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1.

001-es BibID:BIBFORM042481
035-os BibID:(scopus)40049093067 (wos)000253576200006
Első szerző:Fazekas Zsolt (biofizikus)
Cím:Two-sided fluorescence resonance energy transfer for assessing molecular interactions of up to three distinct species in confocal microscopy / Zsolt Fazekas, Miklós Petrás, Ákos Fábián, Zsuzsanna Pályi-Krekk, Péter Nagy, Sándor Damjanovich, György Vereb, János Szöllősi
Dátum:2008
ISSN:1552-4922 1552-4930
Megjegyzések:The role of the expression patterns of proteins involved in oncogenesis can be understood after characterizing their multimolecular interactions. Conventional FRET methods permit the analysis of interaction between two molecular species at the most, which necessitates the introduction of new approaches for studying multicomponent signaling complexes. Flow cytometric as well as microscopic donor (dbFRET) and acceptor (abFRET) photobleaching FRET measurements were performed to determine the association states of ErbB2, b1-integrin, and CD44 receptors. Based on consecutively applied abFRET and dbFRET methods (two-sided FRET), the relationship of b1-integrin?ErbB2 heteroassociation to ErbB2 homoassociation and of b1-integrin?ErbB2 heteroassociation to ErbB2?CD44 heteroassociation was studied by correlating pixel-by-pixel FRET values of the corresponding abFRET and dbFRET images in contour plots. Anticorrelation was observed between b1-integrin?ErbB2 heteroassociation and ErbB2 homoassociation on trastuzumab sensitive N87 and SK-BR-3 cells, while modest positive correlation was found between b1-integrin?ErbB2 and ErbB2?CD44 heteroassociationon trastuzumab resistant MKN-7 cells. The FRET efficiency values of b1-integrin?ErbB2 heteroassociation were markedly higher at the focal adhesion regions on attachedcells than those measured by flow cytometry on detached cells. In conclusion, we implemented an experimental set-up termed two-sided FRET for correlating two pairwiseinteractions of three arbitrarily chosen molecular species. On the basis of our results, we assume that the homoassociation state of ErbB2 is dynamically modulated by its interaction with b1-integrins.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
beta1-integrin
abFRET
analysis
Biophysics
Carcinoma
CD44
Cell Adhesion
Cell Adhesion Molecules
Cell Line
Cells
Cholera Toxin
Confocal
Confocal microscopy
cytology
dbFRET
Energy Transfer
ErbB2
Flow Cytometry
Fluorescein
Fluorescence
fluorescence microscopy
Fluorescence Resonance Energy Transfer
FRET
Hiv-1
Human
Hungary
Image Cytometry
Image Processing
Kinetics
Laser scanning confocal microscopy
Luminescence
methods
Microscopy
Photobleaching
Protein-protein interactions
Proteins
Receptor tyrosine kinase
Research
Signal Transduction
Software
therapy
Trastuzumab resistance
tsFRET
Tyrosine
egyetemen (Magyarországon) készült közlemény
Megjelenés:Cytometry Part A. - 73 : 3 (2008), p. 209-219. -
További szerzők:Petrás Miklós (1977-) (orvos) Fábián Ákos István (1982-) (aneszteziológus) Pályiné Krekk Zsuzsanna (1974-) (molekuláris biológus) Nagy Péter (1971-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus) Vereb György (1965-) (biofizikus, orvos) Szöllősi János (1953-) (biofizikus)
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DOI
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2.

