TRPM4は,Ca2+で活性化された非選択的カチオンチャンネルで,細胞膜の脱極化を媒介する
Pierre Launay1, Andrea Fleig, Anne Laure Perraud
1Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
Cell
|May 23, 2002
まとめ
研究者らは,TRPM4bをカルシウム活性化非選択性 (CAN) カチオンチャンネルとして特定した. このTRPチャネルは,様々な細胞の膜ポテンシャルを調節することによって,カルシウム流入を調節する.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生理学 細胞生理学
- イオンチャネル機能のイオンチャネル機能
背景:
- カルシウム活性化非選択性 (CAN) カチオンチャネルは,神経細胞の活動や流体分泌などの細胞機能に不可欠です.
- TRPチャネルは,様々な刺激を感知することに関与する多様な家族です.
研究 の 目的:
- CANチャネルの分子候補を特定し,特徴づけること.
- 細胞カルシウムシグナル伝達におけるTRPM4bの役割を調査する.
主な方法:
- TRPM4b遺伝子のクローニングと特徴づけ.
- チャンネル特性 (導電性,イオン選択性,活性化運動性) を決定するための電気生理学的記録.
- 受容体媒介カルシウム動員への反応として,TRPM4bの活性化の分析.
主要な成果:
- TRPM4bは,25 pSの単一伝導率を持つカチオンチャネルをコードする.
- TRPM4bは,細胞内カルシウム ([Ca2+]i) によって直接活性化され,K (((D) は ~400 nMである.
- このチャネルはNa+とK+を伝導するが,Ca2+は伝導せず,受容体媒介によるカルシウム増加によって活性化される.
結論:
- TRPM4bは,CANチャネルの分子候補である.
- TRPM4bは,膜ポテンシャルに影響することによって,カルシウムの流入を調節する役割を果たします.
- このメカニズムは,他の経路経由でカルシウムが入る原動力を調節する.
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