Endogenous

LDLR

Low-density lipoprotein receptor (LDL receptor)

The low density lipoprotein receptor (LDLR) gene family consists of cell surface proteins involved in receptor-mediated endocytosis of specific ligands. Low density lipoprotein (LDL) is normally bound at the cell membrane and taken into the cell ending up in lysosomes where the protein is degraded and the cholesterol is made available for repression of microsomal enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, the rate-limiting step in cholesterol synthesis. At the same time, a reciprocal stimulation of cholesterol ester synthesis takes place. Mutations in this gene cause the autosomal dominant disorder, familial hypercholesterolemia. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Sep 2010],

Disease:Defects in LDLR are the cause of familial hypercholesterolemia (FH) [MIM:143890]; a common autosomal semi-dominant disease that affects about 1 in 500 individuals. The receptor defect impairs the catabolism of LDL, and the resultant elevation in plasma LDL-cholesterol promotes deposition of cholesterol in the skin (xanthelasma), tendons (xanthomas), and coronary arteries (atherosclerosis).,Function:Binds LDL, the major cholesterol-carrying lipoprotein of plasma, and transports it into cells by endocytosis. In order to be internalized, the receptor-ligand complexes must first cluster into clathrin-coated pits. In case of HIV-1 infection, functions as a receptor for extracellular Tat in neurons, mediating its internalization in uninfected cells.,online information:LDLR mutation database,online information:The Singapore human mutation and polymorphism database,PTM:N- and O-glycosylated.,similarity:Belongs to the LDLR family.,similarity:Contains 3 EGF-like domains.,similarity:Contains 6 LDL-receptor class B repeats.,similarity:Contains 7 LDL-receptor class A domains.,subunit:Interacts with LDLRAP1. Interacts with SNX17. Interacts with HCV E1/E2 heterodimer. Interacts with HIV-1 Tat.,

Cell membrane ; Single-pass type I membrane protein . Membrane, clathrin-coated pit . Golgi apparatus . Early endosome . Late endosome . Lysosome . Rapidly endocytosed upon ligand binding. .

Brain,Liver,Lymph,Plasma,

>>Endocytosis ;
>>Ovarian steroidogenesis ;
>>Aldosterone synthesis and secretion ;
>>Cortisol synthesis and secretion ;
>>Cushing syndrome ;
>>Bile secretion ;
>>Cholesterol metabolism ;
>>Toxoplasmosis ;
>>Hepatitis C ;
>>Lipid and atherosclerosis