GO:1901029 negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway: Apoptosis Regulation, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1901029 describes any process that stops, prevents, or reduces the frequency, rate, or extent of mitochondrial outer membrane permeabilization (MOMP) during apoptotic signaling.
• MOMP is a point-of-no-return in intrinsic apoptosis; its negative regulation is critical for cell survival and is often dysregulated in cancer and neurodegeneration.
• Key proteins that inhibit MOMP include anti-apoptotic BCL-2 family members (BCL-2, BCL-xL, MCL-1, BCL-W, A1) and other factors that preserve mitochondrial outer membrane integrity.
• The term is a biological process (GO:1901029) and is distinct from positive regulation of MOMP (GO:1901030) and from the MOMP process itself (GO:1901031).
• Dysregulation of MOMP negative regulation contributes to tumorigenesis, chemoresistance, and neuronal apoptosis after irradiation.
• CRISPR-based knockout, knock-in, and overexpression models are essential to dissect the causal roles of MOMP regulators in disease.
Description
The mitochondrial outer membrane permeabilization (MOMP) is a decisive event in the intrinsic apoptotic pathway, leading to the release of cytochrome c and other pro-apoptotic factors from the mitochondrial intermembrane space. The Gene Ontology term GO:1901029, negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway, encompasses any process that stops, prevents, or reduces the frequency, rate, or extent of MOMP during apoptosis. This regulation is essential for cellular homeostasis, allowing cells to survive under stress and preventing inappropriate cell death. Understanding the mechanisms that negatively regulate MOMP is crucial for deciphering how cancer cells evade apoptosis and how neurons succumb to injury. Research into GO:1901029 has revealed a complex interplay between pro- and anti-apoptotic BCL-2 family proteins, as well as non-BCL-2 regulators. For instance, the membrane activity of BOK, a pro-apoptotic BCL-2 family member, can be modulated by cBID, highlighting the fine-tuning of MOMP. Moreover, microRNAs such as miR-23a-3p can down-regulate pro-apoptotic factors, thereby indirectly inhibiting MOMP and promoting neuronal survival after irradiation. These findings underscore the importance of negative regulation of MOMP in both physiological and pathological contexts. This article provides a comprehensive overview of GO:1901029, covering its definition, biological significance, key genes, regulatory mechanisms, disease associations, and experimental approaches. By integrating authoritative QuickGO data with verified PubMed literature, we aim to equip researchers with a robust framework for studying this critical apoptotic checkpoint.
negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway At A Glance
| GO ID | GO:1901029 |
|---|---|
| GO term | negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway |
| Ontology | biological_process |
| Synonym | negative regulation of MOMP; inhibition of MOMP; down-regulation of MOMP |
| Major function | Inhibits mitochondrial outer membrane permeabilization during apoptosis, promoting cell survival |
| Related terms | positive regulation of MOMP (GO:1901030); regulation of MOMP (GO:1901031); MOMP (GO:1901032) |
| Disease relevance | Cancer, neurodegeneration, ischemia-reperfusion injury, autoimmune disorders |
What Is GO:1901029?
GO:1901029 is defined as any process that stops, prevents, or reduces the frequency, rate, or extent of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway. In other words, it encompasses all molecular events that protect the mitochondrial outer membrane from becoming permeable during apoptosis, thereby inhibiting the release of pro-apoptotic factors and preventing cell death.
Why Is negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway Important in Cell Biology?
Negative regulation of MOMP is a fundamental survival mechanism that prevents inappropriate cell death and maintains tissue homeostasis. Its dysregulation is implicated in a wide range of human diseases, including cancer, where overexpression of anti-apoptotic proteins confers resistance to chemotherapy, and neurodegenerative disorders, where excessive apoptosis contributes to neuronal loss. Understanding how MOMP is negatively regulated can reveal therapeutic targets for modulating cell death in disease contexts.
• Prevents accidental or excessive apoptosis, which is vital for normal development and tissue maintenance.
