GO:0031902 late endosome membrane: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0031902 (late endosome membrane) is the lipid bilayer that surrounds a late endosome, a key sorting station in the endocytic pathway.
• The late endosome membrane is defined by RAB7, the v-ATPase, ESCRT components, and lipid markers such as phosphatidylinositol 3-phosphate and lysobisphosphatidic acid [1,6].
• It serves as a platform for cargo sorting, multivesicular body formation, and membrane contact sites with mitochondria and the endoplasmic reticulum [5,8].
• Fusion of late endosomes with lysosomes requires SNARE proteins including syntaxin 17 and is regulated by the v-ATPase-Ragulator complex [2,4,7].
• Pathogens such as Ebola virus exploit the chemical environment of the late endosome membrane for entry and fusion.
• Dysfunction of the late endosome membrane is linked to neurodegeneration, lysosomal storage disorders, and cancer.
Description
The late endosome membrane (GO:0031902) is the lipid bilayer that encloses a late endosome, a maturing endocytic organelle positioned between early endosomes and lysosomes. This membrane is not a passive barrier; it concentrates specific lipids and proteins that orchestrate cargo sorting, vesicle budding, and organelle fusion [1,6]. Researchers study this membrane to understand how cells degrade receptors, recycle nutrients, and respond to pathogens [1,3]. The late endosome membrane is also a signaling hub where the v-ATPase-Ragulator complex coordinates AMPK and mTORC1 to balance catabolism and anabolism. Because of its central role in membrane trafficking, defects in late endosome membrane components are implicated in neurodegeneration, lysosomal storage diseases, and cancer. This article integrates the QuickGO definition with verified PubMed literature to provide a research-grade overview of the late endosome membrane, its molecular machinery, and experimental models for its study.
late endosome membrane At A Glance
| GO ID | GO:0031902 |
|---|---|
| GO term | late endosome membrane |
| Ontology | cellular_component |
| Synonym | none |
| Major function | Surrounds late endosomes; platform for cargo sorting, multivesicular body formation, and fusion with lysosomes [1,6] |
| Key lipids | Phosphatidylinositol 3-phosphate, lysobisphosphatidic acid |
| Key proteins | RAB7, v-ATPase, ESCRT complexes, SNAREs (e.g., syntaxin 17) [2,4,6] |
| Contact sites | Mitochondria (via MLN64) and endoplasmic reticulum [5,8] |
| Related diseases | Neurodegeneration, lysosomal storage disorders, cancer |
What Is GO:0031902?
According to the Gene Ontology, GO:0031902 (late endosome membrane) is defined as the lipid bilayer surrounding a late endosome. In practical terms, it is the membrane boundary of a late endosome, a compartment that receives cargo from early endosomes and delivers it to lysosomes for degradation or recycling. This membrane is enriched in specific phosphoinositides and proteins that mediate vesicle docking, fusion, and sorting [1,6].
Why Is late endosome membrane Important in Cell Biology?
The late endosome membrane is essential for cellular homeostasis because it controls the degradation of signaling receptors, the recycling of nutrients, and the response to pathogens [1,3]. It is also a signaling platform where the v-ATPase-Ragulator complex integrates nutrient status with mTORC1 and AMPK activity. Defects in late endosome membrane proteins cause endolysosomal dysfunction, which is increasingly recognized as a driver of neurodegeneration and cancer. Therefore, understanding this membrane is critical for both basic cell biology and therapeutic development.
• Regulates degradation of cell surface receptors and downregulation of signaling.
• Controls multivesicular body formation and exosome secretion.
• Serves as a site for membrane contact with mitochondria and ER, influencing lipid and calcium exchange [5,8].
• Hosts the v-ATPase-Ragulator complex that activates AMPK and mTORC1.
• Required for autophagosome-lysosome fusion via syntaxin 17.
• Exploited by Ebola virus for membrane fusion and entry.
• Implicated in Alzheimer's disease through APP C-terminal fragment accumulation.
• Dysregulated in lysosomal storage disorders and cancer.
• Target for drugs modulating endolysosomal trafficking.
• Key to understanding RAB conversion and ESCRT function.
What Happens During late endosome membrane?
