GO:0000814 ESCRT II complex: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0000814 (ESCRT II complex) is a cellular_component term describing an endosomal sorting complex required for transport that acts downstream of ESCRT I and upstream of ESCRT III.
• The complex is built from class E vacuolar protein sorting (Vps) proteins and binds ubiquitinated cargoes while recruiting ESCRT III to membranes.
• Human ESCRT-II is required for efficient human immunodeficiency virus type 1 release, linking the complex to viral budding.
• In Xenopus laevis eggs, the ESCRT-II subunit Vps25 confers RNA-binding specificity for purine-rich sequences, revealing a non-canonical RNA-associated role.
• ESCRT-II-dependent ESCRT-III recruitment supports endolysosomal membrane repair, a process relevant to lysosomal integrity and cell survival.
• Dysregulation of ESCRT-II and downstream ESCRT-III is implicated in neurodegeneration, including alpha-synuclein aggregate toxicity.
Description
The ESCRT II complex (GO:0000814) is a conserved endosomal sorting complex required for transport that functions downstream of ESCRT I and is required for membrane recruitment of ESCRT III. It consists of class E vacuolar protein sorting (Vps) proteins and binds ubiquitinated cargoes, positioning it at the interface between cargo recognition and membrane remodeling. Because the complex couples ubiquitin-dependent sorting to ESCRT-III-driven membrane fission and repair, it is central to endosomal trafficking, viral budding, and organelle membrane homeostasis. Researchers study ESCRT-II to understand how cells sort receptors into multivesicular bodies, how enveloped viruses such as HIV-1 hijack the pathway for release, and how membrane repair defects contribute to disease. The complex also has emerging roles beyond canonical trafficking, including RNA recognition in early development. This article summarizes the QuickGO definition, the subunit composition, the molecular mechanism, disease links, and the CRISPR-based methods used to interrogate ESCRT-II function.
ESCRT II complex At A Glance
| GO ID | GO:0000814 |
|---|---|
| GO term | ESCRT II complex |
| Ontology | cellular_component |
| Synonym | endosomal sorting complex required for transport |
| Major function | Endosomal sorting complex required for transport; functions downstream of ESCRT I; required for membrane recruitment of ESCRT III; binds ubiquitinated cargoes |
| Subunit class | Class E vacuolar protein sorting (Vps) proteins |
| Pathway position | Downstream of ESCRT I and upstream of ESCRT III |
| Cargo specificity | Binds ubiquitinated cargoes |
| Representative subunits | Vps22, Vps25, Vps36 (human ESCRT-II subunits) |
What Is GO:0000814?
According to the QuickGO definition, GO:0000814 (ESCRT II complex) is an endosomal sorting complex required for transport that functions downstream of the ESCRT I complex. It consists of class E vacuolar protein sorting (Vps) proteins, is required for the membrane recruitment of the ESCRT III complex, and binds to ubiquitinated cargoes. In other words, ESCRT-II is a protein assembly that receives ubiquitinated cargo from ESCRT-I, helps deliver that cargo into the endosomal sorting pathway, and nucleates ESCRT-III polymerization on membranes to drive sorting and membrane remodeling.
Why Is ESCRT II complex Important in Cell Biology?
The ESCRT II complex is important because it is a required relay point in the ESCRT pathway, converting ubiquitinated cargo recognition by ESCRT-I into ESCRT-III membrane recruitment and fission. This relay underlies multivesicular body sorting, endolysosomal membrane repair, and the release of enveloped viruses such as HIV-1. Because ESCRT-III activity downstream of ESCRT-II is also implicated in membrane repair and in the handling of protein aggregates, ESCRT-II function intersects with lysosomal biology and neurodegeneration. Understanding ESCRT-II therefore informs basic cell biology as well as antiviral, cancer, and neurodegenerative research.
• Acts downstream of ESCRT I and is required for membrane recruitment of ESCRT III, making it a core node in the ESCRT pathway.
• Binds ubiquitinated cargoes, linking cargo sorting to membrane remodeling.
• Supports endolysosomal membrane repair, a process that maintains lysosomal integrity.
• Is required for efficient HIV-1 release, connecting the complex to viral budding.
• Contains class E Vps proteins whose functions are conserved across eukaryotes.
