Affinage

DELE1

DAP3-binding cell death enhancer 1 · UniProt Q14154

Length
515 aa
Mass
55.9 kDa
Annotated
2026-04-28
17 papers in source corpus 11 papers cited in narrative 11 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

DELE1 is a mitochondrial stress sensor that transduces diverse perturbations of mitochondrial homeostasis into activation of the cytosolic integrated stress response (ISR). Under basal conditions, DELE1 is continuously imported across both mitochondrial membranes and degraded by the matrix protease LONP1; upon mitochondrial stress — including membrane depolarization, impaired protein import, compromised presequence processing, or iron deficiency — DELE1 is either cleaved by OMA1 or HtrA2 or arrested at the mitochondrial surface, causing its accumulation in the cytosol where its C-terminal portion assembles into a D4-symmetric octamer that directly binds and activates the eIF2α kinase HRI, triggering eIF2α phosphorylation and ATF4 translation (PMID:32132707, PMID:32132706, PMID:35388015, PMID:37327776, PMID:37550454, PMID:38555279). Octamerization through hydrophobic inter-subunit contacts is required for efficient HRI activation, as assembly-impaired mutants fail to induce ISR signaling (PMID:37550454). In mouse models of mitochondrial myopathy, DELE1-mediated ISR activation maintains proteostasis by upregulating aminoacyl-tRNA biosynthesis; loss of DELE1 causes protein misfolding and compromised growth and survival (PMID:39379554).

Mechanistic history

Synthesis pass · year-by-year structured walk · 8 steps
  1. 2010 Medium

    The initial molecular identity of DELE1 was established as a mitochondrial DAP3-interacting protein that sensitizes cells to death-receptor-induced apoptosis, placing it at the intersection of mitochondria and cell death signaling.

    Evidence Yeast two-hybrid screen for DAP3 partners, co-immunoprecipitation, stable overexpression and siRNA knockdown with caspase activation readouts in mammalian cells

    PMID:20563667

    Open questions at the time
    • DAP3 interaction was from a single lab without reciprocal validation or in vitro reconstitution
    • No connection to stress response signaling was known
    • Mechanism by which DELE1 promotes caspase activation was undefined
  2. 2020 High

    Two independent genome-wide screens converged on the OMA1–DELE1–HRI pathway as the mechanism by which mitochondrial stress activates the integrated stress response: OMA1 cleaves inner-membrane-associated DELE1, and the resulting cytosolic short form directly binds and activates HRI to phosphorylate eIF2α and induce ATF4 translation.

    Evidence CRISPRi screen and haploid genetic screen, subcellular fractionation, co-immunoprecipitation, truncation mapping, DELE1/HRI knockout with eIF2α phosphorylation and ATF4 readouts

    PMID:32132706 PMID:32132707

    Open questions at the time
    • Structural basis of DELE1–HRI interaction was unknown
    • How DELE1 senses stresses other than membrane depolarization was unclear
    • Mechanism by which DELE1 is released from mitochondria was not resolved
  3. 2022 High

    DELE1 was shown to act as a sensor of mitochondrial protein import fidelity: it is continuously sorted across both membranes into the matrix, and perturbations at any step of import — including surface translocation arrest and compromised presequence processing by PITRM1/MPP — license DELE1 for cytosolic release and HRI activation, even without OMA1-mediated cleavage.

    Evidence Genome-wide genetic screen, mitochondrial import assays, subcellular fractionation, domain mapping, loss-of-function with ISR readouts

    PMID:35388015

    Open questions at the time
    • Relative contribution of different import-arrest intermediates to ISR magnitude was unquantified
    • Whether full-length DELE1 precursor and cleaved DELE1 activate HRI identically was unresolved
    • Regulatory role of matrix degradation was not yet characterized
  4. 2023 High

    The steady-state turnover of DELE1 was found to depend on LONP1-mediated degradation after matrix import, and iron deficiency arrests DELE1 import to stabilize it on the mitochondrial surface for HRI activation, establishing a mitochondrial iron-responsive ISR pathway.

