GO:1902902 negative regulation of autophagosome assembly: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1902902 describes any process that stops, prevents, or reduces the frequency, rate, or extent of autophagosome assembly.
• Negative regulation occurs at multiple steps, including phagophore nucleation, autophagosome-lysosome fusion, and SNARE complex assembly.
• Key negative regulators include RUNDC1, HRD1, Myotubularin 2, and ATG2A, which act by sequestering ATG14, inhibiting SNAP29 phase separation, or altering membrane tethering.
• Dysregulation of this process is linked to cancer, neurodegeneration, and viral replication, making it a therapeutic target.
• CRISPR knockout, point mutation, knock-in, and overexpression models are essential to dissect causal roles of candidate genes in this pathway.
• High-throughput screening and bioinformatics can identify novel regulators and their mechanisms in autophagosome assembly.
Description
Autophagy is a conserved catabolic process that delivers cytoplasmic components to lysosomes for degradation. The formation of autophagosomes, double-membrane vesicles that sequester cargo, is a key step in this pathway. GO:1902902, negative regulation of autophagosome assembly, encompasses any process that stops, prevents, or reduces the frequency, rate, or extent of autophagosome assembly. This regulation is critical for cellular homeostasis, and its dysregulation contributes to various diseases, including cancer and neurodegeneration. Understanding the molecular players and mechanisms of this negative regulation is essential for developing targeted therapies. Recent studies have identified several negative regulators, such as RUNDC1, which inhibits autolysosome formation by clasping the ATG14-STX17-SNAP29 complex, and HRD1, which negatively regulates autolysosome formation by inhibiting liquid-liquid phase separation of SNAP29. Additionally, Myotubularin 2 interacts with SEC23A to negatively regulate autophagy at ER exit sites. These findings highlight the complexity and importance of negative regulation in autophagosome assembly.
negative regulation of autophagosome assembly At A Glance
| GO ID | GO:1902902 |
|---|---|
| GO term | negative regulation of autophagosome assembly |
| Ontology | biological_process |
| Synonym | inhibition of autophagosome formation; down-regulation of autophagic vacuole assembly; negative regulation of PAS formation |
| Major function | Stops, prevents, or reduces the frequency, rate, or extent of autophagosome assembly |
| Related processes | Autophagy, autophagosome-lysosome fusion, SNARE complex assembly |
| Key regulators | RUNDC1, HRD1, Myotubularin 2, ATG2A, JMY |
| Disease relevance | Cancer, neurodegeneration, viral replication |
What Is GO:1902902?
GO:1902902, negative regulation of autophagosome assembly, is defined as any process that stops, prevents, or reduces the frequency, rate, or extent of autophagosome assembly. This includes inhibition of autophagic vacuole formation, autophagosome biosynthesis, and PAS formation. It is a biological process that ensures autophagosome formation is tightly controlled in response to cellular conditions.
Why Is negative regulation of autophagosome assembly Important in Cell Biology?
Negative regulation of autophagosome assembly is crucial for preventing excessive or aberrant autophagy, which can lead to cell death or disease. It allows cells to fine-tune autophagic flux in response to stress, nutrient availability, and infection. Dysregulation of this process is implicated in cancer, where autophagy can promote tumor survival or cell death, and in neurodegenerative diseases, where impaired autophagy leads to protein aggregation. Understanding the negative regulators provides potential therapeutic targets for modulating autophagy in disease contexts.
• Prevents excessive autophagy that could cause cell death or tissue damage.
• Balances autophagic flux to maintain cellular homeostasis.
• Plays a role in cancer by modulating tumor cell survival under stress.
• Implicated in neurodegeneration where autophagy impairment leads to protein aggregation.
• Regulates viral replication, as seen with hepatitis B virus and SARS-CoV-2.
• Provides targets for therapeutic intervention in autophagy-related diseases.
• Helps understand the molecular mechanisms of autophagosome-lysosome fusion.
• Essential for normal development and differentiation, as shown in zebrafish.
• Influences immune responses and inflammation through autophagy regulation.
• Key to studying membrane trafficking and organelle biogenesis.
What Happens During negative regulation of autophagosome assembly?
Inhibition of phagophore nucleation
In simple terms: The cell stops the initial membrane structure from forming.
Negative regulation can occur at the earliest stages of autophagosome assembly by preventing the nucleation of the phagophore. For example, Myotubularin 2 interacts with SEC23A at ER exit sites to negatively regulate autophagy, likely by altering membrane composition or trafficking. This step is critical because it sets the stage for autophagosome formation, and its inhibition reduces the overall rate of autophagy.