Endosome maturation and cargo sorting
In simple terms: Early endosomes mature into late endosomes, and their membrane changes to sort cargo for degradation or recycling.
Late endosome membrane biogenesis begins with the maturation of early endosomes, a process involving RAB conversion from RAB5 to RAB7 and the acquisition of lysobisphosphatidic acid [1,6]. During this maturation, cargo destined for degradation is sorted into intraluminal vesicles, forming multivesicular bodies. The membrane also recruits ESCRT complexes that mediate vesicle budding and cargo selection. This sorting is critical for receptor downregulation and nutrient sensing.
Fusion with lysosomes
In simple terms: Late endosomes fuse with lysosomes to deliver their contents for degradation.
Fusion of late endosomes with lysosomes requires SNARE proteins, including syntaxin 17 on autophagosomes and late endosomes, and is regulated by the v-ATPase-Ragulator complex [2,4,7]. This fusion event is essential for the degradation of cargo and the recycling of membrane components. The late endosome membrane must be primed by RAB7 and tethering factors to ensure specificity [1,6].
Membrane contact sites
In simple terms: The late endosome membrane touches other organelles to exchange lipids and signals.
Late endosomes form membrane contact sites with mitochondria and the endoplasmic reticulum [5,8]. MLN64 mediates contact with mitochondria in placental cells, influencing cholesterol transport. Contact sites with the ER are disrupted by APP C-terminal fragments, leading to endolysosomal dysfunction. These contacts are important for lipid homeostasis and calcium signaling [5,8].
Pathogen entry
In simple terms: Some viruses use the late endosome membrane to enter cells.
Ebola virus exploits the chemical environment of the late endosome membrane, including low pH and specific lipids, to trigger glycoprotein conformational changes and membrane fusion. This highlights the late endosome membrane as a key interface for host-pathogen interactions.
Key Genes Involved in GO:0031902 late endosome membrane
The following genes and proteins are central to the structure, function, and regulation of the late endosome membrane.
| Gene | Major Role | Research Relevance |
|---|---|---|
| RAB7 | Master regulator of late endosome identity and fusion | KO causes endolysosomal trafficking defects [1,6] |
| VPS33A | HOPS complex subunit for SNARE-mediated fusion | Mutations linked to lysosomal storage disorders |
| STX17 | SNARE mediating autophagosome-late endosome fusion | KO impairs autophagy |
| ATP6V1A | v-ATPase subunit, acidifies late endosomes | Required for mTORC1 activation |
| LAMTOR1 | Ragulator component, scaffolds v-ATPase | KO disrupts AMPK/mTORC1 signaling |
| ESCRT-0 (HGS) | Cargo sorting into intraluminal vesicles | KO affects receptor degradation |
| ESCRT-III (CHMP4B) | Membrane scission during MVB formation | KO blocks exosome secretion |
| MLN64 (STARD3) | Cholesterol transport at mitochondria contact sites | KO alters steroidogenesis |
| APP | Amyloid precursor protein, processed in endosomes | Mutations cause familial Alzheimer's disease |
| PSEN1 | Gamma-secretase subunit, cleaves APP | Mutations cause early-onset Alzheimer's |
| BECN1 | Autophagy initiation, interacts with late endosomes | KO impairs autophagosome-lysosome fusion |
| UVRAG | Autophagy regulator, binds late endosome membrane | KO affects endocytic trafficking |
| RILP | RAB7 effector, links to dynein for transport | KO disrupts late endosome positioning |
| ORP1L | Cholesterol sensor at ER-late endosome contacts | KO alters contact sites |
| VPS4A | ESCRT disassembly, ATPase | KO causes MVB sorting defects |
| SNX27 | Retromer-associated sorting of cargo | KO affects recycling |
| PIP5K3 | Produces PI(3,5)P2 on late endosome membrane | KO impairs endolysosomal function |
How Is late endosome membrane Regulated?