• The Vps25 subunit can recognize purine-rich RNA sequences in Xenopus eggs, indicating non-canonical roles.
• Downstream ESCRT-III function is impaired by alpha-synuclein aggregates, linking the pathway to neurodegeneration.
• ESCRT III-mediated lysosomal repair, which depends on upstream ESCRT-II function, protects renal tubular cells in cisplatin-induced acute kidney injury.
• Provides a mechanistic entry point for antiviral and membrane-trafficking drug discovery.
• Is a tractable target for CRISPR knockout and knock-in studies of endosomal sorting.
ESCRT II complex: Biological Process, Structure and Molecular Mechanism
What Happens During ESCRT II complex? Cargo Handover from ESCRT-I
In simple terms: ESCRT-II receives ubiquitin-tagged cargo from ESCRT-I and passes it along the sorting pathway.
The ESCRT pathway operates as a sequential cascade in which ESCRT-II functions downstream of ESCRT-I. ESCRT-II binds ubiquitinated cargoes, positioning them for incorporation into the endosomal sorting pathway. This handover step couples cargo recognition to the downstream membrane remodeling machinery.
What Happens During ESCRT II complex? Recruitment of ESCRT-III to Membranes
In simple terms: ESCRT-II acts as a landing pad that brings ESCRT-III to the membrane so it can cut or reshape it.
A defining function of the ESCRT II complex is that it is required for the membrane recruitment of the ESCRT III complex. This recruitment links cargo sorting to ESCRT-III polymerization and membrane fission. ESCRT-III function in membrane fission and repair is a central downstream output of ESCRT-II activity.
What Happens During ESCRT II complex? Endolysosomal Membrane Repair
In simple terms: When lysosomes are damaged, the ESCRT machinery patches the holes, and ESCRT-II is part of that response.
Triggered recruitment of ESCRT machinery promotes endolysosomal repair, a process that depends on the ESCRT cascade. ESCRT-III function in membrane fission and repair is required for this repair activity. ESCRT III-mediated lysosomal repair improves renal tubular cell injury in cisplatin-induced acute kidney injury, demonstrating the physiological importance of the pathway.
What Happens During ESCRT II complex? Viral Release and Non-Canonical RNA Binding
In simple terms: Viruses like HIV-1 use ESCRT-II to bud out of cells, and in some species ESCRT-II can also bind RNA.
Human ESCRT-II complex and its role in human immunodeficiency virus type 1 release demonstrate that the complex is co-opted for viral budding. In Xenopus laevis eggs, the RNA-binding complex ESCRT-II recognizes purine-rich sequences through its subunit Vps25, revealing a non-canonical RNA-associated function. These findings expand the biological roles of ESCRT-II beyond canonical endosomal sorting.
Structure and Composition of ESCRT II complex
In simple terms: ESCRT-II is built from Vps proteins that assemble into a defined complex.
The ESCRT II complex consists of class E vacuolar protein sorting (Vps) proteins. Human ESCRT-II subunits include Vps22, Vps25, and Vps36, and the complex functions in HIV-1 release. The Vps25 subunit mediates purine-rich RNA recognition in Xenopus laevis eggs, indicating that individual subunits can confer specialized binding properties. Assembly of these subunits creates the functional complex that binds ubiquitinated cargo and recruits ESCRT-III.
Molecular Mechanism of ESCRT II complex
In simple terms: ESCRT-II uses ubiquitin-binding and protein-protein interactions to select cargo and call in ESCRT-III.
The molecular mechanism of ESCRT-II centers on binding to ubiquitinated cargoes and on its requirement for membrane recruitment of ESCRT III. This positions ESCRT-II as a molecular adaptor that converts ubiquitin signals into ESCRT-III assembly at membranes. The downstream ESCRT-III machinery then executes membrane fission and repair, a function that can be disrupted by protein aggregates such as alpha-synuclein.
