The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.
You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.
We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.
We are interested in where in or outside the cell the gene product carries out its function.
We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.
Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.
Research plan and verification
- Target identity verified: CHMP3 is the human VPS24, an ESCRT-III/SNF7-family subunit (UniProt Q9Y3E7). Literature places CHMP3 in the ESCRT-III core that executes membrane remodeling and scission; it is the human homolog of yeast Vps24. Domains and family align with SNF7/ESCRT-III assignments and structural literature citing the human CHMP3 crystal structure (PDB 3FRT) (Torre et al., 2024, Cells; Liu et al., 2024, PNAS) (torre2024preservinggenomeintegrity pages 1-3, liu2024threedimensionalarchitectureof pages 8-8). URL: https://doi.org/10.3390/cells13151307 (Cells, 2024); https://doi.org/10.1073/pnas.2319115121 (PNAS, 2024).
Executive summary
- What it is: CHMP3 (VPS24) is a non-enzymatic ESCRT-III polymer subunit that assembles with other ESCRT-III proteins to constrict and sever membrane necks in reverse topology (budding away from the cytosol). VPS4 ATPase disassembles CHMP3-containing polymers after scission (2023–2024 evidence) (torre2024preservinggenomeintegrity pages 1-3, aditya2024reconstitutionofmembrane pages 19-22).
- Where it acts: endosomal limiting membranes (MVB/ILV formation), the intercellular bridge during cytokinetic abscission, the plasma membrane during viral budding, and compartments involved in autophagy and lysosomal microautophagy (LMA) (torre2024preservinggenomeintegrity pages 1-3, shoji2024api(35)p2escrtiiiaxis pages 9-13).
- How it works: CHMP3 co-polymerizes with CHMP2A and CHMP4B; a minimal human scission module for HIV-1 budding comprises CHMP2A, CHMP3, CHMP4B with VPS4B, and CHMP2A–CHMP3 form helical copolymers that engage membranes (Aditya, 2024; Liu, 2024) (aditya2024reconstitutionofmembrane pages 19-22, liu2024threedimensionalarchitectureof pages 8-8).
- Why it matters: ESCRT-III (including CHMP3) is essential for cargo downregulation and neuronal proteostasis; CHMP3 knockdown perturbs endolysosomal clearance of ubiquitinated α-synuclein in neurons (Zenko, 2023) (zenko2023monitoringαsynucleinubiquitination pages 1-2, zenko2023monitoringαsynucleinubiquitination pages 2-3, zenko2023monitoringαsynucleinubiquitination pages 3-5).
| Category | Key point | Evidence/Notes | Year | Source (journal) | URL if present | Context ID |
|---|---|---|---|---|---|---|
| Identity / aliases / family | CHMP3 (also known as VPS24; member of SNF7 / ESCRT-III family; homolog of yeast Vps24) | CHMP3 identified as the human VPS24 / ESCRT-III subunit (homologous to yeast Vps24) and placed in SNF7/ESCRT-III family (role in membrane remodeling) (torre2024preservinggenomeintegrity pages 1-3). | 2024 | Cells | https://doi.org/10.3390/cells13151307 | (torre2024preservinggenomeintegrity pages 1-3) |
| Primary role | Structural ESCRT-III subunit that polymerizes to drive reverse-topology membrane scission; not an enzyme | CHMP3 functions as a polymerizing ESCRT-III subunit (forms filaments/spirals/co-polymers) that effects membrane deformation and is disassembled by VPS4; described as structural rather than catalytic (aditya2024reconstitutionofmembraneb pages 19-22, liu2024threedimensionalarchitectureof pages 8-8, aditya2024reconstitutionofmembrane pages 19-22). | 2024 | (preprint / PNAS studies) | Liu (PNAS) DOI below | (aditya2024reconstitutionofmembraneb pages 19-22, liu2024threedimensionalarchitectureof pages 8-8, aditya2024reconstitutionofmembrane pages 19-22) |
