CAL对β2肾上腺素受体再循环的影响

CAL Interferes with Recycling of the β2-Adrenergic Receptor

目的 探索囊性纤维化跨膜电导调节相关配体（cystic fibrosis transmembrane conductance regulator-associated ligand, CAL）在β2肾上腺素受体（β2-adrenergic receptors, β2AR）内化后的运输过程中的作用.方法 免疫共沉淀实验检测β2AR内化后与CAL的相互作用是否发生改变;细胞免疫荧光染色结合激光共聚焦显微镜监测,初步观察CAL对β2AR内化后运输状况的影响.结果 因激动剂刺激而内化的β2AR与CAL的相互作用并未增强或减弱;CAL可使内化的β2AR不能及时返回细胞膜而滞留于细胞质内,并且二者持续共定位.结论 CAL减缓了因激动剂刺激而内化的β2AR及时再循环返回细胞膜的过程.

Objective To test the role of CAL in the recovery phase and in recycling of β2 ARs.Methods Co-immunoprecipitation assay was performed to determine whether the interaction of internalized β2ARs with CAL changes.Immunofluorescence staining combined with confocal laser scanning microscopy was used to observe the effect of CAL on the trafficking of β2AR after internali-zation.Results The interaction of internalized β2AR and CAL did not increase or decrease in cells stimulated with isoproterenol.After sequestration in response to stimulation by isoproterenol, recy-cling of β2ARs back to the plasma membrane was impaired by CAL.A large pool of receptor can be observed in the cytoplasm rather than in the cell membrane and has been found to co-localize with the CAL.Conclusion CAL blocks the recycling of β2AR after its internalization induced by stimu-lation with isoproterenol.