Blockade of autophagosome-lysosome fusion
In simple terms: The cell prevents the autophagosome from merging with the lysosome.
A major point of negative regulation is the fusion of autophagosomes with lysosomes. RUNDC1 inhibits autolysosome formation by clasping the ATG14-STX17-SNAP29 complex, thereby preventing SNARE-mediated fusion. Similarly, HRD1 negatively regulates autolysosome formation by inhibiting liquid-liquid phase separation of SNAP29, which is required for SNARE complex assembly. These mechanisms ensure that autophagosomes do not fuse prematurely or excessively.
Regulation of SNARE complex assembly
In simple terms: The cell controls the proteins that mediate membrane fusion.
SNARE proteins are essential for autophagosome-lysosome fusion. Negative regulators can interfere with SNARE complex assembly. For instance, RUNDC1 negatively mediates the fusion of autophagosomes with lysosomes by regulating SNARE complex assembly. HRD1 inhibits the phase separation of SNAP29, a key SNARE component, thereby preventing fusion. This regulation is vital for maintaining the balance between autophagosome formation and degradation.
Role of ATG2A in tethering and fusion
In simple terms: A protein called ATG2A helps connect autophagosomes to lysosomes, and its regulation affects fusion.
ATG2A acts as a tether to regulate autophagosome-lysosome fusion in neural cells. While ATG2A is generally positive for fusion, its activity can be modulated by negative regulators. Understanding how ATG2A is inhibited or its function is counteracted provides insight into negative regulation of autophagosome assembly. This is particularly relevant in neurons, where autophagy dysfunction leads to neurodegeneration.
Involvement of actin nucleation and LC3
In simple terms: Proteins that control cell shape and autophagosome membrane can be regulated to stop assembly.
JMY's actin nucleation activity is regulated by TTC5/STRAP and LC3 during autophagy. This regulation can influence autophagosome assembly, as actin dynamics are important for phagophore expansion. Negative regulation may involve inhibiting JMY's activity, thereby reducing autophagosome formation. This highlights the interplay between cytoskeletal dynamics and autophagy regulation.
Key Genes Involved in GO:1902902 negative regulation of autophagosome assembly
The following genes and proteins are key players in the negative regulation of autophagosome assembly, as supported by published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| RUNDC1 | Inhibits autolysosome formation by clasping ATG14-STX17-SNAP29 complex | Studied in zebrafish development and SNARE regulation |
| HRD1 | Negatively regulates autolysosome formation by inhibiting SNAP29 phase separation | Implicated in ER stress and neurodegeneration |
| MTM2 | Interacts with SEC23A to negatively regulate autophagy at ER exit sites | Plant autophagy and membrane trafficking |
| ATG2A | Tethering factor for autophagosome-lysosome fusion; can be negatively regulated | Neural cells and neurodegeneration |
| JMY | Actin nucleation regulated by TTC5/STRAP and LC3 | Cytoskeletal dynamics in autophagy |
| ATG14 | Component of PI3K complex; targeted by RUNDC1 | Autophagosome nucleation |
| STX17 | SNARE protein involved in fusion; targeted by RUNDC1 | Autophagosome-lysosome fusion |
| SNAP29 | SNARE protein; phase separation inhibited by HRD1 | Fusion regulation |
| LC3 | Autophagosome marker; interacts with JMY | Autophagosome formation |
| SEC23A | COPII component; interacts with MTM2 | ER exit sites and autophagy |
| TTC5/STRAP | Regulates JMY actin nucleation | Autophagy and cytoskeleton |
| RNF5 | E3 ubiquitin ligase facilitating SARS-CoV-2 virion release | Viral replication and autophagy |
| SARS-CoV-2 M protein | Mediates virion release via RNF5 | Viral autophagy interaction |
| HBV | Replication regulated by autophagic membranes | Viral hepatitis |
| ATG2A | Tethering factor in neural cells | Neurodegeneration |
| MTM2 | Phosphatase interacting with SEC23A | Plant autophagy |
| RUNDC1 | Negative regulator of autolysosome formation | Zebrafish survival |
| HRD1 | E3 ubiquitin ligase | ER-associated degradation and autophagy |
How Is negative regulation of autophagosome assembly Regulated?
