LRP1 (CD91) binds Hemopexin:heme

Stable Identifier
Reaction [binding]
Homo sapiens
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Once formed in the plasma, the hemopexin:heme complex is rapidly cleared from circulation and it is taken up by the liver (Smith and Morgan 1984, Smith and Morgan 1985, Tolosano et al. 2010, Vinchi et al. 2008), where heme is degraded by heme oxygenases. In mouse, rat and rabbit several experimental evidences led to the postulation of a specific receptor on hepatocytes with high affinity for the hemopexin:heme complex (Smith and Morgan 1981, Smith and Morgan 1984, Smith et al, 1988, Smith et al., 1991), but such a receptor has not been identified to date. The only known hemopexin:heme receptor is LRP1 (CD91) that is ubiquitously expressed and has a low affinity for the complex. LRP1 is a multi-ligand scavenger receptor, involved in endocytosis in some cells types, for example macrophages, and in signaling in other cell types (reviewed in Boucher and Herz 2011). LRP1 is known to act in the metabolism of lipoprotein and it is expressed in several cell types including macrophages, hepatocytes and neurons. Among several ligands, LRP1 (CD91) can bind the hemopexin:heme complex (Hvidberg et al. 2005).
Literature References
PubMed ID Title Journal Year
6480598 Hemopexin-mediated heme uptake by liver. Characterization of the interaction of heme-hemopexin with isolated rabbit liver plasma membranes

Smith, A, Morgan, WT

J. Biol. Chem. 1984
1646599 The murine haemopexin receptor. Evidence that the haemopexin-binding site resides on a 20 kDa subunit and that receptor recycling is regulated by protein kinase C

Farooqui, SM, Smith, A, Morgan, WT

Biochem. J. 1991
15947085 Identification of the receptor scavenging hemopexin-heme complexes

Møller, HJ, Højrup, P, Hvidberg, V, Moestrup, SK, Maniecki, MB, Jacobsen, C

Blood 2005
3891754 Hemopexin-mediated heme transport to the liver. Evidence for a heme-binding protein in liver plasma membranes

Smith, A, Morgan, WT

J. Biol. Chem. 1985
19650691 Heme scavenging and the other facets of hemopexin

Fagoonee, S, Fiorito, V, Tolosano, E, Vinchi, F, Morello, N

Antioxid. Redox Signal. 2010
18556779 Hemopexin prevents endothelial damage and liver congestion in a mouse model of heme overload

Gastaldi, S, Altruda, F, Tolosano, E, Silengo, L, Vinchi, F

Am. J. Pathol. 2008
20920479 Signaling through LRP1: Protection from atherosclerosis and beyond

Boucher, P, Herz, J

Biochem. Pharmacol. 2011
2833500 Importance of ligand-induced conformational changes in hemopexin for receptor-mediated heme transport

Muster, P, Smith, A, Morgan, WT, Burch, MK, Tatum, FM

J. Biol. Chem. 1988
7287740 Hemopexin-mediated transport of heme into isolated rat hepatocytes

Smith, A, Morgan, WT

J. Biol. Chem. 1981
Orthologous Events
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