Engineering of photo-activated ion channels

• Project/Area Number: 25840055
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Biophysics
• Research Institution: The Graduate School for the Creation of New Photonics Industries
• Principal Investigator: Hirano Minako 光産業創成大学院大学, 光産業創成研究科, 講師 (80585167)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2014: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000); Fiscal Year 2013: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: イオンチャネル / 光感受性 / 光制御 / 生物物理学

Outline of Final Research Achievements

We aimed to engineer a photo-sensitive K+ channel and Ca2+ channel by modifying a KcsA channel to regulate cell functions by light. 1) Chimera mutants which had photo-sensitive LOV domains at a cytoplasmic domain of the KcsA showed various activities depending on length of linkers, and the mutant which had a linker consisting of 35 amino acids had higher activity in dark than under blue light. 2) Electrostatic state of E146 at the cytoplasmic domain in the KcsA affected activities. 3) Some mutations in a selectivity filter site in KcsA changed it to be Ca2+ permeable.

Research Products

• [Journal Article] A single amino acid gates the KcsA channel. (2014)
  • Author(s): Hirano, M, Okuno, D, Onishi, Y, Ide, T.
  • Journal Title: Biochem Biophys Res Commun. Volume: 450(4) Issue: 4 Pages: 1537-1540
  • DOI: 10.1016/j.bbrc.2014.07.032
  • Peer Reviewed
• [Journal Article] Automated Parallel Recordings of Topologically Identified Single Ion Channels. (2013)
  • Author(s): Kawano R, Tsuji Y, Sato K, Osaki T, Kamiya K, Hirano M, Ide T, Miki N, Takeuchi S.
  • Journal Title: Scientific Reports Volume: 3 Issue: 1 Pages: 1955-1955
  • DOI: 10.1038/srep01995
  • Peer Reviewed / Open Access
• [Presentation] The cytoplasmic domain regulates inactivation in the KcsA channel (2015)
  • Author(s): Minako Hirano, Daichi Okuno, Yukiko Onishi, Toru Ide
  • Organizer: 第53回 日本生物物理学会
  • Place of Presentation: 金沢大学・角間キャンパス
  • Year and Date: 2015-09-14
• [Presentation] Modifications of ion channel function (2014)
  • Author(s): Minako Hirano, Daichi Okuno, Yukiko Onishi, Hiroaki Yokota, Toru Ide
  • Organizer: 第52回 日本生物物理学会
  • Place of Presentation: 札幌コンベンションセンター
  • Year and Date: 2014-09-27
• [Presentation] Coordination between the cytoplasmic domain and the inactivation gate in the KcsA channel (2013)
  • Author(s): M. Hirano, Y. Onishi, D. Okuno, T. Ide
  • Organizer: 第51回 日本生物物理学会
  • Place of Presentation: 国立京都国際会館
• [Presentation] Reconstitution of ion channel immobilized on solid support into lipid bilayer (2013)
  • Author(s): D. Okuno, M. Hirano, Y. Onishi, T. Ide
  • Organizer: 第51回 日本生物物理学会
  • Place of Presentation: 国立京都国際会館