GO:1902166 negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator: Apoptosis Suppression, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1902166 describes a biological process that stops or reduces the intrinsic apoptotic signaling pathway triggered by DNA damage and mediated by p53 class mediators.
• The term is defined as any process that stops, prevents or reduces the frequency, rate or extent of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator.
• Key genes and proteins involved include TP53, MDM2, MDM4, ATM, ATR, CHEK1, CHEK2, HIC1, BCL2, BAX, and CDKN1A, among others.
• Dysregulation of this process is linked to cancer, neurodegeneration, and premature aging, making it a critical target for therapeutic research.
• CRISPR knockout, point mutation, knock-in, and overexpression models are essential to dissect the causal roles of genes in this pathway.
• Understanding this negative regulation helps explain how cells evade apoptosis, a hallmark of tumorigenesis and chemoresistance.
Description
The Gene Ontology term GO:1902166, negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator, defines a biological process that counteracts the pro-apoptotic signaling cascade initiated by DNA damage and executed through p53 class mediators. This process is fundamental for cell survival decisions, as it determines whether a cell with damaged DNA will undergo programmed cell death or arrest and repair. The term encompasses molecular events that inhibit the intrinsic apoptotic pathway, often by modulating the activity or stability of p53 and its downstream effectors. Researchers study this process to understand how cancer cells escape apoptosis and how normal cells maintain genomic integrity. The QuickGO definition states that it is any process that stops, prevents or reduces the frequency, rate or extent of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator. This definition highlights the negative regulatory nature of the process, distinguishing it from the positive regulation of the same pathway. The intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator involves mitochondrial outer membrane permeabilization and caspase activation, which are tightly controlled by BCL2 family proteins. Negative regulators of this pathway include anti-apoptotic proteins and checkpoint kinases that modulate p53 activity. Understanding the balance between pro- and anti-apoptotic signals is crucial for developing therapies that target apoptosis resistance in diseases such as cancer.
negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator At A Glance
| GO ID | GO:1902166 |
|---|---|
| GO term | negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator |
| Ontology | biological_process |
| Synonym | down regulation of DNA damage response, signal transduction by p53 class mediator resulting in induction of apoptosis; inhibition of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator |
| Major function | Suppression of p53-mediated intrinsic apoptosis following DNA damage |
| Related pathways | p53 signaling, DNA damage response, intrinsic apoptosis, cell cycle arrest |
| Key regulators | MDM2, MDM4, BCL2, BCL2L1, HIC1, ATM, CHEK1, CHEK2 |
| Disease relevance | Cancer, neurodegeneration, aging, chemoresistance |
What Is GO:1902166?
GO:1902166 is a biological process that negatively regulates the intrinsic apoptotic signaling pathway induced by DNA damage and mediated by p53 class mediators. In other words, it includes any molecular mechanism that reduces, prevents, or stops the cascade of events that would otherwise lead to mitochondrial apoptosis following DNA damage sensed by p53 or its family members. This term is distinct from positive regulation of the same pathway and from negative regulation of extrinsic apoptotic signaling.
Why Is negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator Important in Cell Biology?
GO:1902166 is critically important because it governs the decision between cell survival and death after DNA damage. When this negative regulation is too strong, damaged cells may escape apoptosis, leading to tumorigenesis and resistance to chemotherapy. Conversely, when it is too weak, excessive apoptosis can contribute to neurodegeneration and tissue degeneration. Thus, understanding the molecular players and mechanisms of this process is essential for developing targeted therapies that can restore or inhibit apoptosis as needed.
• Controls cell fate after DNA damage, determining whether cells survive or undergo apoptosis.
• Dysregulation is a hallmark of cancer, where apoptosis evasion promotes tumor growth and therapy resistance.
• Plays a role in aging and neurodegenerative diseases where excessive apoptosis contributes to tissue loss.
• Key target for cancer therapeutics aiming to reactivate apoptosis in resistant tumors.
• Involved in the response to genotoxic chemotherapy and radiation.
• Modulates the efficacy of p53-based therapies.
• Provides biomarkers for predicting treatment response.
