LDLR Products

Description

The low density lipoprotein receptor (LDLR) is the founding member of the LDLR family, a group of widely expressed type I transmembrane glycoprotein cell surface scavenger receptors (1-5). Members of the family are endocytic receptors which bind and internalize extracellular ligands, including lipoproteins, exotoxins, and lipid‑carrier complexes but can also co-regulate adjacent cell-surface signaling molecules (3, 4). Mature LDLR consists of an extracellular domain (ECD) with 7 cysteine‑rich complement-like repeats (class A LDL domains), calcium-binding EGF repeats, and beta ‑propeller structures (class B LDL repeats), a transmembrane domain and a cytoplasmic domain with an NPxY-repeat motif. The ECD of cynomologus LDLR shares 94% amino acid sequence identity with human LDLR. LDLR is constitutively and widely expressed and plays a key role in regulating cholesterol homeostasis. The class A LDL domains near the N-terminus of LDLR bind apoB and apoE, the apolipoproteins of low- and very low-density lipoproteins (LDL and VLDL), respectively (1, 2, 4, 7). Hepatocyte LDLR is responsible for endocytosis and clearing of most plasma LDL cholesterol from circulation (2, 7). At the low pH of the endocytic vesicle, it dissociates, allowing degradation of LDL and recycling of LDLR to the cell surface (1, 4). Lack of LDLR expression or function causes familial hypercholesterolemia (FH) and leads to premature cardiovascular disease (4, 7, 8). The protease PCSK9 (proprotein convertase subtilisin/kexin type 9) can also cause increased plasma cholesterol by promoting LDLR degradation rather than recycling to the cell surface (8-10). Additionally, soluble forms of LDLR are reported to be released by phorbol esters or interferons and could serve as a disease marker (5, 11, 12). Several studies have demonstrated a role for LDLR in cancer progression, including liver cancer, leukemia, lung cancer, breast cancer, colorectal cancer, and prostate cancer (13).

Bioinformatics

Uniprot	XP_005588053.1
Product By Gene ID	3949
Alternate Names	FH FHC LDL R LDL receptor LDLCQ2 LDLR low density lipoprotein receptor low-density lipoprotein receptor class A domain-containing protein 3 low-density lipoprotein receptor