Lipoprotein Receptor-Related Protein 5, Low Density (LRP5) Antibody – Sheep Polyclonal

The protein encoded by this gene, low density lipoprotein-related protein 2 (LRP2) or megalin, is a multi-ligand endocytic receptor that is expressed in many different tissues but primarily in absorptive epithilial tissues such as the kidney. This glycoprotein has a large amino-terminal extracellular domain, a single transmembrane domain, and a short carboxy-terminal cytoplasmic tail. The extracellular ligand-binding-domains bind diverse macromolecules including albumin, apolipoproteins B and E, and lipoprotein lipase. The LRP2 protein is critical for the reuptake of numerous ligands, including lipoproteins, sterols, vitamin-binding proteins, and hormones. This protein also has a role in cell-signaling; extracellular ligands include parathyroid horomones and the morphogen sonic hedgehog while cytosolic ligands include MAP kinase scaffold proteins and JNK interacting proteins. Recycling of this membrane receptor is regulated by phosphorylation of its cytoplasmic domain. Mutations in this gene cause Donnai-Barrow syndrome (DBS) and facio-oculoacoustico-renal syndrome (FOAR).[provided by RefSeq, Aug 2009]

LRP2: Acts together with cubilin to mediate HDL endocytosis. May participate in regulation of parathyroid- hormone and para-thyroid-hormone-related protein release. Defects in LRP2 are the cause of Donnai-Barrow syndrome (DBS); also known as faciooculoacousticorenal syndrome (FOAR syndrome). DBS is a rare autosomal recessive disorder characterized by major malformations including agenesis of the corpus callosum, congenital diaphragmatic hernia, facial dysmorphology, ocular anomalies, sensorineural hearing loss and developmental delay. The FOAR syndrome was first described as comprising facial anomalies, ocular anomalies, sensorineural hearing loss, and proteinuria. DBS and FOAR were first described as distinct disorders but the classic distinguishing features between the 2 disorders were presence of proteinuria and absence of diaphragmatic hernia and corpus callosum anomalies in FOAR. Early reports noted that the 2 disorders shared many phenotypic features and may be identical. Although there is variability in the expression of some features (e.g. agenesis of the corpus callosum and proteinuria), DBS and FOAR are now considered to represent the same entity. Belongs to the LDLR family.

Protein type: Receptor, misc.; Membrane protein, integral; Motility/polarity/chemotaxis

Chromosomal Location of Human Ortholog: 2q31.1

Cellular Component: Golgi apparatus; endoplasmic reticulum; endocytic vesicle; lysosome; brush border membrane; lysosomal membrane; apical plasma membrane; plasma membrane; integral to membrane; coated pit; endosome; receptor complex

Molecular Function: protein binding; calcium ion binding; SH3 domain binding

Biological Process: steroid metabolic process; cell proliferation; receptor-mediated endocytosis; phototransduction, visible light; forebrain development; protein amino acid glycosylation; endocytosis; lipid metabolic process; retinoid metabolic process; vitamin D metabolic process

Disease: Donnai-barrow Syndrome