Transcription factor which regulates the transcription of various genes, including those involved in innate immunity and oxidative stress responses (PubMed:20369020, PubMed:28632756, PubMed:30789901). Binds to promoter regions of genes, probably at 5'-[GACGTCA]-3' consensus sequences (PubMed:30789901). Together with transcription factor daf-19, involved in regulation of the serotonergic response of ADF neurons to pathogenic food (PubMed:23505381). Modulates response to infection by the Gram-negative bacterium P.aeruginosa, acting downstream of the p38 signal transduction pathway effector serine/threonine kinase pmk-1 (PubMed:20369020, PubMed:30789901). May act with transcription factor elt-2 to control p38 gene induction in response to bacterial infection (PubMed:26016853). May be phosphorylated by pmk-1 (PubMed:20369020). Regulates transcription of the metallothionein gene, mtl-1, perhaps acting downstream of pmk-1 (PubMed:28632756). Interacts with serine/threonine kinase pmk-1; perhaps in a manner dependent on dual specificity protein kinase sek-1. Expressed in intestinal cells. RNAi-mediated knockdown increases susceptibility to infection by the Gram-negative bacterium P.aeruginosa (PubMed:20369020). Up-regulates expression of metallothionein mtl-1 (PubMed:28632756). Belongs to the bZIP family.