• Offers opportunities for CRISPR-based functional genomics to identify novel regulators.
• Helps explain tissue-specific differences in radiosensitivity.
• Contributes to understanding of stem cell maintenance and genomic stability.
What Happens During negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator?
DNA Damage Sensing and p53 Activation
In simple terms: When DNA is damaged, sensor proteins alert the cell and activate p53, a master regulator that can trigger apoptosis.
DNA damage is detected by sensor kinases such as ATM and ATR, which phosphorylate and activate p53. This activation leads to the transcription of pro-apoptotic genes like BAX and PUMA, initiating the intrinsic apoptotic pathway. Negative regulation of this pathway can occur at this early stage by inhibiting p53 activation or stability.
Inhibition of p53 Transcriptional Activity
In simple terms: Certain proteins can block p53 from turning on death genes, keeping the cell alive.
MDM2 and MDM4 are key negative regulators that bind to p53 and inhibit its transcriptional activity, promoting its degradation. Overexpression of MDM2 or MDM4 reduces p53-mediated apoptosis in response to DNA damage. HIC1 has also been implicated in modulating p53-dependent apoptosis through transcriptional repression.
Mitochondrial Outer Membrane Permeabilization Control
In simple terms: The mitochondria are the executioners of apoptosis; anti-apoptotic proteins can stop them from leaking death signals.
BCL2 and BCL2L1 (BCL-xL) are anti-apoptotic proteins that prevent mitochondrial outer membrane permeabilization (MOMP) by sequestering pro-apoptotic effectors like BAX and BAK. Negative regulation of intrinsic apoptosis often involves upregulation of these anti-apoptotic proteins. This blocks cytochrome c release and caspase activation.
Caspase Cascade Inhibition
In simple terms: Even if mitochondria leak, inhibitors can stop the caspase enzymes that dismantle the cell.
XIAP and other IAP family proteins inhibit caspases 3, 7, and 9, thereby negatively regulating the apoptotic cascade. This inhibition can be overcome by SMAC/DIABLO, but in the context of negative regulation, IAPs play a crucial role. Their activity is often elevated in cancer cells.
Checkpoint Kinase-Mediated Survival Signaling
In simple terms: Kinases like ATM and CHEK2 can also promote survival by activating repair pathways and arresting the cell cycle.
ATM and CHEK2 phosphorylate p53 and other targets to induce cell cycle arrest, allowing time for DNA repair. This survival signaling can indirectly negatively regulate apoptosis by preventing the accumulation of irreparable damage. However, prolonged arrest can also lead to senescence, which is another form of negative regulation of apoptosis.
Key Genes Involved in GO:1902166 negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator
The following genes and proteins are central to the negative regulation of the p53-mediated intrinsic apoptotic pathway, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| TP53 | Tumor suppressor, induces apoptosis upon DNA damage | Central mediator; mutations lead to loss of apoptosis |
| MDM2 | E3 ubiquitin ligase, degrades p53 | Negative regulator; amplified in cancers |
| MDM4 | Inhibits p53 transcriptional activity | Negative regulator; overexpressed in tumors |
| ATM | DNA damage sensor, activates p53 | Initiates pathway; mutations cause ataxia-telangiectasia |
| ATR | DNA damage sensor, activates CHK1 | Responds to replication stress |
| CHEK1 | Checkpoint kinase, phosphorylates p53 | Promotes survival and repair |
| CHEK2 | Checkpoint kinase, stabilizes p53 | Mutations linked to cancer predisposition |
| HIC1 | Transcriptional repressor, modulates p53 | SNPs may affect apoptosis regulation |
| BCL2 | Anti-apoptotic, blocks MOMP | Overexpressed in lymphomas |
| BCL2L1 | Anti-apoptotic, blocks MOMP | Overexpressed in various cancers |
| BAX | Pro-apoptotic, induces MOMP | Effector of apoptosis |
| BAK | Pro-apoptotic, induces MOMP | Effector of apoptosis |
| PUMA | Pro-apoptotic, p53 target | Induces apoptosis |
| NOXA | Pro-apoptotic, p53 target | Induces apoptosis |
| XIAP | Inhibits caspases | Negative regulator of apoptosis |
| CDKN1A | p21, induces cell cycle arrest | Can inhibit apoptosis under certain conditions |
| SIRT1 | Deacetylates p53, reduces activity | Negative regulator of p53 |
How Is negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator Regulated?