001-es BibID:BIBFORM004665
035-os BibID:(scopus)0034033048 (wos)000086686100012
Első szerző:Hederer, Rosemarie A.
Cím:The CD45 tyrosine phosphatase regulates Campath-1H (CD52)-induced TCR-dependent signal transduction in human T cells / Hederer, R. A., Guntermann, C., Miller, N., Nagy, P., Szollosi, J., Damjanovich, S., Hale, G., Alexander, D. R.
Dátum:2000
Megjegyzések:Campath-1H, a humanized mAb undergoing clinical trials for treatment of leukemia, transplantation and autoimmune diseases, produces substantial lymphocyte depletion in vivo.The antibody binds to CD52, a highly glycosylated molecule attached to the membrane by a glycosylphosphatidylinositol anchor. Cross-linked Campath-1H is known to activate T cells in vitro. We have investigated the molecular basis for these effects by comparing the protein tyrosine phosphorylation signals induced by Campath-1H and the CD3 mAb OKT3 in primary T cells, and in CD45(+)TCR(+), CD45(-)TCR(+) and CD45(+)TCR(-) Jurkat subclones transfected with CD52. Our results show that Campath-1H triggers similar tyrosine phosphorylation events as OKT3 in both primary T cells and in the CD45(+)TCR(+) Jurkat sub-clone, albeit at quantitatively lower levels. However, no phospholipase C gamma 1 activation nor calcium signals were detected in response to CD52 ligation. The CD52-mediated induction of protein tyrosine phosphorylation was absolutely dependent upon the expression of both the TCR and the CD45 phosphotyrosine phosphatase at the cell surface. Cross-linking of Campath-1H was essential for signal transduction in all cells investigated. Fluorescence resonance energy transfer was used to demonstrate CD52 homo-association at the cell surface in Jurkat T cells in a TCR- and CD45-independent manner, and CD52-TCR association in CD45(+)TCR(+) cells. We propose a model to explain the activating effects of Campath-1H in which CD52 mAb cross-linking causes the trapping of TCR polypeptides within molecular complexes at the cell surface, thereby inducing signals via the TCR by a process which depends on the CD45-mediated regulation of the p56(lck) and p59(fyn) tyrosine kinases.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Antibodies, Monoclonal
Antibodies, Neoplasm
Antigens, CD
Antigens, CD45
Calcium
Calcium Signaling
Cells, Cultured
Comparative Study
Energy Transfer
enzymology
Fluorescence
genetics
Glycoproteins
Human
immunology
In Vitro
Inositol 1,4,5-Trisphosphate
Isoenzymes
Jurkat Cells
metabolism
Phospholipase C
physiology
Receptors, Antigen, T-Cell
Signal Transduction
Support, Non-U.S.Gov't
T-Lymphocytes
Transfection
Megjelenés:International Immunology. - 12 : 4 (2000), p. 505-516. -
További szerzők:Guntermann, Christine Miller, Nigel Nagy Péter (1971-) (biofizikus) Szöllősi János (1953-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus) Hale, Geoffrey Alexander, Denis R.
Internet cím:DOI
elektronikus változat
Borító:

3.

