Transcriptional activator which is processed and activated during endoplasmic reticulum stress late phase. Binds to the cAMP response element (CRE) and activates transcription through CRE. Regulates the transcription of unfolded protein response target genes, preventing accumulation of unfolded proteins in damaged neurons. Also regulates the expression of SEC23A, accelerating protein trafficking from the ER to the Golgi thereby playing a key role in chondrocyte differentiation and formation of epiphyseal cartilage By similarity.