activating transcription factor-6; cAMP-dependent transcription factor ATF-6 alpha (ATF6)

Function

• transcription facto
• 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') & of ERSE II (5'-ATTGG-N-CCACG-3')
• binding to ERSE requires binding of NF-Y to ERSE
• may 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
• phosphorylated in vitro by MAPK14/P38MAPK
• homodimer & heterodimer with ATF6-beta
• the dimer interacts with the nuclear transcription factor Y (NF-Y) trimer through direct binding to NF-Y subunit C (NF-YC)
• interacts also with the transcription factors GTF2I, YY1 & SRF

Structure

• N-glycosylated
  • the glycosylation status may serve as a sensor for ER homeostasis, resulting in ATF6 activation to trigger the unfolded protein response (UPR)
• the basic domain functions as a nuclear localization signal
• the basic leucine-zipper domain is sufficient for association with the NF-Y trimer & binding to ERSE
• belongs to the bZIP family, ATF subfamily
• contains 1 bZIP domain

Compartment

• endoplasmic reticulum membrane
• single-pass type 2 membrane protein
• processed ATF6: nucleus
• under ER stress the cleaved N- terminal cytoplasmic domain translocates into the nucleus

Expression

ubiquitous

More general terms

• activating transcription factor

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=22926
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:22926
• OMIM: https://mirror.omim.org/entry/605537
• UniProt: http://www.uniprot.org/uniprot/P18850.html