High mobility group 1 and 2 proteins bind preferentially to DNA that contains bulky adducts induced by benzo[a]pyrene diol epoxide and N-acetoxy-acetylaminofluorene.
High mobility group (HMG) proteins 1 and 2 are abundant non-histone chromosomal proteins that bind preferentially DNA that is bent or underwound. Previous studies have shown that these proteins preferentially bind to DNA damaged by the crosslinking agents cis-diammine-dichloro-platinum(II), chromium(III) and UV-C radiation. Here we have studied the binding of HMG-1/2 proteins to a duplex oligonucleotide damaged by benzo(a)pyrene diol epoxide or N-acetoxy-acetylaminofluorene using an electrophoretic mobility shift assay. Both chemicals induce monoadducts that are known to distort DNA structure. The affinities of HMG-1/2 for DNA damaged by benzo[a]pyrene diol epoxide or N-acetoxy-acetylaminofluorene were similar to that for UV-irradiated DNA, which were an order of magnitude higher than for undamaged DNA. In contrast, DNA modified by dimethyl sulfate was not preferentially recognised by HMG-1/2.
Department of Experimental and Clinical Radiobiology, Center of Oncology, Wybrzeze AK 15, 44-100, Gliwice, Poland.
J
J
Lanuszewska
P
P
Widlak
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000494:pharmacology*; D000099:Acetoxyacetylaminofluorene / Q000494:pharmacology*; D000477:Alkylating Agents / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites; D015139:Blotting, Southern; D002273:Carcinogens / Q000494:pharmacology; D018736:DNA Adducts / Q000378:metabolism*; D015342:DNA Probes / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D006609:High Mobility Group Proteins / Q000378:metabolism*; D008297:Male; D051381:Rats
D000477:Alkylating Agents; D002273:Carcinogens; D018736:DNA Adducts; D015342:DNA Probes; D006609:High Mobility Group Proteins; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D000099:Acetoxyacetylaminofluorene