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1.

001-es BibID:BIBFORM046090
Első szerző:Bacsó Zsolt (biofizikus)
Cím:Raft and cytoskeleton associations of an ABC transporter : P-glycoprotein / Zsolt Bacso, Henrietta Nagy, Katalin Goda, László Bene, Ferenc Fenyvesi, János Matkó, Gábor Szabó
Dátum:2004
ISSN:0196-4763
Megjegyzések:A novel flow cytometric assay has been described in an accompanying report (Gombos et al., METHODS: The kinetics of the decrease in immunofluorescence intensity was analyzed after the addition of the raft-preserving Triton X-100 or Nonidet P-40, both of which disrupt the entire membrane. Mild treatments by both detergents leave cells attached to only those proteins that are anchored to the cytoskeleton by rafts or independent of rafts. Agents that affect microfilaments and modulate membrane levels of cholesterol by cyclodextrin were used to distinguish between the raft-mediated and non-raft-related associations of the Pgp. Confocal microscopy and flow cytometric fluorescence energy transfer measurements were used to confirm colocalization of Pgp with raft constituents. RESULTS: The assay was proved to be sensitive enough to resolve differences between the resistance of UIC2-labeled cell-surface Pgps to Triton X-100 versus Nonidet P-40. Approximately 34% of the UIC2 Fab-labeled Pgp molecules were associated with the cytoskeleton through detergent-resistant, cholesterol-sensitive microdomains or directly, whereas approximately 15% were found to be directly linked to the cytoskeleton. Accordingly, confocal microscopy showed that Pgps colocalize with raft markers, mainly in microvilli. Fluorescence resonance energy transfer efficiency data indicating molecular proximity between Pgp and the raft markers CD44, CD59, and G(M1)-gangliosides also suggested that a significant fraction of Pgps resides in raft microdomains. Raft association of Pgp appears to be of functional significance because its modulation markedly affected drug pumping. CONCLUSIONS: By using the flow cytometric detergent resistance assay in kinetic mode, we were able to assess the extent of raft association and actin cytoskeleton anchorage of Pgp expressed at physiologically relevant levels. We demonstrated that a significant fraction of Pgp is raft associated on LS-174-T human colon carcinoma cells and that this localization may influence its transporter function. The kinetic flow cytometric detergent resistance assay presented in this report is considered to be generally applicable for the analysis of molecular interactions of membrane proteins expressed at low levelsújratöltve - BIBFORM004828
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Cytometry. - 61 : 2 (2004), p. 105-116. -
További szerzők:Nagy Henrietta Goda Katalin (1969-) (biofizikus) Bene László (1963-) (biofizikus) Fenyvesi Ferenc (1977-) (gyógyszerész, gyógyszertechnológus) Matkó János (1952-) (biológus) Szabó Gábor (1953-) (biofizikus)
Pályázati támogatás:T032563
OTKA
034393
OTKA
T046945
OTKA
Internet cím:Szerző által megadott URL
DOI
Intézményi repozitóriumban (DEA) tárolt változat
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2.

001-es BibID:BIBFORM004645
035-os BibID:(scopus)0033552675 (wos)000084290400003
Első szerző:Damjanovich Sándor (biofizikus)
Cím:Two-dimensional receptor patterns in the plasma membrane of cells : a critical evaluation of their identification, origin and information content / Damjanovich, S., Bene, L., Matko, J., Matyus, L., Krasznai, Z., Szabo, G., Pieri, C., Gaspar, R., Szollosi, J.
Dátum:1999
Megjegyzések:A concise review is presented on the nature, possible origin and functional significance of cell surface receptor patterns in the plasma membrane of lymphoid cells. A special emphasize has been laid on the available methodological approaches, their individual virtues and sources of errors. Fluorescence energy transfer is one of the oldest available means for studying non-randomized co-distribution patterns of cell surface receptors. A detailed and critical description is given on the generation of two-dimensional cell surface receptor patterns based on pair-wise energy transfer measurements. A second hierarchical-level of receptor clusters have been described by electron and scanning force microscopies after immuno-gold-labeling of distinct receptor kinds. The origin of these receptor islands at a nanometer scale and island groups at a higher hierarchical (mum) level, has been explained mostly by detergent insoluble glycolipid-enriched complexes known as rafts, or detergent insoluble glycolipids (DIGs). These rafts are the most-likely organizational forces behind at least some kind of receptor clustering [K. Simons et al., Nature 387 (1997) 569]. These models, which have great significance in trans-membrane signaling and intra-membrane and intracellular trafficking, are accentuating the necessity to revisit the Singer-Nicolson fluid mosaic membrane model and substitute the free protein diffusion with a restricted diffusion concept.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Biophysics
Cells
Diffusion
Energy Transfer
Fluorescence
Hungary
Microscopy
Megjelenés:Biophysical Chemistry. - 82 : 2-3 (1999), p. 99-108. -
További szerzők:Bene László (1963-) (biofizikus) Matkó János (1952-) (biológus) Mátyus László (1956-) (biofizikus) Krasznai Zoltán (1950-) (biofizikus) Szabó Gábor (1953-) (biofizikus) Pieri, Carlo Gáspár Rezső (1944-) (biofizikus) Szöllősi János (1953-) (biofizikus)
Internet cím:DOI
elektronikus változat
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3.

