A challenge for the creation of extremely long-wavelength absorbing rhodopsin by molecular and structural biological approach

2016 Fiscal Year Final Research Report

• Project/Area Number: 26620005
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Physical chemistry
• Research Institution: Nagoya Institute of Technology
• Principal Investigator: Inoue Keiichi 名古屋工業大学, 工学(系)研究科(研究院), 准教授 (90467001)
• Research Collaborator: Kandori Hideki 名古屋工業大学, 大学院工学研究科, 教授 (70202033) ; Yoshizumi Rei ; Nomura Yurika
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: ロドプシン / レチナール / 波長制御 / 機能転換 / イオンポンプ / 光反応 / 光受容タンパク質 / フラッシュフォトリシス

Outline of Final Research Achievements

In this study, we tried the creation of a new type of rhodopsin absorbing longer-wavelength light. This is expected to be elementary technique to achieve new optogenetic biological tools which are controlled by red- or near-infrared light with higher tissue penetration depth and lower cellular toxicity.
As the results, we newly identified a new light-driven inward H+ pump rhodopsin (PoXeR) from deep-sea bacterium, P. oceani, which has a longer absorption maximum wavelength compared to previously reported molecule.
We also showed that the absorption of rhodopsin with specific function can be red-shifted by introducing their important amino-acid residues to another longer-wavelength absorbing rhodopsin which has different function. In addition, we found a new technique which modifies a highly conserved residue among most of microbial rhodopsins and systematically red-shifts the absorption wavelength.

Free Research Field

物理化学、生物物理学

Academic Significance and Societal Importance of the Research Achievements

本研究では光受容型膜タンパク質であるロドプシンの吸収波長制御について調べ、これまでオプトジェネティクスなどの応用研究で求められていた吸収の長波長化を行う残基の同定に成功し、新たな分子ツール開発につながる、要素技術開発に成功した。また自然界において既知のものより長波長に吸収を持つナトリウムポンプ型ロドプシンを同定し、さらに機能転換によって進化の過程で保存されている構造エレメントの存在を明らかにするなど、微生物におけるタンパク質の分子進化についても知見を得た。