| Sites of action | Multivesicular body (ILV) formation, cytokinetic abscission (midbody), viral budding (e.g., HIV), autophagy / lysosomal microautophagy | ESCRT-III (including CHMP3) mediates MVB/ILV formation, abscission, virus budding; lysosomal microautophagy and selective degradative routes require ESCRT-III paralogs (CHMP2A/B, CHMP4B/C, IST1 implicated) (torre2024preservinggenomeintegrity pages 1-3, aditya2024reconstitutionofmembrane pages 19-22, shoji2024api(35)p2escrtiiiaxis pages 9-13). | 2023–2024 | Cells / bioRxiv / preprints | Shoji et al. bioRxiv DOI: https://doi.org/10.1101/2024.05.26.595979 (see source) | (torre2024preservinggenomeintegrity pages 1-3, aditya2024reconstitutionofmembrane pages 19-22, shoji2024api(35)p2escrtiiiaxis pages 9-13) |
| Interactions | Co-polymerizes/interacts with CHMP2A/CHMP2B and CHMP4 paralogs; functional links to IST1; substrate for VPS4-mediated disassembly | Minimal human scission set includes CHMP2A + CHMP3 + CHMP4B (plus VPS4) in experimental reconstitutions; CHMP2A–CHMP3 form helical co-polymers; VPS4 (ATPase) disassembles ESCRT-III polymers (aditya2024reconstitutionofmembrane pages 19-22, liu2024threedimensionalarchitectureof pages 8-8, shoji2024api(35)p2escrtiiiaxis pages 9-13). | 2024, earlier structural reports | Aditya (2024, reconstitution), Liu (PNAS 2024), Shoji (bioRxiv 2024) | Aditya (preprint), Liu DOI below | (aditya2024reconstitutionofmembrane pages 19-22, liu2024threedimensionalarchitectureof pages 8-8, shoji2024api(35)p2escrtiiiaxis pages 9-13) |
| Structural information | Human CHMP3 crystal referenced (PDB ID 3FRT); CHMP2A–CHMP3 form helical filaments; 3D flat-spiral ESCRT-III architecture resolved (PNAS 2024) | Liu et al. (PNAS 2024) cite the crystal structure of human CHMP3 (PDB 3FRT) and report ESCRT-III flat-spiral architectures on membranes; complementary reconstitution work shows CHMP2A–CHMP3 polymers (liu2024threedimensionalarchitectureof pages 8-8, aditya2024reconstitutionofmembrane pages 19-22). | 2024 | Proceedings of the National Academy of Sciences (PNAS) | https://doi.org/10.1073/pnas.2319115121 | (liu2024threedimensionalarchitectureof pages 8-8, aditya2024reconstitutionofmembrane pages 19-22) |
| Recent mechanistic advances (2023–2024) | (1) In vitro reconstitution shows a minimal human ESCRT-III set for scission (CHMP2A, CHMP3, CHMP4B + VPS4). (2) 3D architecture of ESCRT-III flat spirals clarified (PNAS 2024). (3) Small-molecule modulation of ESCRT-III interfaces: Tantalosin disrupts IST1–CHMP1B (affects recycling and noncanonical LC3 lipidation). (4) PTM regulation: CHMP2B methylation times abscission. | (1) Aditya 2024 reconstitution demonstrates minimal scission set in human proteins. (2) Liu et al. PNAS 2024 resolve flat-spiral architecture and cite CHMP3 structures (aditya2024reconstitutionofmembrane pages 19-22, liu2024threedimensionalarchitectureof pages 8-8). (3) Knyazeva et al. (PNAS Apr 2024) report Tantalosin targeting IST1–CHMP1B complexes (relevant to ESCRT-III functional modulation) (knyazeva2024achemicalinhibitor pages 1-2). (4) Richard et al. Nat Commun 2024: CHMP2B methylation regulates abscission timing (context for ESCRT-III regulation) (richard2024methylationofescrtiii pages 3-6). | 2024 | PNAS / PNAS / Nature Communications / preprint | Tantalosin PNAS DOI: https://doi.org/10.1073/pnas.2317680121; Liu DOI above; Richard DOI (see source) | (aditya2024reconstitutionofmembrane pages 19-22, liu2024threedimensionalarchitectureof pages 8-8, knyazeva2024achemicalinhibitor pages 1-2, richard2024methylationofescrtiii pages 3-6) |
