemaker in migrating cells. Nat Cell Biol 2011; 13:660-7. [PMID: 21572420 PMCID: PMC3746034 DOI: 10.1038/ncb2231] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 03/04/2011] [Indexed: 01/15/2023]
Abstract
The cyclical protrusion and retraction of the leading edge is a hallmark of many migrating cells involved in processes such as development, inflammation, and tumorigenesis. The molecular identity of signaling mechanisms that control these cycles has remained unknown. Here, we used live cell imaging of biosensors to monitor spontaneous morphodynamic and signaling activities, and employed correlative image analysis to examine the role of cAMP-activated Protein Kinase A (PKA) in protrusion regulation. PKA activity at the leading edge is closely synchronized with rapid protrusion and with the activity of RhoA. Ensuing PKA phosphorylation of RhoA and the resulting increased interaction between RhoA and RhoGDI establishes a negative feedback that controls the cycling of RhoA activity at the leading edge. Thus, cooperation between PKA, RhoA, and a RhoGDI forms a pacemaker that governs the morphodynamic behavior of migrating cells.
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Affiliation(s)
- Eugene Tkachenko
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, Mail Code 0726, La Jolla, California 92093, USA
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Liang J, Feng J, Wu WKK, Xiao J, Wu Z, Han D, Zhu Y, Qiu G. Leptin-mediated cytoskeletal remodeling in chondrocytes occurs via the RhoA/ROCK pathway. J Orthop Res 2011; 29:369-74. [PMID: 20886658 DOI: 10.1002/jor.21257] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Accepted: 08/16/2010] [Indexed: 02/04/2023]
Abstract
Leptin affects a number of cell signaling pathways, at present, the mechanism(s) by which leptin affects the cartilage cells in OA patient is not well understood. The current study seeks to elucidate whether leptin induces cytoskeletal remodeling in chondrocytes and the possible involvement of the RhoA/ROCK pathway and its downstream mediators in this process. Fluorescent resonance energy transfer (FRET) and western analysis were used to determine the activations of the key proteins in the RhoA/LIMK1/Cofilin pathway. Accompanying cytoskeletal remodeling was elucidated. Upon leptin stimulation, a substantial increase of RhoA activity localized at one end of the cell was observed from 2 to 30 min post-stimulation. The results of Western blot showed leptin significantly increased LIMK1 and cofilin-2 phosphorylation in a time-dependent manner with maximal stimulation attained 60 min and 24 h post-stimulation, respectively. Chondrocytes stimulated with leptin exhibited an epithelioid morphology with increased cellular spreading. F-actin in leptin-stimulated chondrocytes also showed more intense cytoplasmic staining with occasional localization along filamentous structures. The results indicate that leptin activates the RhoA/ROCK/LIMK/cofilin pathway, which results in cytoskeletal reorganization in chondrocytes. These findings provide novel evidence supporting the possible involvement of leptin and the RhoA pathway in the pathogenesis of OA.
