Interaction of ATF6 and serum response factor

Serum response factor (SRF) is a transcription factor which binds to the serum response element (SRE) in the c-fos promoter, It is required for regulated expression of the c-fos gene as well as other immediate-early genes and some tissue-specific genes, To better understand the regulation of SRF, we used a yeast interaction assay to screen a human HeLa cell cDNA library for SRF-interacting proteins. ATF6, a basic-leucine zipper protein, was isolated by binding to SRF and in particular to its transcriptional activation domain, The binding of ATF6 to SRF was also detected in vitro, An ATF6-VP16 chimera activated expression of an SRE reporter gene in HeLa cells, suggesting that ATF6 can interact with endogenous SRF, More strikingly, an antisense ATF6 construct reduced serum induction of a c-fos reporter gene, suggesting that ATF6 is Involved in activation of transcription by SRF, ATF6 was previously partially cloned as a member of the ATF family, The complete cDNA of ATF6 was isolated, and its expression pattern was described.