The mechanisms by which the binding of growth hormone (GH) to its cell surface receptor
elicits changes in gene transcription are largely unknown. The transcription factor Stat1/p91
has been shown to be activated by GH. Here we show that acute phase response factor or
Stat3 (or an antigenically related protein), is also activated by GH. Stat3 has been implicated
in the interleukin-6-dependent induction of acute phase response genes. GH promotes in
3T3-F442A fibroblasts the tyrosyl phosphorylation of a protein immunoprecipitated by …