Identification of phosphoproteins specific to granulocyte colony- stimulating factor-mediated signaling using 2D-SDS-PAGE

Abstract

Like other cytokines, granulocyte colony-stimulating factor (G-CSF) activates a complex array of signal transduction pathways involving multiple kinases and phosphatases. We sought to identify phosphoproteins specific to G-CSF signaling. Using 2D-SDS-PAGE of 32P-labeled cytosolic extracts, we compared phosphoprotein patterns of NFS-60 cells treated with G-CSF or interleukin-3 (IL-3). We also compared the patterns found after stimulation of M-NFS-60 cells with macrophage-CSF (M-CSF). A large number of phosphoproteins were found that were specific for the G-CSF response. Their distribution contrasted with that of Erk-1-related spots, identified by Western blotting, which were common to G-CSF, ..