Reactome | LRP1:Hemopexin:heme is endocytosed

LRP1:Hemopexin:heme is endocytosed

Stable Identifier

R-HSA-2230983

Type

Reaction [omitted]

Species

Homo sapiens

Compartment

endocytic vesicle membrane, plasma membrane

ReviewStatus

5/5

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The LRP1:hemopexin:heme complex is endocytosed and the complex is dissociated in lysosomes, leading to heme uptake. Heme is then degraded by heme oxygenases. Whereas LRP1 is subsequently recycled to the plasma membrane, the destiny of hemopexin is controversial. Some studies have suggested that hemopexin can be recycled as an intact molecule to the extracellular milieu (Smith and Morgan, 1979). However, it has also been proposed that following hepatic uptake of heme from hemopexin:heme, varying proportions of the protein are either returned to the circulation or degraded in the liver (Potter et al., 1993). Recently, Hvidberg et al. have shown that most hemopexin is degraded in lysosomes (Hvidberg et al., 2005).

Literature References

PubMed ID	Title	Journal	Year
15947085	Identification of the receptor scavenging hemopexin-heme complexes Hvidberg, V, Maniecki, MB, Jacobsen, C, Højrup, P, Møller, HJ, Moestrup, SK	Blood	2005
496916	Haem transport to the liver by haemopexin. Receptor-mediated uptake with recycling of the protein Smith, A, Morgan, WT	Biochem. J.	1979
8424694	In vivo fate of hemopexin and heme-hemopexin complexes in the rat Potter, D, Chroneos, ZC, Baynes, JW, Sinclair, PR, Gorman, N, Liem, HH, Muller-Eberhard, U, Thorpe, SR	Arch. Biochem. Biophys.	1993