| Disease / neuro links | CHMP3 required for endosomal ESCRT I–III pathway that routes ubiquitinated α-synuclein to lysosomes; CHMP3 knockdown impairs clearance (Parkinson's-relevant trafficking) | Zenko et al. (Science Advances 2023) show NBR1-mediated endosomal routing of ubiquitinated α-synuclein requires ESCRT I–III (knockdown of TSG101 or CHMP3 affected degradation), implicating CHMP3 in neuronal proteostasis (quantitative degradation data provided) (zenko2023monitoringαsynucleinubiquitination pages 1-2, zenko2023monitoringαsynucleinubiquitination pages 2-3, zenko2023monitoringαsynucleinubiquitination pages 3-5). | 2023 | Science Advances | https://doi.org/10.1126/sciadv.add8910 | (zenko2023monitoringαsynucleinubiquitination pages 1-2, zenko2023monitoringαsynucleinubiquitination pages 2-3, zenko2023monitoringαsynucleinubiquitination pages 3-5) |
| Quantitative / statistics snippets | Example: cycloheximide chase of ubiquitinated α-synuclein showed remaining signal ≈62.7% ±23.5% at 6 h and ≈23.2% ±6.1% at 24 h (lysosomal degradation kinetics). Minimal human scission set reported: CHMP2A + CHMP3 + CHMP4B + VPS4B required for HIV-1 budding in human cells (experimental reconstitution). | Degradation kinetics numbers from Zenko et al. (Sci Adv 2023) quantify the lysosomal clearance of ubiquitinated α-synuclein; Aditya 2024 reports the minimal ESCRT-III set for membrane detachment in reconstitution experiments (zenko2023monitoringαsynucleinubiquitination pages 2-3, aditya2024reconstitutionofmembrane pages 19-22). | 2023–2024 | Science Advances / preprint | Zenko DOI above; Aditya (preprint) | (zenko2023monitoringαsynucleinubiquitination pages 2-3, aditya2024reconstitutionofmembrane pages 19-22) |
Table: Concise reference table summarizing human CHMP3 (VPS24) identity, primary role, sites of action, interactions, structural data, recent 2023–2024 mechanistic advances, disease links, and key quantitative findings with source citations (context IDs) for rapid use in functional annotation and literature review.
1) Key concepts and definitions with current understanding
- Definition and family: CHMP3 (VPS24) is a core subunit of ESCRT-III (SNF7 family). ESCRT-III subunits are cytosolic in an autoinhibited form and polymerize on membranes into spirals/helices that drive membrane constriction and scission; VPS4 (AAA+ ATPase) catalyzes their disassembly and recycling (Torre et al., 2024) (torre2024preservinggenomeintegrity pages 1-3). URL: https://doi.org/10.3390/cells13151307 (Cells, 2024; published Aug 2024).
- Primary molecular role: structural polymer, not an enzyme. CHMP3 acts as part of hetero-polymers (notably with CHMP2A and CHMP4B) to complete ESCRT-dependent membrane fission in reverse topology processes (Aditya, 2024; Liu, 2024) (aditya2024reconstitutionofmembrane pages 19-22, liu2024threedimensionalarchitectureof pages 8-8). Liu references the human CHMP3 crystal structure (PDB 3FRT) and provides cryo-EM reconstructions of ESCRT-III flat spirals (Liu et al., 2024, PNAS) (liu2024threedimensionalarchitectureof pages 8-8). URL: https://doi.org/10.1073/pnas.2319115121 (PNAS, May 2024).
