Analysis of unconventional orientation of MaxiK channels in the peri-nuclear ER membrane

• Project/Area Number: 24590267
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: General physiology
• Research Institution: Tohoku University
• Principal Investigator: MURATA Yoshimichi 東北大学, 医学(系)研究科(研究院), 講師 (60455780)
• Co-Investigator(Renkei-kenkyūsha): MARUYAMA Yoshio 東北大学, 大学院医学系研究科, 教授 (00133942)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000); Fiscal Year 2014: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2013: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2012: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: イオンチャネル / 小胞体

Outline of Final Research Achievements

We prepared nuclear envelopes (NEs) from HEK293 cells expressing KCa1.1 and observed KCa1.1 currents in the membrane subjected to the patch-clamp technique. The results indicated that the KCa1.1 channels are oriented in the ER membrane as their usual extracellular side faces to cytosol. These observations are inconsistent with the conventional understandings of the protein transport process.
Pharmacological and electrophysiological experiments indicated that KCa1.1 channels in our NE preparation didn't oriented bidirectional. They consisted of unconventional orientation. Electrophysiological experiments showed that KCNMB1 wasn't involved in this phenomenon.

Research Products

• [Journal Article] Voltage-dependent biphasic effects of chloroquine on delayed rectifier K^+-channel currents in murine thymocytes (2012)
  • Author(s): 風間逸郎、丸山芳夫、村田喜理
  • Journal Title: Journal of Physiological Science Volume: (印刷中) Issue: 3 Pages: 267-274
  • DOI: 10.1007/s12576-012-0195-x
  • Peer Reviewed
• [Journal Article] Suppressive effects of nonsteroidal anti-inflammatory drugs diclofenac sodium, salicylate and indomethacin on delayed rectifier K+-channel currents in murine thymocytes (2012)
  • Author(s): Kazama I, Maruyama Y, Murata Y
  • Journal Title: Immunopharmacol Immunotoxicol Volume: 34(5) Issue: 5 Pages: 874-8
  • DOI: 10.3109/08923973.2012.666249
  • Peer Reviewed
• [Presentation] TRPV1チャネルのポア領域に多数存在するbulkyなアミノ酸残基の役割 (2014)
  • Author(s): 村田喜理
  • Organizer: 第９１回日本生理学会大会
  • Place of Presentation: 鹿児島大学郡元キャンパス（鹿児島県鹿児島市）
• [Presentation] HEK293細胞の核周辺小胞体膜における、MaxiKチャネルタンパク質の配向 (2013)
  • Author(s): 村田喜理
  • Organizer: 第４５回東北生理談話会
  • Place of Presentation: 東北大学片平キャンパス（宮城県仙台市）
• [Presentation] MaxiKチャネルタンパク質のHEK293細胞核周辺小胞体膜における配向の生化学的同定
  • Author(s): 村田喜理
  • Organizer: 第９０回日本生理学会大会
  • Place of Presentation: 東京