| Autor: |
Malfatti MC; Laboratory of Molecular Biology and DNA Repair, Department of Medicine (DAME), University of Udine, Udine, Italy., Codrich M; Laboratory of Molecular Biology and DNA Repair, Department of Medicine (DAME), University of Udine, Udine, Italy., Dalla E; Laboratory of Molecular Biology and DNA Repair, Department of Medicine (DAME), University of Udine, Udine, Italy., D'Ambrosio C; Proteomics, Metabolomics and Mass Spectrometry Laboratory, Institute for the Animal Production System in the Mediterranean Environment (ISPAAM), National Research Council (CNR) of Italy, Portici, Italy., Storici F; School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA., Scaloni A; Proteomics, Metabolomics and Mass Spectrometry Laboratory, Institute for the Animal Production System in the Mediterranean Environment (ISPAAM), National Research Council (CNR) of Italy, Portici, Italy., Tell G; Laboratory of Molecular Biology and DNA Repair, Department of Medicine (DAME), University of Udine, Udine, Italy. |
| Abstrakt: |
Aims: The existence of modified ribonucleotide monophosphates embedded in genomic DNA, as a consequence of oxidative stress conditions, including 8-oxo-guanosine and ribose monophosphate abasic site (rAP), has been recently highlighted by several works and associated with oxidative stress conditions. Although human apurinic-apyrimidinic endodeoxyribonuclease 1 (APE1), a key enzyme of the base-excision repair pathway, repairs rAP sites and canonical deoxyribose monophosphate abasic sites with similar efficiency, its incision-repairing activity on 8-oxo-guanosine is very weak. The aims of this work were to: (i) identify proteins able to specifically bind 8-oxo-guanosine embedded in DNA and promote APE1 endoribonuclease activity on this lesion, and (ii) characterize the molecular and biological relevance of this interaction using human cancer cell lines. Results: By using an unbiased proteomic approach, we discovered that the AU-rich element RNA-binding protein 1 (AUF1) actively recognizes 8-oxo-guanosine and stimulates the APE1 enzymatic activity on this DNA lesion. By using orthogonal approaches, we found that: (i) the interaction between AUF1 and APE1 is modulated by H 2 O 2 -treatment; (ii) depletion of APE1 and AUF1 causes the accumulation of single- and double- strand breaks; and (iii) both proteins are involved in modulating the formation of DNA:RNA hybrids. Innovation: These results establish unexpected functions of AUF1 in modulating genome stability and improve our knowledge of APE1 biology with respect to 8-oxo-guanosine embedded in DNA. Conclusion: By showing a novel function of AUF1, our findings shed new light on the process of genome stability in mammalian cells toward oxidative stress-related damages. Antioxid. Redox Signal. 39, 411-431. |
