| ESCRT complex/component | Core subunits / composition | Primary biochemical function | Subcellular localization sites | Key cellular processes | Evidence citations |
|---|---|---|---|---|---|
| ESCRT-0 | HRS/HGS and STAM1/2 in mammals | Recognizes ubiquitinated cargo and PI3P-enriched endosomal membranes; concentrates cargo and recruits ESCRT-I | Endosomal membranes, especially early endosomes/clathrin-rich endosomal microdomains | Initiation of endosomal cargo sorting toward intraluminal vesicles and lysosomal degradation | (pqac-00000001, pqac-00000014, pqac-00000015) |
| ESCRT-I core | Heterotetrameric complex of **TSG101 + VPS28 + one VPS37 paralog (VPS37A/B/C/D) + one MVB12-like subunit (MVB12A, MVB12B, UBAP1, UBA1L, or UMAD1)** | Central bridge between cargo recognition and scission machinery; binds upstream adaptors/cargo, recruits ESCRT-II and/or helps recruit ESCRT-III; provides scaffold for membrane neck organization | Endosomes/MVBs, phagophores/autophagosomes, midbody during cytokinesis, nuclear-envelope-related sites, damaged membranes, virus budding sites | MVB biogenesis, lysosomal targeting of membrane proteins, autophagosome closure, cytokinetic abscission, membrane repair, viral budding/egress | (pqac-00000001, pqac-00000009, pqac-00000017) |
| VPS37D within ESCRT-I | Human VPS37 family paralog in ESCRT-I; interchangeable core subunit replacing VPS37A/B/C in specific ESCRT-I assemblies; UniProt Q86XT2/WBSCR24 | Structural ESCRT-I subunit contributing paralog-specific assembly and pathway specialization; supports ESCRT-I coupling to downstream membrane remodeling, though VPS37D-specific mechanism is less characterized than VPS37A/B | Inferred at ESCRT-I sites: endosomal membranes, MVB pathway compartments, and other ESCRT-I-dependent membrane remodeling sites | Likely participates in canonical ESCRT-I functions; emerging cancer relevance, especially breast cancer biomarker/prognostic associations | (pqac-00000003, pqac-00000005, pqac-00000011) |
| ESCRT-I specialized autophagy module | ESCRT-I containing VPS37A with TSG101, VPS28, and a compatible MVB12-like partner | Recruits/organizes downstream ESCRT machinery on phagophores to enable membrane neck scission and autophagosome closure | Phagophores / nascent autophagosomes | Autophagosome completion and autophagic flux | (pqac-00000000, pqac-00000010, pqac-00000016) |
| ESCRT-I specialized cytokinesis module | ESCRT-I with TSG101, VPS28, VPS37B or VPS37C, and UMAD1 | Stabilizes recruitment platform at the midbody and functionally links upstream ESCRT-I to ESCRT-III dynamics during abscission | Midbody / intercellular bridge | Cytokinetic abscission | (pqac-00000007, pqac-00000008) |
| ESCRT-II | EAP45/VPS36, EAP30/VPS22, and two EAP20/VPS25 subunits | Bridges ESCRT-I to ESCRT-III; contributes to membrane invagination and recruits/activates CHMP6 to seed ESCRT-III assembly | Endosomes; also recruited at other ESCRT-dependent membrane necks | ILV biogenesis, endosomal sorting, cytokinesis, autophagy-related closure events | (pqac-00000001, pqac-00000009, pqac-00000014) |
| ALIX / Bro1-family accessory pathway | ALIX as ESCRT-associated adaptor | Parallel or cooperating upstream recruiter for ESCRT-III; can work with or independently of ESCRT-I/II depending on pathway | Endosomes, midbody, plasma membrane repair sites, virus budding sites, lysosomal damage sites | Cytokinesis, membrane repair, viral budding, exosome biology | (pqac-00000001, pqac-00000006, pqac-00000014) |
| ESCRT-III | CHMP proteins including CHMP6, CHMP4A/B/C, CHMP2A/B, CHMP3, CHMP1A/B, IST1 and others | Executes membrane constriction and reverse-topology scission through dynamic filament assembly on membrane necks | Endosomes, phagophore closure sites, midbody, nuclear envelope, plasma membrane and lysosome repair sites | Final membrane scission/sealing step in ESCRT-dependent pathways | (pqac-00000001, pqac-00000004, pqac-00000009) |
| VPS4 ATPase complex | VPS4A/B with cofactors such as VTA1/LIP5 | ATP-driven remodeling, editing, and disassembly/recycling of ESCRT-III polymers after or during scission | Same sites as active ESCRT-III assemblies | Completion and recycling phase of membrane scission in endosomal sorting, autophagy, cytokinesis, repair, and viral egress | (pqac-00000001, pqac-00000009, pqac-00000012) |
| ESCRT pathway as a whole | Sequential action of ESCRT-0 → ESCRT-I/ALIX → ESCRT-II → ESCRT-III → VPS4 | Performs reverse-topology membrane remodeling: cargo selection, scaffold assembly, neck constriction, scission, and component recycling | Endolysosomal system, autophagosomes, midbody, nuclear envelope, plasma membrane, lysosomes, viral budding sites | Endosomal protein degradation, exosome/ILV formation, autophagy, cytokinesis, membrane repair, organelle homeostasis, infection biology | (pqac-00000001, pqac-00000006, pqac-00000009) |


*Table: This table summarizes the ESCRT machinery from cargo recognition to membrane scission, emphasizing ESCRT-I as the bridging module and locating VPS37D within the human ESCRT-I complex. It is useful for placing VPS37D in the broader mechanistic context of endosomal sorting, autophagy, cytokinesis, and membrane repair.*