- Sites of action:
• Endosomes/MVBs: ESCRT-III executes intralumenal vesicle (ILV) formation for cargo downregulation (Torre et al., 2024) (torre2024preservinggenomeintegrity pages 1-3).
• Cytokinetic abscission: ESCRT-III polymers converge at the intercellular bridge to sever the membrane connection at late cytokinesis; timing is regulated by post-translational modifications in ESCRT-III (Richard et al., 2024) (richard2024methylationofescrtiii pages 3-6). URL: https://doi.org/10.1038/s41467-024-47717-3 (Nat Commun, May 2024).
• Viral budding: Enveloped viruses hijack ESCRT-III; in human cells HIV-1 budding can be supported by a minimal ESCRT-III subset including CHMP2A, CHMP3, CHMP4B plus VPS4B (Aditya, 2024) (aditya2024reconstitutionofmembrane pages 19-22).
• Autophagy/microautophagy: ESCRT-III regulates lysosomal microautophagy (LMA) of STING through PI(3,5)P2-dependent recruitment of ESCRT-III paralogs, mechanistically distinguishing LMA from endosomal ILV formation (Shoji et al., 2024) (shoji2024api(35)p2escrtiiiaxis pages 9-13). URL: https://doi.org/10.1101/2024.05.26.595979 (bioRxiv, May 2024).
2) Recent developments and latest research (2023–2024)
- Minimal ESCRT-III scission module and CHMP3’s role: 2024 reconstitution work motivated by HIV-1 shows that a limited human set (CHMP2A, CHMP3, CHMP4B, plus VPS4B) is sufficient for membrane detachment; ΔC constructs of CHMP2A/CHMP4B were used to probe interactions with CHMP3 and scission on model membranes (Aditya, 2024) (aditya2024reconstitutionofmembrane pages 19-22).
- ESCRT-III architecture: PNAS 2024 resolved the 3D organization of ESCRT-III flat spirals on membranes, referencing the human CHMP3 crystal (PDB 3FRT) and documenting copolymer architecture including CHMP2A–CHMP3 helical assemblies implicated in membrane cleavage (Liu et al., 2024) (liu2024threedimensionalarchitectureof pages 8-8). URL: https://doi.org/10.1073/pnas.2319115121 (May 2024).
- Regulation at abscission by ESCRT-III post-translational modification: SMYD2 mono-methylates CHMP2B K6 at the intercellular bridge; loss of methylation delays CHMP2B polymer dynamics and abscission timing. While this study centers on CHMP2B, it underscores the general principle that ESCRT-III timing at abscission is controlled by PTMs—relevant to CHMP3-containing assemblies (Richard et al., 2024) (richard2024methylationofescrtiii pages 3-6). URL: https://doi.org/10.1038/s41467-024-47717-3 (May 2024).
- Chemical modulation of ESCRT-III function: A small molecule, Tantalosin, inhibits the IST1–CHMP1B interface, impairing endosomal recycling and inducing noncanonical LC3 lipidation at stalled endosomes without disrupting cytokinesis or MVB sorting. This highlights feasibility of targeted ESCRT-III PPI modulation, an approach that could influence processes where CHMP3 acts in concert with ESCRT-III (Knyazeva et al., 2024, PNAS) (knyazeva2024achemicalinhibitor pages 1-2). URL: https://doi.org/10.1073/pnas.2317680121 (Apr 2024).
- ESCRT-III in LMA terminating STING signaling: PI(3,5)P2 controls lysosomal recruitment of ESCRT-III (CHMP4B/C), with knockdowns causing STING vesicle accumulation and sustained IFN signaling. This mechanistic partitioning of ESCRT activities across compartments informs interpretation of CHMP3’s roles in autophagy-linked trafficking (Shoji et al., 2024) (shoji2024api(35)p2escrtiiiaxis pages 9-13). URL: https://doi.org/10.1101/2024.05.26.595979 (May 2024).
