GO:0005166 neurotrophin p75 receptor binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0005166 (neurotrophin p75 receptor binding) is a molecular function describing the binding of a ligand to the p75 neurotrophin receptor (p75NTR), a member of the TNF receptor superfamily.
• p75NTR binds all neurotrophins (NGF, BDNF, NT-3, NT-4) with low affinity and modulates Trk receptor signaling, influencing neuronal survival, death, and differentiation.
• The p75NTR ectodomain contains a cysteine-rich domain that mediates neurotrophin binding, while its intracellular death domain and juxtamembrane region regulate downstream signaling.
• p75NTR is implicated in neurodegeneration, including amyloid-beta-induced dendritic spine pathology in Alzheimer's disease models.
• p75NTR facilitates TrkB signaling and function in hippocampal neurons, highlighting its role in synaptic plasticity.
• p75NTR regulates stem cell biology beyond being a marker, affecting proliferation, survival, and differentiation.
Description
The p75 neurotrophin receptor (p75NTR, also known as TNFRSF16) is a transmembrane receptor that binds all neurotrophins and plays critical roles in the nervous system. The Gene Ontology molecular function term GO:0005166, neurotrophin p75 receptor binding, describes the binding of a neurotrophin ligand to p75NTR. This interaction is central to neurotrophic signaling, influencing neuronal survival, apoptosis, and synaptic plasticity. Unlike Trk receptors, which exhibit high affinity and specificity for individual neurotrophins, p75NTR binds neurotrophins with low affinity and can modulate Trk signaling in a context-dependent manner. Researchers study this binding to understand how neurotrophins dictate cell fate decisions, particularly in neurodegenerative diseases and cancer. The p75NTR is a member of the TNF receptor superfamily, characterized by a distinct extracellular domain with cysteine-rich repeats and an intracellular death domain. Its ability to bind neurotrophins and initiate signaling cascades makes it a key player in both developmental and pathological processes.
neurotrophin p75 receptor binding At A Glance
| GO ID | GO:0005166 |
|---|---|
| GO term | neurotrophin p75 receptor binding |
| Ontology | molecular_function |
| Synonym | neurotrophin p75 receptor ligand |
| Major function | Binding to the p75 neurotrophin receptor, initiating signaling that regulates neuronal survival, death, and differentiation. |
| Receptor | p75NTR (TNFRSF16), a member of the TNF receptor superfamily. |
| Ligands | Neurotrophins: NGF, BDNF, NT-3, NT-4. |
| Affinity | Low-affinity binding compared to Trk receptors. |
| Downstream effects | Modulation of Trk signaling, activation of JNK, NF-kB, and apoptosis. |
What Is GO:0005166?
GO:0005166 neurotrophin p75 receptor binding is defined as the binding to a neurotrophin p75 receptor. In other words, it is the molecular function of a ligand (typically a neurotrophin such as NGF, BDNF, NT-3, or NT-4) physically interacting with the p75 neurotrophin receptor (p75NTR). This binding event is the first step in p75NTR-mediated signaling and can lead to diverse cellular outcomes depending on context.
Why Is neurotrophin p75 receptor binding Important in Cell Biology?
Understanding neurotrophin p75 receptor binding is crucial because it governs fundamental processes in neuronal development, survival, and plasticity, and its dysregulation is linked to neurodegenerative diseases, psychiatric disorders, and cancer. The binding of neurotrophins to p75NTR can either promote cell survival or induce apoptosis, depending on the cellular context and co-receptors present. This dual role makes p75NTR a critical modulator of neural circuit formation and maintenance.
• Regulates neuronal survival and apoptosis during development and in adulthood.
• Modulates Trk receptor signaling, influencing synaptic plasticity and memory.
• Implicated in Alzheimer's disease through amyloid-beta-induced dendritic spine pathology.
• Plays a role in stem cell biology, affecting proliferation and differentiation.
• Involved in retrograde apoptotic signaling in neurons.
• Serves as a therapeutic target for neurodegenerative conditions.
• Contributes to cancer progression and metastasis in some contexts.
• Essential for the development of the peripheral nervous system.
• Mediates responses to injury and inflammation in the nervous system.
• Provides a model for studying TNF receptor superfamily signaling.
Molecular Mechanism of neurotrophin p75 receptor binding
Neurotrophin Binding to p75NTR
In simple terms: Neurotrophins attach to the p75 receptor on the cell surface.
The binding of neurotrophins to p75NTR occurs through the extracellular cysteine-rich domain of the receptor. All four neurotrophins (NGF, BDNF, NT-3, NT-4) can bind p75NTR, albeit with low affinity compared to Trk receptors. This binding is essential for initiating p75NTR-mediated signaling, which can lead to diverse outcomes such as survival or apoptosis.
