Low density lipoprotein receptor-related protein 1 (LRP1), also known as alpha-2-macroglobulin receptor (A2MR), apolipoprotein E receptor (APOER) or cluster of differentiation 91 (CD91), is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 forming a receptor

Receptor (biochemistry)

In biochemistry, a receptor is a molecule found on the surface of a cell, which receives specific chemical signals from neighbouring cells or the wider environment within an organism...

 found in the plasma membrane of cell

Cell biology

Cell biology is a scientific discipline that studies cells – their physiological properties, their structure, the organelles they contain, interactions with their environment, their life cycle, division and death. This is done both on a microscopic and molecular level...

s involved in receptor-mediated endocytosis

Endocytosis

Endocytosis is a process by which cells absorb molecules by engulfing them. It is used by all cells of the body because most substances important to them are large polar molecules that cannot pass through the hydrophobic plasma or cell membrane...

. In humans, the LRP1 protein is encoded by the LRP1 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

.

LRP1 and Alzheimer's disease

Neuron

Neuron

A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...

s require cholesterol

Cholesterol

Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...

 to function. Cholesterol is imported into the neuron by the apolipoprotein apoE4 via LRP1 receptors on the cell surface. It is thought that a causal factor in Alzheimer's is the malfunction of this process which damages neurons by starving them of cholesterol.

Interactions

LRP1 has been shown to interact

Protein-protein interaction

Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...

 with Apolipoprotein E

Apolipoprotein E

Apolipoprotein E is a class of apolipoprotein found in the chylomicron and IDLs that binds to a specific receptor on liver cells and peripheral cells. It is essential for the normal catabolism of triglyceride-rich lipoprotein constituents.-Function:...

, Lipoprotein lipase

Lipoprotein lipase

Lipoprotein lipase is a member of the lipase gene family, which includes pancreatic lipase, hepatic lipase, and endothelial lipase. It is a water soluble enzyme that hydrolyzes triglycerides in lipoproteins, such as those found in chylomicrons and very low-density lipoproteins , into two free...

, Urokinase receptor

Urokinase receptor

The Urokinase receptor, also known as uPA receptor or uPAR or CD87 , is multidomain glycoprotein tethered to the cell membrane with a glycosylphosphotidylinositol anchor...

, MAPK8IP2

MAPK8IP2

C-jun-amino-terminal kinase-interacting protein 2 is an enzyme that in humans is encoded by the MAPK8IP2 gene.-Interactions:MAPK8IP2 has been shown to interact with MAP3K10, Mitogen-activated protein kinase 9, LRP2, LRP1, MAPK8IP3, MAP3K12, MAPK8IP1, MAP2K7 and MAP3K11.-Further reading:...

, Tissue plasminogen activator

Tissue plasminogen activator

Tissue plasminogen activator is a protein involved in the breakdown of blood clots. It is a serine protease found on endothelial cells, the cells that line the blood vessels. As an enzyme, it catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown...

, Thrombospondin 1

Thrombospondin 1

Thrombospondin 1, also known as THBS1, is a protein that in humans in encoded by the THBS1 gene.Thrombospondin 1 is a subunit of a disulfide-linked homotrimeric protein. This protein is an adhesive glycoprotein that mediates cell-to-cell and cell-to-matrix interactions. This protein can bind to...

, SYNJ2BP

SYNJ2BP

Synaptojanin-2-binding protein is a protein that in humans is encoded by the SYNJ2BP gene.-Interactions:SYNJ2BP has been shown to interact with LRP2, ACVR2B, ACVR2A and LRP1.-Further reading:...

, DLG4

DLG4

PSD-95 also known as SAP-90 is a protein that in humans is encoded by the DLG4 gene....

, NOS1AP

NOS1AP

Nitric oxide synthase 1 adaptor protein also known as carboxyl-terminal PDZ ligand of neuronal nitric oxide synthase protein is a protein that in humans is encoded by the NOS1AP gene....

, Calcitonin receptor

Calcitonin receptor

The calcitonin receptor is a G protein-coupled receptor that binds the peptide hormone calcitonin and is involved in maintenance of calcium homeostasis, particularly with respect to bone formation and metabolism ....

, APBB1

APBB1

Amyloid beta A4 precursor protein-binding family B member 1 is a protein that in humans is encoded by the APBB1 gene.-Interactions:APBB1 has been shown to interact with APLP2, TFCP2, LRP1 and Amyloid precursor protein.-Further reading:...

, ITGB1BP1

ITGB1BP1

Integrin beta-1-binding protein 1 is a protein that in humans is encoded by the ITGB1BP1 gene.-Interactions:ITGB1BP1 has been shown to interact with KRIT1, LRP2, CD29 and LRP1.-Further reading:...

, MAPK8IP1

MAPK8IP1

C-jun-amino-terminal kinase-interacting protein 1 is an enzyme that in humans is encoded by the MAPK8IP1 gene.-Interactions:MAPK8IP1 has been shown to interact with MAP3K10, DUSP16, Mitogen-activated protein kinase 9, MAPK8, LRP2, LRP1, MAP3K12, MAP2K7, MAPK8IP2 and MAP3K11.-Further reading:...

, GIPC1

GIPC1

GIPC PDZ domain containing family, member 1 is a protein that in humans is encoded by the GIPC1 gene.-Interactions:GIPC1 has been shown to interact with Beta-1 adrenergic receptor, ITGA5, ITGA6, TPBG, RGS19, TYRP1, GLUT1, Actinin, alpha 1, KIF1B, LRP2, Luteinizing hormone/choriogonadotropin...

 and SHC1

SHC1

SHC-transforming protein 1 is a protein that in humans is encoded by the SHC1 gene. SHC has been found to be important in the regulation of apoptosis and drug resistance in mammalian cells....

.

See also

• Cluster of differentiation
  Cluster of differentiation
  The cluster of differentiation is a protocol used for the identification and investigation of cell surface molecules present on white blood cells, providing targets for immunophenotyping of cells...
  
  
• Low density lipoprotein receptor gene family
  Low density lipoprotein receptor gene family
  The low density lipoprotein receptor gene family code for a class of structurally closely related cell surface receptors that fulfill diverse biological functions in different organs, tissues, and cell types. The role that is most commonly associated with this evolutionarily ancient family is...
  
  

External links