Optogenetic potentials of animal opsin bound to 3,4-dehydroretinal

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K14778
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Animal physiology/Animal behavior
• Research Institution: Osaka City University
• Principal Investigator: Terakita Akihisa 大阪市立大学, 大学院理学研究科, 教授 (30212062)
• Research Collaborator: Koyanagi Mitsumasa ; Nagata Takashi ; Lucas Robert J. ; Schertler Gebhard F. X. ; Deupi Xavier
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 光受容タンパク質 / オプシン / 発色団 / 光遺伝学

Outline of Final Research Achievements

Optogenetics is a biological technique that involves the use of light to control living cells/neurons, which have been genetically modified to express light-sensitive protein, rhodopsins. Rhodopsins sensitive to longer-wavelength of light, which can reach deep regions of tissues is useful for optogenetics. Therefore, in this study, enzymes that convert the normal chromophore (A1-type) to A2-type chromophore, which forms rhodopsins sensitive to longer wavelength of light. When the enzyme and rhodopsin genes are expressed in cultured cells, we found that high ratio of the expressed rhodopsin was bound to A2-type chromophore, indicating the chromophore-conversion enzyme works in cultured cells to supply rhodopsins with A2-type chromophore. We also successfully identified the amino acid residues essential for visible light absorption, in some rhodopsins that would be useful for optogenetic applications.

Free Research Field

分子生理学、動物生理化学、生物物理学、光生物学

Academic Significance and Societal Importance of the Research Achievements

光遺伝学は、神経科学のみならず生命現象の理解に大きく貢献している。脳や組織の深部まで到達する長波長の光を吸収できるロドプシン類変異タンパク質が創生されてきた。しかし、ロドプシン類は多様かつ膨大な数が存在するため、それぞれの種類に対して変異タンパク質を作製するのには限界がある。今回の研究成果は、生体内において遺伝子導入された全てのロドプシン類を長波長シフトできる可能性を示しており、光遺伝学技術の進歩を大きく加速し、脳や神経活動の理解に貢献すると期待される。