GO:1903923 positive regulation of protein processing in phagocytic vesicle: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1903923 describes any process that activates or increases the frequency, rate or extent of protein processing inside a phagocytic vesicle, a key step in antigen presentation and phagosome maturation.
• Protein processing in phagocytic vesicles involves proteolytic cleavage of engulfed cargo and of vesicle-associated proteins, enabling antigen cross-presentation and microbial killing [2,6].
• Key molecular players include SNARE proteins, APOL7C, RNF144A, BECN1, ULK1, TFEB, SQSTM1, and GCN2, which regulate vesicle trafficking, autophagy, and proteolysis [1,2,3,4,5,7].
• Dysregulation of phagocytic protein processing is linked to impaired CD8 T cell immunity, increased susceptibility to intracellular pathogens such as Legionella and Listeria, and cancer progression [2,3,4,5,6].
• CRISPR knockout, point-mutation, knock-in, and overexpression models are essential to dissect the causal roles of these genes in phagocytic vesicle processing [1,2,5,8].
• EDITGENE provides end-to-end CRISPR cell model services, including library screening and bioinformatics, to accelerate research on GO:1903923.
Description
Phagocytic vesicles (phagosomes) are intracellular organelles formed when cells engulf particles, pathogens, or apoptotic bodies. Inside these vesicles, a tightly regulated set of proteolytic events processes both the engulfed cargo and the vesicle membrane proteins, a process essential for antigen presentation and microbial clearance. GO:1903923, positive regulation of protein processing in phagocytic vesicle, captures the upstream signals and molecular machines that accelerate or enhance this proteolytic maturation. Understanding this term is critical because defects in phagosomal protein processing impair immune responses and contribute to chronic infections and autoimmunity [2,6]. Recent studies have identified specific regulators, such as the pore-forming apolipoprotein APOL7C, which drives phagosomal rupture and antigen cross-presentation by dendritic cells, and SNARE proteins, whose ubiquitination modulates autophagy during Legionella infection. These findings highlight the importance of positive regulation for host defense and cellular homeostasis.
positive regulation of protein processing in phagocytic vesicle At A Glance
| GO ID | GO:1903923 |
|---|---|
| GO term | positive regulation of protein processing in phagocytic vesicle |
| Ontology | biological_process |
| Synonym | activation of protein processing in phagosome; upregulation of protein maturation by proteolysis in phagocytic vesicle; positive regulation of peptidolysis during protein maturation in phagosome |
| Major function | Enhances proteolytic processing of proteins within phagocytic vesicles, facilitating antigen presentation and pathogen degradation. |
| Related processes | Phagosome maturation, autophagy, antigen cross-presentation, MHC-I delivery to phagosomes. |
| Key regulators | APOL7C, SNARE proteins, RNF144A, BECN1, ULK1, TFEB, SQSTM1, GCN2 [1,2,3,4,5,7]. |
| Disease relevance | Impaired CD8 T cell immunity, intracellular bacterial infections, cancer metastasis [2,3,4,5,6]. |
What Is GO:1903923?
GO:1903923 is a biological process term defined as any process that activates or increases the frequency, rate or extent of protein processing in phagocytic vesicle. Protein processing in this context refers to the proteolytic cleavage and maturation of proteins within the phagosome, including both cargo-derived antigens and vesicle-resident proteins. Positive regulation can occur through increased recruitment of proteases, enhanced vesicle acidification, or signaling events that promote proteolysis.
Why Is positive regulation of protein processing in phagocytic vesicle Important in Cell Biology?
Positive regulation of protein processing in phagocytic vesicles is a central node in innate and adaptive immunity. It determines how efficiently engulfed pathogens are degraded and how antigens are presented to T cells, directly influencing the outcome of infections and cancer immunosurveillance. Moreover, this process intersects with autophagy and vesicle trafficking pathways, meaning its dysregulation can have broad consequences for cellular stress responses and inflammation [1,3,5].
• Enables efficient degradation of engulfed pathogens, preventing chronic infection [2,3].
• Facilitates antigen cross-presentation to CD8 T cells, critical for antiviral and antitumor immunity [2,6].
• Regulates phagosome maturation and fusion with lysosomes.
• Links autophagy machinery to phagocytic processing, affecting cellular homeostasis [1,5].
• Modulates inflammatory signaling by controlling the release of processed antigens.
• Dysregulation is associated with increased susceptibility to Legionella and Listeria infections [3,5].
• Contributes to cancer progression through effects on exosome secretion and immune evasion.
• Provides potential therapeutic targets for boosting vaccine responses and cancer immunotherapy [2,6].
• Serves as a model for studying membrane trafficking and proteolysis in immune cells.