• Contributes to chemoresistance in cancer by blocking MOMP and apoptosis.
• Protects neurons from apoptosis after insults such as irradiation.
• Regulates immune cell survival and homeostasis.
• Influences mitochondrial quality control and cellular stress responses.
• Provides targets for senolytic and anti-cancer therapies.
• Modulates ischemic injury in heart and brain.
• Plays a role in viral pathogenesis by inhibiting host cell apoptosis.
• Affects autophagy and mitophagy crosstalk.
• Is a key determinant of cell fate in stem cells and during differentiation.
What Happens During negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway?
Inhibition of BAX/BAK Activation
In simple terms: Anti-apoptotic proteins block the activation of BAX and BAK, the main pore-forming proteins.
The intrinsic apoptotic pathway is initiated by cellular stress, leading to activation of BH3-only proteins and subsequent activation of BAX and BAK, which oligomerize and permeabilize the mitochondrial outer membrane. Negative regulation of MOMP often involves anti-apoptotic BCL-2 family members (e.g., BCL-2, BCL-xL, MCL-1) that bind and sequester BH3-only proteins or directly inhibit BAX/BAK, preventing their conformational activation and pore formation. This sequestration maintains mitochondrial integrity and blocks cytochrome c release.
Sequestration of BH3-Only Proteins
In simple terms: Anti-apoptotic proteins trap pro-apoptotic BH3-only proteins, preventing them from activating BAX/BAK.
BH3-only proteins such as BIM, PUMA, tBID, and BAD are essential for triggering MOMP by activating BAX/BAK or neutralizing anti-apoptotic proteins. Negative regulation of MOMP can occur through the binding of anti-apoptotic BCL-2 proteins to these BH3-only proteins, thereby preventing them from engaging BAX/BAK and initiating permeabilization. For example, BCL-xL and MCL-1 sequester BIM and PUMA, respectively, to inhibit apoptosis.
Modulation of BOK Membrane Activity
In simple terms: BOK, a pro-apoptotic protein, can form pores, but its activity is regulated by interactions with other proteins like cBID.
BOK is a BCL-2 family member that can form large, stable toroidal pores in membranes, contributing to MOMP. However, its membrane activity is promoted by cBID, a BH3-only protein, suggesting that negative regulation of MOMP may involve inhibiting BOK's pore-forming ability or its activation by cBID. The precise mechanisms by which BOK is negatively regulated remain an active area of research.
MicroRNA-Mediated Downregulation of Pro-Apoptotic Factors
In simple terms: MicroRNAs can reduce the levels of pro-apoptotic proteins, indirectly inhibiting MOMP.
MicroRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally repress gene expression. Down-regulation of miR-23a-3p after irradiation leads to increased expression of pro-apoptotic factors and enhanced MOMP, whereas its overexpression inhibits MOMP and protects neurons from apoptosis. Thus, miRNAs can act as negative regulators of MOMP by targeting pro-apoptotic genes.
Mitochondrial Quality Control and MOMP Inhibition
In simple terms: Processes that maintain mitochondrial health can prevent MOMP.
Mitochondrial quality control mechanisms, including mitophagy and the mitochondrial unfolded protein response, contribute to cellular survival by removing damaged mitochondria and reducing stress signals that trigger MOMP. For instance, activation of mitophagy can limit the accumulation of reactive oxygen species and prevent BAX/BAK activation, thereby negatively regulating MOMP. The interplay between mitochondrial quality control and apoptosis is complex and context-dependent.
