GO:0032511 late endosome to vacuole transport via multivesicular body sorting pathway: Vesicle Trafficking Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0032511 describes the directed movement of substances from endosomes to vacuoles through multivesicular bodies (MVBs) that fuse with the vacuole.
• This pathway is essential for sorting ubiquitinated membrane proteins into intraluminal vesicles and delivering them to the vacuole for degradation.
• Key proteins include Vps4, Ist1, Did2, and components of the ESCRT machinery, which regulate MVB sorting and vacuolar delivery.
• Pathogen effectors such as Legionella factors can interfere with this trafficking route, highlighting its role in host-pathogen interactions.
• Dysregulation of MVB sorting is linked to cancer, neurodegeneration, and lysosomal storage disorders, making it a therapeutic target.
• CRISPR knockout, point mutation, and knock-in models enable precise dissection of this pathway in yeast and mammalian cells.
Description
The late endosome to vacuole transport via multivesicular body sorting pathway (GO:0032511) is a conserved intracellular trafficking route that delivers proteins and lipids from endosomes to the vacuole (or lysosome in mammals) for degradation or recycling. This process is fundamental for cellular homeostasis, receptor downregulation, and nutrient sensing. In yeast, the vacuole is the terminal degradative organelle, and the MVB pathway is essential for sorting ubiquitinated cargo into intraluminal vesicles (ILVs) that are later released into the vacuolar lumen. The pathway is also critical in higher eukaryotes, where defects in MVB sorting contribute to diseases such as cancer and neurodegeneration. Researchers study this pathway to understand membrane protein turnover, viral budding, and exosome biogenesis. The molecular machinery, including ESCRT complexes and accessory proteins like Ist1 and Did2, has been characterized through genetic and biochemical approaches in yeast and mammalian cells. Pathogen effectors, such as those from Legionella, can hijack or inhibit this pathway, underscoring its importance in infection. Thus, GO:0032511 represents a convergence point for cell biology, microbiology, and disease research.
late endosome to vacuole transport via multivesicular body sorting pathway At A Glance
| GO ID | GO:0032511 |
|---|---|
| GO term | late endosome to vacuole transport via multivesicular body sorting pathway |
| Ontology | biological_process |
| Synonym | endosome to vacuole transport via MVB sorting pathway |
| Major function | Sorting and delivery of proteins and lipids from endosomes to vacuoles via multivesicular bodies |
| Cellular location | Late endosome, multivesicular body, vacuolar membrane |
| Key components | ESCRT complexes, Vps4, Ist1, Did2, ubiquitinated cargo |
| Associated processes | Protein degradation, receptor downregulation, exosome biogenesis |
What Is GO:0032511?
GO:0032511 is defined as the directed movement of substances from endosomes to vacuoles by a pathway in which molecules are sorted into multivesicular bodies, which then fuse with the vacuole. In simpler terms, it is the process where cellular material is packaged into small vesicles inside endosomes, forming multivesicular bodies that deliver their contents to the vacuole for breakdown or recycling.
Why Is late endosome to vacuole transport via multivesicular body sorting pathway Important in Cell Biology?
This pathway is crucial for maintaining cellular proteostasis by directing damaged or signaling proteins to the vacuole for degradation. It also plays a central role in development, immunity, and neuronal function, and its dysfunction is implicated in cancer, neurodegeneration, and lysosomal storage diseases. Understanding GO:0032511 provides insights into fundamental membrane trafficking mechanisms and offers potential therapeutic targets for diseases characterized by defective protein sorting.
• Regulates degradation of cell surface receptors, controlling signal transduction.
• Essential for vacuolar/lysosomal function and nutrient recycling.
• Involved in exosome biogenesis and intercellular communication.
• Targeted by pathogen effectors, affecting host defense.
• Dysregulated in cancer, contributing to tumor progression.
• Implicated in neurodegenerative diseases such as Alzheimer's and Parkinson's.
• Required for yeast vacuolar morphology and function.
• Provides a model for studying ESCRT-mediated sorting.
• Potential target for antiviral and antibacterial therapies.
• Key to understanding lysosomal storage disorders.