001-es BibID:BIBFORM023492
Első szerző:Matkó János (biológus)
Cím:Analysis of cell surface molecular distributions and cellular signaling by flow cytometry / J. Matkó, L. Mátyus, J. Szöllősi, L. Bene, A. Jenei, P. Nagy, A. Bodnár, S. Damjanovich
Dátum:1994
ISSN:1053-0509
Megjegyzések:Flow cytometry is a fast analysis and separation method for large cell populations, based on collection and processing of optical signals gained on a cell-by-cell basis. These optical signals are scattered light and fluorescence. Owing to its unique potential ofStatistical data analysis and sensitive monitoring of (micro)heterogeneities in large cell populations, flow cytometry?in combination with microscopic imaging techniques?is a powerful tool to study molecular details of cellular signal transduction processes as well. The method also has a widespread clinical application, mostly in analysis of lymphocyte subpopulations for diagnostic (or research) purposes in diseases related to the immune system. A special application of flow cytometry is the mapping of molecular interactions (proximity relationships between membrane proteins) at the cell surface, on a cell-by-cell basis. We developed two approaches to study such questions; both are based ondistance-dependent quenching of excited state fluorophores (donors) by fluorescent or dark (nitroxide radical) acceptors via Förstertype dipole-dipole resonance energy transfer (FRET) and long-range electron transfer (LRET) mechanisms, respectively. A critical evaluation of these methods using donor- or acceptor-conjugated monoclonal antibodies (or their Fab fragments) to select the appropriate cell surface receptor or antigen will be presented in comparison with other approaches for similar purposes. The applicability of FRET and LRET for two-dimensional antigen mapping as well as for detection of conformational changes in extracellular domains of membrane-bound proteins is discussed and illustrated by examples of several lymphoma cell lines. Another special application area of flow cytometry is the analysis of different aspects of cellular signal transduction, e.g., changes of intracellular ion (Ca2+, H+, Na+) concentrations, regulation of ion channel activities, or more complex physiological responses of cell to external stimuli via correlated fluorescence and scatter signal analysis, on a cell-by-cell basis. This way different signaling events such as changes in membrane permeability, membrane potential, cell size and shape, ion distribution, cell density, chromatin structure, etc., can be easily and quickly monitored over large cell populations with the advantage of revealing microheterogeneities in the cellular responses. Flow cytometry also offers the possibility to follow the kinetics of slow (minute- and hour-scale) biological processes in cell populations. These applications are illustrated by the example of complex flow cytometric analysis of signaling in extracellular ATP-triggered apoptosis (programmed cell death) of murine thymic lymphocytes.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
fluorescence
flow cytometry
energy transfer
electron transfer
protein-protein interaction
signal transduction
egyetemen (Magyarországon) készült közlemény
Megjelenés:Journal Of Fluorescence 4 : 4 (1994), p. 303-314. -
További szerzők:Mátyus László (1956-) (biofizikus) Szöllősi János (1953-) (biofizikus) Bene László (1963-) (biofizikus) Jenei Attila (1966-) (biofizikus) Nagy Péter (1971-) (biofizikus) Dóczy-Bodnár Andrea (1970-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus)
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DOI
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4.

001-es BibID:BIBFORM006044
Első szerző:Matkó János (biológus)
Cím:Biphasic effect of extracellular ATP on the membrane potential of mouse thymocytes / Matko J., Nagy P., Panyi G., Vereb G. Jr., Bene L., Matyus L., Damjanovich S.
Dátum:1993
Megjegyzések:Extracellular ATP induced changes in the membrane potential of thymocytes from BALB/c mice were analyzed. At concentrations below 0.1 mM, ATP hyperpolarizes the cell membrane on the time scale of development of the Ca(2+)-signal. After a longer time hyperpolarization turns to depolarization. ATP concentrations higher than 0.5 mM caused rapid depolarization without previous hyperpolarization. Verapamil, quinine or the absence of extracellular Ca2+ blocked the hyperpolarization by ATP. In Na(+)-free medium the magnitude of depolarization decreased. Our data suggest a contribution of Ca(2+)-activated K+ channels to the hyperpolarizing effect of ATP at lower concentrations. The direction of membrane potential changes is determined presumably by a sensitive balance of ATP-receptor mediated Ca(2+)- and Na(+)-influx and the Ca(2+)-activated K(+)-channel activity.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Adenosine Triphosphate
Animal
Biophysics
Cell Membrane
cytology
drug effects
Hungary
Kinetics
Membrane Potentials
Mice
Mice,Inbred BALB C
pharmacology
physiology
Quinine
Support,Non-U.S.Gov't
Thymus Gland
Verapamil
Megjelenés:Biochemical and Biophysical Research Communications. - 191 : 2 (1993), p. 378-384. -
További szerzők:Nagy Péter (1971-) (biofizikus) Panyi György (1966-) (biofizikus) Vereb György (1965-) (biofizikus, orvos) Bene László (1963-) (biofizikus) Mátyus László (1956-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus)
Internet cím:elektronikus változat
DOI
Intézményi repozitóriumban (DEA) tárolt változa
Borító:

5.

