Keronninn Moreno de Lima Bessa
From DNA Repair Lab
Undergraduated in Biology at the Federal University of Rio Grande do Norte. Graduated in Biotechnology at the University of Sao Paulo, Brazil (2006).
Project description
Ultraviolet light (UV) generates DNA lesions, cyclobutante pyrimidine dimers (CPDs) and 6-4 pyrimidine-pyrimidone photoproducts being the most frequent ones. These DNA lesions can be removed from the genome by two different DNA repair processes: photoreactivation and nucleotide excision repair (NER). Photoreactivation envolves enzymes named photolyases, which contain chromophores that capture blue photons and use them to repair the UV photoproducts. Interestingly, these enzymes present a high specificity to the target lesion, being classified as CPD-photolyases and 6-4PP-photolyases. Even though photoreactivation has been found widespread in the nature, these enzymes are absent in placental mammals, including humans. In these organisms, repair of UV-induced DNA lesions is performed by NER. Our research work is interested in investigating the effects of CPDs and 6-4PPs on the induction of cellular responses upon UV irradiation. For this purpose, we have constructed adenoviral vectors carrying the marsupial CPD-photolyase and plant 6-4PP-photolyase. By employing these vectors, we have been able to demonstrate that both CPDs and 6-4PPs play important roles in cell death pathways in NER-deficient human fibroblasts, while CPDs are the major signals that lead NER-proficient human cells to death. At this time, we have been employing these recombinant adenoviral vectors for studying the effects of CPDs and 6-4PPs in cellular processes such as DNA replication and RNA transcription, which are inhibited by UV irradiation.
Publications
1. LIMA-BESSA KM, Chiganças V, Stary A, Kannouche P, Sarasin A, Armelini MG, Jacysyn JF, Amarante-Mendes, GP, Cordeiro-Stone M, Cleaver JE, Menck CF. Adenovirus mediated transduction of the human DNA polymerase eta cDNA. DNA Repair, v. 5, p. 925-934, 2006.
2. Armelini MG, Marchetto MC, Muotri AR, LIMA-BESSA KM, Sarasin A, Menck CF. Restoring DNA repair capacity of cells from three distinct diseases by XPD gene-recombinant adenovirus. Cancer Gene Therapy, v. 12, p. 389-396, 2005.
3. LIMA-BESSA KM, Menck CF. Skin cancer: lights on genome lesions. Current Biology, v. 15, p. 58-61, 2005.
4. Martins-Pinheiro M, Galhardo RS, Lage C, LIMA-BESSA KM, Aires KA, Menck CF. Different patterns of evolution for duplicated DNA repair genes in bacteria of the Xanthomonadales group. BMC Evolutionary Biology, v. 4, p. 1-9, 2004.