Enzyme-Type Rhodopsins: Unveiling the Role of Light-Activated Enzymes to Illuminate New Microbial Ecosystems

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K19134
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 40:Forestry and forest products science, applied aquatic science, and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Yoshizawa Susumu 東京大学, 大学院新領域創成科学研究科, 准教授 (00553108)
• Co-Investigator(Kenkyū-buntansha): 加藤 英明 東京大学, 大学院総合文化研究科, 准教授 (80805961)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 海洋微生物 / 光受容体 / メタゲノム / トランスクリプトーム / 微生物型ロドプシン

Outline of Final Research Achievements

In recent years, advancements in genetic analysis technologies have led to the discovery of rhodopsin genes in the genomes of both prokaryotic and eukaryotic microorganisms. While most of these rhodopsins function as light-driven ion transporters, recent reports have identified enzyme-type rhodopsins in some eukaryotic microorganisms. These enzyme-type rhodopsins are encoded by genes that combine a rhodopsin domain and an enzyme domain into a single polypeptide, with the enzyme function being regulated by light. However, the genetic diversity, distribution, and functional mechanisms of enzyme rhodopsins in marine environments remain largely unexplored. This study aims to comprehensively search, classify, and analyze the functions of enzyme rhodopsins in marine eukaryotes, with the goal of elucidating the light-induced metabolic changes in marine microorganisms.

Free Research Field

微生物生態学

Academic Significance and Societal Importance of the Research Achievements

非光合成または眼点を持たない真核微生物の光利用はこれまでなおざりにされてきた。しかしながら、本研究の解析から想像を超える数の酵素型ロドプシンが見つかったことで、従来は光を感知しないと考えられてきた微生物群が“光を感じ・利用している”可能性が示された。本研究で見出した酵素型ロドプシン遺伝子の分布・機能・生理的役割の詳細を解明することで、光に応じた微生物の形態・運動性・光合成効率の変化など“新たな光利用生態の概念”を創出できると考えている。