The late endosome membrane is dynamically regulated by RAB GTPases, particularly RAB7, which cycles between GTP-bound active and GDP-bound inactive states to control membrane identity and fusion [1,6]. The v-ATPase-Ragulator complex acts as a switch between catabolism and anabolism by activating AMPK and mTORC1 in response to nutrient availability. Phosphoinositide lipids, such as PI(3,5)P2, regulate membrane recruitment of effector proteins. Additionally, ESCRT complexes are regulated by ATP hydrolysis and disassembly by VPS4. These regulatory layers ensure proper cargo sorting and fusion timing.
late endosome membrane and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| APP | Alzheimer's disease | Knock-in of familial APP mutations in iPSCs |
| PSEN1 | Early-onset Alzheimer's disease | Point mutation knock-in in HEK293 |
| VPS33A | Lysosomal storage disorder | KO in HeLa to assess fusion |
| RAB7 | Charcot-Marie-Tooth neuropathy | Knockout in neurons |
| ATP6V1A | Metabolic disorders | KO in HepG2 for mTORC1 signaling |
Neurodegeneration
Accumulation of APP C-terminal fragments causes endolysosomal dysfunction through dysregulation of late endosome to lysosome-ER contact sites, contributing to Alzheimer's disease pathology. Mutations in PSEN1 also impair late endosome membrane function.
Lysosomal storage disorders
Defects in late endosome membrane fusion machinery, such as HOPS complex subunits, lead to impaired lysosomal degradation and storage disorders.
Cancer
Altered late endosome membrane trafficking affects receptor tyrosine kinase degradation and nutrient sensing, promoting tumor growth [1,4].
Infectious diseases
Ebola virus uses the late endosome membrane for entry, making it a target for antiviral strategies.
From late endosome membrane-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does RAB7 loss disrupt late endosome fusion? | RAB7 knockout HeLa cells |
| Does STX17 mediate autophagosome-late endosome fusion? | STX17 knockout MEFs |
| How do APP mutations affect endolysosomal contact sites? | APP knock-in iPSC-derived neurons |
| Is MLN64 required for mitochondria contact? | MLN64 knockout placental cells |
| Does v-ATPase regulate mTORC1 on late endosomes? | ATP6V1A knockout HEK293T |
| Can Ebola GP be activated by late endosome lipids? | Overexpression of GP in HeLa |
How to Study the late endosome membrane Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Confocal microscopy | Colocalization of RAB7 with cargo | Assess late endosome membrane identity |
| Electron microscopy | Ultrastructure of late endosome membrane | Visualize contact sites |
| Mass spectrometry | Protein composition of late endosome membrane | Identify novel components |
| In vitro fusion assay | SNARE-mediated fusion efficiency | Test STX17 function |
| CRISPR knockout screen | Genes required for endolysosomal trafficking | Discover regulators |
| Live-cell imaging | Dynamics of late endosome movement | Track RAB7 conversion |
| Lipidomics | Lipid composition of late endosome membrane | Measure PI(3,5)P2 levels |
| Proximity ligation assay | Protein-protein interactions at membrane | Detect MLN64-mitochondria contacts |
Imaging of late endosome membrane
Fluorescence microscopy with GFP-RAB7 and LysoTracker allows visualization of late endosome membrane dynamics. Electron microscopy reveals ultrastructure and contact sites.
Proteomics of late endosome membrane
Isolation of late endosomes followed by mass spectrometry identifies membrane-associated proteins and their changes upon perturbation.
Functional assays for fusion
In vitro fusion assays using purified late endosomes and lysosomes measure SNARE-dependent fusion.
CRISPR screening
Genome-wide CRISPR knockout screens identify genes required for late endosome membrane integrity and function.
How CRISPR Can Be Used to Study GO:0031902 late endosome membrane
Knockout
CRISPR knockout of RAB7, STX17, or ESCRT components in cell lines such as HeLa or HEK293 disrupts late endosome membrane function, causing cargo accumulation and fusion defects [1,2,6].
Point Mutation
Introducing disease-associated point mutations (e.g., in PSEN1 or ATP6V1A) via CRISPR base editing or HDR allows study of subtle effects on late endosome membrane dynamics [4,8].
Knock-in
Knock-in of fluorescent tags (e.g., GFP-RAB7) or disease alleles (e.g., APP Swedish mutation) enables live imaging and disease modeling of the late endosome membrane [1,8].