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Affiliation(s)
- Jinqian Liang
- Department of Orthopaedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Beijing, China
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34
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Fruhwirth GO, Fernandes LP, Weitsman G, Patel G, Kelleher M, Lawler K, Brock A, Poland SP, Matthews DR, Kéri G, Barber PR, Vojnovic B, Ameer‐Beg SM, Coolen ACC, Fraternali F, Ng T. How Förster Resonance Energy Transfer Imaging Improves the Understanding of Protein Interaction Networks in Cancer Biology. Chemphyschem 2011; 12:442-61. [DOI: 10.1002/cphc.201000866] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 01/07/2011] [Indexed: 01/22/2023]
Affiliation(s)
- Gilbert O. Fruhwirth
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
- Comprehensive Cancer Imaging Centre, New Hunt's House, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Luis P. Fernandes
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Gregory Weitsman
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
| | - Gargi Patel
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
| | - Muireann Kelleher
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
| | - Katherine Lawler
- Comprehensive Cancer Imaging Centre, New Hunt's House, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Adrian Brock
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
| | - Simon P. Poland
- Comprehensive Cancer Imaging Centre, New Hunt's House, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Daniel R. Matthews
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
| | - György Kéri
- Vichem Chemie Research Ltd. Herman Ottó utca 15, Budapest, Hungary and Pathobiochemistry Research Group of Hungarian Academy of Science, Semmelweis University, Budapest, 1444 Bp 8. POB 260 (Hungary)
| | - Paul R. Barber
- Gray Institute for Radiation Oncology & Biology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ (UK)
| | - Borivoj Vojnovic
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
- Gray Institute for Radiation Oncology & Biology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ (UK)
| | - Simon M. Ameer‐Beg
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Anthony C. C. Coolen
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
- Department of Mathematics, King's College London, Strand Campus, London, WC2R 2LS (UK)
| | - Franca Fraternali
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Tony Ng
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
- Comprehensive Cancer Imaging Centre, New Hunt's House, Guy's Medical School Campus, NHH, SE1 1UL (UK)
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35
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Gao X, Zhang J. FRET-based activity biosensors to probe compartmentalized signaling. Chembiochem 2010; 11:147-51. [PMID: 20014085 DOI: 10.1002/cbic.200900594] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Xinxin Gao
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Carlin LM, Makrogianneli K, Keppler M, Fruhwirth GO, Ng T. Visualisation of signalling in immune cells. Methods Mol Biol 2010; 616:97-113. [PMID: 20379871 DOI: 10.1007/978-1-60761-461-6_7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Currently, a great number of approaches are employed in investigation of the immune system. These range from experiments in live animals and biochemical techniques to investigate whole organs or cell populations down to single cell and molecular techniques to look at dynamics in specific cell-cell interactions. It is the latter approach that this chapter focusses on. The use of Förster resonance energy transfer (FRET) techniques to probe protein-protein interactions that are involved in receptor signalling to the cytoskeleton in intact cells is now well established. Various FRET biosensors are available to visualise several critical cell processes, giving information about activity and the location of key signalling molecules. As a specific set of examples in this chapter, we have generated variants of the original Rho, Rac and Cdc42 "Raichu" probes and improved their fluorophore combination to make them suitable for FLIM. These were employed in a number of assays to determine signal dynamics in T and NK cells. Specific protocols of how to use these probes and technical notes are described.
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Affiliation(s)
- Leo M Carlin
- Cancer Studies Division/Randall Division of Cellular and Molecular Biophysics, Richard Dimbleby Department of Cancer Research, Guy's Medical School Campus, King's College London, London, UK
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37