Key Genes Involved in GO:1901029 negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway
The following genes and proteins are key players in the negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway.
| Gene | Major Role | Research Relevance |
|---|---|---|
| BCL2 | Anti-apoptotic; binds and inhibits BAX/BAK and BH3-only proteins | Overexpressed in many cancers; target for inhibitors like venetoclax |
| BCL2L1 | Encodes BCL-xL; inhibits MOMP by sequestering BH3-only proteins | Implicated in chemoresistance; studied in neurodegeneration |
| MCL1 | Anti-apoptotic; sequesters BIM and PUMA | Amplified in cancers; target for MCL1 inhibitors |
| BCL2A1 | Encodes A1; inhibits MOMP | Regulates neutrophil survival; role in inflammation |
| BCL2L2 | Encodes BCL-W; anti-apoptotic | Important in spermatogenesis and neuronal survival |
| BOK | Pro-apoptotic; can form pores, but its activity is regulated | Its negative regulation may involve cBID; understudied |
| BAX | Pro-apoptotic; pore-forming effector | Negatively regulated by anti-apoptotic BCL-2 proteins |
| BAK1 | Pro-apoptotic; pore-forming effector | Negatively regulated by anti-apoptotic BCL-2 proteins |
| BID | BH3-only; activates BAX/BAK; cBID promotes BOK pores | Caspase-8 cleavage links extrinsic and intrinsic pathways |
| BBC3 | Encodes PUMA; BH3-only; activated by p53 | Sequestrated by MCL1 and BCL-xL |
| BCL2L11 | Encodes BIM; BH3-only | Sequestrated by MCL1 and BCL-xL; regulated by ERK |
| PMAIP1 | Encodes NOXA; BH3-only | Sequestrated by MCL1; involved in DNA damage response |
| MIR23A | MicroRNA that downregulates pro-apoptotic factors | Down-regulation after irradiation increases MOMP |
| TP53 | Tumor suppressor; transcriptionally activates PUMA and NOXA | Loss of p53 reduces MOMP and apoptosis |
| AKT1 | Survival kinase; phosphorylates and inhibits BAD and caspase-9 | Promotes cell survival by indirectly inhibiting MOMP |
| MAPK1 | ERK2; phosphorylates BIM, targeting it for degradation | Inhibits MOMP in response to growth factors |
| BCL2L10 | Anti-apoptotic; inhibits MOMP | Role in cancer and development |
| CASP8 | Initiator caspase; cleaves BID to tBID | Links extrinsic apoptosis to MOMP |
How Is negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway Regulated?
The negative regulation of MOMP is controlled by a balance between pro- and anti-apoptotic BCL-2 family proteins, which is modulated by transcriptional, post-transcriptional, and post-translational mechanisms. Growth factor signaling through the PI3K/AKT and MAPK/ERK pathways promotes cell survival by inhibiting pro-apoptotic proteins and upregulating anti-apoptotic proteins. For example, AKT phosphorylates BAD, preventing it from binding BCL-xL and inhibiting MOMP. ERK phosphorylates BIM, targeting it for proteasomal degradation, thereby reducing its ability to activate BAX/BAK. Additionally, microRNAs such as miR-23a-3p can downregulate pro-apoptotic factors, indirectly inhibiting MOMP. The tumor suppressor p53 transcriptionally activates PUMA and NOXA, which can override anti-apoptotic protection and promote MOMP. Thus, the regulation of MOMP is a complex integration of survival and death signals.
negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| BCL2 | Follicular lymphoma, chemoresistance | BCL2 overexpression in cancer cell lines; KO in mice |
| MCL1 | Multiple myeloma, breast cancer | MCL1 knockout or knockdown; point mutations to study inhibitor binding |
| BCL2L1 | Chemoresistance in solid tumors | BCL-xL overexpression; CRISPR KO in cancer cells |
| MIR23A | Irradiation-induced neuronal apoptosis | miR-23a-3p knockout or overexpression in neurons |
| BOK | Apoptosis regulation | BOK knockout and knock-in of pore mutants |
Cancer
Overexpression of anti-apoptotic BCL-2 family proteins (e.g., BCL-2, BCL-xL, MCL-1) is a common mechanism by which cancer cells evade apoptosis and develop resistance to chemotherapy. These proteins negatively regulate MOMP, preventing cytochrome c release and caspase activation. Targeting these proteins with BH3 mimetics (e.g., venetoclax) has shown clinical success in hematological malignancies. Understanding the negative regulation of MOMP is therefore critical for developing strategies to overcome chemoresistance.
