GO:0110157 reelin complex: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0110157 reelin complex is an extracellular protein complex that binds lipoprotein receptors VLDLR and APOER2, cadherin-related neuronal receptors (CNRs), or alpha3beta1 integrin to trigger reelin-dependent phosphorylation cascades.
• The reelin complex is essential for neuronal migration, layer formation in the embryonic brain, and synaptic activity in the postnatal and adult brain.
• Core components include the secreted glycoprotein reelin (RELN) and its receptors, such as VLDLR, APOER2 (LRP8), CNRs, and integrins.
• Dysregulation of reelin signaling is linked to neurodevelopmental and neurodegenerative disorders, including epilepsy, autism, and hereditary spastic paraplegia.
• The reelin complex also plays a role in non-neuronal tissues, such as lymphatic signaling and intestinal stem cell regulation.
• CRISPR-based models (knockout, point mutation, knock-in, overexpression) are powerful tools to dissect reelin complex function in health and disease.
Description
The reelin complex (GO:0110157) is an extracellular assembly of proteins that mediates critical signaling events in the developing and adult brain. It is defined by its ability to bind lipoprotein receptors VLDLR and APOER2, cadherin-related neuronal receptors (CNRs), or alpha3beta1 integrin, thereby inducing phosphorylation cascades that regulate neuronal polarization, differentiation, migration, and layer formation. This complex is not only central to embryonic brain development but also influences neuron growth, maturation, and synaptic activity in postnatal and adult brains. Researchers study the reelin complex to understand fundamental mechanisms of brain wiring and to uncover therapeutic targets for neurodevelopmental and neurodegenerative diseases. Beyond the nervous system, reelin complex components have been implicated in lymphatic signaling and intestinal stem cell activity, highlighting its broader biological significance.
reelin complex At A Glance
| GO ID | GO:0110157 |
|---|---|
| GO term | reelin complex |
| Ontology | cellular_component |
| Synonym | None |
| Major function | Binds lipoprotein receptors VLDLR and APOER2, CNRs, or alpha3beta1 integrin to induce reelin-dependent phosphorylation cascades |
| Biological context | Embryonic brain development, neuronal migration, layer formation, synaptic activity |
| Key components | Reelin (RELN), VLDLR, APOER2 (LRP8), CNRs, alpha3beta1 integrin |
| Associated diseases | Epilepsy, autism, hereditary spastic paraplegia |
What Is GO:0110157?
The reelin complex is an extracellular protein complex that binds to specific receptors, including VLDLR, APOER2, CNRs, and alpha3beta1 integrin. Upon binding, it triggers downstream phosphorylation cascades that ultimately affect neuronal polarization, differentiation, migration, and layer formation in the embryonic brain, as well as neuron growth, maturation, and synaptic activity in the postnatal and adult brain.
Why Is reelin complex Important in Cell Biology?
The reelin complex is a master regulator of brain development and function. Its correct assembly and signaling are required for the precise positioning of neurons during cortical layer formation, and its dysfunction leads to severe neurodevelopmental disorders such as epilepsy and autism. Moreover, the reelin complex has been implicated in synaptic plasticity and adult neurogenesis, making it relevant to neurodegenerative conditions and cognitive disorders. Understanding its components and mechanisms is therefore crucial for developing targeted therapies.
• Controls neuronal migration and cortical layer formation during embryonic development.
• Regulates synaptic activity and plasticity in the adult brain.
• Mutations in reelin complex components are associated with epilepsy and autism spectrum disorders.
• The reelin receptor ApoER2 is a cargo for adaptor protein complex AP-4, linking the complex to hereditary spastic paraplegia.
• Reelin signaling influences lymphatic junctional remodeling and intestinal stem cell activity.
• Provides a model system for studying extracellular matrix-receptor signaling.
• Potential therapeutic target for neurodevelopmental and neurodegenerative diseases.
• Involved in aggression-related pathways in human and rodent models.
• Key to understanding brain evolution and cortical expansion.
• Offers opportunities for CRISPR-based functional genomics.
Structure and Composition of reelin complex
Reelin: The Core Ligand
In simple terms: Reelin is the main protein that starts the signaling process.
Reelin is a large secreted glycoprotein that forms the core of the reelin complex. It is encoded by the RELN gene and is produced by Cajal-Retzius cells in the developing brain. Reelin binds to receptors on target neurons to initiate signaling.
