InterPro domain: IPR044280

This entry represents a group of basic leucine zipper (bZIP) transcription factors, including Hac1 from yeasts and HY5/HY5-like from Arabidopsis. Hac1 regulates the unfolded protein response (UPR) induced by abnormal accumulation of unfolded/misfolded proteins in the endoplasmic reticulum (ER) in Saccharomyces cerevisiae [ 1 , 2 , 3 ]. HY5 promotes photomorphogenesis in light [ 4 ]. HY5-like protein, also known as HYH, is involved in blue-light regulation of development and gene expression. HYH and HY5 can, respectively, act as heterodimers and homodimers, thus mediating light-regulated expression of overlapping as well as distinct target genes [ 5 ].

1. Translation Control of HAC1 by Regulation of Splicing in Saccharomyces cerevisiae. Int J Mol Sci 20
2. Stress signaling from the lumen of the endoplasmic reticulum: coordination of gene transcriptional and translational controls. Genes Dev 13, 1211-33
3. Evidence That Base-pairing Interaction between Intron and mRNA Leader Sequences Inhibits Initiation of HAC1 mRNA Translation in Yeast. J Biol Chem 290, 21821-32
4. MicroRNA408 is critical for the HY5-SPL7 gene network that mediates the coordinated response to light and copper. Plant Cell 26, 4933-53
5. Two interacting bZIP proteins are direct targets of COP1-mediated control of light-dependent gene expression in Arabidopsis. Genes Dev. 16, 1247-59