title: Isolation by fluorescence-activated cell sorting of Chinese hamster ovary cell lines with pleiotropic, temperature-conditional defects in receptor recycling.
abstract: We have isolated several Chinese hamster ovary cell lines with temperature-sensitive defects in the recycling of receptors after endocytosis. These cell lines were selected using fluorescence-activated cell sorting for retention of a pulse of labeled transferrin after a chase in the presence of unlabeled transferrin. One of these cell lines, TfT1.11, was selected for further characterization. In TfT1.11 the trapping of transferrin within the cells is paralleled by a loss of cell surface transferrin receptors. Within 4 h after the shift from 33 to 41 degrees C the surface binding of transferrin is reduced to 18% of parental cells at 41 degrees C. The trapping of transferrin and the loss of transferrin receptor from the cell surface are caused by a temperature-conditional 5.5-fold decrease in the initial rate of transferrin recycling. TfT1.11 cells also rapidly lose 89% of their ability to take up alpha 2-macroglobulin after the temperature shift to 41 degrees C. These data indicate that the TfT1.11 cell line has a pleiotropic defect in receptor recycling.
authors.affiliation: Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213.
authors.forename: C C
authors.initials: CC
authors.lastname: Cain
authors.forename: R B
authors.initials: RB
authors.lastname: Wilson
authors.forename: R F
authors.initials: RF
authors.lastname: Murphy
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004705:Endocytosis; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007700:Kinetics; D009154:Mutation; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D013696:Temperature; D014168:Transferrin / Q000378:metabolism; D000511:alpha-Macroglobulins / Q000378:metabolism
chemical_list: D011956:Receptors, Cell Surface; D014168:Transferrin; D000511:alpha-Macroglobulins; D000255:Adenosine Triphosphate