- Neuronal proteostasis and endosomal ESCRT-III (CHMP3 requirement): In living cells and neurons, de novo ubiquitination of α-synuclein targets it to lysosomes via an ESCRT I–III route; knockdown of CHMP3 or TSG101 impairs degradation. Quantitatively, in HEK293 cells the ubiquitinated α-syn fraction decayed to 62.7% ± 23.5% at 6 h and 23.2% ± 6.1% at 24 h, consistent with lysosomal clearance; lysosomal inhibition stabilized the species (Zenko et al., 2023, Sci Adv) (zenko2023monitoringαsynucleinubiquitination pages 1-2, zenko2023monitoringαsynucleinubiquitination pages 2-3, zenko2023monitoringαsynucleinubiquitination pages 3-5). URL: https://doi.org/10.1126/sciadv.add8910 (Jun 2023).
3) Current applications and real-world implementations
- Antiviral strategies: The minimal ESCRT-III set used by HIV-1 (CHMP2A, CHMP3, CHMP4B, VPS4B) supports targeting the ESCRT-III scission machinery to limit viral egress. While direct CHMP3 inhibitors are not reported, small-molecule disruption of ESCRT-III interfaces (IST1–CHMP1B by Tantalosin) provides a precedent for modulating ESCRT assemblies involved in trafficking and potentially viral replication (Aditya, 2024; Knyazeva et al., 2024) (aditya2024reconstitutionofmembrane pages 19-22, knyazeva2024achemicalinhibitor pages 1-2).
- Neurodegeneration research: CHMP3’s necessity for ESCRT-mediated endosomal routing of ubiquitinated α-synuclein to lysosomes suggests a tractable node in pathways relevant to Parkinson’s disease; the Zenko assay enables quantitative monitoring of endosomal ESCRT function in living neurons (Zenko et al., 2023) (zenko2023monitoringαsynucleinubiquitination pages 1-2, zenko2023monitoringαsynucleinubiquitination pages 2-3, zenko2023monitoringαsynucleinubiquitination pages 3-5).
- Cell division therapeutics and biomarkers: Abscission timing depends on ESCRT-III dynamics; CHMP2B methylation alters abscission under cytokinetic stress, proposing ESCRT-III PTMs as possible biomarkers or targets to modulate division fidelity (Richard et al., 2024). Such regulation likely influences CHMP3-containing assemblies at the midbody (richard2024methylationofescrtiii pages 3-6).
- Autophagy–immunity interface: ESCRT-III’s role in STING LMA termination informs interventions in chronic interferonopathies; although CHMP3 was not the direct paralog tested, its ESCRT-III family context frames expectations for compartment-specific ESCRT roles (Shoji et al., 2024) (shoji2024api(35)p2escrtiiiaxis pages 9-13).
4) Expert opinions and analysis from authoritative sources
- Cells 2024 review: Places CHMP3/VPS24 as a core ESCRT-III factor that finalizes scission across diverse membrane contexts—endosomes/MVBs, cytokinesis, plasma membrane repair, and viral budding—emphasizing that ESCRT-III subunits are the executioners of membrane remodeling while VPS4 is the ATPase for turnover (Torre et al., 2024) (torre2024preservinggenomeintegrity pages 1-3). URL: https://doi.org/10.3390/cells13151307 (Aug 2024).
- PNAS 2024 structural paper: Clarifies ESCRT-III spiral architecture on membranes and integrates prior CHMP2A–CHMP3 polymerization and cleavage work, supporting a model where heteropolymer composition and geometry govern scission efficiency (Liu et al., 2024) (liu2024threedimensionalarchitectureof pages 8-8). URL: https://doi.org/10.1073/pnas.2319115121 (May 2024).
