GO:0005770 late endosome: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0005770 late endosome is a prelysosomal endocytic organelle with lower lumenal pH and a distinct protein composition compared with early endosomes.
• Late endosomes are mostly spherical and juxtanuclear, concentrated near the microtubule organizing center, and receive cargo from early endosomes before fusing with lysosomes.
• ER contact sites direct late endosome transport and positioning, linking endosomal trafficking to calcium and lipid signaling.
• Late endosome dysfunction is implicated in neurodegeneration, including CHMP2B-linked TDP-43 pathology and APP C-terminal fragment accumulation in Alzheimer-related models.
• The SIRT1-Rab7 axis regulates late endosomal-dependent mitophagy and inflammatory signaling during sepsis-induced acute lung injury.
• PIKFYVE deficiency perturbs late endosome homeostasis and can induce vacuole-like cataract, highlighting the role of phosphoinositide conversion in late endosome function.
Description
The late endosome (GO:0005770) is a central sorting station in the endocytic pathway, defined as a prelysosomal organelle that is differentiated from early endosomes by lower lumenal pH and a different protein composition. It is more spherical than early endosomes and is typically juxtanuclear, concentrated near the microtubule organizing center, where it receives cargo from early endosomes and prepares it for delivery to lysosomes. Because of its position at the intersection of degradation, recycling, and signaling, the late endosome is a focal point for researchers studying membrane trafficking, autophagy, neurodegeneration, immunity, and metabolic disease. Mechanistically, late endosome function depends on coordinated membrane fusion, phosphoinositide conversion, and contact site formation with the endoplasmic reticulum (ER) and lysosomes. The SNARE syntaxin 17 (STX17) targets autophagosomes for fusion with endosomes/lysosomes, directly linking autophagic flux to late endosomal compartments. The lysosomal v-ATPase-Ragulator complex acts as a common activator for AMPK and mTORC1, providing a switch between catabolism and anabolism that is sensitive to late endosomal/lysosomal status. These findings make the late endosome a tractable node for CRISPR-based functional genomics. In this article, we synthesize the QuickGO definition of GO:0005770 with verified PubMed literature to outline the structure, molecular mechanisms, disease relevance, and research methods for studying late endosomes. We also describe how CRISPR knockout, point mutation, knock-in, overexpression, and library screening can be applied to dissect late endosome biology.
late endosome At A Glance
| GO ID | GO:0005770 |
|---|---|
| GO term | late endosome |
| Ontology | cellular_component |
| Synonym | prevacuolar compartment, PVC |
| Major function | Prelysosomal sorting and transport of endocytic cargo; fusion with lysosomes and autophagosomes; regulation of signaling and mitophagy |
| Cellular position | Mostly juxtanuclear, concentrated near the microtubule organizing center |
| Morphology | More spherical than early endosomes |
| Lumenal pH | Lower than early endosomes |
| Key regulators | Rab7, SIRT1, PIKFYVE, CHMP2B, STX17, v-ATPase-Ragulator |
What Is GO:0005770?
GO:0005770 late endosome is a prelysosomal endocytic organelle that is differentiated from early endosomes by lower lumenal pH and different protein composition. Late endosomes are more spherical than early endosomes and are mostly juxtanuclear, being concentrated near the microtubule organizing center. The term is synonymous with prevacuolar compartment (PVC).
Why Is late endosome Important in Cell Biology?
The late endosome is essential for cellular homeostasis because it controls the transition from endocytic sorting to lysosomal degradation, participates in autophagosome clearance, and serves as a signaling platform for nutrient sensing and inflammation. Disruption of late endosome function leads to accumulation of undegraded cargo, altered mitophagy, and activation of innate immune pathways, which are increasingly recognized in neurodegeneration, sepsis, and metabolic disease. For researchers, GO:0005770 provides a precise ontological anchor for interpreting imaging, proteomic, and CRISPR screening data focused on endolysosomal biology.
• Late endosomes are the main prelysosomal sorting hub for endocytosed cargo, including receptors, lipids, and pathogens.
• They are required for autophagosome-lysosome fusion via STX17, linking autophagy to endosomal trafficking.
• Late endosome-dependent mitophagy regulates NLRP3 and STING activation during sepsis-induced acute lung injury through the SIRT1-Rab7 axis.
• ER contact sites direct late endosome transport, coupling organelle positioning to calcium and lipid exchange.
• CHMP2B truncation disrupts late endosome function and alters TDP-43 aggregation via HSP70 upregulation, implicating late endosomes in frontotemporal dementia biology.
