Cell cycle-associated changes in receptors for IgE during growth and differentiation of a rat basophilic leukemia cell line.
The rat basophilic leukemia cell line (RBL-1) showed an inverse relationship between growth rate and expression of receptor activity for IgE. After prolonged exponential growth, the number of receptors per cell stabilized at 4-6 times 10-5. Cells in stationary cultures, which are arrested in the G1 phase of the cell cycle, continued to accumulate up to 0.9-1.7 times 10-6 receptors/cell with no increase in volume. Upon resuspension in fresh medium at low density, these cells were shown to lose up to 70% of the receptor activity within 4 h. Assessment of cultures synchronized by double thymidine block and cells fractionated by centrifugation of a Ficoll gradient indicated that the RBL-1 cells acquire receptors in the G1 phase of the cell cycle. No accumulation of active receptors occurred during the S and G2 phases, though the average cell volume increased. Cell division resulted in a drop in number of receptors per cell while the number of cell-bound receptors in the culture remained unchanged. This indicates that during mitosis receptors were simply distributed to daughter cells.
D000818:Animals; D000918:Antibody Specificity; D001491:Basophils / Q000276:immunology*; D001665:Binding Sites; D001666:Binding Sites, Antibody; D002460:Cell Line; D007073:Immunoglobulin E; D007074:Immunoglobulin G; D007328:Insulin / Q000378:metabolism; D007457:Iodine Radioisotopes; D007942:Leukemia, Experimental / Q000276:immunology*; D008938:Mitosis; D011817:Rabbits / Q000276:immunology; D051381:Rats / Q000276:immunology; D013997:Time Factors
D007074:Immunoglobulin G; D007328:Insulin; D007457:Iodine Radioisotopes; D007073:Immunoglobulin E