- PNAS 2024 chemical biology: Demonstrates druggability of specific ESCRT-III interfaces (IST1–CHMP1B), with precise phenotypic outcomes distinguishing ESCRT-dependent pathways—evidence that process-specific ESCRT perturbation is feasible without globally blocking ESCRT-III (Knyazeva et al., 2024) (knyazeva2024achemicalinhibitor pages 1-2). URL: https://doi.org/10.1073/pnas.2317680121 (Apr 2024).
5) Relevant statistics and data from recent studies
- α-Synuclein ESCRT-dependent clearance kinetics: In cycloheximide chase of HEK293 cells expressing the BiFC ubiquitination reporter, the ubiquitinated α-synuclein pool was reduced to 62.7% ± 23.5% at 6 h and 23.2% ± 6.1% at 24 h; lysosomal but not proteasomal inhibition stabilized the species; CHMP3 or TSG101 knockdown impeded degradation, and trafficking proceeded via Rab5/Rab7/LAMP1-positive compartments (Zenko et al., 2023, Sci Adv) (zenko2023monitoringαsynucleinubiquitination pages 2-3, zenko2023monitoringαsynucleinubiquitination pages 3-5). URL: https://doi.org/10.1126/sciadv.add8910 (Jun 2023).
- Minimal scission set: Experimental reconstitution and cell-based investigations identified CHMP2A, CHMP3, CHMP4B, and VPS4B as sufficient for late-stage HIV-1 budding/scission in human cells; in vitro, constitutively active constructs enabled dissecting CHMP3 copolymer engagement on GUV membranes (Aditya, 2024) (aditya2024reconstitutionofmembrane pages 19-22).
- Structural references: ESCRT-III flat-spiral architecture solved in PNAS 2024; human CHMP3 crystal structure cited as PDB 3FRT within that paper’s framework (Liu et al., 2024) (liu2024threedimensionalarchitectureof pages 8-8). URL: https://doi.org/10.1073/pnas.2319115121 (May 2024).
- Abscission timing metrics: Loss of CHMP2B K6 methylation (SMYD2-dependent) delayed intercellular bridge resolution and altered ESCRT-III localization dynamics at the midbody, showing PTM control over ESCRT-III timing (Richard et al., 2024) (richard2024methylationofescrtiii pages 3-6). URL: https://doi.org/10.1038/s41467-024-47717-3 (May 2024).
Mechanistic narrative: CHMP3’s function, localization, and pathway roles
- Function: CHMP3/VPS24 is a structural ESCRT-III subunit that co-assembles with CHMP2A and CHMP4B into helical/spiral polymers that constrict membrane necks. VPS4 (ATPase) subsequently binds ESCRT-III MIT-interaction motifs to catalyze filament disassembly, recycling subunits for subsequent rounds (Torre et al., 2024; Aditya, 2024; Liu, 2024) (torre2024preservinggenomeintegrity pages 1-3, aditya2024reconstitutionofmembrane pages 19-22, liu2024threedimensionalarchitectureof pages 8-8).
- Membrane systems where CHMP3 acts:
• Endosomes/MVBs: CHMP3 participates in ESCRT-III polymer formation that invaginates endosomal membranes to form ILVs, thereby sorting ubiquitinated cargo to lysosomes. In neurons and cell lines, α-synuclein ubiquitination triggers NBR1-dependent entry into Rab5+ early endosomes and lysosomal delivery via an ESCRT I–III route that requires CHMP3 (Zenko et al., 2023) (zenko2023monitoringαsynucleinubiquitination pages 1-2, zenko2023monitoringαsynucleinubiquitination pages 3-5).
• Cytokinetic abscission: ESCRT-III transitions from midbody rings to arms before scission. Although CHMP2B methylation was the focus, it demonstrates ESCRT-III’s regulated polymer dynamics at the abscission site, a context where CHMP3-class subunits assemble with CHMP4 and CHMP2 (Richard et al., 2024) (richard2024methylationofescrtiii pages 3-6).
