Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause the recessive genetic disease cystic fibrosis, where the chloride transport across the apical membrane of epithelial cells mediated by the CFTR protein is impaired. CFTR protein trafficking to the plasma membrane (PM) is the result of a complex interplay between the secretory and membrane recycling pathways that control the number of channels present at the membrane. In addition, the ion transport activity of CFTR at the PM is modulated through post-translational protein modifications. Previously we described that spleen tyrosine kinase (SYK) phosphorylates a specific tyrosine residue in the nucleotide-binding domain 1 domain and this modification can regulate the PM abundance of CFTR. Here we identified the underlying biochemical mechanism using peptide pull-down assays followed by mass spectrometry. We identified in bronchial epithelial cells that the adaptor protein SHC1 recognizes tyrosine-phosphorylated CFTR through its phosphotyrosine-binding domain and that the formation of a complex between SHC1 and CFTR is induced at the PM in the presence of activated SYK. The depletion of endogenous SHC1 expression was sufficient to promote an increase in CFTR at the PM of these cells. The results identify a SYK/SHC1 pathway that regulates the PM levels of CFTR channels, contributing to a better understanding of how CFTR-mediated chloride secretion is regulated.

囊性纤维化跨膜电导调节剂（CFTR）基因会导致隐性遗传疾病囊性纤维化，其中CFTR蛋白介导的氯离子通过上皮细胞顶膜的运输受到损害。CFTR蛋白运输到质膜（PM）是分泌和膜循环途径之间复杂相互作用的结果，该途径控制着膜上存在的通道数量。另外，通过翻译后蛋白质修饰来调节CFTR在PM处的离子转运活性。先前我们描述了脾酪氨酸激酶（SYK）磷酸化核苷酸结合域1域中的特定酪氨酸残基，这种修饰可以调节CFTR的PM含量。在这里，我们使用肽下拉测定法接着质谱法确定了潜在的生化机制。我们在支气管上皮细胞中发现，衔接蛋白SHC1通过其磷酸酪氨酸结合结构域识别酪氨酸磷酸化的CFTR，并且在激活的SYK存在下，在PM诱导SHC1和CFTR之间形成复合物。内源性SHC1表达的耗竭足以促进这些细胞PM处CFTR的增加。结果确定了一个调节CFTR通道PM水平的SYK / SHC1途径，有助于更好地了解CFTR介导的氯化物分泌是如何被调节的。内源性SHC1表达的耗竭足以促进这些细胞PM处CFTR的增加。结果确定了一个调节CFTR通道PM水平的SYK / SHC1途径，有助于更好地了解CFTR介导的氯化物分泌是如何被调节的。内源性SHC1表达的耗竭足以促进这些细胞PM处CFTR的增加。结果确定了一个调节CFTR通道PM水平的SYK / SHC1途径，有助于更好地了解CFTR介导的氯化物分泌是如何被调节的。