Granulocyte-Macrophage Colony-stimulating Factor Induces the Transcriptional Activation of egr-1 through a Protein Kinase A-independent Signaling Pathway

摘要: Abstract Granulocyte-macrophage colony-stimulating factor (GM-CSF) rapidly and transiently induces the transcriptional activation of early growth response gene-1 (egr-1) in human factor-dependent myeloid leukemic cell line, TF-1. We previously demonstrated that cAMP element (CRE) is required for GM-CSF-induced egr-1 expression phosphorylation CREB on serine 133 plays a critical role during GM-CSF signal transduction. To determine whether activates signaling pathways through protein kinase Adependent or -independent pathway, we measured levels following forskolin treatment TF-1 cells. Forskolin but not stimulation resulted an increase levels. Transient transfection assays with cells were also performed −116-nucleotide promoter construct inhibitor, PKI. Although PKI inhibited induction construct, it did affect this construct. In present study, A-independent pathway.