The single pore residue Asp523 in PKD2L1 determines Ca2+ permeation of the PKD1L3/PKD2L1 complex
The single pore residue Asp523 in PKD2L1 determines Ca2+ permeation of the PKD1L3/PKD2L1 complex
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DOI：
10.1016/j.bbrc.2010.12.086
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发表时间：
2011-01-28
影响因子：
3.1
通讯作者：
Abe, Keiko
中科院分区：
文献类型：
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作者：
Fujimoto, Chisato;Ishimaru, Yoshiro;Abe, Keiko
多囊肾病1-样3（PKD 1 L3）-多囊肾病2-样1（PKD 2L 1）复合物作为Ca 2+可渗透的非选择性阳离子通道发挥作用，该通道被酸激活并随后被清除;这被称为关闭响应。在这项研究中，我们确定了一个单一的天冬氨酸残基PKD 2L 1，负责的PKD 1 L3/PKD 2L 1复合物的Ca 2+渗透。使用PKD 1 L3和PKD 2L 1的推定孔区域中存在的带负电荷的氨基酸的点突变体的钙成像分析揭示，PKD 2L 1（D523 N）中的天冬氨酸残基（其在PKD 2家族成员中是保守的）的中和消除了Ca 2+渗透，尽管细胞表面表达稳健。相反，PKD 1 L3（D2049 N和E2072 Q）和PKD 2L 1（D525 N和D530 N）的其他带负电荷的残基的中和以及用谷氨酸残基（D523 E）取代Asp（523）对Ca 2+渗透性质几乎没有影响。这些结果表明，PKD 2L 1中的Asp（523）是Ca 2+渗透到PKD 1 L3/PKD 2L 1复合物中的关键决定因素，PKD 2L 1有助于形成PKD 1 L3/PKD 2L 1通道的孔。(C)2010年爱思唯尔公司All rights reserved.
The polycystic kidney disease 1-like 3 (PKD1L3)-polycystic kidney disease 2-like 1 (PKD2L1) complex functions as a Ca2+-permeable, non-selective cation channel that is activated by acid and its subsequent removal; this is called an off-response. In this study, we identified a single aspartic residue in PKD2L1 that is responsible for the Ca2+ permeation of the PKD1L3/PKD2L1 complex. Calcium imaging analysis using point mutants of negatively charged amino acids present in the putative pore regions of PKD1L3 and PKD2L1 revealed that neutralization of the aspartic residue in PKD2L1 (D523N), which is conserved among PKD2 family members, abolished Ca2+ permeation, despite robust cell surface expression. In contrast, neutralization of the other negatively charged residues of PKD1L3 (D2049N and E2072Q) and PKD2L1 (D525N and D530N) as well as substitution of Asp(523) with a glutamate residue (D523E) had little effect on Ca2+ permeation properties. These results demonstrate that Asp(523) in PKD2L1 is a key determinant of Ca2+ permeation into the PKD1L3/PKD2L1 complex and that PKD2L1 contributes to forming the pore of the PKD1L3/PKD2L1 channel. (C) 2010 Elsevier Inc. All rights reserved.