Key Genes Involved in GO:0000814 ESCRT II complex
The following genes and proteins represent the core subunits and functionally linked components of the ESCRT II complex and its downstream ESCRT-III machinery.
| Gene | Major Role | Research Relevance |
|---|---|---|
| VPS25 | Class E Vps subunit of ESCRT-II; confers purine-rich RNA recognition in Xenopus eggs | RNA-binding studies; ESCRT-II assembly |
| VPS22 | Class E Vps subunit of human ESCRT-II | HIV-1 release; complex assembly |
| VPS36 | Class E Vps subunit of human ESCRT-II | HIV-1 release; ubiquitinated cargo binding |
| VPS4 | AAA-ATPase that disassembles ESCRT-III polymers | ESCRT pathway recycling |
| CHMP4B | ESCRT-III subunit involved in membrane fission and repair | Endolysosomal repair; membrane remodeling |
| CHMP2A | ESCRT-III subunit | Membrane fission and repair |
| CHMP3 | ESCRT-III subunit | Membrane fission and repair |
| IST1 | ESCRT-III-associated regulator | ESCRT-III function |
| VPS28 | ESCRT-I subunit upstream of ESCRT-II | Cargo handover to ESCRT-II |
| VPS37 | ESCRT-I subunit | Upstream ESCRT-I function |
| TSG101 | ESCRT-I subunit | Upstream ESCRT-I function; viral budding |
| ALIX | ESCRT-associated adaptor | ESCRT pathway regulation |
| SNF8 | Human ortholog of Vps22 | ESCRT-II complex composition |
| VPS25 human | Human ortholog of Vps25 | ESCRT-II complex composition |
| VPS36 human | Human ortholog of Vps36 | ESCRT-II complex composition |
| SNX1 | Sorting nexin involved in endosomal sorting | Endosomal trafficking |
| RAB7 | Late endosome marker and regulator | Endolysosomal trafficking |
How Is ESCRT II complex Regulated?
ESCRT-II function is regulated by its position in the ESCRT cascade, acting downstream of ESCRT-I and upstream of ESCRT-III. ESCRT-III recruitment to membranes requires ESCRT-II, and ESCRT-III activity is subsequently regulated by disassembly factors such as VPS4. Triggered recruitment of ESCRT machinery to damaged endolysosomes represents a regulated response to membrane injury. In addition, ESCRT-III function can be inhibited by alpha-synuclein aggregates through sequestration and collateral degradation, providing a pathological layer of regulation.
ESCRT II complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| VPS25 | ESCRT-II function and RNA binding | Knockout in Xenopus or human cell lines |
| VPS22 | HIV-1 release | Knockout in HEK293T with HIV-1 reporter |
| VPS36 | HIV-1 release and cargo sorting | Knockout with ubiquitinated cargo reporters |
| CHMP4B | Endolysosomal repair and membrane fission | Knockout in renal tubular cells |
| SNCA | Alpha-synuclein aggregation and ESCRT-III inhibition | Overexpression of alpha-synuclein aggregates |
Neurodegeneration and Protein Aggregates
Alpha-synuclein aggregates inhibit ESCRT-III through sequestration and collateral degradation, linking ESCRT pathway dysfunction to neurodegeneration. Because ESCRT-II is required for ESCRT-III recruitment, impaired ESCRT-II function could contribute to aggregate-related pathology. ESCRT-III function in membrane fission and repair is also relevant to neuronal membrane homeostasis.
Viral Infection and HIV-1 Release
Human ESCRT-II complex and its role in human immunodeficiency virus type 1 release demonstrate that the complex is required for efficient viral budding. This makes ESCRT-II a potential host target for antiviral strategies. The broader ESCRT pathway is conserved and used by multiple enveloped viruses.
Acute Kidney Injury and Lysosomal Repair
ESCRT III-mediated lysosomal repair improves renal tubular cell injury in cisplatin-induced acute kidney injury, indicating that the ESCRT pathway protects renal cells. Since ESCRT-II is required for ESCRT-III recruitment, upstream ESCRT-II function is mechanistically linked to this protective repair process. Endolysosomal repair triggered by ESCRT machinery is a general cell survival mechanism.
Endosomal Sorting and Receptor Downregulation
The ESCRT II complex binds ubiquitinated cargoes and is required for membrane recruitment of ESCRT III, placing it at the center of receptor sorting into multivesicular bodies. Defects in this sorting pathway can alter growth factor receptor downregulation and signaling, which is relevant to cancer biology. The ESCRT pathway is a conserved endosomal sorting system across eukaryotes.
