Polarized expression of functional rat liver asialoglycoprotein receptor in transfected Madin-Darby canine kidney cells.
The rat liver asialoglycoprotein receptor or rat hepatic lectin (RHL) consists of two polypeptide species, a major one designated RHL-1 and a minor one designated RHL-2/3, which exists in two differentially glycosylated forms. We have studied the biosynthesis, targeting, and function of the different forms after transfection of their cDNAs into the polarized Madin-Darby canine kidney cell line. In cells expressing only RHL-1, newly synthesized protein undergoes rapid intracellular degradation and is not detected at the cell surface. In contrast, RHL-2/3 when transfected alone is much more stable and is expressed at the basolateral surface of fiber-grown cells. When both forms are expressed together, newly synthesized RHL-1 escapes rapid degradation and is detected at the basolateral surface. In double transfectants a functional receptor is formed that specifically endocytoses and degrades ligand at the basolateral side.
Department of Cell Biology and Anatomy, Cornell University Medical College, New York, New York 10021.
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Graeve
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Patzak
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Drickamer
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Rodriguez-Boulan
D000818:Animals; D037263:Asialoglycoprotein Receptor; D015153:Blotting, Western; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D002999:Clone Cells; D004247:DNA / Q000235:genetics; D004285:Dogs; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D007668:Kidney / Q000166:cytology / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D051381:Rats; D011971:Receptors, Immunologic / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D014162:Transfection
D037263:Asialoglycoprotein Receptor; D011971:Receptors, Immunologic; D004247:DNA