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Picard M, Petrie RJ, Antoine-Bertrand J, Saint-Cyr-Proulx E, Villemure JF, Lamarche-Vane N. Spatial and temporal activation of the small GTPases RhoA and Rac1 by the netrin-1 receptor UNC5a during neurite outgrowth. Cell Signal 2009; 21:1961-73. [DOI: 10.1016/j.cellsig.2009.09.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 08/11/2009] [Accepted: 09/06/2009] [Indexed: 11/29/2022]
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38
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Aoki K, Matsuda M. Visualization of small GTPase activity with fluorescence resonance energy transfer-based biosensors. Nat Protoc 2009; 4:1623-31. [DOI: 10.1038/nprot.2009.175] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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39
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Kelleher MT, Fruhwirth G, Patel G, Ofo E, Festy F, Barber PR, Ameer-Beg SM, Vojnovic B, Gillett C, Coolen A, Kéri G, Ellis PA, Ng T. The potential of optical proteomic technologies to individualize prognosis and guide rational treatment for cancer patients. Target Oncol 2009; 4:235-52. [PMID: 19756916 PMCID: PMC2778706 DOI: 10.1007/s11523-009-0116-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2009] [Accepted: 08/28/2009] [Indexed: 12/21/2022]
Abstract
Genomics and proteomics will improve outcome prediction in cancer and have great potential to help in the discovery of unknown mechanisms of metastasis, ripe for therapeutic exploitation. Current methods of prognosis estimation rely on clinical data, anatomical staging and histopathological features. It is hoped that translational genomic and proteomic research will discriminate more accurately than is possible at present between patients with a good prognosis and those who carry a high risk of recurrence. Rational treatments, targeted to the specific molecular pathways of an individual's high-risk tumor, are at the core of tailored therapy. The aim of targeted oncology is to select the right patient for the right drug at precisely the right point in their cancer journey. Optical proteomics uses advanced optical imaging technologies to quantify the activity states of and associations between signaling proteins by measuring energy transfer between fluorophores attached to specific proteins. Förster resonance energy transfer (FRET) and fluorescence lifetime imaging microscopy (FLIM) assays are suitable for use in cell line models of cancer, fresh human tissues and formalin-fixed paraffin-embedded tissue (FFPE). In animal models, dynamic deep tissue FLIM/FRET imaging of cancer cells in vivo is now also feasible. Analysis of protein expression and post-translational modifications such as phosphorylation and ubiquitination can be performed in cell lines and are remarkably efficiently in cancer tissue samples using tissue microarrays (TMAs). FRET assays can be performed to quantify protein-protein interactions within FFPE tissue, far beyond the spatial resolution conventionally associated with light or confocal laser microscopy. Multivariate optical parameters can be correlated with disease relapse for individual patients. FRET-FLIM assays allow rapid screening of target modifiers using high content drug screens. Specific protein-protein interactions conferring a poor prognosis identified by high content tissue screening will be perturbed with targeted therapeutics. Future targeted drugs will be identified using high content/throughput drug screens that are based on multivariate proteomic assays. Response to therapy at a molecular level can be monitored using these assays while the patient receives treatment: utilizing re-biopsy tumor tissue samples in the neoadjuvant setting or by examining surrogate tissues. These technologies will prove to be both prognostic of risk for individuals when applied to tumor tissue at first diagnosis and predictive of response to specifically selected targeted anticancer drugs. Advanced optical assays have great potential to be translated into real-life benefit for cancer patients.
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Affiliation(s)
- Muireann T. Kelleher
- Richard Dimbleby Department of Cancer Research, Randall Division & Division of Cancer Studies, Kings College London, 2nd Floor, New Hunt House, Guy’s Medical School Campus, London, SE1 1UL UK
- Department Medical Oncology, Guy’s Hospital, London, SE1 9RT UK
| | - Gilbert Fruhwirth
- Richard Dimbleby Department of Cancer Research, Randall Division & Division of Cancer Studies, Kings College London, 2nd Floor, New Hunt House, Guy’s Medical School Campus, London, SE1 1UL UK
| | - Gargi Patel
- Richard Dimbleby Department of Cancer Research, Randall Division & Division of Cancer Studies, Kings College London, 2nd Floor, New Hunt House, Guy’s Medical School Campus, London, SE1 1UL UK
| | - Enyinnaya Ofo
- Richard Dimbleby Department of Cancer Research, Randall Division & Division of Cancer Studies, Kings College London, 2nd Floor, New Hunt House, Guy’s Medical School Campus, London, SE1 1UL UK
| | - Frederic Festy
