Dynamic regulation of cystic fibrosis transmembrane conductance regulator by competitive interactions of molecular adaptors
Dynamic regulation of cystic fibrosis transmembrane conductance regulator by competitive interactions of molecular adaptors
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DOI：
10.1074/jbc.m610857200
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发表时间：
2007-04-06
影响因子：
4.8
通讯作者：
Lee, Min Goo
中科院分区：
文献类型：
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作者：
Lee, Ji Hyun;Richter, Wito;Lee, Min Goo
由囊性纤维化跨膜传导调节因子（CFTR）的功能低下或功能亢进引起的无序离子转运可能是有害的，并且可能导致危及生命的疾病，如囊性纤维化或分泌性腹泻。因此，CFTR是由精细的积极和消极的调节有效的稳态控制。已经显示，CFTR的表达和活性可以通过基于PDZ（PSD-95/ discs large/ ZO-1）结构域的衔接子正向或负向调节。虽然建立了基于PDZ结构域的衔接子（如EBP 50/NHERF 1）的正调控，但尚不清楚Shank 2对CFTR的负调控机制以及多个衔接子相互作用的影响。在这里，我们证明了EBP 50-CFTR和Shank 2-CFTR协会之间的物理和生理竞争和CFTR活性的动态调节，这些积极和消极的相互作用，使用表面等离子体共振测定和连续的膜片钳实验。此外，尽管EBP 50招募cAMP依赖性蛋白激酶（PKA）复合物到CFTR，但发现Shank 2与环核苷酸磷酸二酯酶PDE 4D在物理和功能上相关，该PDE 4D排除上皮细胞和小鼠大脑中的cAMP/PKA信号。这些研究结果强烈表明，平衡的膜转运蛋白和多个PDZ为基础的衔接子之间的相互作用发挥了关键作用，在上皮运输的稳态调节，并可能在其他组织的膜运输。
Disorganized ion transport caused by hypo- or hyperfunctioning of the cystic fibrosis transmembrane conductance regulator ( CFTR) can be detrimental and may result in life-threatening diseases such as cystic fibrosis or secretory diarrhea. Thus, CFTR is controlled by elaborate positive and negative regulations for an efficient homeostasis. It has been shown that expression and activity of CFTR can be regulated either positively or negatively by PDZ ( PSD-95/ discs large/ ZO-1) domain-based adaptors. Although a positive regulation by PDZ domain-based adaptors such as EBP50/NHERF1 is established, the mechanisms for negative regulation of the CFTR by Shank2, as well as the effects of multiple adaptor interactions, are not known. Here we demonstrate a physical and physiological competition between EBP50-CFTR and Shank2-CFTR associations and the dynamic regulation of CFTR activity by these positive and negative interactions using the surface plasmon resonance assays and consecutive patch clamp experiments. Furthermore whereas EBP50 recruits a cAMP-dependent protein kinase ( PKA) complex to CFTR, Shank2 was found to be physically and functionally associated with the cyclic nucleotide phosphodiesterase PDE4D that precludes cAMP/PKA signals in epithelial cells and mouse brains. These findings strongly suggest that balanced interactions between the membrane transporter and multiple PDZ-based adaptors play a critical role in the homeostatic regulation of epithelial transport and possibly the membrane transport in other tissues.