Acetabularia Rhodopsin I is a Light-Stimulated Proton Pump

作者:Lee Sang Soo; Choi Ah Reum; Kim So Young; Kang Ho Won; Jung Kwang Hwan; Lee Jung Ha*
来源:Journal of Nanoscience and Nanotechnology, 2011, 11(5): 4596-4600.
DOI:10.1166/jnn.2011.3650

摘要

We cloned an intronless, nuclear-encoded opsin gene from an EST library of Acetabularia acetabulum. Acetabularia rhodopsin I (ARI) encodes a protein of 246 amino acids with molecular weight of 27 kDa. ARI was reconstituted in the Xenopus oocyte expression system to characterize its electrophysiological properties utilizing the two-electrode voltage-clamping technique. Oocytes where ARI cRNA was injected displayed outward directed currents in response to light. The maximum action spectrum of ARI was detected at 520 nm green light. Light-stimulated ARI current amplitude was altered by the protons, but not by the other ions in recording solutions, suggesting that the algal rhodopsin is a light-stimulated proton pump. Typical proton-mediated outward current elicited by 520 nm light was characterized with two phases of non-inactivating outward current following initial transient current. Taken together, we here reported cloning of a novel Acetabularia opsin gene which was characterized to be a proton-pump stimulated by light.

  • 出版日期2011-5