The protein encoded by this gene is a transcription factor in the unfolded protein response (UPR) pathway during ER stress. Either as a homodimer or as a heterodimer with ATF6-alpha, the encoded protein binds to the ER stress response element, interacting with nuclear transcription factor Y to activate UPR target genes. The protein is normally found in the membrane of the endoplasmic reticulum, however, under ER stress, the N-terminal cytoplasmic domain is cleaved from the rest of the protein and translocates to the nucleus. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2008],domain:The basic domain functions as a nuclear localization signal.,domain:The basic leucine-zipper domain is sufficient for association with the NF-Y trimer and binding to ERSE.,function:Transcriptional factor that acts in the unfolded protein response (UPR) pathway by activating UPR target genes induced during ER stress. Binds DNA on the 5-CCAC[GA]-3 half of the ER stress response element (ERSE) (5-CCAATN(9)CCAC[GA]-3) when NF-Y is bound to ERSE.,PTM:During unfolded protein response an approximative 60 kDa fragment containing the cytoplasmic transcription factor domain is released by proteolysis. The cleavage is probably performed sequentially by site-1 and site-2 proteases.,PTM:N-glycosylated.,similarity:Belongs to the bZIP family.,similarity:Belongs to the bZIP family. ATF subfamily.,similarity:Contains 1 bZIP domain.,subcellular location:Under ER stress the cleaved N-terminal cytoplasmic domain translocates into the nucleus.,subunit:Homodimer and heterodimer with ATF6-alpha. The dimer interacts with the nuclear transcription factor Y (NF-Y) trimer through direct binding to NF-Y subunit C (NF-YC).,tissue specificity:Ubiquitous.,
