The non-random distribution of UV-induced photoproducts in the nuclear matrix and non-matrix DNA fractions.
The formation of UV-induced photoproducts in the chromatin fractions of human lymphocytes was studied by 32P-post-labeling. A higher level of DNA lesions was found in the matrix-attached DNA fraction as compared to non-matrix DNA of irradiated cells (about 150 and 110 adducts per 10(6) nucleotides, respectively, at a 500 J/m2 254 nm-UV dose). Formation of photoproducts in a MAR (matrix attached region) sequence from the mouse kappa immunoglobulin gene irradiated in vitro was examined as well. The MAR sequence showed a two-fold higher level of adducts as compared to non-MAR DNA. The effect of photoproducts on complex-formation between MAR DNA and proteins of the nuclear matrix was studied in vitro. The amount of UV-induced adducts was 1.5-fold higher in matrix-bound fraction as compared to non-fractionated DNA (and five-fold higher as compared to unbound fraction), which possibly resulted from preferential binding of lesion-containing DNA fragments to the nuclear matrix proteins.
Widlak
P
P
Department of Tumor Biology, Institute of Oncology, Gliwice, Poland.
Bykov
V J
VJ
Hemminki
K
K
Rzeszowska-Wolny
J
J
D000818:Animals; D004247:DNA / Q000378:metabolism / Q000528:radiation effects*; D018736:DNA Adducts / Q000378:metabolism*; D004249:DNA Damage; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000235:genetics / Q000528:radiation effects; D008214:Lymphocytes / Q000528:radiation effects; D051379:Mice; D015530:Nuclear Matrix / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D009687:Nuclear Proteins / Q000378:metabolism / Q000528:radiation effects*
D018736:DNA Adducts; D007145:Immunoglobulin kappa-Chains; D009687:Nuclear Proteins; D004247:DNA