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Nucleic Acids Res. 2016 Sep 19;44(16):7630-45. doi: 10.1093/nar/gkw442. Epub 2016 May 19.

PKCα and HMGB1 antagonistically control hydrogen peroxide-induced poly-ADP-ribose formation.

Author information

1
Department of Molecular Mechanisms of Disease, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland Molecular Life Sciences PhD Program, Life Science Zurich Graduate School, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
2
Department of Molecular Mechanisms of Disease, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland Cancer Biology PhD Program, Life Science Zurich Graduate School, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
3
Institute of Molecular Life Science (IMLS) and Swiss Institute of Bioinformatics (SIB), University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
4
Bayer Technology Services GmbH, D-51368 Leverkusen, Germany.
5
Department of Molecular Mechanisms of Disease, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
6
Department of Molecular Mechanisms of Disease, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland michael.hottiger@dmmd.uzh.ch.

Abstract

Harmful oxidation of proteins, lipids and nucleic acids is observed when reactive oxygen species (ROS) are produced excessively and/or the antioxidant capacity is reduced, causing 'oxidative stress'. Nuclear poly-ADP-ribose (PAR) formation is thought to be induced in response to oxidative DNA damage and to promote cell death under sustained oxidative stress conditions. However, what exactly triggers PAR induction in response to oxidative stress is incompletely understood. Using reverse phase protein array (RPPA) and in-depth analysis of key stress signaling components, we observed that PAR formation induced by H2O2 was mediated by the PLC/IP3R/Ca(2+)/PKCα signaling axis. Mechanistically, H2O2-induced PAR formation correlated with Ca(2+)-dependent DNA damage, which, however, was PKCα-independent. In contrast, PAR formation was completely lost upon knockdown of PKCα, suggesting that DNA damage alone was not sufficient for inducing PAR formation, but required a PKCα-dependent process. Intriguingly, the loss of PAR formation observed upon PKCα depletion was overcome when the chromatin structure-modifying protein HMGB1 was co-depleted with PKCα, suggesting that activation and nuclear translocation of PKCα releases the inhibitory effect of HMGB1 on PAR formation. Together, these results identify PKCα and HMGB1 as important co-regulators involved in H2O2-induced PAR formation, a finding that may have important relevance for oxidative stress-associated pathophysiological conditions.

PMID:
27198223
PMCID:
PMC5027479
DOI:
10.1093/nar/gkw442
[Indexed for MEDLINE]
Free PMC Article

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