LRP1
Description
The LRP1 (LDL receptor related protein 1) is a protein-coding gene located on chromosome 12.
LRP1 is a protein found on the surface of cells that acts as a receptor for a variety of molecules. It plays a role in endocytosis, the process by which cells take up molecules from their environment. LRP1 is also involved in various biological processes, such as lipoprotein metabolism and cell motility. It has been implicated in a number of diseases, including neurodegenerative diseases, atherosclerosis, and cancer. LRP1 is a large protein, with a molecular weight of about 600 kDa. It is composed of two subunits: an alpha-chain and a beta-chain. The alpha-chain is responsible for binding ligands, while the beta-chain anchors the protein to the cell membrane. LRP1 has four ligand-binding domains, each of which binds to different types of molecules. These domains contain cysteine-rich repeats, which are involved in binding to ligands. The extracellular domain of LRP1 is the alpha-chain, which comprises four ligand-binding domains (numbered I-IV) containing two, eight, ten, and eleven cysteine-rich complement-type repeats, respectively. These repeats bind extracellular matrix proteins, growth factors, proteases, protease inhibitor complexes, and other proteins involved in lipoprotein metabolism. Of the four domains, II and IV bind the majority of the protein's ligands. The EGF repeats and β-propeller domains serve to release ligands in low pH conditions, such as inside endosomes, with the β-propeller postulated to displace the ligand at the ligand binding repeats. The transmembrane domain is the β-chain, which contains a 100-residue cytoplasmic tail.
LRP1 is an endocytic receptor involved in the uptake of molecules and particles into cells through a process called endocytosis. It plays a role in the phagocytosis of apoptotic cells, which are cells that have died naturally. LRP1 is essential for early embryonic development and is involved in maintaining proper lipid levels within cells. It also helps clear chylomicron remnants (particles that transport dietary fats) and activated alpha-2-macroglobulin (a protein involved in immune responses) from the bloodstream. LRP1 acts as a receptor for alpha-2-macroglobulin and for TAU/MAPT, a protein involved in Alzheimer's disease. It regulates the endocytosis and spread of TAU/MAPT within cells. LRP1 may also influence other cellular events, including the processing of amyloid precursor protein (APP), which is involved in Alzheimer's disease, kinase-dependent signaling, and neuronal calcium signaling and neurotransmission.
LRP1 is also known as A2MR, APOER, APR, CD91, DDH3, IGFBP-3R, IGFBP3R, IGFBP3R1, KPA, LRP, LRP1A, TGFBR5.