    Evidence Iron chelation experiments, LONP1 knockout/knockdown, mitochondrial import assays, co-immunoprecipitation, erythroid cell model with cell death readout

    PMID:37327776

    Open questions at the time
    • Molecular basis for how iron deficiency impairs DELE1 import was not identified
    • In vivo relevance to iron deficiency anemia or erythropoiesis was not tested
  5. 2023 High

    Cryo-EM structure determination revealed that cleaved DELE1 assembles into a D4-symmetric octamer via two hydrophobic interfaces, and mutagenesis of key oligomerization residues demonstrated that octamerization is functionally required for efficient HRI activation in cells.

    Evidence Cryo-EM at near-atomic resolution, in vitro reconstitution, structure-guided mutagenesis, cell-based ISR activation assays

    PMID:37550454

    Open questions at the time
    • Structure of the DELE1 octamer in complex with HRI was not determined
    • Whether the octamer is the sole signaling-competent species in vivo was unclear
    • Stoichiometry of the DELE1–HRI signaling complex was unknown
  6. 2024 Medium

    The protease landscape was expanded: HtrA2 was identified as an alternative DELE1 protease generating a very-short form (DELE1-VS) under non-depolarizing import stress, a Parkinson's disease-associated HtrA2 mutant showed reduced DELE1 processing, and the concept of mitochondrial protein import stress (MPIS) was proposed as the unifying upstream signal.

    Evidence Endogenous DELE1 detection, protease knockout/knockdown panels, HtrA2 mutant analysis, subcellular fractionation, ISR assays

    PMID:38555279

    Open questions at the time
    • HtrA2 cleavage site on DELE1 was not mapped precisely
    • Functional distinction between DELE1-S and DELE1-VS in activating HRI was not fully resolved
    • In vivo relevance of HtrA2-mediated cleavage was not demonstrated
  7. 2024 High

    In vivo loss of DELE1 in multiple mouse models of mitochondrial myopathy demonstrated that DELE1-mediated ISR is essential for organismal proteostasis: without it, dysregulated protein synthesis causes protein misfolding in muscle and compromises growth and survival.

    Evidence Dele1 knockout crossed with Tfam KO and CHCHD10 knockin mouse models, proteomics, gene expression analysis, growth/survival phenotyping

    PMID:39379554

    Open questions at the time
    • Whether DELE1 loss causes similar phenotypes in non-muscle tissues was not tested
    • Therapeutic potential of enhancing DELE1-ISR axis in mitochondrial disease was not explored
    • Contribution of ATF4-independent DELE1 functions in vivo was not assessed
  8. 2025 Medium

    Prohibitins (PHB1/2) were identified as regulators of DELE1 localization and import at the inner membrane; disruption of prohibitins activates DELE1-dependent ISR independently of OMA1, linking the mitochondrial protein import pre-sequence pathway to ISR through the PHB–DNAJC19 axis.

    Evidence Fluorizoline treatment and PHB knockdown, DELE1 and OMA1 loss-of-function, localization assays, ISR/apoptosis readouts in HeLa and HAP1 cells

    PMID:41291210

    Open questions at the time
    • Direct physical interaction between PHBs and DELE1 was not shown
    • How DNAJC19 mechanistically connects to DELE1 import was not reconstituted
    • Limited to two cell lines without in vivo validation

Open questions

Synthesis pass · forward-looking unresolved questions
  • The structure of the DELE1–HRI signaling complex and the precise mechanism by which DELE1 octamers activate HRI kinase remain unresolved, as does the potential ATF4-independent function of DELE1–HRI signaling in regulating mitochondrial protein import and mitophagy.
  • No structure of the DELE1–HRI complex is available
  • Stoichiometry and dynamics of DELE1–HRI interaction in vivo are unknown
  • ATF4-independent roles of DELE1–HRI in import regulation and mitophagy suppression lack in vivo confirmation

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 3 GO:0098772 molecular function regulator activity 3
Localization
GO:0005739 mitochondrion 4 GO:0005829 cytosol 3
Pathway
R-HSA-8953897 Cellular responses to stimuli 5 R-HSA-392499 Metabolism of proteins 3 R-HSA-5357801 Programmed Cell Death 2
Partners
DAP3HRIHTRA2LONP1OMA1PHBPHB2
Complex memberships
DELE1 octamer