- Biomaterial, Biomimetics & Biophotonics Research Group, King’s College London, London, UK
| | - Paul R. Barber
- Gray Institute for Radiation Oncology & Biology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ UK
| | - Simon M. Ameer-Beg
- Richard Dimbleby Department of Cancer Research, Randall Division & Division of Cancer Studies, Kings College London, 2nd Floor, New Hunt House, Guy’s Medical School Campus, London, SE1 1UL UK
| | - Borivoj Vojnovic
- Richard Dimbleby Department of Cancer Research, Randall Division & Division of Cancer Studies, Kings College London, 2nd Floor, New Hunt House, Guy’s Medical School Campus, London, SE1 1UL UK
- Gray Institute for Radiation Oncology & Biology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ UK
| | - Cheryl Gillett
- Guy’s & St Thomas’ Breast Tissue & Data Bank, King’s College London, Guy’s Hospital, London, SE1 9RT UK
| | - Anthony Coolen
- Department of Mathematics, King’s College London, Strand Campus, London, WC2R 2LS UK
| | - György Kéri
- Vichem Chemie Research Ltd., Herman Ottó utca 15, Budapest, Hungary
- Pathobiochemistry Research Group of Hungarian Academy of Science, Semmelweis University, Budapest, 1444 Bp 8. POB 260, Hungary
| | - Paul A. Ellis
- Department Medical Oncology, Guy’s Hospital, London, SE1 9RT UK
| | - Tony Ng
- Richard Dimbleby Department of Cancer Research, Randall Division & Division of Cancer Studies, Kings College London, 2nd Floor, New Hunt House, Guy’s Medical School Campus, London, SE1 1UL UK
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Hyun YM, Chung HL, McGrath JL, Waugh RE, Kim M. Activated integrin VLA-4 localizes to the lamellipodia and mediates T cell migration on VCAM-1. THE JOURNAL OF IMMUNOLOGY 2009; 183:359-69. [PMID: 19542447 DOI: 10.4049/jimmunol.0803388] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Lymphocyte migration from blood into lymphoid tissues or to sites of inflammation occurs through interactions between cell surface integrins and their ligands expressed on the vascular endothelium and the extracellular matrix. VLA-4 (alpha(4)beta(1)) is a key integrin in the effective trafficking of lymphocytes. Although it has been well established that integrins undergo functionally significant conformational changes to mediate cell adhesion, there is no mechanistic information that explains how these are dynamically and spatially regulated during lymphocyte polarization and migration. Using dynamic fluorescence resonance energy transfer analysis of a novel VLA-4 FRET sensor under total internal reflection fluorescence microscopy, we show that VLA-4 activation localizes to the lamellipodium in living cells. During T cell migration on VCAM-1, VLA-4 activation concurs with spatial redistribution of chemokine receptor and active Rap1 at the leading edge. Selective inhibition of the activated VLA-4 at the leading edge with a small molecule inhibitor is sufficient to block T cell migration. These data suggest that a subpopulation of activated VLA-4 is mainly localized to the leading edge of polarized human T cells and is critical for T cell migration on VCAM-1.
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Affiliation(s)
- Young-Min Hyun
- Department of Microbiology and Immunology, David H. Smith Center for Vaccine Biology and Immunology, University of Rochester, NY 14642, USA
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41
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Sann S, Wang Z, Brown H, Jin Y. Roles of endosomal trafficking in neurite outgrowth and guidance. Trends Cell Biol 2009; 19:317-24. [PMID: 19540123 DOI: 10.1016/j.tcb.2009.05.001] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 05/04/2009] [Accepted: 05/07/2009] [Indexed: 02/06/2023]
Abstract
Membrane trafficking and cargo delivery are essential for axonal and dendritic growth and guidance. Neurons have numerous diverse post-Golgi vesicles and recent advances have clarified their identity and regulation. Combinatorial approaches using in vivo imaging of 'intracellular cargo address labels' and functional perturbation have provided insight into these processes. In particular, the UNC-51 kinase regulates the trafficking of early endosomes and their axon guidance molecular cargos in several types of neurons in multiple organisms. Vesicular compartments bearing features of recycling endosomes, late endosomes or lysosomes also contribute to membrane addition and protein trafficking during neurite outgrowth and extension. New work shows that ubiquitylation of cargos and Rab effectors further specifies the trafficking routes of post-Golgi vesicles. These findings have begun to provide a more detailed view of the molecular mechanisms involved in neurite outgrowth and guidance. Additionally, high-resolution light microscopy imaging promises greater temporal and spatial understanding of vesicular exchange and maturation in neurons in the near future.