• APP C-terminal fragment accumulation causes endolysosomal dysfunction through dysregulation of late endosome-to-lysosome-ER contact sites, relevant to Alzheimer disease.
• PIKFYVE deficiency perturbs late endosome homeostasis and induces vacuole-like cataract, linking phosphoinositide metabolism to lens pathology.
• The lysosomal v-ATPase-Ragulator complex at late endosomal/lysosomal membranes activates AMPK and mTORC1, integrating nutrient status with growth control.
• Late endosome markers and morphology are widely used readouts in high-content imaging and CRISPR screens for trafficking genes.
• Dysregulated late endosome function is a common theme in cancer, neurodegeneration, and inflammatory disease models.
What Happens During late endosome?
Cargo delivery from early endosomes
In simple terms: Material taken into the cell first arrives in early endosomes and is then handed off to late endosomes.
Early endosomes mature into late endosomes through a series of membrane and content changes, including lumenal acidification and acquisition of late endosomal markers such as Rab7. This maturation step is accompanied by a shift in protein composition and a more spherical, juxtanuclear morphology. ER contact sites contribute to the positioning and transport of late endosomes, ensuring efficient cargo transfer toward the perinuclear region.
Fusion with lysosomes and autophagosomes
In simple terms: Late endosomes fuse with lysosomes and with autophagosomes to deliver their contents for degradation.
Late endosome-lysosome fusion is a regulated process that requires SNARE proteins, Rab GTPases, and tethering factors. The hairpin-type tail-anchored SNARE syntaxin 17 (STX17) targets autophagosomes for fusion with endosomes/lysosomes, directly connecting autophagic cargo to the late endosomal system. This fusion step is essential for degradation of autophagic substrates and for recycling of membrane components.
Contact site formation with ER and lysosomes
In simple terms: Late endosomes physically touch the endoplasmic reticulum and lysosomes to exchange lipids and calcium and to coordinate transport.
ER contact sites direct late endosome transport, and disruption of these contacts alters endosomal positioning and function. In Alzheimer-related models, accumulation of APP C-terminal fragments causes endolysosomal dysfunction through dysregulation of late endosome-to-lysosome-ER contact sites. These contact sites are therefore emerging as signaling platforms that integrate organelle communication with disease-relevant cargo handling.
Nutrient sensing and signaling at the late endosome
In simple terms: Late endosomes help the cell sense nutrients and decide whether to build or break down molecules.
The lysosomal v-ATPase-Ragulator complex acts as a common activator for AMPK and mTORC1, functioning as a switch between catabolism and anabolism at the late endosomal/lysosomal surface. This places the late endosome at the center of nutrient-sensing pathways that control cell growth and autophagy. In sepsis-induced acute lung injury, the SIRT1-Rab7 axis attenuates NLRP3 and STING activation through late endosomal-dependent mitophagy, illustrating how late endosome signaling modulates inflammation.
Phosphoinositide conversion and membrane homeostasis
In simple terms: Lipid identity changes on late endosomes control their shape and function.
PIKFYVE deficiency perturbs late endosome homeostasis and induces vacuole-like cataract, demonstrating that phosphoinositide conversion is required for normal late endosome morphology and function. This lipid-based regulation complements protein-based mechanisms such as Rab7 and SNARE activity.
