Fig. 1.

Trafficking of LDLR in the presence of PCSK9 (a) or following PCSK9 inhibition by a monoclonal antibody (b). a Secreted PCSK9 binds to LDLR on the liver cell surface and mediates the lysosomal degradation of the complex formed by PCSK9, LDLR, and LDL [68]. b In the presence of a monoclonal antibody that binds to PCSK9, the PCSK9-mediated degradation of LDLR is inhibited, resulting in an increased uptake of LDL-cholesterol by LDLR as more LDLR are recycled at the cell surface [72]. LDL low-density lipoprotein, LDLR low-density lipoprotein receptor, PCSK9 proprotein convertase subtilisin/kexin type 9