001-es BibID:BIBFORM065104
035-os BibID:(WoS)000380371400013 (Scopus)84993661764
Első szerző:Mocsár Gábor (biofizikus)
Cím:MHC I expression regulates co-clustering and mobility of interleukin-2 and -15 receptors in T cells / G. Mocsár, J. Volkó, D. Rönnlund, J. Widengren, P. Nagy, J. Szöllősi, K. Tóth, C. K. Goldman, S. Damjanovich, T. A. Waldmann, A. Bodnár, G. Vámosi
Dátum:2016
ISSN:0006-3495
Megjegyzések:MHC glycoproteins form supramolecular clusters with interleukin-2 and -15 receptors in lipid rafts of T cells.The role of highly expressed MHC I in maintaining these clusters is unknown. We knocked down MHC I inFT7.10 human T cells, and studied protein clustering at two hierarchic levels: molecular aggregations andmobility by FRET and fluorescence correlation spectroscopy, and segregation into larger domains orsuperclusters by superresolution STED microscopy. FCS based molecular brightness analysis revealed thatthe studied molecules diffused as tight aggregates of several proteins of a kind. Knockdown reduced thenumber of MHC I containing molecular aggregates and their average MHC I content, and decreased theheteroassociation of MHC I with IL-2R?/IL-15R?. The mobility of not only MHC I but also that of IL-2R?/IL-15R? increased, corroborating the general size decrease of tight aggregates. A multifaceted analysis of STEDimages revealed that the diameter of MHC I superclusters diminished from 400-600 to 200-300 nm, whereasthose of IL-2R?/IL-15R? hardly changed. MHC I and IL-2R?/IL-15R? colocalized with GM1 gangliosiderichlipid rafts, but MHC I clusters retracted to smaller subsets of GM1- and IL-2R?/IL-15R?-rich areas uponknockdown. Our results prove that changes in expression level may significantly alter the organization andmobility of interacting membrane proteins.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Biophysical Journal. - 111 : 1 (2016), p. 100-112. -
További szerzők:Volkó Julianna (1983-) (biotechnológus) Rönnlund, Daniel Widengren, Jerker Nagy Péter (1971-) (biofizikus) Szöllősi János (1953-) (biofizikus) Tóth Katalin (Heidelberg) Goldman, Caroline K. Damjanovich Sándor (1936-2017) (biofizikus) Waldmann, Thomas A. Dóczy-Bodnár Andrea (1970-) (biofizikus) Vámosi György (1967-) (biofizikus)
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DOI
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Borító:

6.

001-es BibID:BIBFORM046282
Első szerző:Nagy Péter (biofizikus)
Cím:Ion-channel activities regulate transmembrane signaling in thymocyte apoptosis and T-cell activation / Nagy Péter, Panyi György, Jenei Attila, Bene László, Gáspár Rezső, Matkó János, Damjanovich Sándor
Dátum:1995
ISSN:0165-2478
Megjegyzések:Several examples have shown that plasma membrane ion channels (e.g., Ca2+ and K+ channels) make an important contribution to lymphocyte activation or thymocyte apoptosis. Here we report on the importance of these ion channels in the sensitivity or resistance of lymphoid cells to extracellular ATP-induced apoptosis. Thymocytes of Balb/c mice responded to extracellular ATP (ATPex) sensitively, with an immediate increase in the intracellular calcium level and later with an increased membrane permeability to low MW markers. Mature (medullary) thymocytes showed a higher sensitivity than did cortical thymocytes. Three human lymphoma cell lines, including SUPT13, a cell line reported to be sensitive to TcR/CD3 activation-induced apoptosis, showed a high resistance to ATPex action. These observations suggest that maturation/differentiation state-dependent activity or disappearance of early ATP-receptor operated signaling systems (including ion channels) are critical for the cells in developing towards apoptosis. Using the patch-clamp technique we demonstrated that bretylium tosylate (a particular K(+)-channel blocker) known as inhibitor of T-lymphocyte proliferation also influences the single-channel properties of voltage-gated K+ channels through depressing whole-cell K+ currents. This finding is yet another example underlying the importance of K+ channel activity in T-lymphocyte proliferation.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Immunology Letters. - 44 : 2-3 (1995), p. 91-95. -
További szerzők:Panyi György (1966-) (biofizikus) Jenei Attila (1966-) (biofizikus) Bene László (1963-) (biofizikus) Gáspár Rezső (1921-2001) (fizikus) Matkó János (1952-) (biológus) Damjanovich Sándor (1936-2017) (biofizikus)
Pályázati támogatás:T14655
OTKA
F13335
OTKA
T6163
OTKA
T6221
OTKA
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DOI
Intézményi repozitóriumban (DEA) tárolt változat
Borító:

7.

