A transcription factor which is a key regulator in various cellular processes; including environment stress resistance (oxygen levels, hydrogen sulfide and cyanide levels and heat), negative regulation of cell apoptosis in ASJ neurons by inhibition of cep-1 via transcriptional activation of tyr-2, resistance/susceptibility to pathogenic bacteria, lifespan and brood size (PubMed:11427734, PubMed:12006646, PubMed:12686697, PubMed:15781453, PubMed:18477695, PubMed:19461873, PubMed:21093262, PubMed:19889840, PubMed:20520707, PubMed:20400959). Involved in mediating susceptibility to enteropathogenic E.coli (PubMed:16091039). Increased levels of hif-1 activity confer resistance to P.aeruginosa-mediated death but also confer susceptibility to S.aureus infection (PubMed:20865124, PubMed:22792069). Required for aha-1 nuclear localization (PubMed:11427734). Following hypoxic stress, up-regulates serotonin levels through activation of tph-1 expression (PubMed:20400959). Role in life span extension is dependent of temperature (PubMed:21241450). Not required for survival in anoxic conditions (PubMed:11427734). Involved in iron homeostasis by repressing transcription of ferritin ftn-1 and ftn-2, and divalent metal transporter smf-3 (PubMed:22396654, PubMed:22194696). May be involved in manganese homeostasis by repressing divalent metal transporter smf-3 (PubMed:22194696). Binds to aha-1 (PubMed:11427734). Interacts (hydroxylated on Pro-621) with vhl-1; the interaction induces hif-1 degradation (PubMed:11595184). Expressed in all somatic cells. By heat acclimation, hypoxia and addition of 50 ppm hydrogen sulfide (PubMed:11427734, PubMed:12686697, PubMed:19889840). By low iron levels (PubMed:22194696). Hydroxylation on Pro-621 by egl-9 during normoxia conditions is required for vhl-1-mediated proteasomal degradation. 66% do not survive embryogenesis when cultured in hypoxic conditions of 1% oxygen. Able to survive anoxic conditions (PubMed:11427734, PubMed:12006646). Inefficient translocation of aha-1 to the nucleus (PubMed:11427734). Inability to acclimate to heat (PubMed:12686697). Partial resistance to paralysis and killing by enteropathogenic E.coli and P.aeruginosa (PubMed:16091039, PubMed:20865124). Extends lifespan in a temperature dependent manner but not when grown with a restricted diet (PubMed:19461873, PubMed:21093262). At lower temperatures impairs lifespan because of a vulval integrity defect (PubMed:21241450). Unable to survive in even relatively low concentrations of hydrogen sulfide (PubMed:19889840). Reduced body levels of Mn(2+) and iron (PubMed:22194696). In low iron conditions, only 20% of animals reach the L4 larval stage (PubMed:22194696). RNAi-mediated knockdown causes an increase in ftn-1 and ftn-2 mRNA levels in normal conditions and prevents the repression of smf-3, ftn-1 and to a lesser extent ftn-2 mRNA transcription in response to low iron levels (PubMed:22194696).