Serum Response Factor Accessory Protein 1 (SAP1)

ELK4 is a member of the Ets family of transcription factors and of the ternary complex factor (TCF) subfamily. Proteins of the TCF subfamily form a ternary complex by binding to the serum response factor and the serum response element in the promoter of the c-fos proto-oncogene. The protein encoded by this gene is phosphorylated by the kinases, MAPK1 and MAPK8. Several transcript variants have been described for this gene.Subsequently, they identified a related protein, SAP2, by its cDNA sequence homology with the SAP1 cDNA. These proteins contain 3 regions of homology to a third protein, ELK1, which also functions as an SRF accessory protein and is immunologically related to HeLa cell TCF. The SAP1, SAP2, and ELK1 mRNAs are ubiquitous.