Transcription factor that binds to purine-rich DNA sequences. Forms a ternary complex with SRF and the ETS and SRF motifs of the serum response element (SRE) on the promoter region of immediate early genes such as FOS and IER2 (By similarity) (PubMed:17156131). Induces target gene transcription upon JNK-signaling pathway stimulation (PubMed:17156131). Interacts in its sumoylated form with PIAS2/PIASX which enhances its transcriptional activator activity. Interacts with MAD2L2; the interaction is direct and promotes phosphorylation by the kinases MAPK8 and/or MAPK9. Interacts with POU1F1. Sumoylation represses transcriptional activator activity as it results in recruitment of HDAC2 to target gene promoters which leads to decreased histone acetylation and reduced transactivator activity. It also regulates nuclear retention. On mitogenic stimulation, phosphorylated on C-terminal serine and threonine residues by MAPK1. Ser-382 and Ser-388 are the preferred sites for MAPK1. In vitro, phosphorylation by MAPK1 potentiates ternary complex formation with the serum responses factors, SRE and SRF. Also phosphorylated on Ser-382 by MAPK8 and/or MAKP9. Phosphorylation leads to loss of sumoylation and restores transcriptional activator activity. Phosphorylated and activated by CAMK4, MAPK11, MAPK12 and MAPK14 (By similarity). Upon bFGF stimulus, phosphorylated by PAK1 (PubMed:17156131). Belongs to the ETS family.