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Blake HL, Robinson D. QM/MM studies of contemporary and novel membrane raft fluorescent probes. Molecules 2014; 19:10230-41. [PMID: 25029071 PMCID: PMC6271554 DOI: 10.3390/molecules190710230] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 07/09/2014] [Accepted: 07/10/2014] [Indexed: 11/22/2022] Open
Abstract
We have studied a number of contemporary and novel membrane probes, selected for their structural similarity to membrane raft components, in order to properly anchor themselves within a sphingolipid/cholesterol rich region. A QM/MM approach was adopted in order to understand the structural and electrostatic influences of fluorescence emission shifts of the probes in different lipid and solvation environments. The proposed modifications to the membrane probes have shown encouraging data relating not only to emission shifts within the membrane, but also their ability to anchor within a membrane raft domain and the stability to internalization within a membrane system.
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Affiliation(s)
- Hannah L Blake
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - David Robinson
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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Yadav RB, Burgos P, Parker AW, Iadevaia V, Proud CG, Allen RA, O'Connell JP, Jeshtadi A, Stubbs CD, Botchway SW. mTOR direct interactions with Rheb-GTPase and raptor: sub-cellular localization using fluorescence lifetime imaging. BMC Cell Biol 2013; 14:3. [PMID: 23311891 PMCID: PMC3549280 DOI: 10.1186/1471-2121-14-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 12/21/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The mammalian target of rapamycin (mTOR) signalling pathway has a key role in cellular regulation and several diseases. While it is thought that Rheb GTPase regulates mTOR, acting immediately upstream, while raptor is immediately downstream of mTOR, direct interactions have yet to be verified in living cells, furthermore the localisation of Rheb has been reported to have only a cytoplasmic cellular localization. RESULTS In this study a cytoplasmic as well as a significant sub-cellular nuclear mTOR localization was shown , utilizing green and red fluorescent protein (GFP and DsRed) fusion and highly sensitive single photon counting fluorescence lifetime imaging microscopy (FLIM) of live cells. The interaction of the mTORC1 components Rheb, mTOR and raptor, tagged with EGFP/DsRed was determined using fluorescence energy transfer-FLIM. The excited-state lifetime of EGFP-mTOR of ~2400 ps was reduced by energy transfer to ~2200 ps in the cytoplasm and to 2000 ps in the nucleus when co-expressed with DsRed-Rheb, similar results being obtained for co-expressed EGFP-mTOR and DsRed-raptor. The localization and distribution of mTOR was modified by amino acid withdrawal and re-addition but not by rapamycin. CONCLUSIONS The results illustrate the power of GFP-technology combined with FRET-FLIM imaging in the study of the interaction of signalling components in living cells, here providing evidence for a direct physical interaction between mTOR and Rheb and between mTOR and raptor in living cells for the first time.
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Affiliation(s)
- Rahul B Yadav
- Central Laser Facility, STFC, Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, Oxon OX110QX, UK
| | - Pierre Burgos
- Central Laser Facility, STFC, Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, Oxon OX110QX, UK
| | - Anthony W Parker
- Central Laser Facility, STFC, Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, Oxon OX110QX, UK
| | - Valentina Iadevaia
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK
| | - Christopher G Proud
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK
| | | | | | - Ananya Jeshtadi
- School of Life Sciences, Headington Campus, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Christopher D Stubbs
- Central Laser Facility, STFC, Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, Oxon OX110QX, UK
| | - Stanley W Botchway
- Central Laser Facility, STFC, Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, Oxon OX110QX, UK
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Direct interaction of baculovirus capsid proteins VP39 and EXON0 with kinesin-1 in insect cells determined by fluorescence resonance energy transfer-fluorescence lifetime imaging microscopy. J Virol 2011; 86:844-53. [PMID: 22072745 DOI: 10.1128/jvi.06109-11] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Autographa californica multiple nucleopolyhedrovirus (AcMNPV) replicates in the nucleus of insect cells to produce nucleocapsids, which are transported from the nucleus to the plasma membrane for budding through GP64-enriched areas to form budded viruses. However, little is known about the anterograde trafficking of baculovirus nucleocapsids in insect cells. Preliminary confocal scanning laser microscopy studies showed that enhanced green fluorescent protein (EGFP)-tagged nucleocapsids and capsid proteins aligned and colocalized with the peripheral microtubules of virus-infected insect cells. A colchicine inhibition assay of virus-infected insect cells showed a significant reduction in budded virus production, providing further evidence for the involvement of microtubules and suggesting a possible role of kinesin in baculovirus anterograde trafficking. We investigated the interaction between AcMNPV nucleocapsids and kinesin-1 with fluorescence resonance energy transfer-fluorescence lifetime imaging microscopy (FRET-FLIM) and show for the first time that AcMNPV capsid proteins VP39 and EXON0, but not Orf1629, interact with the tetratricopeptide repeat (TPR) domain of kinesin. The excited-state fluorescence lifetime of EGFP fused to VP39 or EXON0 was quenched from 2.4 ± 1 ns to 2.1 ± 1 ns by monomeric fluorescent protein (mDsRed) fused to TPR (mDsRed-TPR). However, the excited-state fluorescence lifetime of an EGFP fusion of Orf1629 remained unquenched by mDsRed-TPR. These data indicate that kinesin-1 plays an important role in the anterograde trafficking of baculovirus in insect cells.