• Viral budding: The minimal human scission set (CHMP2A–CHMP3–CHMP4B with VPS4B) mirrors the ESCRT-III module hijacked by HIV-1 to pinch off virions at the plasma membrane (Aditya, 2024) (aditya2024reconstitutionofmembrane pages 19-22).
• Autophagy/LMA: ESCRT-III also executes membrane remodeling at lysosomes to terminate STING signaling by LMA; PI(3,5)P2 controls recruitment of specific ESCRT-III paralogs (CHMP4B/C) to lysosomes, illustrating compartment-specific ESCRT-III assemblies that are mechanistically distinct from ILV biogenesis (Shoji et al., 2024) (shoji2024api(35)p2escrtiiiaxis pages 9-13).
- Interactions:
• CHMP2A/CHMP3: Co-polymerize into helical filaments that can effect membrane cleavage; this pairing is a core unit in minimal scission modules (Liu et al., 2024; Aditya, 2024) (liu2024threedimensionalarchitectureof pages 8-8, aditya2024reconstitutionofmembrane pages 19-22).
• CHMP4: CHMP4B partners with CHMP2A/CHMP3 in reconstitution; CHMP4-based protomers nucleate ESCRT-III assemblies (Aditya, 2024; Liu, 2024) (aditya2024reconstitutionofmembrane pages 19-22, liu2024threedimensionalarchitectureof pages 8-8).
• IST1: Functions with ESCRT-III in specific topologies (e.g., endosomal tubules) and is druggable at its interface with CHMP1B; this reveals that ESCRT-III complexes can be selectively modulated without globally inhibiting ESCRT-III scission (Knyazeva et al., 2024) (knyazeva2024achemicalinhibitor pages 1-2).
• VPS4: The AAA+ ATPase that binds ESCRT-III subunits (including CHMP family members) and powers filament disassembly, essential for ESCRT turnover (Torre et al., 2024) (torre2024preservinggenomeintegrity pages 1-3).
Limitations and open questions
- Precise sequence of CHMP2A–CHMP3–CHMP4B exchange and VPS4-driven remodeling during scission is still being refined despite improved in vitro reconstitutions and cryo-EM architectures (Aditya, 2024; Liu, 2024) (aditya2024reconstitutionofmembrane pages 19-22, liu2024threedimensionalarchitectureof pages 8-8).
- Compartment-specific paralog requirements (e.g., LMA vs ILV) indicate tailored ESCRT-III assemblies; systematic mapping of CHMP3’s paralog-specific roles in LMA remains to be fully delineated (Shoji et al., 2024) (shoji2024api(35)p2escrtiiiaxis pages 9-13).
Data and source list (URLs and dates)
- Torre ML, Burla R, Saggio I. Preserving Genome Integrity: Unveiling the Roles of ESCRT Machinery. Cells. 2024 Aug;13:1307. URL: https://doi.org/10.3390/cells13151307 (torre2024preservinggenomeintegrity pages 1-3).
- Liu M et al. Three-dimensional architecture of ESCRT-III flat spirals on the membrane. PNAS. 2024 May;121:e2319115121. URL: https://doi.org/10.1073/pnas.2319115121 (liu2024threedimensionalarchitectureof pages 8-8).
- Aditya P. Reconstitution of membrane scission by minimal ESCRT-III complexes. 2024 (preprint/unknown journal; 2024). Highlights minimal human set CHMP2A/CHMP3/CHMP4B + VPS4B for HIV-1 budding; co-polymerization on GUVs (aditya2024reconstitutionofmembrane pages 19-22).
- Knyazeva A et al. A chemical inhibitor of IST1-CHMP1B interaction impairs endosomal recycling and induces noncanonical LC3 lipidation. PNAS. 2024 Apr;121:e2317680121. URL: https://doi.org/10.1073/pnas.2317680121 (knyazeva2024achemicalinhibitor pages 1-2).
