open access

https://hdl.handle.net/2115/95988

Contribution of Proteorhodopsin to Light-Dependent Biological Responses in Hymenobacter nivis P3T Isolated from Red Snow in Antarctica

英語

2024-09-17

American Chemical Society

Biochemistry

63(18)

2257-2265

Proteorhodopsin (PR) is a major family of microbial rhodopsins that function as light-driven outward proton pumps. PR is now widely recognized for its ecological importance as a molecule responsible for solar energy flow in various ecosystems on the earth. However, few concrete examples of the actual use of light by natural microorganisms via PR have been demonstrated experimentally. This study reveals one example of that in a cryophilic bacterium Hymenobacter nivis P3T isolated from red snow in Antarctica. The results demonstrate light-dependent biochemical and biological responses in H. nivis cells, such as the proton pump activity of H. nivis PR (HnPR), which leads to the production of proton motive force, cellular ATP production, and cell growth. In addition, the results of this study demonstrate the photochemical properties of a PR, namely, HnPR, in the membrane of a natural host bacterium. The photocycle of HnPR was much faster than other PRs even at 5 degrees C, indicating that the proton pump function of HnPR has adapted to the low-temperature environment of Antarctica. Although it is well-known that PR helps natural host microorganisms to use light energy, this study provides another concrete example for understanding the biological role of PR by demonstrating the link between the molecular functions of PR and the light-dependent biochemical and biological responses of a PR-bearing host.

学術雑誌論文

Accepted Manuscript

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Biochemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/articlesonrequest/AOR-EDNVRTHDFAWBE7X22TKI.

0006-2960