Exposure to UV light causes increased biotinylation of histones in Jurkat cells.
Biotin in breakdown products of biotinylated carboxylases serves as substrate for biotinylation of histones by biotinidase. Here we determined whether biotinylation of histones might play a role in repair of damaged DNA and in apoptosis. Jurkat cells were exposed to UV light to induce DNA damage. Abundance of thymine dimers increased about three times in response to UV exposure, consistent with DNA damage. Biotin-containing carboxylases were degraded in response to UV exposure, as judged by Western blot analysis and carboxylase activities. Mitochondrial integrity decreased in response to UV exposure (as judged by confocal microscopy), facilitating the release of breakdown products of carboxylases from mitochondria. Biotinylation of histones increased in response to UV exposure; biotinylation of histones did not occur specifically at sites of newly repaired DNA. UV exposure triggered apoptosis, as judged by caspase-3 activity and analysis by confocal microscopy. In summary, this study provided evidence that increased biotinylation of histones in DNA-damaged cells might either be a side product of carboxylase degradation or a step during apoptosis.
Peters
Dorothea M
DM
Department of Nutritional Science and Dietetics, University of Nebraska at Lincoln, Lincoln 68583, USA.
Griffin
Jacob B
JB
Stanley
J Steven
JS
Beck
Mary M
MM
Zempleni
Janos
J
D017209:Apoptosis; D001710:Biotin / Q000378:metabolism*; D019921:Biotinylation; D015153:Blotting, Western; D019735:Carbon-Carbon Ligases / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D004249:DNA Damage / Q000528:radiation effects; D004260:DNA Repair; D004307:Dose-Response Relationship, Radiation; D006657:Histones / Q000378:metabolism*; D006801:Humans; D019169:Jurkat Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000378:metabolism / Q000528:radiation effects; D011740:Pyrimidine Dimers / Q000378:metabolism; D011766:Pyruvate Carboxylase / Q000378:metabolism; D014466:Ultraviolet Rays
D006657:Histones; D011740:Pyrimidine Dimers; D001710:Biotin; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D019735:Carbon-Carbon Ligases; D011766:Pyruvate Carboxylase; C022458:propionyl CoA carboxylase (ATP-hydrolyzing); C021573:methylcrotonoyl-CoA carboxylase