The function of Ensembl gene identifier ENSG00000081791 (DELE1, DAP3 binding cell death enhancer 1) is as follows. Protein kinase activator that acts as a key activator of the integrated stress response (ISR) following various stresses, such as iron deficiency, mitochondrial stress or mitochondrial DNA breaks (PubMed:32132706, PubMed:32132707, PubMed:35388015, PubMed:37327776, PubMed:37550454, PubMed:37832546, PubMed:38340717). Detects impaired protein import and processing in mitochondria, activating the ISR (PubMed:35388015). May also required for the induction of death receptor-mediated apoptosis through the regulation of caspase activation (PubMed:20563667). {ECO:0000269|PubMed:20563667, ECO:0000269|PubMed:32132706, ECO:0000269|PubMed:32132707, ECO:0000269|PubMed:35388015, ECO:0000269|PubMed:37327776, ECO:0000269|PubMed:37550454, ECO:0000269|PubMed:37832546, ECO:0000269|PubMed:38340717}. [DAP3-binding cell death enhancer 1]: Protein kinase activator that activates the ISR in response to iron deficiency: iron deficiency impairs mitochondrial import, promoting DELE1 localization at the mitochondrial surface, where it binds and activates EIF2AK1/HRI to trigger the ISR. . [DAP3-binding cell death enhancer 1 short form]: Protein kinase activator generated by protein cleavage in response to mitochondrial stress, which accumulates in the cytosol and specifically binds to and activates the protein kinase activity of EIF2AK1/HRI (PubMed:32132706, PubMed:32132707, PubMed:37327776, PubMed:37550454, PubMed:37832546, PubMed:38340717). It thereby activates the integrated stress response (ISR): EIF2AK1/HRI activation promotes eIF-2-alpha (EIF2S1) phosphorylation, leading to a decrease in global protein synthesis and the induction of selected genes, including the transcription factor ATF4, the master transcriptional regulator of the ISR (PubMed:32132706, PubMed:32132707, PubMed:37327776, PubMed:37550454, PubMed:37832546). Also acts as an activator of PRKN- independent mitophagy: activates the protein kinase activity of EIF2AK1/HRI in response to mitochondrial damage, promoting eIF-2-alpha (EIF2S1) phosphorylation, leading to mitochondrial localization of EIF2S1 followed by induction of mitophagy (PubMed:38340717). {ECO:0000269|PubMed:32132706, ECO:0000269|PubMed:32132707, ECO:0000269|PubMed:37327776, ECO:0000269|PubMed:37550454, ECO:0000269|PubMed:37832546, ECO:0000269|PubMed:38340717}.