Recombinant Human Proprotein convertase subtilisin/kexin type 9 (PCSK9) (Active)

Function

Crucial player in the regulation of plasma cholesterol homeostasis. Binds to low-density lipid receptor family members: low density lipoprotein receptor (LDLR), very low density lipoprotein receptor (VLDLR), apolipoprotein E receptor (LRP1/APOER) and apolipoprotein receptor 2 (LRP8/APOER2), and promotes their degradation in intracellular acidic compartments (PubMed:18039658). Acts via a non-proteolytic mechanism to enhance the degradation of the hepatic LDLR through a clathrin LDLRAP1/ARH-mediated pathway. May prevent the recycling of LDLR from endosomes to the cell surface or direct it to lysosomes for degradation. Can induce ubiquitination of LDLR leading to its subsequent degradation (PubMed:17461796, PubMed:18197702, PubMed:18799458, PubMed:22074827). Inhibits intracellular degradation of APOB via the autophagosome/lysosome pathway in a LDLR-independent manner. Involved in the disposal of non-acetylated intermediates of BACE1 in the early secretory pathway (PubMed:18660751). Inhibits epithelial Na(+) channel (ENaC)-mediated Na(+) absorption by reducing ENaC surface expression primarily by increasing its proteasomal degradation. Regulates neuronal apoptosis via modulation of LRP8/APOER2 levels and related anti-apoptotic signaling pathways

Subcellular Location

Cytoplasm; Secreted; Endosome; Lysosome; Cell surface; Endoplasmic reticulum; Golgi apparatus

Disease Association

Hypercholesterolemia, familial, 3 (FHCL3) : A form of hypercholesterolemia, a disorder of lipoprotein metabolism characterized by elevated serum low-density lipoprotein (LDL) cholesterol levels, which result in excess deposition of cholesterol in tissues and leads to xanthelasma, xanthomas, accelerated atherosclerosis and increased risk of premature coronary heart disease. FHCL3 inheritance is autosomal dominant. [The disease is caused by variants affecting the gene represented in this entry]

Tissue Specificity

Expressed in neuro-epithelioma, colon carcinoma, hepatic and pancreatic cell lines, and in Schwann cells

Subunit

Monomer. Can self-associate to form dimers and higher multimers which may have increased LDLR degrading activity. The precursor protein but not the mature protein may form multimers. Interacts with APOB, VLDLR, LRP8/APOER2 and BACE1. The full-length immature form (pro-PCSK9) interacts with SCNN1A, SCNN1B and SCNN1G. The pro-PCSK9 form (via C-terminal domain) interacts with LDLR. Interacts (via the C-terminal domain) with ANXA2 (via repeat Annexin 1); the interaction inhibits the degradation of LDLR (PubMed:18799458)

• Chiang L.W. et al. Nucleic acid molecules derived from rat brain and programmed cell death models. (03-M)
• Ding K. et al. Evidence for positive selection in the C-terminal domain of the cholesterol metabolism gene PCSK9 based on phylogenetic analysis in 14 primate species. — PLoS ONE (2007)
• Ota T. et al. Complete sequencing and characterization of 21,243 full-length human cDNAs. — Nat. Genet. (2004)
• PubMed: CI-2Q51O0FGUC3G8 (NOV-)
• PubMed: CI-3BNV2K4FQF2VI (DEC-)
• Gregory S.G. et al. The DNA sequence and biological annotation of human chromosome 1. — Nature (2006)
• Mural R.J. et al. PubMed: CI-5GBD0VIIJ7C63 (SEP-)
• Seidah N.G. et al. The secretory proprotein convertase neural apoptosis-regulated convertase 1 (NARC-1): liver regeneration and neuronal differentiation. — Proc. Natl. Acad. Sci. U.S.A. (2003)