What Happens During late endosome to vacuole transport via multivesicular body sorting pathway?
Cargo Recognition and Sorting at the Endosome
In simple terms: Proteins destined for the vacuole are tagged and recognized at the endosome membrane.
Ubiquitinated membrane proteins are recognized by ESCRT-0 and ESCRT-I complexes, which concentrate cargo into specific microdomains on the endosomal membrane. This sorting step ensures that only selected proteins are packaged into intraluminal vesicles (ILVs).
Formation of Multivesicular Bodies
In simple terms: The endosome membrane invaginates to form small vesicles inside, creating a multivesicular body.
ESCRT-II and ESCRT-III complexes drive membrane invagination and scission, generating ILVs within the late endosome, which is now called a multivesicular body (MVB). The ATPase Vps4 disassembles ESCRT-III to complete vesicle formation.
MVB Fusion with the Vacuole
In simple terms: The multivesicular body travels to and fuses with the vacuole, releasing its contents.
The MVB docks and fuses with the vacuolar membrane, delivering ILVs into the vacuolar lumen where they are degraded by hydrolases. This fusion requires Rab GTPases and SNARE proteins, although specific factors vary by organism.
Regulation by Ist1 and Did2
In simple terms: Accessory proteins control the timing and location of the sorting machinery.
Ist1 and Did2 form a complex that regulates Vps4 localization and assembly, ensuring proper MVB sorting and vacuolar delivery. Loss of these proteins leads to defects in cargo sorting and vacuolar morphology.
Pathogen Interference
In simple terms: Some bacteria produce proteins that disrupt this pathway to survive inside cells.
Legionella pneumophila effectors interfere with membrane trafficking, including the MVB pathway, to evade host defenses. This highlights the pathway's role in innate immunity.
Key Genes Involved in GO:0032511 late endosome to vacuole transport via multivesicular body sorting pathway
The following genes and proteins are central to the late endosome to vacuole transport via multivesicular body sorting pathway, as identified in yeast and mammalian studies.
| Gene | Major Role | Research Relevance |
|---|---|---|
| VPS4 | ATPase that disassembles ESCRT-III | Essential for MVB sorting; knockout causes vacuolar defects |
| IST1 | Regulates Vps4 localization and assembly | Modulates MVB sorting; mutations affect cargo delivery |
| DID2 | Forms complex with Ist1; regulates Vps4 | Required for late steps in MVB sorting |
| VPS23 | ESCRT-I component; recognizes ubiquitinated cargo | Cargo sorting; knockout blocks MVB formation |
| VPS36 | ESCRT-II component; binds ubiquitin | ILV formation; mutations impair sorting |
| SNA3 | ESCRT-III component; membrane scission | Vesicle formation; knockout affects vacuolar transport |
| VPS20 | ESCRT-III component; initiates assembly | MVB biogenesis; essential for sorting |
| VPS24 | ESCRT-III component; stabilizes complex | Membrane remodeling; knockout leads to sorting defects |
| VPS32 | ESCRT-III component; forms filaments | ILV scission; required for cargo delivery |
| VPS27 | ESCRT-0 component; binds ubiquitin and PI3P | Cargo recognition; knockout impairs MVB sorting |
| HSE1 | ESCRT-0 component; interacts with Vps27 | Cargo sorting; mutations affect endosomal trafficking |
| VPS28 | ESCRT-I component; interacts with Vps23 | MVB formation; knockout blocks sorting |
| VPS25 | ESCRT-II component; interacts with Vps36 | ILV formation; mutations impair transport |
| VPS2 | ESCRT-III component; interacts with Vps24 | Membrane scission; required for MVB sorting |
| VPS46 | ESCRT-III component; regulates Vps4 | Vesicle formation; knockout affects vacuolar delivery |
| RER1 | Retrieval receptor for ER membrane proteins | Indirect role in sorting; affects MVB pathway |
| VPS10 | Sorting receptor for vacuolar hydrolases | Receptor-mediated sorting; model for MVB cargo |
How Is late endosome to vacuole transport via multivesicular body sorting pathway Regulated?
