Key activator of the integrated stress response (ISR) following mitochondrial stress (PubMed:32132706, PubMed:32132707). In response to mitochondrial stress, cleaved by the protease OMA1, generating the DAP3-binding cell death enhancer 1 short form (DELE1(S) or S-DELE1), which translocates to the cytosol and activates EIF2AK1/HRI to trigger the ISR (PubMed:32132706, PubMed:32132707). Essential for the induction of death receptor-mediated apoptosis through the regulation of caspase activation (PubMed:20563667). 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). 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). Interacts with DAP3. Interacts (via TPR repeats) with EIF2AK1/HRI; activating the protein kinase activity of EIF2AK1/HRI, thereby promoting the integrated stress response (ISR). Associates with the mitochondrion inner membrane in response to mitochondrial stress, leading to its proteolytic processing by OMA1, and generation of the AP3-binding cell death enhancer 1 short form (DELE1(S) or S-DELE1). This short form is generated by proteolytic processing by OMA1 in response to mitochondrial stress, leading to translocation to the cytosol. Detected in liver, skeletal muscle, kidney, pancreas, spleen, thyroid, testis, ovary, small intestine and colon. The TPR repeats bind to and activate EIF2AK1/HRI. Cleaved by OMA1 in response to mitochondrial stress, generating the DAP3-binding cell death enhancer 1 short form (DELE1(S) or S-DELE1) that accumulates in the cytosol and activates the protein kinase activity of EIF2AK1/HRI (PubMed:32132706, PubMed:32132707). Protein cleavage by OMA1 can take place at different positions, and apparently does not require a specific sequence motif (PubMed:32132707). Belongs to the DELE1 family. Extended N-terminus. Stress - Issue 230 of November 2020