Megalin is a receptor for apolipoprotein M and kidney-specific megalin-deficiency confers urinary excretion of apolipoprotein M.

摘要: Apolipoprotein ( apo) M is a novel apolipoprotein belonging to the lipocalin protein superfamily, i.e. proteins binding small lipophilic compounds. Like other apolipoproteins, it expressed in hepatocytes and secreted into plasma where associates with high-density lipoprotein particles. In addition, apoM at high levels kidney tubule cells. this study, we show that multiligand receptor megalin, which proximal cells, for mediates its uptake kidney. To examine recombinant was Escherichia coli used surface plasmon resonance cell culture studies. The results showed immobilized megalin [ dissociation constant K-d) similar 0.3-1 mu M] endocytosed by cultured rat yolk sac cells megalin-dependent manner. importance of vivo, analyzed mice tissue-specific deficiency Megalin associated pronounced urinary excretion apoM, whereas not detected normal mouse, human, or urine. Gel filtration analysis apoM-containing particles were devoid apoA-1. suggest binds megalin-mediated endocytosis tubules prevents