Evaluation of the Interaction Between Proprotein Convertase Subtilisin/Kexin Type 9 and Sterol Carrier Protein-

Proprotein convertase subtilisin/kexin type 9 (PCSK9) works by degrading the low-density lipoprotein (LDL) receptor. Low or high levels of PCSK9 are associated with diabetes development. Thus, the identification of PCSK9 partners that might mediate the link between PCSK9 levels and diabetes is critical. Sterol carrier protein-2 (SCP2) is involved in the intracellular trafficking of lipids and cholesterol. Preliminary studies identified SCP2 as a protein that interacts with PCSK9. Herein, I concentrated on evaluating the interaction between PCSK9 and SCP2. Gene expression studies were used to determine the expression levels of PCSK9 and SCP2 in hepatic cells. Co-immunoprecipitation and in vitro competition studies employing ELISA were carried out to confirm the interaction between PCSK9 and SCP2 and to determine the effects of this interaction. The results indicated that PCSK9 and SCP2 do interact in hepatic cell lysates and that this interaction prevented complex formation between PCSK9 and the LDL receptor.