Vectorial targeting of apical and basolateral plasma membrane proteins in a human adenocarcinoma epithelial cell line.
We studied the surface delivery pathways followed by newly synthesized plasma membrane proteins in intestinal cells. To this end, we developed an assay and characterized an epithelial cell line (SK-CO-15) derived from human colon adenocarcinoma. Polarized confluent monolayers (2000 omega.cm2), grown on polycarbonate filter chambers, were pulsed with radioactive methionine/cysteine and, at different times of chase, the protein fraction reaching the apical or basolateral surface was recovered by domain-selective biotinylation, immunoprecipitation, and immobilized streptavidin precipitation. Both an apical and a basolateral marker were found to be delivered vectorially to the respective surface, with a sorting efficiency of 50:1 for the basolateral marker and 14:1 for the apical marker.
Le Bivic
A
A
Department of Cell Biology and Anatomy, Cornell University Medical College, New York, NY 10021.
Real
F X
FX
Rodriguez-Boulan
E
E
D000230:Adenocarcinoma; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D003110:Colonic Neoplasms; D004848:Epithelium / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D007700:Kinetics; D008565:Membrane Proteins / Q000096:biosynthesis*; D008854:Microscopy, Electron; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured / Q000378:metabolism* / Q000648:ultrastructure
D008565:Membrane Proteins; D009363:Neoplasm Proteins