Immunoglobulin Like Domain Containing Receptor 1 (ILDR1)

ILDR1-alpha is a type I membrane protein with a signal sequence, an Ig-like extracellular domain, a transmembrane region, and a C-terminal domain containing a cysteine-rich region, which is probably involved in interactions with other proteins, a dileucine motif, which may promote internalization and intracellular sorting, and an arginine-rich region. ILDR1-alpha-prime has 39 unique N-terminal residues and lacks the dileucine motif. ILDR1-beta lacks the cysteine-rich region and the transmembrane region and is therefore likely to be a soluble protein. ILDR1 shares homology with rat lipolysis-stimulated receptor (Lsr), suggesting that ILDR1 may be involved in lipoprotein transport. Immunoblot analysis showed expression of 70-kD (alpha), 66-kD (alpha-prime) and 60-kD (beta) ILDR1 proteins under reducing conditions.