Allosteric modulation balances thermodynamic stability and restores function of ΔF508 CFTR.
Allosteric modulation balances thermodynamic stability and restores function of ΔF508 CFTR.
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DOI：
10.1016/j.jmb.2012.03.001
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发表时间：
2012-05-25
影响因子：
5.6
通讯作者：
Riordan, John R.
中科院分区：
文献类型：
--
作者：
Aleksandrov, Andrei A.;Kota, Pradeep;Cui, Liying;Jensen, Tim;Alekseev, Alexey E.;Reyes, Santiago;He, Lihua;Gentzsch, Martina;Aleksandrov, Luba A.;Dokholyan, Nikolay V.;Riordan, John R.
大多数囊性纤维化是由CFTR中单个残基（F508）的缺失引起的，该残基破坏了离子通道蛋白的折叠和生物合成成熟。了解潜在机制和克服缺陷的进展仍然不完整。在这里，我们发现人类ΔF508 CFTR通道活性的热不稳定性在细胞附着的膜斑块和平面磷脂双层中都很明显，而在一些非哺乳动物物种的相应突变CFTR中没有观察到。这些更稳定的同源物与哺乳动物同源物的区别在于，它们在第一核苷酸结构域（NBD1）的几个关键动态位置上替换了脯氨酸残基，包括结构多样化区（SDR）、伽马磷酸盐开关环和调控插入（RI）。分子动力学分析表明，脯氨酸的加入可以降低这些位点的柔韧性，并提高ΔF508 NBD1向野生型的展开转变的温度。通过实验将这些脯氨酸与同样在SDR中已被识别的I539T抑制突变一起引入全长人ΔF508 CFTR，恢复了通道功能和热力学稳定性，以及其在细胞表面的运输和寿命。因此，虽然通过质量控制系统规避其剔除的细胞操作使ΔF508 CFTR在生理温度下功能失调，但恢复动态蛋白质固有稳定性和通道活性之间的微妙平衡将恢复到接近正常状态。
Most cystic fibrosis is caused by a deletion of a single residue (F508) in CFTR that disrupts the folding and biosynthetic maturation of the ion channel protein. Progress towards understanding the underlying mechanisms and overcoming the defect remain incomplete. Here we show that the thermal instability of human ΔF508 CFTR channel activity evident in both cell-attached membrane patches and planar phospholipid bilayers is not observed in corresponding mutant CFTRs of several non-mammalian species. These more stable orthologs are distinguished from their mammalian counterparts by the substitution of proline residues at several key dynamic locations in the first nucleotide domain (NBD1), including the structurally diverse region (SDR), the gamma phosphate switch loop and the Regulatory Insertion (RI). Molecular Dynamic analyses revealed that addition of the prolines could reduce flexibility at these locations and increase the temperatures of unfolding transitions of ΔF508 NBD1 to that of the wild-type. Introduction of these prolines experimentally into full-length human ΔF508 CFTR together with the already recognized I539T suppressor mutation, also in the SDR, restored channel function and thermodynamic stability as well as its trafficking to and lifetime at the cell surface. Thus, while cellular manipulations that circumvent its culling by quality control systems leave ΔF508 CFTR dysfunctional at physiological temperature, restoration of the delicate balance between the dynamic protein’s inherent stability and channel activity returns a near-normal state.
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影响因子：
3.7
作者：
Hoelen H;Kleizen B;Schmidt A;Richardson J;Charitou P;Thomas PJ;Braakman I
通讯作者：
Braakman I
影响因子：
5.5
作者：
Cui, L;Aleksandrov, L;Aleksandrov, AA
通讯作者：
Aleksandrov, AA
影响因子：
5.6
作者：
Cui, Liying;Aleksandrov, Luba;Riordan, John R.
通讯作者：
Riordan, John R.
DOI：
10.1016/s1359-0278(98)00072-8
发表时间：
1998-01-01
期刊：
FOLDING & DESIGN
影响因子：
--
作者：
Dokholyan, NV;Buldyrev, SV;Shakhnovich, EI
通讯作者：
Shakhnovich, EI
影响因子：
4.8
作者：
deCarvalho, ACV;Gansheroff, LJ;Teem, JL
通讯作者：
Teem, JL