TY - JOUR
T1 - Modifying pH-sensitive PCSK9/LDLR interactions as a strategy to enhance hepatic cell uptake of low-density lipoprotein cholesterol (LDL-C)
AU - Ben-Naim, Lital
AU - Khalaila, Isam
AU - Papo, Niv
N1 - © The Author(s) 2022. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: [email protected].
PY - 2022/2/17
Y1 - 2022/2/17
N2 - LDL-receptor (LDLR)-mediated uptake of LDL-C into hepatocytes is impaired by lysosomal degradation of LDLR, which is promoted by proprotein convertase subtilisin/kexin type 9 (PCSK9). Cell surface binding of PCSK9 to LDLR produces a complex that translocates to an endosome, where the acidic pH strengthens the binding affinity of PCSK9 to LDLR, preventing LDLR recycling to the cell membrane. We present a new approach to inhibit PCSK9-mediated LDLR degradation, namely, targeting the PCSK9/LDLR interface with a PCSK9-antagonist, designated Flag-PCSK9PH, which prevents access of WT PCSK9 to LDLR. In HepG2 cells, Flag-PCSK9PH, a truncated version (residues 53-451) of human WT PCSK9, strongly bound LDLR at the neutral pH of the cell surface but dissociated from it in the endosome (acidic pH), allowing LDLR to exit the lysosomes intact and recycle to the cell membrane. Flag-PCSK9PH thus significantly enhanced cell-surface LDLR levels and the ability of LDLR to take up extracellular LDL-C.
AB - LDL-receptor (LDLR)-mediated uptake of LDL-C into hepatocytes is impaired by lysosomal degradation of LDLR, which is promoted by proprotein convertase subtilisin/kexin type 9 (PCSK9). Cell surface binding of PCSK9 to LDLR produces a complex that translocates to an endosome, where the acidic pH strengthens the binding affinity of PCSK9 to LDLR, preventing LDLR recycling to the cell membrane. We present a new approach to inhibit PCSK9-mediated LDLR degradation, namely, targeting the PCSK9/LDLR interface with a PCSK9-antagonist, designated Flag-PCSK9PH, which prevents access of WT PCSK9 to LDLR. In HepG2 cells, Flag-PCSK9PH, a truncated version (residues 53-451) of human WT PCSK9, strongly bound LDLR at the neutral pH of the cell surface but dissociated from it in the endosome (acidic pH), allowing LDLR to exit the lysosomes intact and recycle to the cell membrane. Flag-PCSK9PH thus significantly enhanced cell-surface LDLR levels and the ability of LDLR to take up extracellular LDL-C.
UR - http://www.scopus.com/inward/record.url?scp=85124775727&partnerID=8YFLogxK
U2 - https://doi.org/10.1093/protein/gzab032
DO - https://doi.org/10.1093/protein/gzab032
M3 - Article
C2 - 35174858
SN - 1741-0126
VL - 35
JO - Protein Engineering, Design and Selection
JF - Protein Engineering, Design and Selection
M1 - gzab032
ER -