The negative regulation of autophagosome assembly is itself tightly regulated by various signaling pathways. For example, the E3 ubiquitin ligase HRD1 is induced under ER stress and negatively regulates autolysosome formation by inhibiting SNAP29 phase separation. RUNDC1 levels or activity may be controlled by developmental cues, as its inhibition affects zebrafish survival. Additionally, Myotubularin 2 interacts with SEC23A, suggesting regulation at ER exit sites. These regulators respond to cellular conditions such as nutrient status, stress, and infection, ensuring autophagosome assembly is appropriately suppressed when needed.
negative regulation of autophagosome assembly and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| RUNDC1 | Cancer, developmental disorders | Zebrafish knockout, cancer cell lines |
| HRD1 | Neurodegeneration, ER stress | Mouse models, neuronal cell lines |
| ATG2A | Neurodegeneration | Neural cell lines, iPSC-derived neurons |
| RNF5 | Viral infection (SARS-CoV-2) | Vero cells, lung epithelial cells |
| MTM2 | Plant autophagy, not human disease | Arabidopsis knockout |
Cancer
Autophagy plays a dual role in cancer, and its negative regulation can influence tumor progression. RUNDC1, a negative regulator of autolysosome formation, may affect cancer cell survival under stress. HRD1, which inhibits SNAP29 phase separation, is implicated in ER stress responses that are often dysregulated in cancer. Targeting these negative regulators could modulate autophagy for therapeutic benefit.
Neurodegeneration
Impaired autophagy contributes to neurodegenerative diseases such as Alzheimer's and Parkinson's. ATG2A, a tethering factor in neural cells, is essential for autophagosome-lysosome fusion, and its negative regulation could exacerbate protein aggregation. HRD1, which negatively regulates autolysosome formation, may be protective or detrimental depending on context. Understanding these mechanisms is crucial for developing therapies.
Viral infection
Viruses manipulate autophagy for their replication. Hepatitis B virus replication is regulated by autophagic membranes. SARS-CoV-2 membrane protein-mediated virion release is facilitated by RNF5, an E3 ubiquitin ligase that may influence autophagy. Negative regulation of autophagosome assembly could be a viral strategy to evade degradation or enhance release.
From negative regulation of autophagosome assembly-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does RUNDC1 negatively regulate autophagosome assembly in vivo? | Zebrafish knockout or knockdown |
| How does HRD1 inhibit SNAP29 phase separation? | Knockout cell lines with reconstitution of mutants |
| What is the role of ATG2A in neural autophagy? | Conditional knockout mice or iPSC-derived neurons |
| Does MTM2 regulate autophagy at ER exit sites? | Arabidopsis knockout or overexpression |
| How does JMY actin nucleation affect autophagosome formation? | Knockout cells with rescue experiments |
| Can RNF5 modulate SARS-CoV-2 release via autophagy? | Overexpression and knockout in viral infection models |
How to Study the negative regulation of autophagosome assembly Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorescence microscopy | Autophagosome number, co-localization with lysosomes | Assess fusion and assembly |
| Western blot | LC3-II levels, p62 degradation | Measure autophagic flux |
| Co-immunoprecipitation | Protein interactions | Identify complexes |
| CRISPR knockout screening | Gene function in autophagy | Discover regulators |
| RNA-seq | Transcriptional changes | Identify pathways |
| Proteomics | Protein abundance and modifications | Study phase separation |
| Live-cell imaging | Dynamic fusion events | Real-time regulation |
Fluorescence microscopy
Visualizing autophagosomes and lysosomes using fluorescent markers such as LC3-GFP and LAMP1-RFP allows assessment of autophagosome assembly and fusion. Co-localization indicates fusion, while accumulation of autophagosomes without fusion suggests negative regulation.
Western blotting
Monitoring LC3-II levels and p62 degradation provides a readout of autophagic flux. Increased LC3-II and p62 accumulation indicate inhibition of autophagosome assembly or degradation.
Co-immunoprecipitation
Identifying protein-protein interactions, such as RUNDC1 with ATG14-STX17-SNAP29, helps elucidate mechanisms of negative regulation.
CRISPR screening
Genome-wide knockout screens can identify novel negative regulators of autophagosome assembly. Cells with reduced autophagy can be selected and genes identified.
How CRISPR Can Be Used to Study GO:1902902 negative regulation of autophagosome assembly
Knockout
CRISPR knockout of candidate negative regulators such as RUNDC1 or HRD1 can confirm their role in inhibiting autophagosome assembly. Loss of function may lead to increased autophagosome-lysosome fusion and altered autophagic flux.
Point Mutation
Introducing point mutations in key domains, such as the SNAP29 phase separation domain or RUNDC1's ATG14-binding region, can dissect specific mechanisms without completely abolishing protein function.
Knock-in
Knock-in of tagged versions (e.g., GFP, HA) of negative regulators allows for localization and interaction studies in endogenous contexts, providing insights into their dynamic regulation.