Key Genes Involved in GO:0005770 late endosome
The following genes and proteins are experimentally implicated in late endosome (GO:0005770) biology, based on the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| RAB7 | Late endosomal GTPase controlling maturation, transport, and fusion | Central marker and regulator; target for KO and point-mutation studies of late endosome function |
| SIRT1 | Deacetylase that regulates the Rab7 axis and late endosomal-dependent mitophagy | Links metabolism and inflammation; relevant to sepsis and lung injury models |
| CHMP2B | ESCRT-III component; truncation disrupts late endosome function | Frontotemporal dementia models; TDP-43 aggregation and HSP70 upregulation |
| STX17 | Autophagosomal SNARE targeting autophagosomes for fusion with endosomes/lysosomes | Key for autophagy-late endosome crosstalk; KO and knock-in studies |
| PIKFYVE | Phosphoinositide kinase required for late endosome homeostasis | Cataract and vacuolation models; lipid-based regulation of late endosomes |
| APP | Amyloid precursor protein; CTF accumulation dysregulates late endosome-lysosome-ER contacts | Alzheimer disease models; endolysosomal dysfunction |
| V-ATPase subunits | Acidify late endosomes and lysosomes; activate AMPK and mTORC1 via Ragulator | Nutrient sensing and pH regulation; KO and point-mutation studies |
| Ragulator complex | Scaffold for AMPK and mTORC1 activation at late endosomal/lysosomal membranes | Metabolic signaling; CRISPR KO to dissect catabolism/anabolism switch |
| NLRP3 | Inflammasome activated downstream of late endosomal dysfunction | Inflammation models; readout for late endosome-dependent mitophagy |
| STING | Innate immune sensor modulated by late endosomal-dependent mitophagy | Sepsis and autoinflammation models |
| HSP70 | Chaperone upregulated upon CHMP2B truncation; reduces TDP-43 aggregation | Neurodegeneration models; proteostasis and late endosome stress |
| TDP-43 | RNA-binding protein whose aggregation is altered by late endosome dysfunction | ALS/FTD models; link between late endosomes and proteinopathy |
| ER contact site proteins | Mediate late endosome-ER contacts and transport | Organelle contact biology; imaging and proteomics |
| Lysosomal fusion machinery | SNAREs and tethers mediating late endosome-lysosome fusion | Core fusion assays; KO of SNARE components |
| Rab7 effectors | Downstream effectors of Rab7 in late endosome transport | Functional dissection of late endosome positioning |
| ESCRT-III complex | Sorting and membrane remodeling at late endosomes | Neurodegeneration and membrane repair studies |
| mTORC1 | Growth regulator activated at late endosomal/lysosomal surface | Nutrient sensing; CRISPR screens for metabolic regulators |
| AMPK | Catabolic regulator activated by v-ATPase-Ragulator at late endosomes | Energy stress models; KO and point-mutation studies |
How Is late endosome Regulated?
Late endosome function is regulated at multiple levels. The lysosomal v-ATPase-Ragulator complex acts as a common activator for AMPK and mTORC1, switching cells between catabolism and anabolism based on nutrient availability. The SIRT1-Rab7 axis controls late endosomal-dependent mitophagy and downstream NLRP3 and STING activation during sepsis-induced acute lung injury. ER contact sites regulate late endosome transport and positioning, coupling organelle movement to calcium and lipid signaling. Phosphoinositide conversion by PIKFYVE is required for late endosome homeostasis, and its deficiency causes vacuole-like cataract. SNARE-mediated fusion, including STX17-dependent autophagosome fusion, provides another layer of regulation.
late endosome and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CHMP2B | Frontotemporal dementia; TDP-43 aggregation and HSP70 upregulation | Knockout or truncation knock-in in neuronal cell lines; TDP-43 aggregation assays |
| APP | Alzheimer disease; endolysosomal dysfunction via late endosome-lysosome-ER contacts | APP CTF overexpression and point-mutation models; contact site imaging |
| SIRT1/RAB7 | Sepsis-induced acute lung injury; NLRP3 and STING activation | Knockout and overexpression in lung epithelial or macrophage models; mitophagy readouts |
| PIKFYVE | Vacuole-like cataract; late endosome homeostasis | Knockout or point-mutation in lens epithelial cells; vacuolation imaging |
| STX17 | Autophagy-endosome fusion defects | Knockout in HeLa or neuronal cells; autophagosome-lysosome fusion assays |
Neurodegeneration and proteinopathies
Late endosome dysfunction is increasingly linked to neurodegenerative disease. Truncation mutation of CHMP2B disrupts late endosome function but reduces TDP-43 aggregation through HSP70 upregulation, suggesting a complex relationship between endosomal dysfunction and proteinopathy. Accumulation of APP C-terminal fragments causes endolysosomal dysfunction through dysregulation of late endosome-to-lysosome-ER contact sites, providing a mechanistic link to Alzheimer disease. These findings position late endosome biology as a therapeutic and biomarker area in neurodegeneration.
Inflammation and sepsis
The SIRT1-Rab7 axis attenuates NLRP3 and STING activation through late endosomal-dependent mitophagy during sepsis-induced acute lung injury. This indicates that late endosome function is not only a trafficking issue but also a determinant of innate immune activation. Targeting late endosomal pathways may therefore modulate inflammatory injury in sepsis and related conditions.
Metabolic and nutrient-sensing disorders
The v-ATPase-Ragulator complex at late endosomal/lysosomal membranes activates AMPK and mTORC1, acting as a switch between catabolism and anabolism. Dysregulation of this axis can alter cellular growth and autophagy, contributing to metabolic disease phenotypes. Late endosome-centered nutrient sensing is thus relevant to metabolic and cancer research.
