Acetylation regulates DNA repair mechanisms in human cells.
The p300-mediated acetylation of enzymes involved in DNA repair and replication has been previously shown to stimulate or inhibit their activities in reconstituted systems. To explore the role of acetylation on DNA repair in cells we constructed plasmid substrates carrying inactivating damages in the EGFP reporter gene, which should be repaired in cells through DNA mismatch repair (MMR) or base excision repair (BER) mechanisms. We analyzed efficiency of repair within these plasmid substrates in cells exposed to deacetylase and acetyltransferase inhibitors, and also in cells deficient in p300 acetyltransferase. Our results indicate that protein acetylation improves DNA mismatch repair in MMR-proficient HeLa cells and also in MMR-deficient HCT116 cells. Moreover, results suggest that stimulated repair of mismatches in MMR-deficient HCT116 cells is done though a strand-displacement synthesis mechanism described previously for Okazaki fragments maturation and also for the EXOI-independent pathway of MMR. Loss of p300 reduced repair of mismatches in MMR-deficient cells, but did not have evident effects on BER mechanisms, including the long patch BER pathway. Hypoacetylation of the cells in the presence of acetyltransferase inhibitor, garcinol generally reduced efficiency of BER of 8-oxoG damage, indicating that some steps in the pathway are stimulated by acetylation.
a Department of Microbiology and Immunology , School of Medicine and Dentistry, University of Rochester , Rochester , NY , USA.
Dorota
D
Piekna-Przybylska
a Department of Microbiology and Immunology , School of Medicine and Dentistry, University of Rochester , Rochester , NY , USA.
Robert A
RA
Bambara
b Department of Biology , Indiana University-Purdue University Indianapolis , Indianapolis , IN , USA.
Lata
L
Balakrishnan
D000107:Acetylation; D000595:Amino Acid Sequence; D020137:Base Pair Mismatch; D001483:Base Sequence; D004247:DNA / Q000235:genetics* / Q000378:metabolism; D053843:DNA Mismatch Repair; D004260:DNA Repair; D004261:DNA Replication; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006147:Guanine / Q000031:analogs & derivatives / Q000378:metabolism; D045325:HCT116 Cells; D006367:HeLa Cells; D006801:Humans; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D016415:Sequence Alignment; D013729:Terpenes / Q000494:pharmacology; D050880:p300-CBP Transcription Factors / Q000235:genetics* / Q000378:metabolism; D000099224:p300-CBP-Associated Factor
D004247:DNA; D004791:Enzyme Inhibitors; D049452:Green Fluorescent Proteins; D006147:Guanine; D013729:Terpenes; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor; C453560:7,8-dihydro-8-oxoguanine; C485184:enhanced green fluorescent protein; C054597:garcinol
Acetylation; BER; DNA repair; MMR; p300