The Phosphorylated Forms of the Transcription Factor, Egr-1, Bind to DNA More Efficiently than Non-phosphorylated

The transcription factor, Early growth response-1, Egr-1, occurs in several forms differing in length due to three alternate translation start sites (1). Egr-1 has also been reported to be phosphorylated although a role for this modification is unknown. Using dephosphorylation and hyperphosphorylation studies, we show here that phosphorylated Egr-1 is much more efficiently bound to its DNA binding element (GCE) and binds in a dose-dependent fashion. Egr-1 plays complex roles in growth regulation and we suggest that alternate forms of phosphorylated Egr-1 may account for this.