• Enables high-throughput CRISPR screens to identify novel regulators of phagosomal processing [1,2,5].
What Happens During positive regulation of protein processing in phagocytic vesicle?
Initiation of phagosome maturation
In simple terms: After a cell engulfs a particle, the vesicle begins to mature by acquiring proteins that will digest its contents.
Phagosome maturation starts with the recruitment of early endosomal markers and the activation of small GTPases. Positive regulation of protein processing involves signals that accelerate this maturation, such as phosphorylation events mediated by ULK1, which activates protein phosphatase 2A and autophagy. This step is crucial for subsequent proteolytic processing.
Proteolytic activation and cargo processing
In simple terms: Enzymes inside the vesicle become active and start cutting up proteins from the engulfed material.
Acidification of the phagosome activates proteases like cathepsins, which cleave both cargo and vesicle membrane proteins. Positive regulation can occur through increased delivery of proteases or enhanced protease activity. For example, APOL7C drives phagosomal rupture, releasing antigens for cross-presentation, a form of protein processing. SNARE proteins, regulated by ubiquitination, control membrane fusion events necessary for protease delivery.
Autophagy-phagosome crosstalk
In simple terms: Autophagy, the cell's recycling system, helps deliver additional enzymes and membranes to the phagosome.
Proteins such as TFEB and SQSTM1 coordinate autophagosome biogenesis with phagosomal processing during starvation. RNF144A targets BECN1 for degradation, inhibiting autophagy and thereby modulating phagosomal protein processing during Listeria infection. This crosstalk ensures efficient degradation of engulfed material [1,5].
Antigen release and presentation
In simple terms: After proteins are cut into pieces, these fragments are loaded onto molecules that show them to immune cells.
Processed peptides are loaded onto MHC-I molecules within the phagosome, a route that is particularly important for cross-presentation to CD8 T cells. Positive regulation enhances the efficiency of this pathway, as shown by APOL7C-mediated phagosomal rupture. This step is critical for generating protective immune responses.
Key Genes Involved in GO:1903923 positive regulation of protein processing in phagocytic vesicle
The following genes and proteins have been experimentally implicated in regulating protein processing within phagocytic vesicles.
| Gene | Major Role | Research Relevance |
|---|---|---|
| APOL7C | Pore-forming apolipoprotein that drives phagosomal rupture | Enhances antigen cross-presentation by dendritic cells |
| SNARE proteins | Mediate membrane fusion; ubiquitination regulates autophagy | Modulate phagosomal processing during Legionella infection |
| RNF144A | E3 ubiquitin ligase targeting BECN1 for degradation | Inhibits autophagy, affecting phagosomal processing during Listeria infection |
| BECN1 | Core autophagy protein; regulated by RNF144A | Links autophagy to phagocytic processing |
| ULK1 | Kinase that phosphorylates striatin, activating PP2A | Regulates autophagy initiation and phagosome maturation |
| TFEB | Transcription factor coordinating autophagosome biogenesis | Regulates ribophagy and phagosomal processing during starvation |
| SQSTM1 | Autophagy receptor linking cargo to autophagosomes | Coordinates autophagosome biogenesis with phagosomal processing |
| GCN2 | Kinase regulated by TRIM56-mediated ubiquitination | Affects secretory autophagy and exosome secretion in cancer |
| TRIM56 | E3 ubiquitin ligase targeting GCN2 | Promotes CD147-induced exosome secretion and metastasis |
| CD147 | Induces secretory autophagy-dependent exosome secretion | Promotes NSCLC metastasis |
| Striatin | Subunit of PP2A; phosphorylated by ULK1 | Activates PP2A and autophagy |
| PP2A | Phosphatase activated by ULK1-striatin axis | Regulates autophagy and phagosomal processing |
| MHC-I | Presents processed antigens to CD8 T cells | Delivered to phagosomes via multiple routes |
| Cathepsins | Proteases that degrade cargo in phagosomes | Execute protein processing in phagocytic vesicles |
| Rab GTPases | Regulate vesicle trafficking and fusion | Control phagosome maturation |
| V-ATPase | Proton pump that acidifies phagosomes | Enables protease activation |
| LC3 | Autophagosome marker; involved in phagosome fusion | Links autophagy to phagosomal processing [1,5] |
| ATG proteins | Core autophagy machinery | Facilitate autophagosome formation and cargo delivery [1,5] |
How Is positive regulation of protein processing in phagocytic vesicle Regulated?
