A SUMO switch in EGF receptor signaling. SUMOylation is a protein modification that regulates hundreds of proteins, many of which function in transcription. We discovered that EGF specifically induces rapid but transient de-SUMOylation of several transcriptional co-regulators not previously linked to EGF-receptor signaling. We hypothesize that their coordinated demodification contributes to the global transcriptional response of cells to EGF. During the first funding period, we aim to identify upstream signals, molecular mechanisms and transcriptional consequences of IRF2BP1 de-SUMOylation and to develop tools to manipulate this pathway.