Evidence

Reading pass · 11 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2020 DELE1 is associated with the inner mitochondrial membrane and, upon mitochondrial stress, is cleaved by the OMA1 protease; the resulting short form accumulates in the cytosol where it directly interacts with and activates the eIF2α kinase HRI, triggering phosphorylation of eIF2α and ATF4 translation as part of the integrated stress response. DELE1 is also required for ATF4 translation downstream of eIF2α phosphorylation. Genome-wide CRISPR interference screen, subcellular fractionation, co-immunoprecipitation, loss-of-function (knockdown/knockout) with eIF2α phosphorylation and ATF4 induction readouts Nature High 32132706 32132707
2020 Mitochondrial stress activates OMA1, which cleaves DELE1 into a short form that accumulates in the cytosol and binds HRI via its C-terminal portion to activate HRI-mediated ISR signaling. Haploid genetic screen, genome engineering, co-immunoprecipitation, truncation mapping, knockdown/knockout with CHOP/eIF2α readouts Nature High 32132706 32132707
2022 DELE1 is continuously sorted across both mitochondrial membranes into the matrix and acts as a sensor of perturbations in mitochondrial protein import and processing. DELE1 molecules in transit become licensed for mitochondrial release and stress signaling through proteolytic removal of N-terminal sorting signals. Import defects at the mitochondrial surface allow uncleaved DELE1 precursors to directly bind and activate HRI without cleavage. DELE1 additionally responds to compromised presequence processing by the matrix proteases PITRM1 and MPP. Genome-wide genetic screen, subcellular fractionation, import assays, loss-of-function with ISR readouts, domain mapping Nature communications High 35388015
2023 Iron deficiency regulates DELE1 through its mitochondrial import: under steady-state conditions DELE1 is degraded by the matrix-resident protease LONP1 after import; upon iron chelation, DELE1 import is arrested, stabilizing DELE1 on the mitochondrial surface to activate HRI-mediated ISR. This defines a mitochondrial iron-responsive pathway. Iron chelation experiments, LONP1 knockout/knockdown, mitochondrial import assays, co-immunoprecipitation, loss-of-function in erythroid cell model with cell death readout Molecular cell High 37327776
2023 The C-terminal cleavage product of human DELE1 assembles into a high-order octameric oligomer with D4 symmetry via two sets of hydrophobic inter-subunit interactions. Key oligomerization residues were identified, and assembly-impaired DELE1 mutants are compromised in their ability to activate HRI-dependent ISR signaling in cells. Cryo-electron microscopy structure determination, in vitro reconstitution, mutagenesis, cell-based ISR activation assays Nature structural & molecular biology High 37550454
2010 DELE1 (originally named DELE) was identified as a DAP3-binding protein via yeast two-hybrid screening and confirmed to interact with DAP3 in mammalian cells. Stable DELE1 expression sensitizes cells to TNF-α and TRAIL-induced apoptosis; DELE1 knockdown rescues cells from apoptosis and inhibits activation of caspase-3, caspase-8, and caspase-9 induced by TNF-α, anti-Fas, or TRAIL. Yeast two-hybrid screening, co-immunoprecipitation in mammalian cells, stable overexpression, siRNA knockdown with caspase activation and cell death readouts Apoptosis Medium 20563667
2024 Mitochondrial protein import stress (MPIS) is identified as the overarching stress detected by DELE1. Endogenous DELE1 can be cleaved into two forms: DELE1-S (upon depolarizing stress, OMA1-dependent in HeLa) and DELE1-VS (upon non-depolarizing MPIS, generated during halted translocation). The mitochondrial protease HtrA2 mediates DELE1 cleavage into DELE1-VS; a Parkinson's disease-associated HtrA2 mutant shows reduced DELE1 processing ability. DELE1-S cleavage appears to occur in the cytosol. Endogenous DELE1 detection, protease knockout/knockdown, HtrA2 mutant analysis, subcellular fractionation, loss-of-function ISR assays Communications biology Medium 38555279
2024 In mouse models of mitochondrial myopathy, OMA1 and DELE1 sense disruption of the inner mitochondrial membrane and activate the mitochondrial ISR to upregulate pathways for aminoacyl-tRNA biosynthesis and protein synthesis building blocks. Absence of DELE1 (mt-ISR) causes dysregulated protein synthesis, protein misfolding in muscle, and failure of growth and survival in early-onset mitochondrial myopathy mice. Diverse mouse models (Tfam KO, CHCHD10 G58R and S59L knockin), Dele1 knockout, proteomics, gene expression analysis, growth/survival phenotyping The EMBO journal High 39379554
2025 Prohibitins (PHB1/2) regulate the localization and import of DELE1 at the inner mitochondrial membrane; targeting PHBs (by fluorizoline or knockdown) impairs mitochondrial protein import pre-sequence pathway and causes DELE1-dependent ISR activation and apoptosis, with OMA1 dispensable for ISR activation in this context. PHBs interact with DNAJC19 to preserve the mitochondrial protein import pathway. Fluorizoline treatment, PHB knockdown, DELE1 and OMA1 loss-of-function, localization assays, ISR/apoptosis readouts in HeLa and HAP1 cells Cell death and differentiation Medium 41291210
2026 De novo designed protein binders that engage a critical interface required for DELE1 oligomerization block DELE1 octamer assembly in vitro, suppress ATF4 induction during mitochondrial stress in cells, and impair recovery of mitochondrial morphology, while preserving DELE1's ability to bind HRI. Crystal structure analysis and targeted mutagenesis confirm the binding interface. De novo protein design, in vitro reconstitution of DELE1 oligomerization, crystal structure determination, targeted mutagenesis, cell-based ATF4/ISR assays bioRxivpreprint Medium 41717097
2024 The DELE1-HRI axis of the ISR suppresses PINK1-dependent mitophagy under non-depolarizing mitochondrial stress by positively regulating mitochondrial protein import efficiency, independent of ATF4 activation. Without ISR, increased protein synthesis overwhelms mitochondrial import machinery, causing PINK1 accumulation and triggering mitophagy. DELE1/HRI loss-of-function, PINK1 accumulation assays, mitophagy readouts, protein synthesis manipulation under depolarizing and non-depolarizing stress bioRxivpreprint Low 38529505