Lipoprotein Receptors: VLDLR and APOER2
In simple terms: These are the receptors that reelin binds to on the cell surface.
VLDLR and APOER2 (also known as LRP8) are lipoprotein receptors that act as primary receptors for reelin. They are single-pass transmembrane proteins that dimerize upon reelin binding and trigger intracellular phosphorylation cascades. ApoER2 is also a cargo for adaptor protein complex AP-4, linking it to intracellular trafficking.
Cadherin-Related Neuronal Receptors (CNRs)
In simple terms: CNRs are alternative receptors that can also bind reelin.
Cadherin-related neuronal receptors (CNRs) are a family of transmembrane proteins that can bind reelin and mediate downstream signaling. They contribute to the diversity of reelin responses in different neuronal populations.
Integrin alpha3beta1
In simple terms: Integrins are another type of receptor that reelin can use.
The alpha3beta1 integrin heterodimer is an additional receptor for reelin. Binding of reelin to integrins can activate signaling pathways that regulate cell adhesion and migration.
Assembly and Secretion
In simple terms: The complex forms when reelin is secreted and binds to receptors on the cell surface.
The reelin complex assembles extracellularly when secreted reelin binds to its receptors on the surface of target cells. This binding induces receptor clustering and activation of downstream kinases, such as Fyn and Dab1 phosphorylation. Reelin secretion has been studied in lymphatic endothelial cells, where VE-cadherin proximity interactome revealed mechanisms of reelin secretion.
Key Genes Involved in GO:0110157 reelin complex
The following genes encode key components of the reelin complex and its signaling pathway.
| Gene | Major Role | Research Relevance |
|---|---|---|
| RELN | Encodes reelin, the core ligand of the complex | Mutations cause lissencephaly, epilepsy, autism |
| VLDLR | Reelin receptor; mediates downstream phosphorylation | Associated with cerebellar hypoplasia |
| LRP8 (APOER2) | Reelin receptor; interacts with AP-4 adaptor complex | Linked to hereditary spastic paraplegia |
| DAB1 | Adaptor protein phosphorylated upon reelin binding | Key downstream effector of reelin signaling |
| FYN | Src-family kinase that phosphorylates Dab1 | Mediates reelin-dependent cytoskeletal changes |
| CNR1 | Cadherin-related neuronal receptor | Alternative reelin receptor |
| ITGA3 | Alpha3 integrin subunit | Forms alpha3beta1 integrin with ITGB1 |
| ITGB1 | Beta1 integrin subunit | Forms alpha3beta1 integrin with ITGA3 |
| AP4M1 | Adaptor protein complex 4 subunit | Mutations cause hereditary spastic paraplegia |
| AP4B1 | Adaptor protein complex 4 subunit | Mutations cause hereditary spastic paraplegia |
| AP4E1 | Adaptor protein complex 4 subunit | Mutations cause hereditary spastic paraplegia |
| AP4S1 | Adaptor protein complex 4 subunit | Mutations cause hereditary spastic paraplegia |
| CDH5 | VE-cadherin, involved in reelin secretion in lymphatics | Regulates lymphatic junctional remodeling |
| PROX1 | Lymphatic endothelial transcription factor | Linked to reelin secretion in lymphatics |
| LGR5 | Intestinal stem cell marker | Reelin complex influences stem cell activity |
| RELN | Reelin glycoprotein | Also implicated in aggression pathways |
| RELN | Reelin glycoprotein | Role in neuronal migration |
How Is reelin complex Regulated?
The reelin complex is regulated at multiple levels. Reelin secretion and availability are controlled by proteolytic cleavage and interactions with extracellular matrix components. Receptor levels, including VLDLR and APOER2, are modulated by intracellular trafficking, such as AP-4-mediated transport. Downstream signaling is regulated by phosphorylation of Dab1 and feedback loops involving Fyn kinase. Additionally, reelin expression is influenced by transcription factors and epigenetic mechanisms in different brain regions.
reelin complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| RELN | Lissencephaly, epilepsy, autism | Reln knockout mouse; patient iPSC-derived neurons |
| LRP8 (APOER2) | Hereditary spastic paraplegia | Apoer2 knockout mouse; AP-4 deficient cell lines |
| AP4M1 | Hereditary spastic paraplegia | AP-4 knockout iPSC-derived neurons |
| DAB1 | Neurodevelopmental disorders | Dab1 knockout mouse |
| CDH5 | Lymphatic remodeling | VE-cadherin knockout lymphatic endothelial cells |
Neurodevelopmental Disorders
Disruption of the reelin complex leads to severe neurodevelopmental disorders. Mutations in RELN cause lissencephaly, a condition characterized by impaired neuronal migration and cortical malformation. Reelin signaling defects are also associated with epilepsy and autism spectrum disorders, as highlighted in studies of developmental and epileptic encephalopathies.