001-es BibID:BIBFORM059574
Első szerző:Nagy Péter (biofizikus)
Cím:Measuring FRET in flow cytometry and microscopy / Péter Nagy, György Vereb, Sándor Damjanovich, László Mátyus, János Szöllősi
Dátum:2006
Tárgyszavak:Orvostudományok Elméleti orvostudományok könyvfejezet
Flow Cytometry
Microscopy
Megjelenés:Current Protocols in Cytometry. - p. 1-13.
További szerzők:Vereb György (1965-) (biofizikus, orvos) Damjanovich Sándor (1936-2017) (biofizikus) Mátyus László (1956-) (biofizikus) Szöllősi János (1953-) (biofizikus)
Pályázati támogatás:OTKA-F049025
OTKA
OTKA-T043509
OTKA
OTKA-T043061
OTKA
OTKA-T037831
OTKA
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
Borító:

8.

001-es BibID:BIBFORM044572
Első szerző:Nagy Péter (biofizikus)
Cím:Activation-dependent clustering of the erbB2 receptor tyrosine kinase detected by scanning near-field optical microscopy / Péter Nagy, Attila Jenei, Achim K. Kirsch, János Szöllősi, Sándor Damjanovich, Thomas M. Jovin
Dátum:1999
Megjegyzések:ErbB2 (HER2, Neu), a member of the epidermal growth factor (EGF) receptor tyrosine kinase family, is often overexpressed in breast cancer and other malignancies. ErbB2 homodimerizes but also presents as a common auxiliary subunit of the EGF and heregulin receptors (erbB1 or EGFR; and erbB3-4, respectively), with which it heteroassociates. ErbB2 is generally regarded as an orphan (ligand-less) receptor with a very potent kinase domain activated either via its associated partners or constitutively as a consequence of discrete mutations. It follows that the extent and regulation of its cell surface interactions are of central importance. We have studied the large-scale association pattern of erbB2 in quiescent and activated cells labeled with fluorescent anti-erbB2 monoclonal antibodies using scanning near-field optical microscopy (SNOM). ErbB2 was found to be concentrated in irregular membrane patches with a mean diameter of approx. 0.5 microm in nonactivated SKBR3 and MDA453 human breast tumor cells. The average number of erbB2 proteins in a single cluster on nonactivated SKBR3 cells was about 10(3). Activation of SKBR3 cells with EGF, heregulin as well as a partially agonistic anti-erbB2 monoclonal antibody led to an increase in the mean cluster diameter to 0.6-0.9 microm, irrespective of the ligand. The EGF-induced increase in the erbB2 cluster size was inhibited by the EGFR-specific tyrosine kinase inhibitor PD153035. The average size of erbB2 clusters on the erbB2-transfected line of CHO cells (CB2) was similar to that of activated SKBR3 cells, a finding correlated with the increased base-line tyrosine phosphorylation of erbB2 in cells expressing only erbB2. We conclude that an increase in cluster size may constitute a general phenomenon in the activation of erbB2.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Animal
antagonists and inhibitors
chemistry
Cho Cells
Enzyme Activation
Enzyme Inhibitors
Hamsters
Human
metabolism
methods
Microscopy
Microscopy, Atomic Force
Microscopy, Confocal
pharmacology
Quinazolines
Receptor Protein-Tyrosine Kinases
Receptor, Epidermal Growth Factor
Receptor, erbB-2
Support, Non-U.S.Gov't
Tumor Cells, Cultured
egyetemen (Magyarországon) készült közlemény
Megjelenés:Journal of Cell Science 112 : Pt 11 (1999), p. 1733-1741. -
További szerzők:Jenei Attila (1966-) (biofizikus) Kirsch, Achim K. Szöllősi János (1953-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus) Jovin, Thomas M.
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
Szerző által megadott URL
Borító:

9.

