Se. Adunyah et al., REGULATION OF JUN EXPRESSION AND ACTIVATION OF AP-1 ACTIVITY BY ERYTHROPOIETIN, Biochemical and biophysical research communications, 221(2), 1996, pp. 213-218
Erythropoietin (EPO) is a molecule which regulates hemoglobin gene exp
ression during erythroid proliferation and differentiation. However, t
he mechanism by which it regulates gene expression is poorly understoo
d. Secondly, unlike other hematopoietic factors which induce expressio
n of early response genes, it is unknown whether EPO is capable of ind
ucing the expression and activation of early response genes. In this s
tudy, evidence is presented that EPO induces the expression of early r
esponse genes c-jun, junD and c-fos mRNA, stimulates jun protein synth
esis and induces activation of 5 x AP-1/CAT activity in human erythrol
eukemia K562 cells. Also, EPO appears to regulate jun expression at tr
anscriptional, post transcriptional and translational levels. These ob
servations suggest that jun and fos expression may be relevant in the
mechanism of growth control by EPO. (C) 1996 Academic Press, Inc.