An investigation into the mechanism regulating the oxidative stress-dependent activation of the Keap1-Nrf2 pathway

2016 Fiscal Year Research-status Report

• Project/Area Number: 16K19027
• Research Institution: Tohoku University
• Principal Investigator: Baird Liam 東北大学, 知の創出センター, 特任助教 (90724914)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 細胞内シグナル伝達

Outline of Annual Research Achievements

We developed a new Nrf2 Dual-ETGE transgenic mouse in which to study the mechanism of Nrf2 activation in vivo. Through analysis of macrophages derived from these mice, we found that the absence of the DLG motif in this tighter-binding Nrf2 mouse line did not inhibit the chemical induced activation of Nrf2 in response to a wide variety of well described Nrf2 activators. In a complementary set of experiments, we assayed the stoichiometry of the Keap1-Nrf2-Cul3 complex, and found that the make-up of this is complex is unaffected by chemical activation of Nrf2. This suggests that the Keap1 complex is inactivated by inducers, but that this activation is not caused by the dissociation of the Keap1 complex upon chemical activation of Nrf2.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

As we found that the Dual-ETGE Nrf2 transgenic mouse line does not display a phenotype different from wild-type mice in response to classical inducers, we would like to more thoroughly investigate the phenotype of these mice in response to other Nrf2 activators, including during inhibition of autophagy, during which Nrf2 activity is thought to be induced by p62.

Strategy for Future Research Activity

As a complementary approach to the generation of the Dual ETGE Nrf2 transgenic mice, in the future we would also like to use NMR spectroscopy using recombinant Keap1 and Nrf2 proteins in order to gain a deeper understanding of the mechanism of Nrf2 activation. In particular, we would like to focus on the changes induced in the structure of Keap1 by chemical activators of Nrf2 in order to gain a more complete understanding of how Keap1 is inactivated in response to cellular stress.

Causes of Carryover

This year I spent less money than originally expected as I did not pay for any mouse costs.

Expenditure Plan for Carryover Budget

In the next fiscal year, I plan to focus more on NMR experiments, which require some expensive reagents, and therefore the money that I did not spend in 2016 will be spent on experimental reagents in 2017.