low density lipoprotein receptor adapter protein 1 (autosomal recessive hypercholesterolemia protein, LDLRAP1, ARH, ARH1, ARH2, FHCB1)

Function

• adapter protein (clathrin-associated sorting protein)
• role in endocytosis of the LDL receptor (LDLR) in polarized cells
• role in LDL binding & internalization but not for receptor clustering in coated pits
• facilitates endocytocis of LDLR & LDLR-LDL complexes from coated pits by stabilizing the interaction between LDLR & structural components of the pits
• internalization of other LDLR family members
• binds to soluble clathrin trimers
• binds to the adapter protein complex 2 (AP-2 beta-2 subunit)
• binds to phosphoinositides, which regulate clathrin bud assembly at the cell surface
• interacts with the VLDL receptor (VLDLR)

Structure

• contains 1 PID domain

Compartment

cytoplasm

Expression

• expressed kidney, liver, placenta > brain, heart, muscle, colon, spleen, intestine, lung, leukocytes

Pathology

• defects in LDLRAP1 are the cause of autosomal recessive hypercholesterolemia

More general terms

• phosphoprotein

Database

• OMIM: https://mirror.omim.org/entry/603813
• OMIM: https://mirror.omim.org/entry/605747
• UniProt: http://www.uniprot.org/uniprot/Q5SW96.html