PCSK9: Structure and function. PCSK9 and low-density lipoprotein receptor. Mutations and their effects

© 2016 Elsevier España, S.L.U. y Sociedad Española de Arteriosclerosis Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to the low-density lipoprotein receptor (LDLr) and then targets it for lysosomal degradation in cells, thus preventing LDLr from recycling back to the hepatocyte surface, with a consequent decrease in LDLr density and clearance of LDL-cholesterol (LDLc). There have been reports of both gain-of-function mutations in the PCSK9 gene that cause a marked increase in LDLc conentrations and loss-of-function mutations, which lead to modest reductions in LDLc and low rates of coronary heart disease. The PCSK9 gene has become a promising therapeutic target to reduce blood cholesterol levels. This review discusses the most interesting recent data on PCSK9 regulation and its molecular function in cholesterol homeostasis.