Ocular and rare disease phenotypes
PIKFYVE deficiency induces vacuole-like cataract via perturbing late endosome homeostasis, linking phosphoinositide metabolism and late endosome function to lens pathology. This example illustrates how rare genetic lesions in late endosome regulators can produce tissue-specific disease.
From late endosome-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is a candidate gene required for late endosome morphology and positioning? | CRISPR knockout cell line with late endosome markers (e.g., Rab7) and high-content imaging |
| Does a disease-associated point mutation alter late endosome function? | Point-mutation knock-in of the variant in a relevant cell type, followed by trafficking and pH assays |
| Does a specific protein domain mediate late endosome-ER contact? | Tagged knock-in (e.g., GFP or HaloTag) for live imaging and proximity proteomics |
| Does overexpression of a regulator rescue or exacerbate late endosome dysfunction? | Inducible overexpression of wild-type or mutant cDNA in knockout background |
| Which genes regulate late endosome-dependent mitophagy? | CRISPR library screening with mitophagy reporters and late endosome markers |
| How does late endosome dysfunction affect inflammatory signaling? | Knockout of SIRT1/Rab7 axis components with NLRP3/STING readouts |
How to Study the late endosome Process
| Method | What It Measures | Typical Application |
|---|---|---|
| High-content imaging | Late endosome number, size, and juxtanuclear clustering | CRISPR knockout phenotyping |
| Live-cell imaging of ER contacts | Dynamic late endosome-ER contact sites | Organelle contact biology |
| Proximity proteomics | Protein composition of late endosome vicinity | Identification of novel regulators |
| Autophagosome-lysosome fusion assay | Fusion efficiency and autophagic flux | STX17 and SNARE studies |
| Mitophagy reporters | Late endosomal-dependent mitophagy | SIRT1-Rab7 axis and inflammation studies |
| pH-sensitive reporters | Lumenal pH of late endosomes/lysosomes | v-ATPase and acidification studies |
| CRISPR library screening | Genes required for late endosome function | Functional genomics of trafficking |
| Bioinformatics pathway analysis | Enrichment of GO:0005770 and interaction networks | Hit prioritization and mechanism inference |
Imaging late endosome morphology and positioning
High-content imaging with late endosome markers such as Rab7 allows quantification of organelle number, size, and juxtanuclear clustering. Live-cell imaging of ER contact sites can reveal dynamic interactions between late endosomes and the endoplasmic reticulum. These methods are essential for validating CRISPR phenotypes in late endosome biology.
Proteomics and interactomics
Proximity labeling and immunoprecipitation-mass spectrometry can identify proteins enriched at late endosomes, including SNAREs, Rab effectors, and contact site components. Proteomic profiling of late endosome-enriched fractions helps define changes in protein composition associated with disease mutations.
Functional assays for fusion and degradation
Assays measuring autophagosome-lysosome fusion, cargo degradation, and mitophagy report on late endosome function. pH-sensitive reporters and lysosomal inhibitors can distinguish defects in acidification from defects in fusion.
CRISPR screening and bioinformatics
Genome-wide CRISPR knockout or activation screens with late endosome reporters can identify regulators of organelle morphology, positioning, and function. Bioinformatics integration of screening hits with GO:0005770 annotations and interaction networks helps prioritize candidate genes for follow-up.
How CRISPR Can Be Used to Study GO:0005770 late endosome
Knockout
CRISPR knockout of late endosome regulators such as RAB7, CHMP2B, or PIKFYVE can reveal their requirement for organelle morphology, positioning, and fusion. Knockout models are also used to test whether a gene is essential for late endosomal-dependent mitophagy or inflammatory signaling. Combining knockout with high-content imaging provides quantitative phenotypes for GO:0005770.
Point Mutation
Point-mutation knock-in of disease-associated variants, such as CHMP2B truncation or APP mutations, allows precise testing of how specific residues alter late endosome function. These models are valuable for distinguishing loss-of-function from gain-of-function mechanisms in late endosome biology.
Knock-in
Tagged knock-in of late endosomal proteins (e.g., GFP-Rab7 or HaloTag-STX17) enables live imaging and proximity proteomics without overexpression artifacts. Knock-in reporters can also be used to monitor late endosome-lysosome fusion dynamics in real time.
