Activating transcription factor 6 (ATF6) is a transcription factor that acts during endoplasmic reticulum stress by activating unfolded protein response target genes.Binds DNA on the 5’-CCAC[GA]-3’half of the ER stress response element (ERSE) (5’-CCAAT-N(9)-CCAC[GA]-3’) and of ERSE II (5’-ATTGG-N-CCACG-3’).Binding to ERSE requires binding of NF-Y to ERSE.Could also be involved in activation of transcription by the serum response factor.During unfolded protein response an approximative 50 kDa fragment containing the cytoplasmic transcription factor domain is released by proteolysis.The cleavage seems to be performed sequentially by site-1 and site-2 proteases.The fully glycosylated form of ATF6 a 670 amino acid protein exhibits an electrophoretic mobility of ~90 kDa in denaturing SDS-gels in part because of the glycosylated modifications.ATF6 has 3 consensus sites for N-linked glycosylation and exists constitutively as a glycosylated protein.Differentially glycosylated ATF6 forms may result from mu