001-es BibID:BIBFORM004878
035-os BibID:(scopus)26444586247 (wos)000232299300007
Első szerző:Nagy Péter (biofizikus)
Cím:Novel calibration method for flow cytometric fluorescence resonance energy transfer measurements between visible fluorescent proteins / Nagy, P., Bene, L., Hyun, W. C., Vereb, G., Braun, M., Antz, C., Paysan, J., Damjanovich, S., Park, J. W., Szollosi, J.
Dátum:2005
ISSN:1552-4922
Megjegyzések:The combination of fluorescence resonance energy transfer (FRET) and flow cytometry offers a statistically firm approach to study protein associations. Fusing green fluorescent protein (GFP) to a studied protein usually does not disturb the normal function of a protein, but quantitation of FRET efficiency calculated between GFP derivatives poses a problem in flow cytometry. METHODS: We generated chimeras in which cyan fluorescent protein (CFP) was separated by amino acid linkers of different sizes from yellow fluorescent protein (YFP) and used them to calibrate the cell-by-cell flow cytometric FRET measurements carried out on two different dual-laser flow cytometers. Then, CFP-Kip1 was coexpressed in yeast cells with YFP and cyclin-dependent kinase-2 (Cdk2) and served as a positive control for FRET measurements, and CFP-Kip1 coexpressed with a random peptide fused to YFP was the negative control. RESULTS: We measured donor, direct, and sensitized acceptor fluorescence intensities and developed a novel way to calculate a factor (alpha) that characterized the fluorescence intensity of acceptor molecules relative to the same number of excited donor molecules, which is essential for quantifying FRET efficiency. This was achieved by calculating FRET efficiency in two different ways and minimizing the squared difference between the two results by changing alpha. Our method reliably detected the association of Cdk2 with its inhibitor, Kip1, whereas the nonspecific FRET efficiency between Cdk2 and a random peptide was negligible. We identified and sorted subpopulations of yeast cells showing interaction between the studied proteins. CONCLUSIONS: We have described a straightforward novel calibration method to accurately quantitate FRET efficiency between GFP derivatives in flow cytometry
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
analysis
Biophysics
Calibration
Cells
chemistry
Cyclin-Dependent Kinase 2
Cyclin-Dependent Kinase Inhibitor p27
Energy Transfer
Flow Cytometry
Fluorescence
Fluorescence Resonance Energy Transfer
Hungary
metabolism
methods
Protein Binding
Proteins
Research
Saccharomyces cerevisiae
Saccharomyces cerevisiae Proteins
Support
Megjelenés:Cytometry. Part A. - 67 : 2 (2005), p. 86-96. -
További szerzők:Bene László (1963-) (biofizikus) Hyun, William C. Vereb György (1965-) (biofizikus, orvos) Braun, Manuel Antz, Christof Paysan, Jacques Damjanovich Sándor (1936-2017) (biofizikus) Park, John W. Szöllősi János (1953-) (biofizikus)
Internet cím:elektronikus változat
DOI
Borító:

10.