The negative regulation of the p53-mediated intrinsic apoptotic pathway is itself tightly regulated by various signaling mechanisms. For example, the PI3K/AKT pathway promotes cell survival by phosphorylating and inhibiting pro-apoptotic proteins like BAD and caspase-9. Additionally, the NF-kB pathway induces anti-apoptotic proteins such as BCL2 and XIAP. Cellular stress responses like the unfolded protein response (UPR) can also modulate apoptosis sensitivity. Furthermore, epigenetic modifications, including histone acetylation and DNA methylation, influence the expression of key regulators like HIC1. The balance between these survival and death signals determines cell fate.
negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| TP53 | Li-Fraumeni syndrome, multiple cancers | Knockout and point mutation cell lines |
| MDM2 | Amplified in sarcomas and other cancers | Overexpression and knockout models |
| BCL2 | Follicular lymphoma | Knock-in and overexpression models |
| HIC1 | Epigenetically silenced in various cancers | Knockout and point mutation models |
| CDKN1A | Cancer, aging | Knockout and overexpression models |
Cancer
In cancer, negative regulation of p53-mediated apoptosis is often enhanced, allowing tumor cells to survive DNA damage and resist chemotherapy. Overexpression of MDM2, MDM4, or anti-apoptotic BCL2 family proteins is common in many malignancies. Targeting these negative regulators, for example with MDM2 inhibitors like nutlin-3, can restore apoptosis and sensitize tumors to treatment. HIC1, a transcriptional repressor, is frequently silenced in cancers and may contribute to apoptosis resistance.
Neurodegeneration
In neurodegenerative diseases, excessive apoptosis contributes to neuronal loss. However, negative regulation of apoptosis may be protective in some contexts. For instance, upregulation of anti-apoptotic proteins like BCL2 has been observed in neurons surviving injury. Understanding the balance is crucial for developing neuroprotective strategies.
Aging and Senescence
Cellular senescence, a state of permanent cell cycle arrest, is closely linked to apoptosis resistance. Senescent cells accumulate with age and secrete pro-inflammatory factors, contributing to aging and age-related diseases. Negative regulation of apoptosis in senescent cells allows them to persist, making them targets for senolytic therapies. The p53 pathway plays a dual role in senescence and apoptosis, with negative regulators influencing the choice between these fates.
From negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of MDM2 enhance p53-mediated apoptosis? | MDM2 knockout cell line |
| Does a specific p53 mutation affect apoptosis induction? | Point mutation knock-in of TP53 |
| Does overexpression of BCL2 protect against DNA damage-induced apoptosis? | BCL2 overexpression stable cell line |
| Does HIC1 regulate p53 stability? | HIC1 knockout and tagged knock-in |
| Can CRISPR activation of pro-apoptotic genes overcome resistance? | CRISPRa overexpression library screening |
| What is the role of ATM in negative regulation? | ATM knockout and kinase-dead knock-in |
How to Study the negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout screening | Gene essentiality for survival | Identify negative regulators of apoptosis |
| RNA-seq | Transcriptional changes | Profile p53 target genes |
| Proteomics | Protein expression and modifications | Quantify apoptotic regulators |
| Phosphoproteomics | Kinase signaling | Map DNA damage response |
| Flow cytometry | Apoptosis and cell cycle | Validate apoptosis phenotypes |
| Immunoblotting | Protein cleavage and expression | Detect caspase activation |
| Luciferase reporter assays | p53 transcriptional activity | Measure p53 function |
CRISPR Screening
Genome-wide CRISPR knockout or activation screens can identify novel negative regulators of p53-mediated apoptosis. Cells are treated with DNA-damaging agents, and sgRNAs that confer survival advantage are enriched. This approach has uncovered genes like MDM2 and BCL2 family members.