From ESCRT II complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is VPS25 required for ESCRT-II assembly? | CRISPR knockout of VPS25 in human cell lines |
| Does ESCRT-II loss impair HIV-1 release? | Knockout of VPS22 or VPS36 with HIV-1 release assay |
| Does ESCRT-II loss impair endolysosomal repair? | Knockout of ESCRT-II subunits with lysosomal damage assay |
| Does a point mutation in VPS25 abolish RNA binding? | Point-mutation knock-in at the RNA-binding interface |
| Where does ESCRT-II localize during repair? | Tagged knock-in of ESCRT-II subunits with fluorescent tags |
| Does ESCRT-II overexpression enhance ESCRT-III recruitment? | Overexpression of ESCRT-II subunits |
How to Study the ESCRT II complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Live-cell fluorescence imaging | Recruitment of ESCRT-II to damaged endolysosomes | Endolysosomal repair studies |
| Affinity purification mass spectrometry | ESCRT-II protein interactions | Cargo and partner identification |
| Electrophoretic mobility shift assay | RNA binding by Vps25 | Non-canonical RNA recognition |
| HIV-1 release assay | Viral budding efficiency | Antiviral target validation |
| CRISPR knockout screening | Requirement for ESCRT-II subunits | Pathway dependency mapping |
| Immunofluorescence | Co-localization with endosomal markers | Endosomal sorting studies |
| Western blot | Protein stability after knockout | Complex assembly validation |
| Proteomics of ESCRT-III | Downstream assembly changes | Membrane repair mechanism |
Fluorescence Imaging of ESCRT-II Recruitment
Live-cell imaging of tagged ESCRT-II subunits allows visualization of triggered recruitment of ESCRT machinery to damaged endolysosomes. Co-localization with late endosome markers such as RAB7 can define the site of action. Imaging of ESCRT-III subunits downstream of ESCRT-II reports on pathway activation.
Proteomic Analysis of ESCRT-II Interactors
Affinity purification of ESCRT-II subunits followed by mass spectrometry can identify cargo and partner proteins, building on the known interaction with ubiquitinated cargoes. Proteomic profiling of ESCRT-III complexes can reveal how ESCRT-II loss alters downstream assembly. Such approaches help define the molecular mechanism of ESCRT-II in sorting.
RNA-Binding Assays for ESCRT-II
The Xenopus laevis ESCRT-II complex recognizes purine-rich sequences through Vps25, so RNA-binding assays such as electrophoretic mobility shift assays can test this activity. Mutational analysis of Vps25 can map the RNA-binding interface. These methods reveal non-canonical functions of ESCRT-II beyond membrane trafficking.
Viral Release Assays
HIV-1 release assays in cells depleted of ESCRT-II subunits quantify the requirement for the complex in viral budding. These assays can be combined with knockout or knockdown of VPS22 and VPS36. The ESCRT pathway is widely used by enveloped viruses, so similar assays apply to other viral systems.
How CRISPR Can Be Used to Study GO:0000814 ESCRT II complex
Knockout
CRISPR knockout of ESCRT-II subunits such as VPS25, VPS22, or VPS36 can test the requirement for the complex in endosomal sorting, HIV-1 release, and endolysosomal repair. Loss-of-function models help define which processes depend on ESCRT-II versus other ESCRT components. Knockout of downstream ESCRT-III subunits provides a comparison for pathway hierarchy.
Point Mutation
Point-mutation knock-in can dissect specific residues required for ubiquitinated cargo binding or for Vps25-mediated RNA recognition. Such models separate binding functions from complex assembly. Point mutations in ESCRT-III subunits can also reveal domains required for membrane repair downstream of ESCRT-II.
Knock-in
Tagged knock-in of ESCRT-II subunits enables live-cell tracking of complex localization during endolysosomal repair. Fluorescent knock-in lines allow co-localization studies with ESCRT-III and endosomal markers. Knock-in of disease-relevant variants can model altered ESCRT-II function.
Overexpression
Overexpression of ESCRT-II subunits can test whether increased complex levels enhance ESCRT-III recruitment or viral release. Overexpression models are useful for structure-function studies of individual subunits such as Vps25. Controlled overexpression can also reveal dominant-negative effects of mutant subunits.
