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Investigation of molecular mechanisms underlying environment-dependent regulation of ion permeation through mammalian potassium channels.

Research Project

Project/Area Number 17K15109
Research Category

Grant-in-Aid for Young Scientists (B)

Allocation TypeMulti-year Fund
Research Field Biophysics
Research InstitutionInstitute for Molecular Science

Principal Investigator

Tsukamoto Hisao  分子科学研究所, 生命・錯体分子科学研究領域, 助教 (90579814)

Project Period (FY) 2017-04-01 – 2020-03-31
Project Status Completed (Fiscal Year 2019)
Budget Amount *help
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2018: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2017: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Keywordsイオンチャネル / 赤外分光 / 蛍光標識 / 膜タンパク質 / GPCR / リポソーム / 蛍光分光 / 受容体
Outline of Final Research Achievements

Generally, potassium ion channels selectively permeate potassium ions and block sodium ions to generate potentials across biological membranes. However, some potassium channels, such as a two-pore domain potassium channel TWIK-1, can permeate sodium ions under specific conditions. It is poorly understood how the potassium channels regulate their ion selectivity. We aimed to reveal molecular mechanisms underlying the "loose" ion selectivity of TWIK-1 using infrared and fluorescence spectroscopic techniques. Infrared spectroscopy revealed that the selective filter moiety in TWIK1 possesses lower the affinity for potassium ions. Also, fluorescence spectroscopy showed that an "entry" site for ions in the extracellular domain of TWIK-1 becomes more opened depending on sodium concentrations. These results suggested that the selectivity filter and the entry site in the extracellular domain cooperatively play important roles in unconventional sodium permeability in TWIK-1.

Academic Significance and Societal Importance of the Research Achievements

細胞内外に電位差を生み出すために重要な、カリウムイオンチャネルがカリウムイオンを通すが、より小さなナトリウムイオンは通さないメカニズムは、主にX線結晶構造解析から明らかにされ、2003年度のノーベル化学賞の対象となっている。TWIK-1の結晶構造も2012年に報告されているが、選択フィルタ部位の構造が他のカリウムイオンチャネルと同一であり、なぜイオン選択性が低いのか不明のままであった。今回の研究成果は、TWIK-1の「緩い」イオン選択性を生み出す分子メカニズムに新しい知見を与えるものであり、カリウムイオンチャネルの機能制御機構をより深く理解する上で意義深いと考えている。

Report

(4 results)
  • 2019 Annual Research Report   Final Research Report ( PDF )
  • 2018 Research-status Report
  • 2017 Research-status Report
  • Research Products

    (18 results)

All 2020 2019 2018 2017 Other

All Int'l Joint Research (1 results) Journal Article (6 results) (of which Int'l Joint Research: 4 results,  Peer Reviewed: 6 results,  Open Access: 2 results) Presentation (10 results) (of which Int'l Joint Research: 1 results,  Invited: 5 results) Remarks (1 results)

  • [Int'l Joint Research] Paul Scherrer Institute(スイス)

    • Related Report
      2019 Annual Research Report
  • [Journal Article] Session 2SFA-the symposium "Elucidation of biological functions by optical control" on BSJ2019 at Miyazaki, Japan.2020

    • Author(s)
      Hisao Tsukamoto、Yoshinori Shichida
    • Journal Title

      Biophysical Reviews

      Volume: 12 Issue: 2 Pages: 279-280

    • DOI

      10.1007/s12551-020-00640-5

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed
  • [Journal Article] The counterion-retinylidene Schiff base interaction of an invertebrate rhodopsin rearranges upon light activation2019

    • Author(s)
      Nagata Takashi, Koyanagi Mitsumasa, Tsukamoto Hisao, Mutt Eshita, Schertler Gebhard F. X., Deupi Xavier, Terakita Akihisa
    • Journal Title

      COMMUNICATIONS BIOLOGY

      Volume: 2 Issue: 1 Pages: 180-180

    • DOI

      10.1038/s42003-019-0409-3

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Structural properties determining low K+affinity of the selectivity filter in the TWIK1 K+channel2018

    • Author(s)
      Tsukamoto Hisao、Higashi Masahiro、Motoki Hideyoshi、Watanabe Hiroki、Ganser Christian、Nakajo Koichi、Kubo Yoshihiro、Uchihashi Takayuki、Furutani Yuji
    • Journal Title

      Journal of Biological Chemistry

      Volume: 293 Issue: 18 Pages: 6969-6984

    • DOI

      10.1074/jbc.ra118.001817

    • Related Report
      2018 Research-status Report 2017 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] A Go-type opsin mediates the shadow reflex in the annelid Platynereis dumerilii2018