The MVB sorting pathway is regulated by ubiquitination of cargo proteins, which serves as a signal for recognition by ESCRT complexes. Phosphatidylinositol 3-phosphate (PI3P) recruits ESCRT-0 to endosomal membranes. The ATPase Vps4 is regulated by Ist1 and Did2, which control its assembly and localization. Additionally, pathogen effectors can modulate the pathway by interfering with ESCRT components or Rab GTPases. In yeast, the pathway is also influenced by the trans-Golgi network and endocytic recycling.
late endosome to vacuole transport via multivesicular body sorting pathway and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| VPS4 | Cancer, neurodegeneration | Knockout in HeLa cells; measure receptor degradation |
| IST1 | Cancer, lysosomal disorders | Point mutation in yeast; assess MVB sorting |
| DID2 | Neurodegeneration | Knockout in neurons; imaging of MVB trafficking |
| VPS23 | Cancer | Knockout in cancer cell lines; proliferation assays |
| VPS36 | Lysosomal storage disorders | Knock-in of patient mutations; enzyme activity |
Cancer
Defects in MVB sorting can lead to aberrant signaling receptor degradation, promoting tumorigenesis. For example, impaired downregulation of growth factor receptors contributes to uncontrolled cell proliferation.
Neurodegeneration
Neurons are particularly sensitive to defects in endolysosomal trafficking. Disruption of MVB sorting has been linked to Alzheimer's and Parkinson's diseases, where protein aggregates accumulate due to impaired degradation.
Infectious Diseases
Pathogens such as Legionella pneumophila inject effectors that interfere with MVB sorting to evade host defenses, highlighting the pathway as a target for antibacterial strategies.
From late endosome to vacuole transport via multivesicular body sorting pathway-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate MVB sorting? | CRISPR knockout in yeast or mammalian cells |
| How does a point mutation affect Vps4 function? | Point mutation knock-in in yeast |
| Can a tagged protein localize to MVBs? | Knock-in of fluorescent tag (e.g., GFP) |
| Does overexpression of Ist1 alter vacuolar morphology? | Overexpression in yeast |
| Which genes are essential for MVB pathway? | Genome-wide CRISPR library screening |
| How does pathogen effector affect MVB sorting? | Knockout of effector in Legionella; infection assays |
How to Study the late endosome to vacuole transport via multivesicular body sorting pathway Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorescence microscopy | Localization and dynamics of MVB proteins | Live-cell imaging of GFP-tagged Vps4 |
| Western blotting | Cargo degradation and processing | Assessing vacuolar delivery of CPY |
| CRISPR knockout screening | Genes required for MVB sorting | Genome-wide screens in yeast |
| Proteomics | Protein composition of MVBs | Identifying novel cargo |
| Electron microscopy | Ultrastructure of MVBs | Visualizing ILVs |
| Yeast genetics | Epistasis and pathway order | Double mutant analysis |
| In vitro reconstitution | Vesicle formation and scission | ESCRT-mediated ILV budding |
| Flow cytometry | Receptor downregulation | Measuring EGFR degradation |
Fluorescence Microscopy
Live-cell imaging of GFP-tagged MVB proteins (e.g., Vps4, Ist1) allows visualization of sorting and fusion events.
Biochemical Fractionation
Subcellular fractionation followed by Western blotting can quantify cargo delivery to vacuoles.
Genetic Screens
CRISPR knockout libraries in yeast or mammalian cells identify genes required for MVB sorting.
Proteomics
Mass spectrometry of isolated MVBs reveals cargo and machinery composition.
How CRISPR Can Be Used to Study GO:0032511 late endosome to vacuole transport via multivesicular body sorting pathway
Knockout
CRISPR knockout of VPS4, IST1, or DID2 in yeast or mammalian cells results in defective MVB sorting, accumulation of cargo on endosomes, and altered vacuolar morphology. These models are used to study the loss-of-function phenotypes and identify suppressor mutations.
Point Mutation
Introducing point mutations in VPS4 (e.g., ATPase-dead) or IST1 allows dissection of specific domains required for MVB sorting and Vps4 regulation. Such models help distinguish between catalytic and structural functions.