Overexpression
Overexpression of negative regulators like RUNDC1 or HRD1 can suppress autophagosome assembly, leading to autophagosome accumulation and reduced degradation, useful for studying downstream effects.
How EDITGENE Supports negative regulation of autophagosome assembly Research
Researchers studying negative regulation of autophagosome assembly-related genes often need to determine whether a candidate gene is causally involved in the pathway, and what precise step it regulates. EDITGENE provides comprehensive CRISPR services to enable such investigations.
Contact EDITGENE today to design your custom CRISPR model for negative regulation of autophagosome assembly research.
Frequently Asked Questions About negative regulation of autophagosome assembly
What is GO:1902902?
GO:1902902 is the Gene Ontology term for negative regulation of autophagosome assembly, defined as any process that stops, prevents, or reduces the frequency, rate, or extent of autophagosome assembly.
What genes are involved in negative regulation of autophagosome assembly?
Key genes include RUNDC1, HRD1, MTM2, ATG2A, and JMY, which act at various steps to inhibit autophagosome formation or fusion.
How does RUNDC1 inhibit autophagy?
RUNDC1 inhibits autolysosome formation by clasping the ATG14-STX17-SNAP29 complex, preventing SNARE-mediated fusion.
What is the role of HRD1 in autophagy?
HRD1 negatively regulates autolysosome formation by inhibiting liquid-liquid phase separation of SNAP29, a key SNARE protein.
How is autophagosome assembly negatively regulated?
It can be negatively regulated at multiple steps, including phagophore nucleation, SNARE complex assembly, and autophagosome-lysosome fusion, by proteins such as RUNDC1, HRD1, and MTM2.
What diseases are associated with dysregulation of autophagosome assembly?
Dysregulation is linked to cancer, neurodegeneration, and viral infections such as hepatitis B and SARS-CoV-2.
What methods are used to study negative regulation of autophagosome assembly?
Common methods include fluorescence microscopy, Western blotting, co-immunoprecipitation, and CRISPR screening.
Can CRISPR be used to study negative regulators of autophagy?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are powerful tools to dissect gene function in this pathway.
What is the difference between autophagosome assembly and autolysosome formation?
Autophagosome assembly is the formation of the double-membrane vesicle, while autolysosome formation is the fusion of the autophagosome with the lysosome; negative regulation can target either step.
How does MTM2 regulate autophagy?
MTM2 interacts with SEC23A at ER exit sites to negatively regulate autophagy, likely by affecting membrane trafficking.
Conclusion
Negative regulation of autophagosome assembly (GO:1902902) is a critical process that ensures autophagy is tightly controlled. Key regulators such as RUNDC1, HRD1, and MTM2 act at distinct steps to inhibit autophagosome formation or fusion. Dysregulation of this process contributes to cancer, neurodegeneration, and viral infections. Understanding these mechanisms offers therapeutic opportunities, and CRISPR-based models are invaluable for dissecting gene function. EDITGENE provides comprehensive services to support such research.
References
- 1. Zheng Z et al.. 2025. ATG2A acts as a tether to regulate autophagosome-lysosome fusion in neural cells.. Autophagy 21(8):1767-1778 PMID: 40083067
- 2. Liu X et al.. 2019. Regulation of JMY's actin nucleation activity by TTC5/STRAP and LC3 during autophagy.. Autophagy 15(3):373-374 PMID: 30593260
- 3. Chuang YC et al.. 2023. Regulation of hepatitis B virus replication by autophagic membranes.. Autophagy 19(4):1357-1358 PMID: 36037301
- 4. Li X et al.. 2025. Myotubularin 2 interacts with SEC23A and negatively regulates autophagy at ER exit sites in Arabidopsis.. Autophagy 21(1):141-159 PMID: 39177202
- 5. Zhang R et al.. 2023. RUNDC1 inhibits autolysosome formation and survival of zebrafish via clasping ATG14-STX17-SNAP29 complex.. Cell Death Differ 30(10):2231-2248 PMID: 37684417
- 6. Qu W et al.. 2026. HRD1 negatively regulates autolysosome formation by inhibiting liquid-liquid phase separation of SNAP29.. Cell Rep 45(2):116914 PMID: 41615796
- 7. Yuan Z et al.. 2021. The E3 Ubiquitin Ligase RNF5 Facilitates SARS-CoV-2 Membrane Protein-Mediated Virion Release.. mBio 13(1):e0316821 PMID: 35100873
- 8. Zhang R et al.. 2024. RUNDC1 negatively mediates the fusion of autophagosomes with lysosomes via regulating SNARE complex assembly.. Autophagy 20(2):454-456 PMID: 37876308
