Evidence for a heterodimeric structure of megalin in liver macrophages

Megalin (LRP2) is an endocytotic transmembrane receptor of about 600 kDa and belongs to the low density lipoprotein receptor family. It is located at the apical surface of several epithelia, where it binds and internalizes many physiologically relevant molecules. Recently, we identified megalin-expressing macrophages in fibrotic liver of mice [1]. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) of liver homogenates under reducing conditions and immunoblotting using an antibody directed against the cytoplasmic tail of megalin revealed only a single 35 kDa-band corresponding to the megalin C-terminal fragment (M…