Biochemical and biophysical approaches to probe CFTR structure.
Biochemical and biophysical approaches to probe CFTR structure.
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探测 CFTR 结构的生物化学和生物物理方法。
DOI：
10.1007/978-1-61779-117-8_24
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Thomas,PhilipJ
中科院分区：
文献类型：
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作者：
Schmidt,Andre;Mendoza,JuanL;Thomas,PhilipJ
囊性纤维化跨膜调节因子（CFTR）是一种多结构域的膜整合蛋白，在上皮细胞液体分泌中起重要作用（见第21章）。它的活性在隐性遗传疾病囊性纤维化（CF）中是有缺陷的。最常见的导致CF的突变是CFTR的第一个核苷酸结合结构域（NBD 1）中的F508 del。这种突变在超过90%的所有CF患者的至少一个等位基因上发现。已知其通过分泌途径干扰CFTR的运输/成熟，导致质膜功能丧失。值得注意的是，通过添加基因内第二位点抑制突变或改变本体溶剂条件（例如通过降低温度或添加渗透剂）来校正运输缺陷，导致在膜处出现功能通道-因此，拯救的F508 del-CFTR保留可测量的功能。从X射线晶体学数据的NBD 1的高分辨率结构模型表明，F508暴露在域的表面上的位置预测的同源ABC转运蛋白结构位于与细胞内环（ICLs）连接跨膜跨度的接口。确定F508 del突变直接对NBD 1折叠或对结构域组装步骤或结构域折叠和组装的相对影响需要用于评估分离结构域的结构和稳定性的方法。
The cystic fibrosis transmembrane regulator (CFTR) is a multi-domain integral membrane protein central to epithelial fluid secretion (seeChapter 21). Its activity is defective in the recessive genetic disease cystic fibrosis (CF). The most common CF-causing mutation is F508del in the first nucleotide binding domain (NBD1) of CFTR. This mutation is found on at least one allele of more than 90% of all CF patients. It is known to interfere with the trafficking/maturation of CFTR through the secretory pathway, leading to a loss-of-function at the plasma membrane. Notably, correction of the trafficking defect by addition of intragenic second-site suppressor mutations, or the alteration of bulk solvent conditions, such as by reducing the temperature or adding osmolytes, leads to appearance of functional channels at the membrane – thus, the rescued F508del-CFTR retains measurable function. High-resolution structural models of NBD1 from X-ray crystallographic data indicate that F508 is exposed on the surface of the domain in a position predicted by homologous ABC transporter structures to lie at the interface with the intracellular loops (ICLs) connecting the transmembrane spans. Determining the relative impact of the F508del mutation directly on NBD1 folding or on steps of domain assembly or both domain folding and assembly requires methods for evaluating the structure and stability of the isolated domain.