001-es BibID:BIBFORM004628
035-os BibID:(scopus)0032190410 (wos)000076205700017
Első szerző:Damjanovich Sándor (biofizikus)
Cím:Supramolecular receptor structures in the plasma membrane of lymphocytes revealed by flow cytometric energy transfer, scanning force- and transmission electron-microscopic analyses / Damjanovich, S., Matko, J., Matyus, L., Szabo, G. jr., Szollosi, J., Pieri, J. C., Farkas, T., Gaspar, R.
Dátum:1998
ISSN:196-4763
Megjegyzések:Receptors in the plasma membrane of blood cells in general and in that of lymphocytes in particular are supposed to move around in a random walk fashion relatively freely driven by thermal diffusion, as described by the Singer-Nicolson fluid mosaic membrane model. In this article we summarized data and techniques that indicated nonrandom codistribution patterns of receptor superstructures under conditions, where the generation of such molecular colocalizations by the methods themselves were excluded. Application of fluorescence energy transfer in a flow cytometer helped to analyze such codistribution patterns in cell populations. After normalizing energy transfer values for possible differences between labeling ratios of the targeting monoclonal antibodies and using the mean values of energy transfer distribution curves, two-dimensional receptor maps were generated from data obtained in a pair-wise fashion between receptors. Major histocompatibility complex (MHC) class I and II, intercellular adhesion molecule-1 (ICAM-1), TcR-CD3-CD4, tetraspan molecules (CD81, CD82, CD53), and the subunits of the multisubunit IL-2 receptor displayed nonrandom codistribution patterns sometimes with, but very frequently without induction by their ligand. Immunogold-bead "sandwich" labeling analyzed by atomic force microscopy has shown that such receptor "islands" existed also in "receptor-island-groups". This indicated the existence of nonrandom receptor distribution of MHC class I and II molecules also at an elevated hierarchical level. An analysis is given herein concerning a standardized approach. The apparent incompatibility of these supramolecular patterns with the Singer-Nicolson type "free-protein and lipid-mobility paradigm" was resolved by recommending an additional emphasis on the mosaicism of the membrane besides receptor mobility.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
analysis
Antibodies
Antigens
Antigen
blood
Monoclonal
chemistry
Diffusion
Dyes
Energy Transfer
Flow Cytometry
Fluorescence
Fluorescent Dyes
HLA Antigens
Human
Hungary
Immunoglobulins
Fab
Immunohistochemistry
immunology
Intercellular Adhesion Molecule-1
Interleukin-2
Lymphocytes
Macromolecular Systems
Major Histocompatibility Complex
Membrane Fluidity
methods
Microscopy
Atomic Force
Microspheres
Modelsl
Motion
Receptor-CD3 Complex
T-Cell
Receptors
Cell Surface
Support
Non-U.S.Gov't
Tumor Cells
Cultured
Megjelenés:Cytometry. - 33 : 2 (1998), p. 225-233. -
További szerzők:Matkó János (1952-) (biológus) Mátyus László (1956-) (biofizikus) Szabó Gábor (1953-) (biofizikus) Szöllősi János (1953-) (biofizikus) Pieri, J. C. Farkas Tamás (1971-) (biológus) Gáspár Rezső (1944-) (biofizikus)
Internet cím:DOI
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4.