The process is regulated at multiple levels. ULK1 phosphorylation of striatin activates PP2A, which in turn promotes autophagy and phagosomal processing. TFEB and SQSTM1 coordinate autophagosome biogenesis with phagosomal maturation during starvation. RNF144A negatively regulates autophagy by targeting BECN1 for degradation, thereby modulating phagosomal processing during Listeria infection. Additionally, TRIM56-mediated ubiquitination of GCN2 affects secretory autophagy and exosome secretion, indirectly influencing phagocytic pathways.
positive regulation of protein processing in phagocytic vesicle and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| APOL7C | Impaired antigen cross-presentation | Knockout dendritic cells |
| SNARE proteins | Legionella infection | Knockout macrophages |
| RNF144A | Listeria infection | Knockout macrophages |
| CD147 | NSCLC metastasis | Overexpression in lung cancer cells |
| GCN2 | Cancer metastasis | Knockout cancer cells |
Infectious diseases
Pathogens such as Legionella and Listeria manipulate phagosomal processing to survive. Legionella effectors ubiquitinate SNARE proteins to alter autophagy, while Listeria induces RNF144A to degrade BECN1 and inhibit autophagy. Defects in positive regulation can lead to impaired bacterial clearance and chronic infection [2,3,5].
Cancer
CD147 promotes NSCLC metastasis by inducing secretory autophagy-dependent exosome secretion via TRIM56-mediated degradation of GCN2. This pathway intersects with phagocytic processing, suggesting that dysregulation of GO:1903923 could contribute to tumor progression and immune evasion [4,6].
Immune disorders
Impaired antigen cross-presentation due to defective phagosomal processing can lead to inadequate CD8 T cell responses, affecting vaccine efficacy and antitumor immunity [2,6]. APOL7C-mediated phagosomal rupture is critical for cross-presentation, and its dysfunction may underlie immune deficiencies.
From positive regulation of protein processing in phagocytic vesicle-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate phagosomal processing? | CRISPR knockout in macrophage cell line |
| Does a specific mutation affect protein processing? | Point mutation knock-in in primary dendritic cells |
| How does gene X affect antigen cross-presentation? | Tagged knock-in of MHC-I in dendritic cells |
| Does overexpression of gene X enhance processing? | Overexpression in phagocytic cells |
| What is the role of gene X in bacterial infection? | Knockout mice infected with Legionella |
| Can gene X be targeted for cancer therapy? | Knockout in tumor cells followed by exosome analysis |
How to Study the positive regulation of protein processing in phagocytic vesicle Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout screening | Loss-of-function effects on phagosomal processing | Identify novel regulators |
| Proteomics | Protein cleavage products and abundance | Quantify processing efficiency |
| Live-cell imaging | Phagosome maturation and rupture | Visualize APOL7C function |
| Cross-presentation assay | CD8 T cell activation | Assess antigen processing |
| Western blot | Protein degradation and cleavage | Validate specific gene effects |
| Immunofluorescence | Localization of processing machinery | Study SNARE and autophagy proteins |
| RNA-seq | Transcriptional changes in phagocytic cells | Identify pathways regulated by TFEB |
| Ribo-seq | Translation efficiency of processing genes | Measure global translation during infection |
CRISPR screening
Genome-wide CRISPR knockout screens can identify novel regulators of phagosomal protein processing. For example, screens in dendritic cells have uncovered APOL7C as a key factor in phagosomal rupture. Libraries targeting autophagy and trafficking genes are particularly useful [1,5].
Proteomics
Mass spectrometry-based proteomics of isolated phagosomes can quantify processing intermediates and identify cleavage products. This approach reveals the impact of specific genes on proteolytic events.
Imaging
Live-cell imaging with fluorescently tagged phagosomal markers and pH-sensitive dyes allows real-time monitoring of vesicle maturation and rupture. APOL7C-mediated rupture has been visualized using such techniques.
Functional assays
Antigen cross-presentation assays using OVA-coated beads and OT-I T cells measure the efficiency of phagosomal processing. These assays are standard for evaluating positive regulators [2,6].
How CRISPR Can Be Used to Study GO:1903923 positive regulation of protein processing in phagocytic vesicle
Knockout
CRISPR knockout of candidate genes such as APOL7C, RNF144A, or SNARE proteins in macrophage or dendritic cell lines can reveal their requirement for phagosomal protein processing. For example, APOL7C knockout impairs phagosomal rupture and cross-presentation, while RNF144A knockout enhances autophagy and may alter processing.
Point Mutation
Introducing point mutations in catalytic residues of proteases or in phosphorylation sites of regulatory proteins (e.g., ULK1 targets) can dissect their specific contributions to positive regulation. Such models are valuable for understanding mechanism.
Knock-in
Tagged knock-in of MHC-I or phagosomal markers allows tracking of antigen processing and presentation in live cells. This approach has been used to study MHC-I delivery routes to phagosomes.
