Evidence for selective transport of two brush-border glycoproteins from endoplasmic reticulum to Golgi complex in rabbit enterocytes.
In vivo pulse-chase labeling of rabbit jejunum loops was used in conjunction with subcellular fractionation and quantitative immunoprecipitation to compare the intracellular transport kinetics of aminopeptidase with that of a 140 kDa brush-border antigen not belonging to the hydrolase class. As judged by the maturation kinetics of Asn-linked glycans, these glycoproteins were found to be transported from the endoplasmic reticulum into the Golgi apparatus at different rates (t1/2 = 25-50 min). The transport from the Golgi complex to the brush-border was rapid and seemed to occur at the same rate for both glycoproteins. In keeping with these kinetic data, the steady-state levels of aminopeptidase and the 140 kDa antigen in the Golgi complex were low, although that of aminopeptidase was significantly higher.
D000626:Aminopeptidases / Q000378:metabolism; D000818:Animals; D000941:Antigens; D001692:Biological Transport; D018826:CD13 Antigens; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006023:Glycoproteins / Q000276:immunology / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D007163:Immunosorbent Techniques; D007583:Jejunum / Q000648:ultrastructure*; D007700:Kinetics; D008871:Microvilli / Q000378:metabolism*; D011817:Rabbits
D000941:Antigens; D006023:Glycoproteins; D000626:Aminopeptidases; D018826:CD13 Antigens