001-es BibID:BIBFORM046091
Első szerző:Gombos Imre
Cím:Cholesterol sensitivity of detergent resistance : a rapid flow cytometric test for detecting constitutive or induced raft association of membrane proteins / Imre Gombos, Zsolt Bacsó, Cynthia Detre, Henrietta Nagy, Katalin Goda, Márton Andrásfalvy, Gábor Szabó, János Matkó
Dátum:2004
ISSN:0196-4763
Megjegyzések:Lipid rafts are cholesterol- and glycosphingolipid-rich microdomains in the cellular plasma membranes that play critical roles in compartmentalization (concentration, coupling, and isolation) of receptors and signal molecules. Therefore, detecting constitutive or induced raft associations of such proteins is of central interest in cell biology. This has mostly been done with time- and cell-consuming immunobiochemical techniques affected by several sources of artifacts. A flow cytometric analysis of immunocytochemical staining under differential circumstances of detergent treatment offers a new alternative to this method. METHODS: Membrane microdomains are resistant to nonionic detergents due to extensive, strong interactions between their molecular constituents. We used this feature to develop a rapid flow cytometric assay of differential detergent resistance based on immunocytochemical labeling of extracellular domain epitopes in membrane proteins. Data evaluation is based on comparative detection of their detergent solubility without and with cholesterol depletion of cell membranes, resolved by moderate concentrations of nonionic detergents. RESULTS: Nonionic detergents Triton X-100 and Nonidet-40 (0.05-0.1%) in cold or Brij-98 (0.1-0.5%) at 37 degrees C efficiently resolved detergent solubility or resistance of many lymphocyte cell surface proteins. Kinetic data revealed that a short (5-10 min) detergent treatment is sufficient for this assay. Comparison of detergent solubility in untreated and cholesterol-depleted cells differentiated membrane proteins associated with or excluded from raft microdomains, respectively. Confocal microscopy showed that this mild detergent treatment leaves the cytoskeleton of the cells intact, with a detectable expression of raft marker detergent-resistant proteins attached to it. An induced association with rafts of immunoglobulin E receptors upon antigen cross-linking was also easily detectable in rat mast cells by this approach. CONCLUSIONS: A protocol is proposed for a rapid (5-10 min) test of detergent resistance of membrane proteins in cells. The approach requires only a small amount of cells (10(4)/sample) and offers a good resolution of detergent solubility or resistance of membrane proteins, also in terms of the underlying mechanisms, with an advantage of applicability for all conventional bench-top flow cytometers.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Cytometry. Part A. - 61A : 2 (2004), p. 117-126. -
További szerzők:Bacsó Zsolt (1963-) (biofizikus) Detre, Cynthia Nagy Henrietta Goda Katalin (1969-) (biofizikus) Andrásfalvy Márton Szabó Gábor (1953-) (biofizikus) Matkó János (1952-) (biológus)
Pályázati támogatás:T034393
OTKA
TS044711
OTKA
T032563
OTKA
T046945
OTKA
Internet cím:Szerző által megadott URL
DOI
Intézményi repozitóriumban (DEA) tárolt változat
Borító:

5.

001-es BibID:BIBFORM035567
035-os BibID:WOS:000221319900021
Első szerző:Gombos Imre
Cím:Flow cytofluorimetric analysis of differential detergent resistance (FCDRA) : a rapid test of raft-association of membrane proteins / Gombos, I., Bacso, Zs., Detre, C., Szabo, G., Andrasfalvy, M., Prechl, J., Matko, J.
Dátum:2004
ISSN:1552-4922
Tárgyszavak:Orvostudományok Elméleti orvostudományok idézhető absztrakt
egyetemen (Magyarországon) készült közlemény
Megjelenés:Cytometry Part A. - 59A :1 (2004), p. 30. -
További szerzők:Bacsó Zsolt (1963-) (biofizikus) Detre, Cynthia Szabó Gábor (1953-) (biofizikus) Andrásfalvy Márton Prechl József Matkó János (1952-) (biológus)
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