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Affiliation(s)
- Sharon Sann
- Division of Biological Sciences, University of California, San Diego, CA 92093, USA.
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42
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Sarkar P, Koushik SV, Vogel SS, Gryczynski I, Gryczynski Z. Photophysical properties of Cerulean and Venus fluorescent proteins. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:034047. [PMID: 19566339 PMCID: PMC2754229 DOI: 10.1117/1.3156842] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Cerulean and Venus are recently developed fluorescent proteins, often used as a donor-acceptor pair by researchers in Forster resonance energy transfer-based colocalization studies. We characterized the fluorescent properties of these two proteins in a broad spectral range (form ultraviolet to visible region). Excitation spectra, lifetimes, and polarization spectra show significant energy transfer from aromatic amino acids to the fluorescent protein chromophore. High steady-state anisotropy values and the lack of a fast component in anisotropy decays show that the fluorescent protein chromophore is rigidly fixed within the protein structure. Furthermore, we show that the chromophores are not accessible to external quenchers, such as acrylamide or potassium iodide (KI), allowing the removal of "unwanted" background in the environment with external quencher, while leaving the Cerulean/Venus fluorescence unchanged.
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Affiliation(s)
- Pabak Sarkar
- University of North Texas Health Science Center, Center for Commercialization of Fluorescent Technologies, 3500 Camp Bowie Boulevard, Fort Worth, Texas 76107, USA
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Mingle LA, Bonamy G, Barroso M, Liao G, Liu G. LPA-induced mutually exclusive subcellular localization of active RhoA and Arp2 mRNA revealed by sequential FRET and FISH. Histochem Cell Biol 2009; 132:47-58. [PMID: 19365637 DOI: 10.1007/s00418-009-0589-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2009] [Indexed: 11/26/2022]
Abstract
We previously demonstrated that mRNAs for the subunits of the Arp2/3 complex localize to protrusions in fibroblasts (Mingle et al. in J Cell Sci 118:2425-2433, 2005). However, the signaling pathway that regulates Arp2/3 complex mRNA localization remains unknown. In this study we have identified lysophosphatidic acid (LPA) as a potent inducer of Arp2 mRNA localization to protrusions in fibroblasts via the RhoA-ROCK pathway. As RhoA is known to be activated locally in the cells, we sought to understand how spatial activation of Rho affects Arp2 mRNA localization. By sequentially performing fluorescence resonance energy transfer (FRET) and fluorescence in situ hybridization (FISH), we have visualized active RhoA and Arp2 mRNA in the same cells. Upon LPA stimulation, approximately two times more cells than those in the serum-free medium showed mutually exclusive localization of active RhoA and Arp2 mRNA. These results demonstrate the importance of localized activation of Rho in Arp2 mRNA localization and provide new insights as to how Rho regulates Arp2/3 complex mRNA localization. To our best knowledge, this is the first report in which FRET and FISH are combined to detect localized protein activity and mRNA in the same cells. This method should be easily adopted for the detection of other fluorescence protein based biosensors and DNA/RNA in the same cells.
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Affiliation(s)
- Lisa A Mingle
- Center for Cell Biology and Cancer Research, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12208, USA
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44
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Integrating receptor signal inputs that influence small Rho GTPase activation dynamics at the immunological synapse. Mol Cell Biol 2009; 29:2997-3006. [PMID: 19307303 DOI: 10.1128/mcb.01008-08] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Rho GTPase Cdc42 regulates cytoskeletal changes at the immunological synapse (IS) that are critical to T-cell activation. By imaging fluorescent activity biosensors (Raichu) using fluorescence lifetime imaging microscopy, Cdc42 activation was shown to display kinetics that are conditional on the specific receptor input (through two IS-associated receptors, CD3 and beta1 integrin). CD3-triggered Cdc42 activity is dependent on the cyto-2 (NPIY) motif of the beta1 integrin cytoplasmic domain. Perturbations of the ezrin-radixin-moesin (ERM) function blocked CD3- and beta1-dependent increases in Cdc42 activity. Both IS-associated receptors probably lie on a serial molecular pathway and transduce signals through the ERM-dependent machinery that is responsible for the remodeling and stabilization of the synapse. Cdc42 activity is impaired in beta1 integrin-deficient T cells that form conjugates with antigen-presenting cells but is partially restored in the context of an antigen-specific synapse. This restoration of Cdc42 activity is due, at least in part, to the recruitment and activation of beta2 integrin.
