The expression of functional erythropoietin receptors on an interleukin-3 dependent cell line

Abstract We report the expression of the erythropoietin receptors on an interleukin-3 dependent cell line. By the transfer into medium supplemented with erythropoietin, DA-1 cells were converted to an erythropoietin dependent growth state. [ 125 I] erythropoietin was used to detect receptors specific for this hormone on the cell surface. Binding studies revealed that erythropoietin bound to 131 ± 23 receptors/cell with a Kd of 0.54 ± 0.2 nM. When the cells were incubated at 37°C trichloroaceti acid soluble radioactivity appeared in the medium after [ 125 I] erythropoietin binding began to decrease suggesting that the decline represents the degradation of cell associated [ 125 I] erythropietin- receptor complexes.