SNX17 regulates the protein level of plasma membrane associated Jag1a. (A) Knockdown of SNX17 reduced the total as well as plasma membrane associated Jag1a protein levels while over-expression of SNX17 enhanced the protein levels of Jag1a. Plasma membrane proteins were labeled with biotin and isolated with the Pierce Cell Surface Protein Isolation Kit and detected by western blot. GAPDH and TFR were the loading control. (B) SNX17 was not required for the endocytosis of Jag1a. Plasma membrane proteins were labeled with biotin and allowed to be endocytosed for 1 h. The remaining cell surface biotin was stripped and the internalized biotin-labeled proteins were immunoprecipitated then detected by western blot. (C) Subcellular distribution of Jag1a. The majority of intracellular Jag1a was detected at the Hrs-positive vesicles.