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001-es BibID:	BIBFORM001315
Első szerző:	Offer, Hagai
Cím:	p53 modulates base excision repair activity in a cell cycle-specific manner after genotoxic stress / Hagai Offer, Irit Zurer, Gaspar Banfalvi, Marian Reha'k, Ayellet Falcovitz, Michael Milyavsky, Naomi Goldfinger, Varda Rotter
Dátum:	2001
ISSN:	0008-5472 1538-7445
Megjegyzések:	To elucidate the nature of the cross-talk between the p53 protein and the DNA repair machinery, we have investigated the relationship between the two throughout the cell cycle. Base excision repair (BER) was analyzed in cell cycle phase-enriched populations of lymphoid cells expressing wild-type p53. Our study yielded the following novel findings: (a) BER exhibited two distinct peaks of activity, one associated with the G0-G1 checkpoint and the second with the G2-M checkpoint; (b) although the overall BER activity was reduced after exposure of cells to 400R, there was an augmentation of the G0-G1-associated BER activity and a reduction in the G2-M-associated BER activity; and (c) modulations in these patterns of BER after genotoxic stress were found to be p53 regulated. p53 protein levels induced after gamma-irradiation were distributed evenly in the various cell cycle populations (analyzed by the PAb-248 anti-p53 monoclonal antibody). However, both the dephosphorylation of serine 376 of p53 (contained in the PAb-421 epitope) and the specific DNA binding activity, as well as apoptosis, were enhanced toward the G2-M populations. Furthermore, inactivation of wild-type p53, mediated by mutant p53 expression, abolished the alterations in the BER pattern and showed no induction of a G2-M-associated apoptosis after gamma-irradiation. These results suggest that after genotoxic stress, stabilized p53 enhances the G0-G1-associated BER activity, whereas it predominantly reduces BER activity at the G2-M-enriched populations and instead induces apoptosis. After genotoxic stress, p53 functions as a modulator that determines the pattern of BER activity and apoptosis in a cell cycle-specific manner.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk DNS hibajavítás bázis kivágásos repair gamma sugárzás p53
Megjelenés:	Cancer Research. - 61 : 1 (2001), p. 88-96. -
További szerzők:	Zurer, Irit Rehák Mariann Falcovitz, Ayellet Milyavsky, Michael Goldfinger, Naomi Rotter, Varda Bánfalvi Gáspár (1943-) (sejtbiológus, gyógyszerész)
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat Szerző által megadott URL
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001-es BibID:	bibEBI00010496
Első szerző:	Rehák Mariann
Cím:	Subphases of DNA replication in Drosophila cells / M. Rehak, I. Csuka, E. Szepessy, G. Banfalvi
Dátum:	2000
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	DNA and cell biology. - 19 (2000), p. 607-612. -
További szerzők:	Csuka Ildikó Szepessy Edit Bánfalvi Gáspár (1943-) (sejtbiológus, gyógyszerész)
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001-es BibID:	BIBFORM001308
Első szerző:	Szemán-Nagy Gábor (biológia tanár-molekuláris biológus)
Cím:	Gamma irradiation-induced apoptosis in murine pre-B cells prevents the condensation of fibrillar chromatin in early S phase / G. Nagy, M. Gacsi, M. Rehak, A. G. Basnakian, M. Klaisz, G. Banfalvi
Dátum:	2004
ISSN:	1360-8185
Megjegyzések:	Local changes in chromatin structure leading to temporally distinct geometric forms were characterized in nuclei of reversibly permeabilized cells. Reversal of permeabilization was tested by 3H-thymidine incorporation and trypan blue dye exclusion. Apoptotic changes were visualized in a cell cycle dependent manner at the chromatin level by fluorescent microscopy in non-irradiated cells and after 400 rad Co60 irradiation. Fluorescent microscopy of chromatin structures belonging mainly to the interphase of the cell cycle confirmed the existence of specific geometric forms in nuclei of non-irradiated cells. In this control population, the following main transitory forms of condensing chromatin were distinguished: decondensed veil-like structures and fibrous structures in early and mid S phase (2.0-2.5 average C-value), chromatin bodies, semicircles later in mid S phase (3.0-3.5 C), precondensed chromosomes in late S (3.5-3.7 C) and metaphase chromosomes at the end and after S phase (3.7-4.0 C). Our results show that upon gamma-irradiation (a) the cellular and nuclear sizes were increased, (b) the DNA content was lower in each elutriated subpopulation of cells, (c) the progression of the cell cycle was arrested in the early S phase at 2.4 C value, (d) the chromatin condensation was blocked between the fibrillar chromatin and precondensed elongated chromosomal forms, and (e) the number and size of apoptotic bodies were inversely correlated with the progression of the cell cycle, with many small apoptotic bodies in early S phase and less and larger apoptotic bodies in late S phase.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban gamma sugárzás kromatin kondenzálás fibrilláris kromatin
Megjelenés:	Apoptosis. - 9 : 6 (2004), p. 765-776. -
További szerzők:	Gácsi Mariann Rehák Mariann Basnakian, Alexei G. Klaisz Mariann Bánfalvi Gáspár (1943-) (sejtbiológus, gyógyszerész)
Internet cím:	elektronikus változat
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