Source papers

Stage 0 corpus · 17 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2020 Mitochondrial stress is relayed to the cytosol by an OMA1-DELE1-HRI pathway. Nature 504 32132707
2020 A pathway coordinated by DELE1 relays mitochondrial stress to the cytosol. Nature 386 32132706
2022 DELE1 tracks perturbed protein import and processing in human mitochondria. Nature communications 75 35388015
2023 A mitochondrial iron-responsive pathway regulated by DELE1. Molecular cell 60 37327776
2023 DELE1 oligomerization promotes integrated stress response activation. Nature structural & molecular biology 36 37550454
2022 The Mitochondrial PHB2/OMA1/DELE1 Pathway Cooperates with Endoplasmic Reticulum Stress to Facilitate the Response to Chemotherapeutics in Ovarian Cancer. International journal of molecular sciences 30 35163244
2010 Identification of DELE, a novel DAP3-binding protein which is crucial for death receptor-mediated apoptosis induction. Apoptosis : an international journal on programmed cell death 30 20563667
2022 DELE1 is protective for mitochondrial cardiomyopathy. Journal of molecular and cellular cardiology 20 36539111
2017 Identification of G-quadruplex structures that possess transcriptional regulating functions in the Dele and Cdc6 CpG islands. BMC molecular biology 18 28655335
2024 Cytosolic retention of HtrA2 during mitochondrial protein import stress triggers the DELE1-HRI pathway. Communications biology 15 38555279
2024 DELE1 maintains muscle proteostasis to promote growth and survival in mitochondrial myopathy. The EMBO journal 15 39379554
2023 DELE1 haploinsufficiency causes resistance to mitochondrial stress-induced apoptosis in monosomy 5/del(5q) AML. Leukemia 9 38102204
2022 Death associated protein‑3 (DAP3) and DAP3 binding cell death enhancer‑1 (DELE1) in human colorectal cancer, and their impacts on clinical outcome and chemoresistance. International journal of oncology 9 36382667
2025 Targeting prohibitins activates the ISR through DELE1-HRI by impairing protein import into the mitochondrial matrix. Cell death and differentiation 1 41291210
2025 Trifloxystrobin induces oxidative stress-dependent activation of the OMA1-DELE1-HRI integrated stress response leading to apoptosis in human neuroblastoma cells. Environmental pollution (Barking, Essex : 1987) 1 41422903
2024 DELE1 promotes translation-associated homeostasis, growth, and survival in mitochondrial myopathy. bioRxiv : the preprint server for biology 1 38529505
2026 De novo design of protein binders that target DELE1 to inhibit the mitochondrial stress response. bioRxiv : the preprint server for biology 0 41717097