The coactivator activator CoAA regulates PEA3 group member transcriptional activity.

The PEA3 (polyoma enhancer activator 3) group members [ERM (ETS-related molecule), ER81 (ETS-related 81) and PEA3] of the Ets transcription factor family are involved in migration and dissemination processes during organogenesis and cancer development. In the present study, we report that the hnRNP (heterogeneous nuclear ribonucleoprotein)-like protein CoAA (Coactivator activator) interacts with the PEA3 group members and modulates their transcriptional activity. We also demonstrate that the CoAA YQ domain, containing tyrosine/glutamine-rich hexapeptide repeats, is necessary for the interaction, whereas the two N-terminal RRMs (RNA recognition motifs) of CoAA are required to enhance transcriptional activity. Finally, we show that CoAA is involved in the migration-enhancing action of PEA3 on MCF7 human cancer cells, suggesting that CoAA might be an important regulator of PEA3 group member activity during metastasis.