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Ligand‐induced endocytosis of the asialoglycoprotein receptor: evidence for heterogeneity in subunit oligomerization
Author(s) -
Bider Marc D,
Spiess Martin
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)00947-8
Subject(s) - endocytic cycle , endocytosis , asialoglycoprotein receptor , internalization , ligand (biochemistry) , receptor , protein subunit , oligomer , chemistry , microbiology and biotechnology , cytosol , biophysics , biochemistry , biology , enzyme , in vitro , hepatocyte , organic chemistry , gene
The hepatic asialoglycoprotein receptor, a non‐covalent hetero‐oligomer of two subunits, is a constitutively cycling endocytic receptor. However, the ligand asialoorosomucoid caused downregulation of up to 40% of surface binding sites and a twofold increase in internalization rate. This was not the result of receptor crosslinking, since monovalent ligands had the same effect. Ligand binding thus appears to transmit a signal to the cytosolic portion of the receptor not unlike in signaling receptors. The two subunits were endocytosed at different average rates lower than that of ligand, indicating heterogeneity in oligomer formation and potentially in ligand specificity.