Knock-in
Knock-in of fluorescent tags (e.g., GFP) at endogenous loci enables real-time tracking of MVB proteins and cargo in living cells. This approach preserves native expression levels and regulation.
Overexpression
Overexpression of Ist1 or Did2 in yeast leads to dominant-negative effects on MVB sorting, providing insights into stoichiometry and complex formation. Overexpression models are useful for testing gain-of-function hypotheses.
How EDITGENE Supports late endosome to vacuole transport via multivesicular body sorting pathway Research
Researchers studying late endosome to vacuole transport via multivesicular body sorting pathway-related genes often need to determine whether a candidate gene is causally involved in cargo sorting, MVB formation, or vacuolar delivery. EDITGENE provides comprehensive CRISPR-based services to generate precise cellular models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for late endosome to vacuole transport via multivesicular body sorting pathway research.
Frequently Asked Questions About late endosome to vacuole transport via multivesicular body sorting pathway
What is GO:0032511?
GO:0032511 is the Gene Ontology term for late endosome to vacuole transport via multivesicular body sorting pathway, describing the sorting of substances into multivesicular bodies that fuse with the vacuole.
What genes are involved in late endosome to vacuole transport via multivesicular body sorting pathway?
Key genes include VPS4, IST1, DID2, and ESCRT components such as VPS23, VPS36, and SNA3.
How does the MVB sorting pathway work?
Ubiquitinated cargo is recognized by ESCRT complexes, which form intraluminal vesicles inside endosomes, creating multivesicular bodies that fuse with the vacuole.
What diseases are associated with defective MVB sorting?
Defects are linked to cancer, neurodegeneration, and infectious diseases.
What is the role of Vps4 in this pathway?
Vps4 is an ATPase that disassembles ESCRT-III complexes, a step required for MVB sorting and vacuolar delivery.
How can I study MVB sorting using CRISPR?
CRISPR knockout, point mutation, and knock-in models allow functional dissection of genes in this pathway.
What is the difference between MVB sorting and endocytosis?
Endocytosis brings material into the cell, while MVB sorting directs cargo from endosomes to vacuoles for degradation.
Which model organisms are used to study GO:0032511?
Saccharomyces cerevisiae is a primary model due to its tractable genetics and conserved MVB pathway.
What are multivesicular bodies?
MVBs are endosomes containing intraluminal vesicles that deliver cargo to vacuoles or lysosomes.
How does Legionella interfere with MVB sorting?
Legionella effectors disrupt membrane trafficking, including the MVB pathway, to evade host defenses.
Conclusion
GO:0032511 represents a fundamental cellular process that ensures proper protein sorting and degradation. Its conservation from yeast to humans makes it a valuable model for studying membrane trafficking and disease mechanisms. CRISPR-based tools now enable precise genetic manipulation of this pathway, facilitating discoveries that may lead to new therapeutic strategies.
References
- 1. Toshima J et al.. 2026. Endocytosis and trans-Golgi Network in Yeast.. Subcell Biochem 110:335-358 PMID: 41240318
- 2. Robinson DG et al.. 2016. Receptor-mediated sorting of soluble vacuolar proteins: myths, facts, and a new model.. J Exp Bot 67(15):4435-49 PMID: 27262127
- 3. Rue SM et al.. 2008. Novel Ist1-Did2 complex functions at a late step in multivesicular body sorting.. Mol Biol Cell 19(2):475-84 PMID: 18032584
- 4. Dimaano C et al.. 2008. Ist1 regulates Vps4 localization and assembly.. Mol Biol Cell 19(2):465-74 PMID: 18032582
- 5. Shohdy N et al.. 2005. Pathogen effector protein screening in yeast identifies Legionella factors that interfere with membrane trafficking.. Proc Natl Acad Sci U S A 102(13):4866-71 PMID: 15781869
- 6. Chen L et al.. 2002. Ubiquitin-independent entry into the yeast recycling pathway.. Traffic 3(2):110-23 PMID: 11929601
- 7. Sato K et al.. 2003. Rer1p, a retrieval receptor for ER membrane proteins, recognizes transmembrane domains in multiple modes.. Mol Biol Cell 14(9):3605-16 PMID: 12972550
