Understanding of mechanism underlying intracellular sorting of hepatocanalicular transporters

点击翻译按钮获取中文摘要

Bile salt export pump (BSEP) localizes on canalicular membrane of hepatocytes and mediates biliary excretion of bile salts. BSEP dysfunction attributed to its internalization from hepatocanalicular membrane and subsequent degradation causes intrahepatic cholestasis. At present, no medical therapy for this disease state has been established, because the regulatory mechanism of cell surface expression of BSEP remains to be elucidated. In this study, we explored it focusing on posttranslational machinery and demonstrated that ubiquitination, a posttranslational modification, of BSEP plays a role in its internalization via clathrin-mediated endocytosis involving the AP2 adaptor complex,an adaptor protein required for cargo selection in clathrin-mediated endocytosis.