Hereditary Spastic Paraplegia
The reelin receptor ApoER2 (LRP8) is a cargo for adaptor protein complex AP-4. Mutations in AP-4 subunits cause hereditary spastic paraplegia, a neurodegenerative disorder affecting motor neurons. This links reelin complex trafficking to motor neuron degeneration.
Neuropsychiatric and Behavioral Disorders
Reelin complex components have been implicated in aggression and other behavioral traits. An integrated analysis of genes and pathways for aggression identified reelin signaling as a significant contributor in human and rodent models.
Non-Neuronal Roles
Beyond the brain, the reelin complex influences lymphatic and intestinal biology. Lymphatic VE-cadherin proximity interactome revealed mechanisms of reelin secretion, and lymphatics act as a signaling hub to regulate intestinal stem cell activity.
From reelin complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does RELN mutation impair neuronal migration? | RELN knockout or point-mutation knock-in mouse |
| How does ApoER2 trafficking affect spastic paraplegia? | APOER2 tagged knock-in in neurons |
| What is the role of reelin in synaptic plasticity? | Conditional RELN knockout in adult brain |
| Can reelin overexpression rescue migration defects? | Reelin overexpression transgenic mouse |
| How does reelin complex affect intestinal stem cells? | Lgr5+ stem cell-specific knockout |
| What are the interactors of reelin complex? | Proximity labeling (BioID) in reelin-expressing cells |
How to Study the reelin complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout | Loss of gene function | Study reelin complex component necessity |
| RNA-seq | Transcriptional changes | Identify downstream targets of reelin signaling |
| BioID proteomics | Protein-protein interactions | Map reelin complex interactome |
| Phospho-Dab1 immunoblot | Reelin pathway activation | Quantify signaling strength |
| Live-cell imaging | Neuronal migration dynamics | Assess reelin-dependent motility |
| Electrophysiology | Synaptic activity | Measure effects on plasticity |
| Behavioral tests | Cognitive and social behaviors | Model neuropsychiatric phenotypes |
| Single-cell RNA-seq | Cell-type-specific responses | Dissect heterogeneity in reelin signaling |
Genetic and Genomic Approaches
CRISPR-Cas9 knockout, point mutation, and knock-in models are essential to dissect the function of reelin complex genes. RNA-seq and single-cell transcriptomics can reveal downstream transcriptional changes upon reelin signaling activation or disruption.
Proteomic and Interactomic Methods
Proximity-dependent biotin identification (BioID) and co-immunoprecipitation coupled with mass spectrometry can identify novel components and interactors of the reelin complex. These methods have been used to map the proximity interactome of VE-cadherin and reelin secretion.
Imaging and Functional Assays
Live-cell imaging of neuronal migration in organotypic slices and in vivo two-photon microscopy can visualize reelin-dependent processes. Phospho-specific antibodies against Dab1 are used to monitor reelin pathway activation.
Behavioral and Electrophysiological Studies
Electrophysiology in brain slices from conditional knockout mice can assess synaptic activity and plasticity. Behavioral tests in reelin mutant mice reveal cognitive and social deficits relevant to neuropsychiatric disorders.
How CRISPR Can Be Used to Study GO:0110157 reelin complex
Knockout
CRISPR knockout of RELN, VLDLR, APOER2, or DAB1 in cell lines and animal models abolishes reelin complex function, leading to impaired neuronal migration and signaling. These models are used to study loss-of-function phenotypes and to validate drug targets.
Point Mutation
Introducing disease-associated point mutations (e.g., in RELN or LRP8) via CRISPR base editing or homology-directed repair allows precise modeling of patient-specific variants. Such models help determine whether a mutation is pathogenic and how it affects reelin complex assembly.
Knock-in
Knock-in of tagged versions of reelin complex components (e.g., GFP-RELN or HA-APOER2) enables live-cell imaging and proteomic analysis. Knock-in of human disease alleles into mouse models recapitulates human pathology.
