Diverse photoreceptors in phytoplankton: A novel light utilization mechanism by microbial rhodopsin.

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K19224
• 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): 神川 龍馬 京都大学, 人間・環境学研究科, 助教 (40627634)
• Project Period (FY): 2018-06-29 – 2021-03-31
• Keywords: 海洋微生物 / 微生物生態 / ロドプシン / 植物プランクトン / 光エネルギー

Outline of Final Research Achievements

Elucidation of physiological roles of proton-pumping rhodopsin in eukaryotic phytoplankton would change our view on diversity and history of light-utilization systems on the earth, given importance of phytoplankton as primary producers. In this study, we have successfully identified more than 50 rhodopsin genes from phytoplankton and analyzed their function and spectroscopic characteristics. These results showed that the rhodopsin found in Pseudonitzschia (PngR) functions as a light-driven proton pump. In addition, we unveiled the intracellular localization of the PngR, with the heterologous expression system in the model diatom Phaeodactylum tricornutum. The results of localization analysis suggest that PngR is deeply involved in the function of photosynthesis.

Free Research Field

海洋微生物

Academic Significance and Societal Importance of the Research Achievements

海洋の一次生産を支える植物プランクトン、彼らは光合成以外の光受容機構を持っているのだろうか？本研究では、クロロフィルとは異なる光受容体“ロドプシン”が植物プランクトンに広く分布すること、光駆動型のイオンポンプとして働くこと、葉緑体に局在することなどを明らかにした。