Activation of APE1/Ref-1 is dependent on reactive oxygen species generated after purinergic receptor stimulation by ATP.
Apurinic apyrimidinic endonuclease redox effector factor-1 (APE1/Ref-1) is involved both in the base excision repair (BER) of DNA lesions and in the eukaryotic transcriptional regulation. APE1/Ref-1 is regulated at both the transcriptional and post-translational levels, through control of subcellular localization and post-translational modification. In response to stress conditions, several cell types release ATP, which exerts stimulatory effects on eukaryotic cells via the purinergic receptors (P2) family. By using western blot and immunofluorescence analysis on a human tumour thyroid cell line (ARO), we demonstrate that purinergic stimulation by extracellular ATP induces quick cytoplasm to nucleus translocation of the protein at early times and its neosynthesis at later times. Continuous purinergic triggering by extracellular ATP released by ARO cells is responsible for the control of APE1/Ref-1 intracellular level. Interference with intracellular pathways activated by P2 triggering demonstrates that Ca2+ mobilization and intracellular reactive oxygen species (ROS) production are responsible for APE1/Ref-1 translocation. The APE1/Ref-1 activities on activator protein-1 (AP-1) DNA binding and DNA repair perfectly match its nuclear enrichment upon ATP stimulation. The biological relevance of our data is reinforced by the observation that APE1/Ref-1 stimulation by ATP protects ARO cells by H2O2-induced cell death. Our data provide new insights into the complex mechanisms regulating APE1/Ref-1 functions.
Pines
Alex
A
Department of Biomedical Sciences and Technologies, University of Udine, 33100 Udine, Italy.
Perrone
Lorena
L
Bivi
Nicoletta
N
Romanello
Milena
M
Damante
Giuseppe
G
Gulisano
Massimo
M
Kelley
Mark R
MR
Quadrifoglio
Franco
F
Tell
Gianluca
G
D021581:Active Transport, Cell Nucleus; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D016923:Cell Death; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000201:enzymology; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D019255:NADPH Oxidases / Q000378:metabolism; D011493:Protein Kinase C / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011983:Receptors, Purinergic / Q000378:metabolism*
D017382:Reactive Oxygen Species; D011983:Receptors, Purinergic; D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide; D019255:NADPH Oxidases; D011493:Protein Kinase C; C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D002118:Calcium