- Shoji T et al. A PI(3,5)P2/ESCRT-III axis terminates STING signalling by facilitating TSG101-mediated lysosomal microautophagy. bioRxiv. 2024 May. URL: https://doi.org/10.1101/2024.05.26.595979 (shoji2024api(35)p2escrtiiiaxis pages 9-13).
- Richard A et al. Methylation of ESCRT-III components regulates the timing of cytokinetic abscission. Nat Commun. 2024 May;15:4023. URL: https://doi.org/10.1038/s41467-024-47717-3 (richard2024methylationofescrtiii pages 3-6).
- Zenko D et al. Monitoring α-synuclein ubiquitination dynamics reveals key endosomal effectors mediating its trafficking and degradation. Sci Adv. 2023 Jun;9:eadd8910. URL: https://doi.org/10.1126/sciadv.add8910 (zenko2023monitoringαsynucleinubiquitination pages 1-2, zenko2023monitoringαsynucleinubiquitination pages 2-3, zenko2023monitoringαsynucleinubiquitination pages 3-5).
Conclusion
Human CHMP3 (VPS24; UniProt Q9Y3E7) is a core, non-enzymatic ESCRT-III subunit in the SNF7 family that polymerizes with CHMP2A and CHMP4B to effect membrane scission at endosomes, the cytokinetic bridge, and the plasma membrane during viral budding, with roles also in autophagy-linked pathways. Recent 2023–2024 advances define minimal scission modules including CHMP3, clarify ESCRT-III spiral architectures, reveal small-molecule modulation of ESCRT-III interfaces, and provide quantitative evidence for CHMP3-dependent endosomal proteostasis in neurons (torre2024preservinggenomeintegrity pages 1-3, liu2024threedimensionalarchitectureof pages 8-8, aditya2024reconstitutionofmembrane pages 19-22, knyazeva2024achemicalinhibitor pages 1-2, shoji2024api(35)p2escrtiiiaxis pages 9-13, zenko2023monitoringαsynucleinubiquitination pages 1-2, zenko2023monitoringαsynucleinubiquitination pages 2-3, zenko2023monitoringαsynucleinubiquitination pages 3-5, richard2024methylationofescrtiii pages 3-6).
References
(torre2024preservinggenomeintegrity pages 1-3): Mattia La Torre, Romina Burla, and Isabella Saggio. Preserving genome integrity: unveiling the roles of escrt machinery. Cells, 13:1307, Aug 2024. URL: https://doi.org/10.3390/cells13151307, doi:10.3390/cells13151307. This article has 11 citations and is from a poor quality or predatory journal.
(liu2024threedimensionalarchitectureof pages 8-8): Mingdong Liu, Yunhui Liu, Tiefeng Song, Liuyan Yang, Lei Qi, Yu-Zhong Zhang, Yong Wang, and Qing-Tao Shen. Three-dimensional architecture of escrt-iii flat spirals on the membrane. Proceedings of the National Academy of Sciences of the United States of America, May 2024. URL: https://doi.org/10.1073/pnas.2319115121, doi:10.1073/pnas.2319115121. This article has 7 citations and is from a highest quality peer-reviewed journal.
(aditya2024reconstitutionofmembrane pages 19-22): P Aditya. Reconstitution of membrane scission by minimal escrt-iii complexes. Unknown journal, 2024.
(shoji2024api(35)p2escrtiiiaxis pages 9-13): Tsumugi Shoji, Ayumi Shinojima, Satoshi Kusumi, Daisuke Koga, Kojiro Mukai, Jun Nakayama, Shigeki Higashiyama, Yoshihiko Kuchitsu, and Tomohiko Taguchi. A pi(3,5)p2/escrt-iii axis terminates sting signalling by facilitating tsg101-mediated lysosomal microautophagy. bioRxiv, May 2024. URL: https://doi.org/10.1101/2024.05.26.595979, doi:10.1101/2024.05.26.595979. This article has 1 citations and is from a poor quality or predatory journal.
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