Neurodegeneration
In neurodegenerative diseases such as Alzheimer's and Parkinson's, excessive apoptosis contributes to neuronal loss. However, in some contexts, such as after irradiation, neurons may upregulate anti-apoptotic factors to survive. For instance, down-regulation of miR-23a-3p after irradiation leads to increased pro-apoptotic factors and neuronal apoptosis, suggesting that maintaining miR-23a-3p levels could protect neurons by inhibiting MOMP. Thus, modulating the negative regulation of MOMP may have therapeutic potential in neurodegeneration.
Ischemia-Reperfusion Injury
During ischemia-reperfusion injury, such as in myocardial infarction or stroke, excessive MOMP leads to cell death. Negative regulation of MOMP by anti-apoptotic proteins can limit infarct size, but may also contribute to adverse remodeling. Therapeutic strategies aimed at inhibiting MOMP are being explored for cardioprotection and neuroprotection.
Autoimmunity
Defects in apoptosis can lead to autoimmune diseases due to impaired deletion of autoreactive lymphocytes. Negative regulation of MOMP in immune cells can promote their survival, potentially exacerbating autoimmunity. Conversely, enhancing MOMP in autoreactive cells could be therapeutic.
From negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X inhibit MOMP? | CRISPR knockout of gene X followed by MOMP assays |
| Does mutation Y affect anti-apoptotic function? | Point mutation knock-in of gene X in cells |
| Does overexpression of gene X protect from apoptosis? | CRISPR activation or cDNA overexpression |
| How does gene X interact with BAX/BAK? | Tagged knock-in for co-immunoprecipitation |
| What is the role of gene X in tumor growth? | Xenograft models with gene X KO or overexpression |
| Can gene X be targeted for therapy? | CRISPR library screening for resistance to BH3 mimetics |
How to Study the negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Cytochrome c release assay | MOMP induction | Assess negative regulation by anti-apoptotic proteins |
| JC-1 staining | Mitochondrial membrane potential | Detect MOMP in live cells |
| Annexin V/PI | Apoptosis | Quantify cell death after MOMP |
| Caspase-3/7 activity | Caspase activation | Measure downstream apoptosis |
| Co-immunoprecipitation | Protein interactions | Study BCL-2 family complexes |
| CRISPR knockout screen | Gene function | Identify negative regulators of MOMP |
| RNA-seq | Transcriptional changes | Analyze gene expression after apoptotic stimuli |
| Ribo-seq | Translation efficiency | Study post-transcriptional regulation of MOMP regulators |
Measuring MOMP
MOMP can be assessed by several methods, including cytochrome c release assays, mitochondrial membrane potential measurements (e.g., TMRE, JC-1), and detection of BAX/BAK activation by immunofluorescence or crosslinking. These techniques are fundamental to studying negative regulation of MOMP.
Apoptosis Assays
Apoptosis is commonly measured by annexin V/PI staining, caspase activity assays, and DNA fragmentation (TUNEL). These assays help determine whether a gene of interest negatively regulates MOMP and promotes survival.
CRISPR Screening
Genome-wide CRISPR knockout or activation screens can identify genes that negatively regulate MOMP. For example, screens for resistance to BH3 mimetics can uncover anti-apoptotic factors. Such screens are powerful for discovering novel regulators.
Proteomics and Interactomics
Mass spectrometry-based proteomics can identify protein-protein interactions and post-translational modifications of BCL-2 family proteins. These approaches reveal how anti-apoptotic proteins are regulated and how they inhibit MOMP.
How CRISPR Can Be Used to Study GO:1901029 negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway
Knockout
CRISPR knockout of anti-apoptotic genes (e.g., BCL2, MCL1) can sensitize cells to apoptosis and reduce MOMP inhibition. Knockout of pro-apoptotic genes (e.g., BAX, BAK1) can also prevent MOMP, but this is positive regulation. For studying negative regulation, knocking out candidate inhibitors and measuring MOMP is a direct approach.