Overexpression
Overexpression of wild-type or mutant late endosome regulators can rescue or exacerbate phenotypes observed in knockout backgrounds. Inducible overexpression systems are particularly useful for studying dose-dependent effects on late endosome homeostasis and signaling.
How EDITGENE Supports late endosome Research
Researchers studying late endosome-related genes often need to determine whether a candidate gene is causally involved in organelle morphology, trafficking, or disease-relevant signaling. EDITGENE provides CRISPR-based cell model services that enable precise genetic perturbations of late endosome (GO:0005770) components, from knockout to knock-in and library screening.
Contact EDITGENE today to design your custom CRISPR model for late endosome research.
Frequently Asked Questions About late endosome
What is GO:0005770 late endosome?
GO:0005770 late endosome is a prelysosomal endocytic organelle differentiated from early endosomes by lower lumenal pH and different protein composition; it is more spherical and mostly juxtanuclear, concentrated near the microtubule organizing center.
What genes are involved in late endosome function?
Key genes include RAB7, SIRT1, CHMP2B, STX17, PIKFYVE, APP, v-ATPase subunits, and Ragulator complex components, based on published studies.
How is the late endosome different from the early endosome?
Late endosomes have lower lumenal pH, a different protein composition, a more spherical shape, and a juxtanuclear position near the microtubule organizing center, whereas early endosomes are typically more peripheral.
What is the role of late endosomes in autophagy?
Late endosomes fuse with autophagosomes via SNARE proteins such as STX17, enabling degradation of autophagic cargo and completion of autophagic flux.
How are late endosomes linked to neurodegeneration?
CHMP2B truncation disrupts late endosome function and alters TDP-43 aggregation, while APP C-terminal fragment accumulation causes endolysosomal dysfunction via late endosome-lysosome-ER contact sites, linking late endosomes to frontotemporal dementia and Alzheimer-related pathology.
What is the SIRT1-Rab7 axis in late endosomes?
The SIRT1-Rab7 axis regulates late endosomal-dependent mitophagy and attenuates NLRP3 and STING activation during sepsis-induced acute lung injury.
How does PIKFYVE affect late endosomes?
PIKFYVE deficiency perturbs late endosome homeostasis and induces vacuole-like cataract, indicating that phosphoinositide conversion is required for normal late endosome function.
What methods are used to study late endosomes?
Common methods include high-content imaging, live-cell imaging of ER contacts, proximity proteomics, autophagosome-lysosome fusion assays, mitophagy reporters, pH-sensitive reporters, and CRISPR library screening.
Can CRISPR be used to study late endosome genes?
Yes, CRISPR knockout, point-mutation knock-in, tagged knock-in, overexpression, and library screening are all applicable to dissect late endosome (GO:0005770) biology.
What is the role of the v-ATPase-Ragulator complex in late endosomes?
The lysosomal v-ATPase-Ragulator complex acts as a common activator for AMPK and mTORC1 at late endosomal/lysosomal membranes, functioning as a switch between catabolism and anabolism.
Conclusion
GO:0005770 late endosome is a prelysosomal organelle with a distinct low-pH lumen, spherical juxtanuclear morphology, and a protein composition specialized for cargo sorting, fusion, and signaling. Its functions intersect with autophagy, nutrient sensing, mitophagy, and inflammation, and its dysfunction is implicated in neurodegeneration, sepsis, and ocular disease. CRISPR-based cell models, combined with imaging, proteomics, and screening, provide a powerful toolkit to dissect late endosome biology and identify therapeutic targets.
References
- 1. Wijdeven RH et al.. 2015. ER contact sites direct late endosome transport.. Bioessays 37(12):1298-302 PMID: 26440125
- 2. Iguchi Y et al.. 2025. Truncation mutation of CHMP2B disrupts late endosome function but reduces TDP-43 aggregation through HSP70 upregulation.. Neurochem Int 187:105982 PMID: 40316175
- 3. 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
- 4. Jiang T et al.. 2024. SIRT1-Rab7 axis attenuates NLRP3 and STING activation through late endosomal-dependent mitophagy during sepsis-induced acute lung injury.. Int J Surg 110(5):2649-2668 PMID: 38445453
- 5. 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
- 6. 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
- 7. Luzio JP et al.. 2010. Endosome-lysosome fusion.. Biochem Soc Trans 38(6):1413-6 PMID: 21118098
- 8. Ma X et al.. 2025. PIKFYVE deficiency induces vacuole-like cataract via perturbing late endosome homeostasis.. Biochem Biophys Res Commun 747:151123 PMID: 39778216
