Regulation of the initiation of base excision repair by the protein-protein interactions

2015 Fiscal Year Final Research Report

• Project/Area Number: 25340036
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Risk sciences of radiation and chemicals
• Research Institution: Osaka Prefecture University
• Principal Investigator: KUBO KIHEI 大阪府立大学, 生命環境科学研究科(系), 教授 (40117619)
• Co-Investigator(Kenkyū-buntansha): Takenaka Shigeo 大阪府立大学, 生命環境科学研究科, 准教授 (10280067) ; YAMAMOTO RYOHEI 大阪府立大学, 生命環境科学研究科, 講師 (20457998)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 塩基除去修復 / DSB / MPG / PIKK / RPA2 / タンパク質相互作用 / ノックダウン / Pol beta

Outline of Final Research Achievements

The regulation of initiation of base excision repair (BER) by MPG was investigated using mouse embryonic fibroblasts (MEF). In growth-arrested MEF, the excision of MMS-induced methylated bases was greatly suppressed while the sensitivity was significantly lower as compared with growing cells. The APEX protein content was reduced in growth-arrested MEF or PolB-deficient MEFs. Furthermore, MPG was also decreased in these cells. After the immunoprecipitation with FLAG-tagged MPG, co-precipitated proteins were analyzed by LC/MS/MS and 13 novel proteins were identified. After MMS-treatment, the enhanced interactions with 7 proteins including MLH1, a DnaJ homolog protein and proteasome-related proteins were observed, while the interaction with 5 proteins including Hsc70 were unchanged. Reduced interaction of MPG with RPA2 and increased interaction with p53 suggest that the production of DSB as a result of BER altered protein interaction with MPG via activation of PIKK.

Free Research Field

放射線生物学