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Abstract
Many eukaryotic cells can elicit intracellular signaling relays to produce pseudopodia and move up to the chemoattractant gradient (chemotaxis) or move randomly in the absence of extracellular stimuli and nutrients (random movement). A precise spatiotemporal regulation of Ras-GTPases, such as Ras and Rap, is crucial to induce pseudopodia formation and cellular adhesion during the chemotaxis and random movement. Here, we describe biochemical and real-time imaging methods for using Dictyostelium to understand the signaling events important for chemotaxis and random cell movement. The chapter includes (1) a biochemical method to assess Ras and Rap1 activation in response to chemoattractant, (2) an imaging method to detect endogenous Ras and Rap1 activation in moving cells, and (3) a simultaneous imaging method to decipher the precise order and localization of these signaling events. With a combination of powerful Dictyostelium genetics, these methods will facilitate to elucidate a dynamic activation of Ras proteins and their inter relay with other signaling molecules during chemotaxis and random movement.
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Affiliation(s)
- Atsuo T Sasaki
- Department of Systems Biology, Harvard Medical School and Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, MA, USA
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Yamazaki Y, Umeda K, Wada M, Nada S, Okada M, Tsukita S, Tsukita S. ZO-1- and ZO-2-dependent integration of myosin-2 to epithelial zonula adherens. Mol Biol Cell 2008; 19:3801-11. [PMID: 18596233 DOI: 10.1091/mbc.e08-04-0352] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
For the zonula adherens (ZA) to be established by linear arrangement of adherens junctions (AJs) in epithelial sheet cells, critical for the epithelial cell sheet formation and intercellular barrier function, myosin-2 is supposedly integrated into the ZA with the result of overlapping localization of E-cadherin/actin/myosin-2. Here, we immunofluorescently showed that myosin-2 failed to be integrated into the ZA in cultured epithelial-type ZO1(ko)/2(kd) Eph4 cells lacking ZO-1 and -2 (zonula occludens-1 and -2) by knockout and knockdown, respectively. Instead, a linearized but fragmented arrangement of AJs was formed in the way that it was positive for E-cadherin/actin, but negative for myosin-2 (designated prezonula-AJ). Transfection of full-length ZO-1 or ZO-2, or ZO-1 lacking its PDZ (PSD-95/discs large/zonula occludens-1)-1/2 domains (but not one lacking PDZ-1/2/3) into ZO1(ko)/2(kd) Eph4 cells restored the junctional integration of myosin-2 with prezonula-AJ to establish the ZA. Transfection of dominant-active RhoA or Rho-kinase (ROCK), as well as administration of lysophosphatidic acid or Y27632, which activates RhoA or inhibits ROCK, respectively, suggested that RhoA regulated the junctional integration of myosin-2 into ZA in a manner such that ROCK played a necessary but not-sufficient role. Fluorescence resonance energy transfer analyses revealed that spatiotemporal Rho-activation occurred in a ZO-1/2-dependent way to establish ZA from primordial forms in epithelial cells.
