3p5b
From Proteopedia
The structure of the LDLR/PCSK9 complex reveals the receptor in an extended conformation
Structural highlights
DiseasePCSK9_HUMAN Defects in PCSK9 are the cause of hypercholesterolemia autosomal dominant type 3 (HCHOLA3) [MIM:603776. A familial condition characterized by elevated circulating cholesterol contained in either low-density lipoproteins alone or also in very-low-density lipoproteins.[1] FunctionPCSK9_HUMAN 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. 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. 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. 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.[2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedThe protein PCSK9 (proprotein convertase subtilisin/kexin type 9) is a key regulator of low-density lipoprotein receptor (LDLR) levels and cardiovascular health. We have determined the crystal structure of LDLR bound to PCSK9 at neutral pH. The structure shows LDLR in a new extended conformation. The PCSK9 C-terminal domain is solvent exposed, enabling cofactor binding, whereas the catalytic domain and prodomain interact with LDLR epidermal growth factor(A) and beta-propeller domains, respectively. Thus, PCSK9 seems to hold LDLR in an extended conformation and to interfere with conformational rearrangements required for LDLR recycling. Mechanistic implications for LDL receptor degradation from the PCSK9/LDLR structure at neutral pH.,Lo Surdo P, Bottomley MJ, Calzetta A, Settembre EC, Cirillo A, Pandit S, Ni YG, Hubbard B, Sitlani A, Carfi A EMBO Rep. 2011 Dec 1;12(12):1300-5. doi: 10.1038/embor.2011.205. PMID:22081141[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Homo sapiens | Large Structures | Bottomley MJ | Calzetta A | Carfi A | Cirillo A | Hubbard B | Lo Surdo P | Ni Y | Pandit S | Settembre EC | Sitlani A
