INTEGRATION OF MAP KINASE SIGNAL-TRANSDUCTION PATHWAYS AT THE SERUM RESPONSE ELEMENT

The ternary complex factor (TCF) subfamily of ETS-domain transcription factors bind with serum response factor (SRF) to the serum response e lement (SRE) and mediate increased gene expression. The TCF protein El k-1 is phosphorylated by the JNK and ERK groups of mitogen-activated p rotein (MAP) kinases causing increased DNA binding, ternary complex fo rmation, and transcriptional activation. Activated SRE-dependent gene expression is induced by JNK in cells treated with interleukin-1 and b y ERK after treatment with phorbol ester. The Elk-1 transcription fact or therefore integrates MAP kinase signaling pathways in vivo to coord inate biological responses to different extracellular stimuli.