Transcriptional regulation of ferritin and antioxidant genes by HIPK2 under genotoxic stress.

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Citation

Hailemariam K, Iwasaki K, Huang BW, Sakamoto K, Tsuji Y

Transcriptional regulation of ferritin and antioxidant genes by HIPK2 under genotoxic stress.

J Cell Sci. 2010 Nov 15;123(Pt 22):3863-71. doi: 10.1242/jcs.073627. Epub 2010 Oct 27.

PubMed ID
20980392 [ View in PubMed
]
Abstract

ATF1 (activating transcription factor 1), a stimulus-induced CREB family transcription factor, plays important roles in cell survival and proliferation. Phosphorylation of ATF1 at Ser63 by PKA (cAMP-dependent protein kinase) and related kinases was the only known post-translational regulatory mechanism of ATF1. Here, we found that HIPK2 (homeodomain-interacting protein kinase 2), a DNA-damage-responsive nuclear kinase, is a new ATF1 kinase that phosphorylates Ser198 but not Ser63. ATF1 phosphorylation by HIPK2 activated ATF1 transcription function in the GAL4-reporter system. ATF1 is a transcriptional repressor of ferritin H, the major intracellular iron storage gene, through an ARE (antioxidant-responsive element). HIPK2 overrode the ATF1-mediated ARE repression in a kinase-activity-dependent manner in HepG2 cells. Furthermore, DNA-damage-inducing agents doxorubicin, etoposide and sodium arsenite induced ferritin H mRNA expression in HIPK2(+/+) MEF cells, whereas it was significantly impaired in HIPK2(-/-) MEF cells. Induction of other ARE-regulated detoxification genes such as NQO1 (NADPH quinone oxidoreductase 1), GST (glutathione S-transferase) and HO1 (heme oxygenase 1) by genotoxic stress was also decreased in HIPK2-deficient cells. Taken together, these results suggest that HIPK2 is a new ATF1 kinase involved in the regulation of ferritin H and other antioxidant detoxification genes in genotoxic stress conditions.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
Cyclic AMP-dependent transcription factor ATF-1P18846Details
Homeodomain-interacting protein kinase 2Q9H2X6Details