两个连续过器控制P2X7阴离子选择性,中心孔中的Ser342和细胞质接口的侧面酸性残留物
Fritz Markwardt1, Eike Christian Schön1, Michaela Raycheva2
1Julius-Bernstein-Institute of Physiology, Martin-Luther-University, Magdeburger Straße 6, D-06097 Halle/Saale, Germany.
PNAS nexus
|September 12, 2024
概括
人类的P2X7受体.
科学领域:
- 分子生物学分子生物学
- 离子通道功能 离子通道功能
- 细胞表面受体细胞表面受体
背景情况:
- 人类P2X7受体 (hP2X7R) 是一个ATP导离子通道,对细胞反应至关重要.
- 它的孔隙被氨酸残留物 (S342) 封闭,并且具有参与离子选择性的酸性残留物.
研究的目的:
- 研究特定残留物在人类P2X7受体的离子选择性和门中的作用.
- 为了确定突变如何影响阴离子和阴离子的透性.
主要方法:
- 在Xenopus laevis卵细胞中的电压电生理学.
- 关键残留物 (S342,E14,D352,D356) 的位点定向突变发生.
- 对离子 (Na+,Tris+) 和离子 (Cl-) 的离子透性的分析.
主要成果:
- 将S342转化为氨酸减少了对Na+对Tris+的选择性,但保持了阴离子选择性.
- 将酸性残留物 (E14,D352,D356) 的突变与S342突变相结合,改变了选择性,允许离子 (Cl-) 透.
- 特定的双重突变将受体转化为化物选择性通道.
结论:
- hP2X7R的离子选择性由两步过机制确定,其中包括一个中央尺寸选择性门 (S342) 和细胞质酸性残留物.
- 这些残留物集体形成离子过器,决定离子通道.
- 修改这些残留物可以从根本上改变道的离子选择性概况.
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