Low density lipoprotein receptor-related protein 2 also known as LRP-2 or megalin is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
which in humans is encoded by the ''LRP2''
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
.
Function
LRP2 was identified as the antigen of rat experimental membranous nephropathy (Heyman nephritis) and originally named gp330 and subsequently megalin
and later LRP2. LRP2/megalin is a multiligand binding
receptor found in the
plasma membrane of many absorptive epithelial
cell
Cell most often refers to:
* Cell (biology), the functional basic unit of life
Cell may also refer to:
Locations
* Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...
s. LRP2/megalin is a member of a family of receptors with structural similarities to the low density lipoprotein receptor (
LDLR). LRP2/megalin functions to mediate
endocytosis of ligands leading to degradation in lysosomes or transcytosis. LRP2/megalin can also form complexes with
cubilin
Cubilin is a protein that in humans is encoded by the ''CUBN'' gene.
Function
Cubilin (CUBN) acts as a receptor for intrinsic factor-vitamin B12 complexes. The role of receptor is supported by the presence of 27 CUB domains. Cubilin shows a re ...
: those complexes are able to reabsorb several molecules and can be inhibited by sodium maleate. LRP2 is expressed in epithelial cells of the
thyroid
The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thy ...
(thyrocytes), where it can serve as a receptor for the protein
thyroglobulin (Tg).
Clinical significance
Mutations in the LRP2 gene are associated with
Donnai-Barrow syndrome.
Interactions
LRP2 has been shown to
interact with:
*
DAB2,
*
DLG4,
GIPC1
GIPC PDZ domain containing family, member 1 (GIPC1) is a protein that in humans is encoded by the ''GIPC1'' gene. GIPC was originally identified as it binds specifically to the C terminus of RGS-GAIP, a protein involved in the regulation of G prot ...
,[
* ITGB1BP1,][
* ]LDL-receptor-related protein associated protein
Low density lipoprotein receptor-related protein-associated protein 1 also known as LRPAP1 or RAP is a chaperone protein which in humans is encoded by the LRPAP1 gene.
Function
LRPAP1 is involved with trafficking of certain members of the LD ...
,LDLRAP1
Low-density lipoprotein receptor adapter protein 1 is a protein that in humans is encoded by the ''LDLRAP1'' gene.
The protein encoded by this gene is a cytosolic protein which contains a phosphotyrosine binding (PTB) domain. The PTB domain has b ...
,MAPK8IP1
C-jun-amino-terminal kinase-interacting protein 1 is an enzyme that in humans is encoded by the ''MAPK8IP1'' gene.
The protein encoded by this gene is a regulator of the pancreatic beta-cell function. It is highly similar to JIP-1, a mouse protein ...
,[
* MAPK8IP2,]NOS1AP
Nitric oxide synthase 1 adaptor protein (NOS1AP) also known as carboxyl-terminal PDZ ligand of neuronal nitric oxide synthase protein (CAPON) is a protein that in humans is encoded by the ''NOS1AP'' gene.
This gene encodes a cytosolic protein tha ...
,[ and
* SYNJ2BP.][
]
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Donnai-Barrow Syndrome
{{Lipoprotein metabolism