001-es BibID:BIBFORM005090
Első szerző:Nagy Péter (biofizikus)
Cím:ICAM-1 inhibits the homocluster formation of MHC-I in colon carcinoma cells / Nagy, P., Vamosi, G., Damjanovich, S., Damjanovich, L.
Dátum:2006
ISSN:006-291X (Print)
Megjegyzések:ICAM-1 and MHC-I proteins play fundamental roles in antigen presentation, activation of T lymphocytes, and immune responses against tumor cells. Both of them participate in the formation of lipid raft-associated membrane protein clusters. We found significant colocalization between ICAM-1 and MHC-I at the level of large-scale associations. We combined RNA interference and fluorescence resonance energy transfer studies to show that ICAM-1 promotes the partial disassembly of MHC-I homoclusters on LS-174T colon carcinoma cells. Interferon-gamma (IFN-gamma) treatment induced an increase in the expression of MHC-I and ICAM-1 resulting in decreased MHC-I homoassociation. Small interfering RNAs directed against ICAM-1 restored the homoassociation of MHC-I without influencing the expression level of MHC-I by eliminating ICAM-1 molecules interspersed in MHC-I clusters. We conclude that the composition of membrane protein clusters is dynamically altered in response to both physiological and experimentally elicited changes in antigen expression levels.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Antigen Presentation
Antigens
Biophysics
Carcinoma
Cell Line, Tumor
Cells
Colonic Neoplasms
Energy Transfer
Fluorescence
Fluorescence Resonance Energy Transfer
genetics
Histocompatibility Antigens
Histocompatibility Antigens Class I
Humans
Hungary
Intercellular Adhesion Molecule-1
Lymphocytes
metabolism
Protein Binding
Proteins
Research
RNA,Small Interfering
Support
T-Lymphocytes
Megjelenés:Biochemical and Biophysical Research Communications. - 347 : 3 (2006), p. 758-763. -
További szerzők:Vámosi György (1967-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus) Damjanovich László (1960-) (általános sebész)
Internet cím:DOI
elektronikus változat
Borító:

11.

001-es BibID:BIBFORM004713
035-os BibID:(scopus)0037112996 (wos)000179662300005
Első szerző:Nagy Péter (biofizikus)
Cím:Lipid rafts and the local density of ErbB proteins influence the biological role of homo- and heteroassociations of ErbB2 / Nagy, P., Vereb, G., Sebestyen, Z., Horvath, G., Lockett, S. J., Damjanovich, S., Park, J. W., Jovin, T. M., Szollosi, J.
Dátum:2002
Megjegyzések:The ErbB family of transmembrane receptor tyrosine kinases plays an important role in the pathogenesis of many cancers. The four members of the family, ErbB1-4, form various homo- and heterodimers during the course of signal transduction. A second hierarchical level of molecular associations involving 10(2)-10(3) molecules, termed large-scale clustering, has also been identified, but the regulatory factors and biological consequences of such structures have not been systematically evaluated. In this report, we describe the states of association of ErbB2 and their relationship to local ErbB3 density and lipid rafts based on quantitative fluorescence microscopy of SKBR-3 breast cancer cells. Clusters of ErbB2 colocalized with lipid rafts identified by the GM1-binding B subunit of cholera toxin. Pixel-by-pixel analysis of fluorescence resonance energy transfer between labeled antibodies indicated that the homoassociation (homodimerization) of ErbB2 was proportional to the local density of ErbB2 and inversely proportional to that of ErbB3 and of the raft-specific lipid GM1. Crosslinking lipid rafts with the B subunit of cholera toxin caused dissociation of the rafts and ErbB2 clusters, an effect that was independent of the cytoskeletal anchoring of ErbB2. Crosslinking also decreased ErbB2-ErbB3 heteroassociation and the EGF- and heregulin-induced tyrosine phosphorylation of Shc. When cells were treated with the anti-ErbB2 monoclonal antibody 4D5 (parent murine version of Trastuzumab used in the immunotherapy of breast cancer), internalization of the antibody was inhibited by crosslinking of lipid rafts, but the antiproliferative activity of 4D5 was retained and even enhanced. We conclude that local densities of ErbB2 and ErbB3, as well as the lipid environment profoundly influence the association properties and biological function of ErbB2.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Adaptor Proteins,Signal Transducing
Adaptor Proteins,Vesicular Transport
analysis
Antibodies
Antibodies,Monoclonal
Antineoplastic Agents
Biophysics
Breast Neoplasms
Carcinoma
Cell Division
Cell Membrane
Cell Transformation,Neoplastic
Cells
Cholera Toxin
Cytoskeletal Proteins
Dimerization
drug effects
Energy Transfer
Eukaryotic Cells
Female
Fluorescence
Fluorescence Resonance Energy Transfer
genetics
Humans
Hungary
Macromolecular Substances
Membrane Microdomains
metabolism
Microscopy
Oncogene Proteins v-erbB
pharmacology
Phosphorylation
physiology
Protein Binding
Protein-Tyrosine Kinases
Proteins
Receptor Protein-Tyrosine Kinases
Receptor,erbB-2
Receptor,erbB-3
Receptors,Cell Surface
Research
Signal Transduction
Support
Tumor Cells,Cultured
ultrastructure
Megjelenés:Journal of Cell Science. - 115 : Pt 22 (2002), p. 4251-4262. -
További szerzők:Vereb György (1965-) (biofizikus, orvos) Sebestyén Zsolt Horváth Gábor (1974-) (biofizikus) Lockett, Steven J. Damjanovich Sándor (1936-2017) (biofizikus) Park, John W. Jovin, Thomas M. Szöllősi János (1953-) (biofizikus)
Internet cím:elektronikus változat
elektronikus változat
Borító:

12.

001-es BibID:BIBFORM004687
Első szerző:Nagy Péter (biofizikus)
Cím:Cell fusion experiments reveal distinctly different association characteristics of cell-surface receptors / Péter Nagy, László Mátyus, Attila Jenei, György Panyi, Sándor Varga, János Matkó, János Szöllősi, Rezső Gáspár, Thomas M. Jovin, Sándor Damjanovich
Dátum:2001
Megjegyzések:The existence of small- and large-scale membrane protein clusters, containing dimers, oligomers and hundreds of proteins, respectively, has become widely accepted. However, it is largely unknown whether the internal structure of these formations is dynamic or static. Cell fusion was used to perturb the distribution of existing membrane protein clusters, and to investigate their mobility and associations. Scanning near-field optical microscopy, confocal and electron microscopy were applied to detect the exchange of proteins between large-scale protein clusters, whereas photobleaching fluorescence energy transfer was used to image the redistribution of existing small-scale membrane protein clusters. Large-scale clusters of major histocompatibility complex (MHC)-I exchanged proteins with each other and with MHC-II clusters. Similarly to MHC-I, large-scale MHC-II clusters were also dynamic. Exchange of components between small-scale protein clusters was not universal: intermixing did not take place in the case of MHC-II homoclusters; however, it was observed for homoclusters of MHC-I and for heteroclusters of MHC-I and MHC-II. These processes required a fluid state of the plasma membrane, and did not depend on endocytosis-mediated recycling of proteins. The redistribution of large-scale MHC-I clusters precedes the intermixing of small-scale clusters of MHC-I indicating a hierarchy in protein association. Investigation of a set of other proteins (alpha subunit of the interleukin 2 receptor, CD48 and transferrin receptor) suggested that a large-scale protein cluster usually exchanges components with the same type of clusters. These results offer new insight into processes requiring time-dependent changes in membrane protein interactions.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Biophysics
Cell Fusion
Cell Line
Cell Membrane
chemistry
Dyes
Energy Transfer
Fluorescence
Fluorescent Dyes
Gold Colloid
Histocompatibility Antigens
Histocompatibility Antigens Class I
Histocompatibility Antigens Class II
Human
Hungary
Interleukin-2
Major Histocompatibility Complex
Membrane Microdomains
metabolism
methods
Microscopy
Microscopy,Fluorescence
physiology
Proteins
Receptor Aggregation
Receptors,Cell Surface
Receptors,Interleukin-2
Support,Non-U.S.Gov't
Megjelenés:Journal of Cell Science 114 : Pt 22 (2001), p. 4063-4071. -
További szerzők:Mátyus László (1956-) (biofizikus) Jenei Attila (1966-) (biofizikus) Panyi György (1966-) (biofizikus) Varga Sándor (1943-) (biofizikus) Matkó János (1952-) (biológus) Szöllősi János (1953-) (biofizikus) Gáspár Rezső (1944-) (biofizikus) Jovin, Thomas M. Damjanovich Sándor (1936-2017) (biofizikus)
Internet cím:elektronikus változat
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