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Affiliation(s)
- Yuji Yamazaki
- Laboratory of Biological Science, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
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Prinz A, Reither G, Diskar M, Schultz C. Fluorescence and bioluminescence procedures for functional proteomics. Proteomics 2008; 8:1179-96. [DOI: 10.1002/pmic.200700802] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Takatsuka A, Yagi R, Koike M, Oneyama C, Nada S, Schmedt C, Uchiyama Y, Okada M. Ablation of Csk in neural crest lineages causes corneal anomaly by deregulating collagen fibril organization and cell motility. Dev Biol 2008; 315:474-88. [PMID: 18262517 DOI: 10.1016/j.ydbio.2008.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 12/29/2007] [Accepted: 01/04/2008] [Indexed: 12/25/2022]
Abstract
Src family kinases (SFKs) have been implicated in the regulation of cell motility. To verify their in vivo roles during development, we generated mutant mice in which Csk, a negative regulator of SFKs, was inactivated in neural crest lineages using the Protein zero promoter in a Cre-loxP system. Inactivation of Csk caused deformities in various tissues of neural crest origins, including facial dysplasia and corneal opacity. In the cornea, the stromal collagen fibril was disorganized and there was an overproduction of collagen 1a1 and several metalloproteases. The corneal endothelium failed to overlie the central region of the eye and the peripheral endothelium displayed a disorganized cytoskeleton. Corneal mesenchymal cells cultured from mutant mice showed attenuated cell motility. In these cells, p130 Crk-associated substrate (Cas) was hyperphosphorylated and markedly downregulated. The expression of a dominant negative Cas (Cas Delta SD) could suppress the cell motility defects. Fluorescence resonance energy transfer analysis revealed that activation of Rac1 and Cdc42 was depolarized in Csk-inactivated cells, which was restored by the expression of either Csk or Cas Delta SD. These results demonstrate that the SFKs/Csk circuit plays crucial roles in corneal development by controlling stromal organization and by ensuring cell motility via the Cas-Rac/Cdc42 pathways.
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Affiliation(s)
- Atsuko Takatsuka
- Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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Birkenfeld J, Nalbant P, Bohl BP, Pertz O, Hahn KM, Bokoch GM. GEF-H1 modulates localized RhoA activation during cytokinesis under the control of mitotic kinases. Dev Cell 2007; 12:699-712. [PMID: 17488622 PMCID: PMC1965589 DOI: 10.1016/j.devcel.2007.03.014] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 12/21/2006] [Accepted: 03/19/2007] [Indexed: 01/22/2023]
Abstract
Formation of the mitotic cleavage furrow is dependent upon both microtubules and activity of the small GTPase RhoA. GEF-H1 is a microtubule-regulated exchange factor that couples microtubule dynamics to RhoA activation. GEF-H1 localized to the mitotic apparatus in HeLa cells, particularly at the tips of cortical microtubules and the midbody, and perturbation of GEF-H1 function induced mitotic aberrations, including asymmetric furrowing, membrane blebbing, and impaired cytokinesis. The mitotic kinases Aurora A/B and Cdk1/Cyclin B phosphorylate GEF-H1, thereby inhibiting GEF-H1 catalytic activity. Dephosphorylation of GEF-H1 occurs just prior to cytokinesis, accompanied by GEF-H1-dependent GTP loading on RhoA. Using a live cell biosensor, we demonstrate distinct roles for GEF-H1 and Ect2 in regulating Rho activity in the cleavage furrow, with GEF-H1 catalyzing Rho activation in response to Ect2-dependent localization and initiation of cell cleavage. Our results identify a GEF-H1-dependent mechanism to modulate localized RhoA activation during cytokinesis under the control of mitotic kinases.
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Affiliation(s)
| | - Perihan Nalbant
- The Scripps Research Institute Departments of Immunology and Cell Biology 10550 N. Torrey Pines Road La Jolla, California 92037 Phone (858) 784-8217; Fax (858) 784-8218
| | - Benjamin P. Bohl
- The Scripps Research Institute Departments of Immunology and Cell Biology 10550 N. Torrey Pines Road La Jolla, California 92037 Phone (858) 784-8217; Fax (858) 784-8218
| | | | | | - Gary M. Bokoch
- The Scripps Research Institute Departments of Immunology and Cell Biology 10550 N. Torrey Pines Road La Jolla, California 92037 Phone (858) 784-8217; Fax (858) 784-8218
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