Overexpression
CRISPR activation (CRISPRa) or transgenic overexpression of RELN can rescue migration defects or enhance synaptic function. Overexpression models are useful for gain-of-function studies and for testing therapeutic potential.
How EDITGENE Supports reelin complex Research
Researchers studying reelin complex-related genes often need to determine whether a candidate gene is causally involved in neuronal migration, synaptic function, or disease. EDITGENE provides end-to-end CRISPR solutions to accelerate this discovery process.
Contact EDITGENE today to design your custom CRISPR model for reelin complex research.
Frequently Asked Questions About reelin complex
What is the reelin complex?
The reelin complex is an extracellular protein assembly that binds receptors like VLDLR, APOER2, CNRs, and alpha3beta1 integrin to trigger signaling cascades essential for brain development and function.
What genes are involved in the reelin complex?
Key genes include RELN, VLDLR, LRP8 (APOER2), DAB1, FYN, CNR1, ITGA3, and ITGB1.
What is the function of GO:0110157?
GO:0110157 describes the reelin complex, which regulates neuronal migration, layer formation, and synaptic activity through phosphorylation cascades.
How is the reelin complex linked to disease?
Mutations in reelin complex components are associated with epilepsy, autism, lissencephaly, and hereditary spastic paraplegia.
What are the receptors for reelin?
Reelin binds lipoprotein receptors VLDLR and APOER2, cadherin-related neuronal receptors (CNRs), and alpha3beta1 integrin.
What research methods are used to study the reelin complex?
Common methods include CRISPR knockout, RNA-seq, BioID proteomics, phospho-Dab1 immunoblotting, live-cell imaging, and electrophysiology.
Is the reelin complex involved in non-neuronal tissues?
Yes, reelin signaling has been implicated in lymphatic remodeling and intestinal stem cell regulation.
What is the role of ApoER2 in the reelin complex?
ApoER2 (LRP8) is a receptor for reelin and is also a cargo for adaptor protein complex AP-4, linking it to hereditary spastic paraplegia.
How can CRISPR be used to study the reelin complex?
CRISPR can create knockout, point mutation, knock-in, and overexpression models to dissect gene function and model diseases.
What cell models are available for reelin complex research?
EDITGENE provides custom knockout, point mutation, knock-in, and overexpression cell models for reelin complex genes in neuronal and other cell types.
Conclusion
The reelin complex (GO:0110157) is a critical extracellular signaling hub that orchestrates brain development and function. Its components, including reelin, VLDLR, APOER2, CNRs, and integrins, mediate diverse downstream effects ranging from neuronal migration to synaptic plasticity. Dysregulation of this complex is linked to severe neurological and psychiatric disorders, making it a prime target for therapeutic intervention. Advanced CRISPR-based models and multi-omics approaches will continue to unravel its mechanisms and translational potential.
References
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- 2. Specchio N et al.. 2025. The epilepsy-autism phenotype associated with developmental and epileptic encephalopathies: New mechanism-based therapeutic options.. Epilepsia 66(4):970-987 PMID: 39985505
- 3. Niec RE et al.. 2022. Lymphatics act as a signaling hub to regulate intestinal stem cell activity.. Cell Stem Cell 29(7):1067-1082.e18 PMID: 35728595
- 4. Caracci MO et al.. 2024. The Reelin receptor ApoER2 is a cargo for the adaptor protein complex AP-4: Implications for Hereditary Spastic Paraplegia.. Prog Neurobiol 234:102575 PMID: 38281682
- 5. Zhang-James Y et al.. 2019. An integrated analysis of genes and functional pathways for aggression in human and rodent models.. Mol Psychiatry 24(11):1655-1667 PMID: 29858598
- 6. Lambert de Rouvroit C et al.. 2001. Neuronal migration.. Mech Dev 105(1-2):47-56 PMID: 11429281
- 7. Caracci MO et al.. 2023. The Reelin Receptor ApoER2 is a Cargo for the Adaptor Protein Complex AP-4: Implications for Hereditary Spastic Paraplegia.. bioRxiv PMID: 38187774
- 8. Serafin DS et al.. 2024. Proximity interactome of lymphatic VE-cadherin reveals mechanisms of junctional remodeling and reelin secretion.. Nat Commun 15(1):7734 PMID: 39232006