RNA Sequencing (RNA-seq)
RNA-seq can profile transcriptional changes after DNA damage to identify genes whose expression correlates with apoptosis resistance. It helps reveal p53 target genes and negative feedback loops.
Proteomics and Phosphoproteomics
Mass spectrometry-based proteomics can quantify protein abundance and phosphorylation events in the p53 pathway. This identifies post-translational modifications that regulate apoptosis.
Apoptosis Assays
Flow cytometry with Annexin V/PI staining, caspase activity assays, and TUNEL staining measure apoptosis rates. These are used to validate hits from screens.
How CRISPR Can Be Used to Study GO:1902166 negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator
Knockout
CRISPR knockout of negative regulators such as MDM2 or BCL2 can sensitize cells to apoptosis, validating their roles. Knockout of TP53 itself abolishes p53-mediated apoptosis, serving as a control.
Point Mutation
Introducing point mutations in TP53 (e.g., R175H) or in kinase domains of ATM can dissect specific functions. This helps distinguish between DNA binding and transactivation activities.
Knock-in
Knock-in of tagged versions of p53 or its regulators allows for live-cell imaging and interaction studies. This can reveal dynamic localization and complex formation.
Overexpression
Overexpression of anti-apoptotic genes like BCL2 or MDM2 can confer resistance to DNA damage-induced apoptosis. This models clinical scenarios of apoptosis evasion.
How EDITGENE Supports negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator Research
Researchers studying negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator-related genes often need to determine whether a candidate gene is causally involved in apoptosis suppression or whether it is merely a bystander. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell models for such functional studies.
Contact EDITGENE today to design your custom CRISPR model for negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator research.
Frequently Asked Questions About negative regulation of intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator
What is GO:1902166?
GO:1902166 is a Gene Ontology term for the biological process that negatively regulates the intrinsic apoptotic signaling pathway in response to DNA damage by p53 class mediator.
What genes are involved in negative regulation of p53-mediated apoptosis?
Key genes include MDM2, MDM4, BCL2, BCL2L1, HIC1, XIAP, and SIRT1, among others.
How does p53 induce apoptosis after DNA damage?
p53 activates transcription of pro-apoptotic genes like BAX, PUMA, and NOXA, leading to mitochondrial outer membrane permeabilization and caspase activation.
What diseases are associated with dysregulation of this pathway?
Cancer, neurodegeneration, and aging are major diseases linked to altered negative regulation of p53-mediated apoptosis.
How can CRISPR be used to study this pathway?
CRISPR knockout, point mutation, knock-in, and overexpression models allow functional dissection of genes in the pathway.
What is the role of MDM2 in this process?
MDM2 is an E3 ubiquitin ligase that targets p53 for degradation, thereby negatively regulating apoptosis.
What is the role of BCL2 in apoptosis?
BCL2 is an anti-apoptotic protein that blocks mitochondrial outer membrane permeabilization, inhibiting apoptosis.
How is this pathway regulated?
It is regulated by phosphorylation, ubiquitination, and transcriptional control, involving kinases like ATM, ATR, and AKT.
What experimental models are used to study this pathway?
Common models include CRISPR-engineered cell lines, mouse models, and patient-derived organoids.
Why is negative regulation of apoptosis important in cancer?
It allows cancer cells to survive DNA damage and resist chemotherapy, making it a therapeutic target.
Conclusion
GO:1902166 represents a critical biological process that fine-tunes the cell's response to DNA damage by suppressing p53-mediated apoptosis. Understanding its molecular mechanisms and key regulators is essential for developing therapies that can modulate apoptosis in cancer, neurodegeneration, and aging. CRISPR-based models and functional genomics are powerful tools to dissect this pathway and identify new therapeutic targets.
References
- 1. Annanya A et al.. 2024. Computational Analysis of Single Nucleotide Polymorphisms in Human HIC1 Gene.. Cureus 16(3):e56664 PMID: 38646326
- 2. Zarneshan SN et al.. 2023. Exploiting pivotal mechanisms behind the senescence-like cell cycle arrest in cancer.. Adv Protein Chem Struct Biol 135:1-19 PMID: 37061329
