Domain-to-domain coupling in voltage sensor domain proteins

2016 Fiscal Year Final Research Report

• Project/Area Number: 25253016
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: General physiology
• Research Institution: Osaka University
• Principal Investigator: Okamura Yasushi 大阪大学, 医学系研究科, 教授 (80201987)
• Co-Investigator(Kenkyū-buntansha): 中川 敦史 大阪大学, たんぱく質研究所, 教授 (20188890) ; 藤原 祐一郎 大阪大学, 医学(系)研究科(研究院), 准教授 (20532980) ; 坂田 宗平 大阪大学, 医学(系)研究科(研究院), 招へい教員 (40528006) ; 筒井 秀和 大阪大学, 医学(系)研究科(研究院), 講師 (30392038)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: イオンチャネル / 酵素 / 膜電位

Outline of Final Research Achievements

Toward understanding general principle of domain-to-domain coupling in membrane proteins, we have exploited advantages of voltage-sensor domain proteins including voltage-gated proton channel (VSOP/Hv1) and voltage-sensing phosphatase. Approach of electrophysiology, voltage clamp fluorometery of cysteine-based method as well as fluorescent unnatural amino acid incorporation based on the genetic method enabled to reveal intermediate state of enzyme coupled to partially activated voltage sensor in VSP. X-ray crystal structure of voltage-gated proton channel was solved at 3.45 angstrom resolution as the zinc bound closed state, showing two S4 helices running straight next to each other within dimer in membrane which formed continuous helix down to the dimer cytoplasmic coiled coil at the C-terminus.

Free Research Field

分子生理学、神経科学