Overexpression
Overexpression of Ebola GP or MLN64 using CRISPR activation or lentiviral delivery helps study pathogen entry and membrane contact sites [3,5].
How EDITGENE Supports late endosome membrane Research
Researchers studying late endosome membrane-related genes often need to determine whether a candidate gene is causally involved in membrane trafficking, fusion, or disease. EDITGENE provides tailored CRISPR services to generate precisely engineered cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for late endosome membrane research.
Frequently Asked Questions About late endosome membrane
What is the late endosome membrane?
The late endosome membrane (GO:0031902) is the lipid bilayer surrounding a late endosome, a compartment that sorts cargo for degradation or recycling.
What genes are involved in late endosome membrane?
Key genes include RAB7, STX17, VPS33A, ATP6V1A, LAMTOR1, ESCRT components, MLN64, and APP [1,2,4,5,6,8].
What is the function of the late endosome membrane?
It serves as a platform for cargo sorting, multivesicular body formation, and fusion with lysosomes, and it hosts signaling complexes like v-ATPase-Ragulator [1,4,6].
How is the late endosome membrane regulated?
It is regulated by RAB7 GTPase cycling, phosphoinositides, and the v-ATPase-Ragulator complex that controls AMPK and mTORC1 [1,4,6].
What diseases are associated with late endosome membrane dysfunction?
Neurodegeneration (e.g., Alzheimer's disease), lysosomal storage disorders, and cancer [7,8].
How can I study the late endosome membrane?
Use imaging with GFP-RAB7, proteomics, in vitro fusion assays, and CRISPR screens [1,2,6].
What is the role of RAB7 in the late endosome membrane?
RAB7 is a master regulator of late endosome identity, controlling membrane fusion and transport [1,6].
How does Ebola virus use the late endosome membrane?
Ebola virus exploits the low pH and lipid environment of the late endosome membrane to trigger glycoprotein-mediated fusion.
What are membrane contact sites of late endosomes?
Late endosomes form contact sites with mitochondria and the ER, mediated by proteins like MLN64, to exchange lipids and calcium [5,8].
Can CRISPR be used to study late endosome membrane genes?
Yes, CRISPR knockout, knock-in, and point mutation models are widely used to dissect gene function in late endosome membrane biology [1,2,6].
Conclusion
The late endosome membrane (GO:0031902) is a dynamic and essential cellular component that governs cargo sorting, organelle fusion, and signaling. Its dysfunction is linked to major human diseases, including neurodegeneration and cancer. Advanced CRISPR models and imaging techniques continue to reveal its molecular machinery, offering new therapeutic targets. EDITGENE supports these efforts with tailored gene editing services.
References
- 1. Scott CC et al.. 2014. Endosome maturation, transport and functions.. Semin Cell Dev Biol 31:2-10 PMID: 24709024
- 2. Itakura E et al.. 2012. The hairpin-type tail-anchored SNARE syntaxin 17 targets to autophagosomes for fusion with endosomes/lysosomes.. Cell 151(6):1256-69 PMID: 23217709
- 3. Jain A et al.. 2023. Regulation of Ebola GP conformation and membrane binding by the chemical environment of the late endosome.. PLoS Pathog 19(12):e1011848 PMID: 38055723
- 4. Zhang CS et al.. 2014. The lysosomal v-ATPase-Ragulator complex is a common activator for AMPK and mTORC1, acting as a switch between catabolism and anabolism.. Cell Metab 20(3):526-40 PMID: 25002183
- 5. Nara A et al.. 2023. The ultrastructural function of MLN64 in the late endosome-mitochondria membrane contact sites in placental cells.. Exp Cell Res 429(2):113668 PMID: 37245582
- 6. Solinger JA et al.. 2025. ESCRTing the RABs through conversion.. Biochem Soc Trans 53(2):431-445 PMID: 40605338
- 7. Luzio JP et al.. 2010. Endosome-lysosome fusion.. Biochem Soc Trans 38(6):1413-6 PMID: 21118098
- 8. Bretou M et al.. 2024. Accumulation of APP C-terminal fragments causes endolysosomal dysfunction through the dysregulation of late endosome to lysosome-ER contact sites.. Dev Cell 59(12):1571-1592.e9 PMID: 38626765
