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001-es BibID:	BIBFORM006025
Első szerző:	Balázs Margit (sejtbiológus, molekuláris genetikus)
Cím:	Fluorescent tetradecanoylphorbol acetate : a novel probe of phorbol ester binding domains / Balázs, M., Szöllösi, J., Lee, W. C., Haugland, R. P., Guzikowski, A. P., Fulwyler, M. J., Damjanovich, S., Feuerstein, B. G., Pershadsingh, H. A.
Dátum:	1991
Megjegyzések:	Protein kinase C (PKC) has a prominent role in signal transduction of many bioactive substances. We synthesized the fluorescent derivative, phorbol-13-acetate-12-N-methyl-N-4-(N,N'-di(2-hydroxyethyl)amino)-7-n itr obenz-2-oxa-1,3-diazole-aminododecanoate (N-C12-Ac(13)) of 12-O-tetradecanoylphorbol-13-acetate (TPA) to monitor the location of phorbol ester binding sites and evaluate its potential use as a probe of PKC in viable cells. The excitation maximum wavelength of N-C12-Ac(13) is close to 488 nm, facilitating its use in argon-ion laser flow and imaging cytometry. When incubated with 100 nM N-C12-Ac(13) at 25 degrees C, P3HR-1 Burkitt lymphoma cells accumulated the dye rapidly, reaching maximum fluorescence within 25 min, 20-fold above autofluorescence. Addition of unlabeled TPA significantly decreased the fluorescence of N-C12-Ac(13) stained cells in a dose-dependent manner indicating specific displacement of the bound fluoroprobe. Competitive displacement of [3H]-phorbol-12,13-dibutyrate ([3H]-PBu2) from rat brain cytosol with N-C12-Ac(13) gave an apparent dissociation constant (Kd) of 11 nM. N-C12-Ac(13) possessed biological activity similar to TPA. Like TPA (final concentration 65 nM) N-C12-Ac(13), at a lower concentration (51 nM), induced expression of Epstein-Barr viral glycoprotein in P3HR-1 cells, differentiation of promyelocytic HL60 cells, and caused predicted changes in the mitotic cycle of histiocytic DD cells. Microspectrofluorometric images of single cells labeled with N-C12-Ac(13) showed bright fluorescence localized intracellularly and dim fluorescence in the nuclear region, consistent with dye binding mainly to cytoplasmic structures and/or organelles and being mostly excluded from the nucleus. Because of the high level of non-specific binding of N-C12-Ac(13), this probe is not ideal for visualizing PKC in intact cells, but would be a valuable fluoroprobe to investigate the kinetic properties of purified PKC. Also, knowledge gained from these studies allows us to predict structures of fluorescent phorbols likely to have less non-specific binding and, consequently, be potentially useful for monitoring PKC in viable cells.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban analysis Animal Antigens,Viral Binding Sites Brain Chemistry Cell Cycle chemical synthesis Cytosol Dyes Female Flow Cytometry Fluorescence Fluorescence Polarization Fluorescent Dyes Gene Expression Herpesvirus 4,Human Image Processing,Computer-Assisted immunology metabolism Oxadiazoles pharmacology Phorbol Esters Protein Kinase C Rats Rats,Inbred Strains Signal Transduction Support,Non-U.S.Gov't Support,U.S.Gov't,P.H.S. Tetradecanoylphorbol Acetate Tumor Cells,Cultured
Megjelenés:	Journal of Cellular Biochemistry. - 46 : 3 (1991), p. 266-276. -
További szerzők:	Szöllősi János (1953-) (biofizikus) Lee, W. C. Haugland, R. P. Guzikowski, A. P. Fulwyler, Mack J. Damjanovich Sándor (1936-2017) (biofizikus) Feuerstein, Burt G. Pershadsingh, Harrihar A.
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001-es BibID:	BIBFORM004634
035-os BibID:	(scopus)0032101894 (wos)000073937700007
Első szerző:	Nagy Péter (biofizikus)
Cím:	EGF-induced redistribution of erbB2 on breast tumor cells : flow and image cytometric energy transfer measurements / Nagy, P., Bene, L., Balazs, M., Hyun, W. C., Lockett, S. J., Chiang, N. Y., Waldman, F., Feuerstein, B. G., Damjanovich, S., Szollosi, J.
Dátum:	1998
Megjegyzések:	erbB2, a member of the epidermal growth factor (EGF) receptor-type tyrosine kinase receptor family, is overexpressed in breast carcinomas with poor prognosis. We examined the cell surface association of this receptor with itself and with other cell surface proteins by the Forster-type fluorescence resonance energy transfer using whole antibodies and Fab fragments. We found that erbB2 molecules homoassociate in unstimulated SK-BR-3, BT474 and BT474-M (a metastatic version of the parent BT474 line) breast tumor cells, and that the interaction was enhanced by EGF treatment in suspensions of SK-BR-3 and BT474-M cells. BT474 cells (with low EGF receptor expression) and attached SK-BR-3 cells do not respond to EGF. Image microscopic energy transfer measurements found considerable pixel-by-pixel heterogeneity in the homoassociation state of erbB2. In accordance with the EGF-induced redistribution of erbB2, EGF receptor was found to be in close proximity to erbB2 in FRET measurements. By labeling different epitopes on erbB2 and the lipid bilayer, we were able to prepare an epitope map of erbB2 molecule. Our data suggest the existence of dynamic cell surface patterns of erbB2 and point to functions fulfilled by these molecular complexes.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk analysis biosynthesis Breast Neoplasms Carcinoma Cell Membrane chemistry drug effects Energy Transfer Epidermal Growth Factor Female Flow Cytometry Fluorescence Human Hungary metabolism methods Models Molecular pharmacology Receptor erbB-2 Receptors Transferrin Support Non-U.S.Gov't Tumor Cells,Cultured Squamous Cell ultrastructure
Megjelenés:	Cytometry. - 32 : 2 (1998), p. 120-131. -
További szerzők:	Bene László (1963-) (biofizikus) Balázs Margit (1952-) (sejtbiológus, molekuláris genetikus) Hyun, William C. Lockett, Steven J. Chiang, Nancy Y. Waldman, Frederick Feuerstein, Burt G. Damjanovich Sándor (1936-2017) (biofizikus) Szöllősi János (1953-) (biofizikus)
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