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HIPK2 regulates double‐strand break signaling by controlling WIP1 phosphatase at the protein level (550.1)
Author(s) -
Choi Dong Wook,
Na Wooju,
Choi Cheol Yong
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.550.1
Subject(s) - phosphorylation , microbiology and biotechnology , genome instability , phosphatase , dna damage , signal transduction , dna repair , chemistry , biology , dna , biochemistry
Double‐strand break (DSB) signaling, induced by ionizing radiation and other damage reagents, prevents genomic instability and tumoriogenesis. Features of DSB signaling are tight regulation of phospho‐dynamics of key players including ATM, H2AX, CHK2. In this study, we identified that WIP1, serine/threonine phosphatase involving termination of DSB signaling, is responsible for initiation of DSB signaling in a HIPK2‐dependent manner. Under normal condition, WIP1 maintained at a low level by proteasomal degradation through HIPK2‐mediated phosphorylation, which is important for proper activation of DSB repair signaling in response to ionizing radiation. After completion of DNA repair, HIPK2 is phosphorylated by AMPK, which induces dissociation of WIP1 from phosphorylated HIPK2. We found that HIPK2 is indispensible for DSB‐induced foci formation and cell cycle check point activation. In addition, using HIPK2 heterozygote mice, we demonstrated that HIPK2 has an essential role in survival of mice in response to ionizing radiation. Taken together, we suggest that AMPK‐HIPK2‐WIP1 axis plays a key role in the initiation and termination of DSB repair signaling cascade through fine‐tuning of WIP1 protein level.