Overexpression
Overexpression of positive regulators like APOL7C or TFEB can enhance phagosomal processing and boost antigen cross-presentation. This strategy is useful for gain-of-function studies and for developing therapeutic applications [1,2].
How EDITGENE Supports positive regulation of protein processing in phagocytic vesicle Research
Researchers studying positive regulation of protein processing in phagocytic vesicle-related genes often need to determine whether a candidate gene is causally involved in this process or merely correlated with it. EDITGENE provides the CRISPR tools and cell models necessary to establish causality and dissect molecular mechanisms.
Contact EDITGENE today to design your custom CRISPR model for positive regulation of protein processing in phagocytic vesicle research.
Frequently Asked Questions About positive regulation of protein processing in phagocytic vesicle
What is GO:1903923?
GO:1903923 is a Gene Ontology biological process term defined as any process that activates or increases the frequency, rate or extent of protein processing in phagocytic vesicle.
What genes are involved in positive regulation of protein processing in phagocytic vesicle?
Key genes include APOL7C, SNARE proteins, RNF144A, BECN1, ULK1, TFEB, SQSTM1, GCN2, and TRIM56 [1,2,3,4,5,7].
How does protein processing in phagocytic vesicles affect immunity?
It enables degradation of pathogens and generation of antigens for cross-presentation to CD8 T cells, which is critical for antiviral and antitumor immunity [2,6].
What diseases are associated with defects in phagosomal protein processing?
Defects are linked to increased susceptibility to Legionella and Listeria infections, impaired vaccine responses, and cancer progression [2,3,4,5,6].
What experimental models are used to study GO:1903923?
CRISPR knockout, point mutation, knock-in, and overexpression cell models, as well as CRISPR library screening, are commonly used [1,2,5,8].
How does autophagy crosstalk with phagosomal protein processing?
Autophagy proteins such as BECN1, LC3, TFEB, and SQSTM1 coordinate membrane delivery and cargo degradation within phagosomes [1,5].
What is the role of APOL7C in phagosomal processing?
APOL7C forms pores in the phagosomal membrane, causing rupture that releases antigens for cross-presentation.
Can CRISPR screens identify new regulators of phagosomal processing?
Yes, genome-wide CRISPR screens in dendritic cells have successfully identified APOL7C and other regulators.
What methods measure protein processing in phagocytic vesicles?
Proteomics, live-cell imaging, antigen cross-presentation assays, and Western blot are commonly used [2,6].
How can EDITGENE help my research on GO:1903923?
EDITGENE provides custom CRISPR cell models, library screening, and bioinformatics to study genes involved in phagosomal protein processing [1,2,5].
Conclusion
GO:1903923, positive regulation of protein processing in phagocytic vesicle, is a critical biological process at the intersection of innate immunity, autophagy, and antigen presentation. Its dysregulation contributes to infectious diseases and cancer, making it an attractive target for therapeutic intervention. Continued research using advanced CRISPR models and functional assays will uncover new regulators and mechanisms, potentially leading to novel immunotherapies.
References
- 1. Iavazzo M et al.. 2026. TFEB coordinates autophagosome biogenesis and ribophagy during starvation via SQSTM1.. Sci Adv 12(1):eaea9302 PMID: 41477847
- 2. Gonzales GA et al.. 2024. The pore-forming apolipoprotein APOL7C drives phagosomal rupture and antigen cross-presentation by dendritic cells.. Sci Immunol 9(101):eadn2168 PMID: 39485861
- 3. Mukherjee R et al.. 2025. Phosphoribosyl ubiquitination of SNARE proteins regulates autophagy during Legionella infection.. EMBO J 44(15):4252-4279 PMID: 40506485
- 4. Yang J et al.. 2026. CD147 promotes NSCLC metastasis by inducing secretory autophagy-dependent exosome secretion via TRIM56-mediated ubiquitination and degradation of GCN2.. Cell Death Differ 33(6):1152-1174 PMID: 41413248
- 5. Yang B et al.. 2025. RNF144A inhibits autophagy by targeting BECN1 for degradation during L. monocytogenes infection.. Autophagy 21(4):789-806 PMID: 39608349
- 6. Blander JM. 2023. Different routes of MHC-I delivery to phagosomes and their consequences to CD8 T cell immunity.. Semin Immunol 66:101713 PMID: 36706521
- 7. Hu Z et al.. 2021. ULK1 phosphorylation of striatin activates protein phosphatase 2A and autophagy.. Cell Rep 36(13):109762 PMID: 34592149
- 8. Kinchen JM et al.. 2010. Identification of two evolutionarily conserved genes regulating processing of engulfed apoptotic cells.. Nature 464(7289):778-82 PMID: 20305638