How EDITGENE Supports ESCRT II complex Research
Researchers studying ESCRT II complex-related genes often need to determine whether a candidate gene is causally involved in endosomal sorting, membrane repair, or viral release, and which subunit domains are required. EDITGENE provides the CRISPR cell models and screening services needed to move from correlation to mechanism.
Contact EDITGENE today to design your custom CRISPR model for ESCRT II complex research.
Frequently Asked Questions About ESCRT II complex
What is the ESCRT II complex?
The ESCRT II complex (GO:0000814) is an endosomal sorting complex required for transport that functions downstream of ESCRT I, consists of class E Vps proteins, binds ubiquitinated cargoes, and is required for membrane recruitment of ESCRT III.
What genes are involved in the ESCRT II complex?
Core subunits include VPS25, VPS22, and VPS36, with VPS25 mediating purine-rich RNA recognition in Xenopus eggs.
What is the function of GO:0000814?
GO:0000814 describes an endosomal sorting complex required for transport that binds ubiquitinated cargoes and recruits ESCRT III to membranes.
How does ESCRT-II differ from ESCRT-I and ESCRT-III?
ESCRT-II functions downstream of ESCRT I and is required for membrane recruitment of ESCRT III, placing it between cargo recognition and membrane fission.
Is ESCRT-II involved in HIV-1 release?
Yes, the human ESCRT-II complex plays a role in human immunodeficiency virus type 1 release.
Can ESCRT-II bind RNA?
The Xenopus laevis ESCRT-II complex recognizes purine-rich sequences through its subunit Vps25.
What diseases are linked to ESCRT-II dysfunction?
ESCRT pathway dysfunction is linked to neurodegeneration through alpha-synuclein aggregate inhibition of ESCRT-III, and to acute kidney injury through impaired lysosomal repair.
How is ESCRT-II studied in the lab?
Common methods include live-cell imaging of tagged subunits, affinity purification mass spectrometry, RNA-binding assays, and HIV-1 release assays.
What CRISPR models are used for ESCRT-II research?
Knockout, point-mutation, knock-in, and overexpression models of ESCRT-II subunits are used to test sorting, repair, and viral release functions.
Why is ESCRT-II important for endolysosomal repair?
ESCRT-II is required for ESCRT-III recruitment, and ESCRT-III mediates endolysosomal membrane repair, a process that protects cells from lysosomal damage.
Conclusion
The ESCRT II complex (GO:0000814) is a conserved endosomal sorting complex that binds ubiquitinated cargoes and is required for ESCRT-III recruitment, placing it at the center of membrane trafficking, endolysosomal repair, and viral budding. Its subunits, including VPS25, VPS22, and VPS36, provide tractable targets for CRISPR-based dissection of pathway hierarchy and mechanism. Emerging links to neurodegeneration and kidney injury underscore the biomedical importance of understanding ESCRT-II function. Combining knockout, point-mutation, knock-in, and overexpression models with imaging and proteomics offers a rigorous route to define how ESCRT-II controls membrane remodeling in health and disease.
References
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- 2. Skowyra ML et al.. 2018. Triggered recruitment of ESCRT machinery promotes endolysosomal repair.. Science 360(6384) PMID: 29622626
- 3. Burigotto M et al.. 2026. ESCRT-III function in membrane fission and repair.. Nat Rev Mol Cell Biol 27(4):297-315 PMID: 41299081
- 4. Tian Z et al.. 2025. ESCRT III-mediated lysosomal repair improve renal tubular cell injury in cisplatin-induced AKI.. Autophagy 21(9):1927-1944 PMID: 40152606
- 6. Langelier C et al.. 2006. Human ESCRT-II complex and its role in human immunodeficiency virus type 1 release.. J Virol 80(19):9465-80 PMID: 16973552
- 7. Sitron CS et al.. 2025. α-Synuclein aggregates inhibit ESCRT-III through sequestration and collateral degradation.. Mol Cell 85(18):3505-3523.e17 PMID: 40934925
- 8. Emerman AB et al.. 2018. The RNA-binding complex ESCRT-II in Xenopus laevis eggs recognizes purine-rich sequences through its subunit, Vps25.. J Biol Chem 293(32):12593-12605 PMID: 29903915