Point Mutation
Point mutations can be introduced into anti-apoptotic genes to disrupt their binding to BH3-only proteins or BAX/BAK, thereby abolishing their negative regulation of MOMP. Such models help map functional domains and interactions.
Knock-in
Knock-in of tagged versions of anti-apoptotic proteins (e.g., GFP-BCL2) allows live-cell imaging and interaction studies. Knock-in of disease-associated mutations can model their effects on MOMP regulation.
Overexpression
Overexpression of anti-apoptotic genes via CRISPR activation or cDNA constructs can enhance negative regulation of MOMP and confer resistance to apoptosis. This is useful for studying gain-of-function mechanisms in cancer.
How EDITGENE Supports negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway Research
Researchers studying negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway-related genes often need to determine whether a candidate gene is causally involved in inhibiting MOMP or is merely a bystander. EDITGENE provides a comprehensive suite of CRISPR services to enable such functional studies with precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway research.
Frequently Asked Questions About negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway
What is GO:1901029?
GO:1901029 is a Gene Ontology term for any process that stops, prevents, or reduces the frequency, rate, or extent of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway.
What genes are involved in negative regulation of MOMP?
Key genes include anti-apoptotic BCL-2 family members such as BCL2, BCL2L1 (BCL-xL), MCL1, BCL2A1, and BCL2L2, as well as microRNAs like miR-23a-3p.
How is MOMP negatively regulated?
MOMP is negatively regulated by proteins that sequester BH3-only proteins or inhibit BAX/BAK activation, preventing pore formation and cytochrome c release.
Why is negative regulation of MOMP important in cancer?
Cancer cells often overexpress anti-apoptotic proteins to block MOMP, leading to chemoresistance and tumor survival.
What diseases are associated with dysregulated MOMP inhibition?
Cancer, neurodegeneration, ischemia-reperfusion injury, and autoimmune diseases are linked to altered negative regulation of MOMP.
How can I study negative regulation of MOMP using CRISPR?
CRISPR knockout, knock-in, point mutation, and overexpression models allow functional dissection of candidate genes in MOMP regulation.
What is the role of miR-23a-3p in MOMP?
Down-regulation of miR-23a-3p after irradiation increases pro-apoptotic factors and promotes MOMP, while its overexpression inhibits MOMP and protects neurons.
What is BOK and how is it regulated?
BOK is a pro-apoptotic BCL-2 family member that forms toroidal pores; its activity is promoted by cBID and may be negatively regulated by other factors.
What methods measure MOMP?
Cytochrome c release assays, JC-1 staining, and BAX/BAK activation assays are commonly used to measure MOMP.
How does EDITGENE support MOMP research?
EDITGENE provides CRISPR knockout, point mutation, knock-in, overexpression cell models, and library screening services to study genes involved in MOMP regulation.
Conclusion
GO:1901029, negative regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway, is a critical biological process that governs cell survival by preventing mitochondrial permeabilization. Its dysregulation is central to cancer, neurodegeneration, and other diseases, making it a prime target for therapeutic intervention. Leveraging CRISPR-based models and advanced screening technologies, researchers can dissect the molecular players and pathways that control MOMP, paving the way for novel treatments.
References
- 1. Fernández-Marrero Y et al.. 2017. The membrane activity of BOK involves formation of large, stable toroidal pores and is promoted by cBID.. FEBS J 284(5):711-724 PMID: 28064468
- 2. Marzetti E et al.. 2024. Mitochondrial Quality Control Processes at the Crossroads of Cell Death and Survival: Mechanisms and Signaling Pathways.. Int J Mol Sci 25(13) PMID: 39000412
- 3. Sabirzhanov B et al.. 2020. Down-Regulation of miR-23a-3p Mediates Irradiation-Induced Neuronal Apoptosis.. Int J Mol Sci 21(10) PMID: 32456284