    • Author(s)
      Ayers Thomas、Tsukamoto Hisao、Guhmann Martin、Veedin Rajan Vinoth Babu、Tessmar-Raible Kristin
    • Journal Title

      BMC Biology

      Volume: 16 Issue: 1 Pages: 41-41

    • DOI

      10.1186/s12915-018-0505-8

    • Related Report
      2018 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] A Go-type Opsin mediates the shadow reflex in the annelid Platynereis dumerilii.2018

    • Author(s)
      T. Ayers, H. Tsukamoto, M. Guhmann, V. B. Veedin Rajan, K. Tessmar-Raible.
    • Journal Title

      BMC Biol

      Volume: 印刷中

    • Related Report
      2017 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] A ciliary opsin in the brain of a marine annelid zooplankton is ultraviolet-sensitive, and the sensitivity is tuned by a single amino acid residue.2017

    • Author(s)
      Tsukamoto H, Chen IS, Kubo Y, Furutani Y
    • Journal Title

      J Biol Chem

      Volume: 292 Issue: 31 Pages: 12971-12980

    • DOI

      10.1074/jbc.m117.793539

    • Related Report
      2017 Research-status Report
    • Peer Reviewed
  • [Presentation] 無脊椎動物オプシンの物性を利用してイオンチャネルを光操作する2019

    • Author(s)
      塚本寿夫
    • Organizer
      ISSPワークショップ「レチナールタンパク質の光機能発現の物理と化学」
    • Related Report
      2019 Annual Research Report
    • Invited
  • [Presentation] ”総力戦”としての光操作技術2019

    • Author(s)
      塚本寿夫
    • Organizer
      第57回日本生物物理学会年会
    • Related Report
      2019 Annual Research Report
    • Invited
  • [Presentation] チャネル機能の操作ツールとしての無脊椎動物光受容体2019

    • Author(s)
      塚本寿夫
    • Organizer
      生理研研究会「イオンチャネルと生体膜のダイナミズム:構造生物学の先にあるもの」
    • Related Report
      2019 Annual Research Report
    • Invited
  • [Presentation] 無脊椎動物が持つ繊毛型オプシンが示す多様な機能特性2018

    • Author(s)
      塚本寿夫, 古谷祐詞
    • Organizer
      第20回日本光生物学協会年会
    • Related Report
      2018 Research-status Report
  • [Presentation] Investigation of ligand-protein interaction in a G protein-coupled receptor via ATR-FTIR spectroscopy.2018

    • Author(s)
      H. Tsukamoto, Y. Furutani
    • Organizer
      第56回日本生物物理学会年会
    • Related Report
      2018 Research-status Report
  • [Presentation] Infrared spectroscopic and biochemical properties of a mammalian two-pore domain potassium channel TWIK-12018

    • Author(s)
      Hisao Tsukamoto, Koichi Nakajo, Yoshihiro Kubo, Yuji Furutani
    • Organizer
      The 49th Natl. Inst. Physiol. Sci (NIPS) International Symposium “Ion channels: looking back, seeing ahead"
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Presentation] 動物プランクトンの脳内紫外光受容体が持つ分子特性2018

    • Author(s)
      塚本寿夫, I-Shan Chen, 久保義弘, 古谷祐詞
    • Organizer
      「機能タンパク質の構造と機能のダイナミクスと、それに基づく細胞・生体システム作動機構の研究拠点の形成」 平成29年度末シンポジウム
    • Related Report
      2017 Research-status Report
    • Invited
  • [Presentation] 動物プランクトンの脳ではたらく紫外光受容体の分光・電気生理解析2017

    • Author(s)
      塚本寿夫, I-Shan Chen, 久保義弘, 古谷祐詞
    • Organizer
      第2回イオンチャネル研究会
    • Related Report
      2017 Research-status Report
    • Invited
  • [Presentation] Functional properties and the regulating mechanisms of a mammalian two-pore domain potassium channel TWIK-12017

    • Author(s)
      Hisao Tsukamoto, Koichi Nakajo, Yoshihiro Kubo, Yuji Furutani.
    • Organizer
      第55回日本生物物理学会年会
    • Related Report
      2017 Research-status Report
  • [Presentation] 動物プランクトンの脳ではたらく繊毛型オプシンの分子特性2017

    • Author(s)
      塚本寿夫, I-Shan Chen, 久保義弘, 古谷祐詞
    • Organizer
      日本動物学会第88回富山大会
    • Related Report
      2017 Research-status Report
  • [Remarks] 動物プランクトンの脳ではたらく、紫外線センサータンパク質

    • URL

      https://www.ims.ac.jp/news/2017/06/21_3728.html

    • Related Report
      2017 Research-status Report

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Published: 2017-04-28   Modified: 2021-02-19  

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