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Robinson D, Besley NA, O’Shea P, Hirst JD. Di-8-ANEPPS Emission Spectra in Phospholipid/Cholesterol Membranes: A Theoretical Study. J Phys Chem B 2011; 115:4160-7. [DOI: 10.1021/jp1111372] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- David Robinson
- School of Chemistry and ‡School of Biology, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - Nicholas A. Besley
- School of Chemistry and ‡School of Biology, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - Paul O’Shea
- School of Chemistry and ‡School of Biology, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - Jonathan D. Hirst
- School of Chemistry and ‡School of Biology, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
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Robinson D, Besley NA, O’Shea P, Hirst JD. Calculating the Fluorescence of 5-Hydroxytryptophan in Proteins. J Phys Chem B 2009; 113:14521-8. [DOI: 10.1021/jp9071108] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- David Robinson
- School of Chemistry, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom, and Cell Biophysics Group, School of Biology, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Nicholas A. Besley
- School of Chemistry, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom, and Cell Biophysics Group, School of Biology, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Paul O’Shea
- School of Chemistry, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom, and Cell Biophysics Group, School of Biology, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Jonathan D. Hirst
- School of Chemistry, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom, and Cell Biophysics Group, School of Biology, University Park, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
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Robinson D, Besley NA, Lunt EAM, O’Shea P, Hirst JD. Electronic Structure of 5-Hydroxyindole: From Gas Phase to Explicit Solvation. J Phys Chem B 2009; 113:2535-41. [DOI: 10.1021/jp808943d] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- David Robinson
- School of Chemistry, and Cell Biophysics Group, School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Nicholas A. Besley
- School of Chemistry, and Cell Biophysics Group, School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Elizabeth A. M. Lunt
- School of Chemistry, and Cell Biophysics Group, School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Paul O’Shea
- School of Chemistry, and Cell Biophysics Group, School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Jonathan D. Hirst
- School of Chemistry, and Cell Biophysics Group, School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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Botchway SW, Parker AW, Bisby RH, Crisostomo AG. Real-time cellular uptake of serotonin using fluorescence lifetime imaging with two-photon excitation. Microsc Res Tech 2008; 71:267-73. [DOI: 10.1002/jemt.20548] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Beatty KE, Liu JC, Xie F, Dieterich DC, Schuman EM, Wang Q, Tirrell DA. Fluorescence Visualization of Newly Synthesized Proteins in Mammalian Cells. Angew Chem Int Ed Engl 2006; 45:7364-7. [PMID: 17036290 DOI: 10.1002/anie.200602114] [Citation(s) in RCA: 250] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Kimberly E Beatty
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
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Bisby RH, Botchway SW, Dad S, Parker AW. Single- and multi-photon excited fluorescence from serotonin complexed with beta-cyclodextrin. Photochem Photobiol Sci 2006; 5:122-5. [PMID: 16395437 PMCID: PMC1934424 DOI: 10.1039/b508602g] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Accepted: 10/04/2005] [Indexed: 11/21/2022]
Abstract
The fluorescence of serotonin on binding with beta-cyclodextrin has been studied using both steady state and time-resolved methods. Steady state fluorescence intensity of serotonin at 340 nm showed approximately 30% increase in intensity on binding with K(A) approximately 60 dm(3) mol(-1) and the fluorescence lifetimes showed a corresponding increase. In contrast, the characteristic green fluorescence ('hyperluminescence') of serotonin observed upon multiphoton near-infrared excitation with sub-picosecond pulses was resolved into two lifetime components assigned to free and bound serotonin. The results are of interest in relation to selective imaging and detection of serotonin using the unusual hyperluminescence emission and in respect to recent determinations of serotonin by capillary electrophoresis in the presence of cyclodextrin. The results also suggest that hyperluminescence occurs from multiphoton excitation of a single isolated serotonin molecule.
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Affiliation(s)
- Roger H Bisby
- Biosciences Research Institute, University of Salford, Salford, UK.
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