Receptor Conformational Changes and Complex Formation
In simple terms: When neurotrophins bind, the p75 receptor changes shape and can team up with other proteins.
Upon neurotrophin binding, p75NTR undergoes conformational changes that allow it to form complexes with other receptors, such as TrkA or TrkB, or with co-receptors like sortilin. These complexes modulate signaling specificity and intensity. For example, the formation of high-affinity TrkA-p75NTR complexes enhances neurotrophin signaling.
Intracellular Signaling Initiation
In simple terms: The receptor sends signals inside the cell by activating specific pathways.
The intracellular domain of p75NTR contains a death domain and a juxtamembrane region that recruit adaptor proteins and activate signaling cascades, including JNK, NF-kB, and caspase pathways. This can lead to either cell survival or apoptosis depending on the cellular context and the presence of co-receptors.
Modulation of Trk Signaling
In simple terms: The p75 receptor can influence signals from Trk receptors, which are important for neuron growth and survival.
p75NTR can facilitate or inhibit Trk receptor signaling. For instance, it enhances TrkB signaling and function in hippocampal neurons, contributing to synaptic plasticity. Conversely, in some contexts, p75NTR can promote apoptosis by sequestering neurotrophins or forming inhibitory complexes with Trk receptors.
Retrograde Apoptotic Signaling
In simple terms: The p75 receptor can send death signals from the nerve terminal back to the cell body.
p75NTR mediates retrograde apoptotic signaling, where neurotrophin binding at distal axons triggers apoptotic signals that are transported to the cell body, leading to neuronal death. This process is important during development and in neurodegenerative conditions.
Key Genes Involved in GO:0005166 neurotrophin p75 receptor binding
The following genes and proteins are key players in neurotrophin p75 receptor binding and its downstream effects.
| Gene | Major Role | Research Relevance |
|---|---|---|
| NGFR (p75NTR) | Encodes the p75 neurotrophin receptor, binds all neurotrophins | Central to neurotrophin signaling, apoptosis, and survival |
| NGF | Neurotrophin ligand, binds p75NTR and TrkA | Prototype ligand for p75NTR, involved in pain and neurodegeneration |
| BDNF | Neurotrophin ligand, binds p75NTR and TrkB | Regulates synaptic plasticity and survival |
| NTF3 (NT-3) | Neurotrophin ligand, binds p75NTR and TrkC | Involved in development of proprioceptive neurons |
| NTF4 (NT-4) | Neurotrophin ligand, binds p75NTR and TrkB | Modulates survival and differentiation |
| NTRK1 (TrkA) | High-affinity receptor for NGF, interacts with p75NTR | Forms high-affinity complexes with p75NTR |
| NTRK2 (TrkB) | High-affinity receptor for BDNF/NT-4, interacts with p75NTR | p75NTR facilitates TrkB signaling |
| NTRK3 (TrkC) | High-affinity receptor for NT-3 | Can be modulated by p75NTR |
| SORT1 (Sortilin) | Co-receptor for p75NTR, forms complexes with pro-neurotrophins | Mediates pro-neurotrophin-induced apoptosis |
| RIP2 (RIPK2) | Adaptor protein binding p75NTR death domain | Activates NF-kB and JNK pathways |
| TRAF6 | E3 ubiquitin ligase, interacts with p75NTR | Regulates survival signaling |
| NRAGE (MAGED1) | Adaptor protein binding p75NTR | Mediates apoptosis and cell cycle arrest |
| BEX1 | Adaptor protein binding p75NTR | Modulates neuronal differentiation |
| JNK | Stress-activated kinase activated by p75NTR | Mediates apoptosis |
| CASPASE-3 | Executioner caspase activated by p75NTR | Induces apoptosis |
| NF-KB | Transcription factor activated by p75NTR | Promotes survival or inflammation |
| AKT | Survival kinase modulated by p75NTR | Influences cell survival |
| RhoA | Small GTPase activated by p75NTR | Regulates growth cone collapse |
How Is neurotrophin p75 receptor binding Regulated?
The binding of neurotrophins to p75NTR is regulated at multiple levels. Receptor expression is controlled by transcription factors and developmental cues. Post-translational modifications, such as glycosylation and cleavage by proteases (e.g., alpha-secretase and gamma-secretase), can modulate ligand binding and signaling. Additionally, the presence of co-receptors like sortilin or Trk receptors alters the affinity and downstream effects of neurotrophin binding. Neurotrophin availability is regulated by secretion and extracellular matrix interactions.
neurotrophin p75 receptor binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| NGFR | Alzheimer's disease, neurodegeneration | APP/PS1 mouse model with p75NTR knockout |
| NGFR | Motor neuron disease | SOD1-G93A ALS mouse model |
| NGFR | Cancer stem cell maintenance | Xenograft models with p75NTR knockdown |
| BDNF | Depression, synaptic plasticity | BDNF knockout mice |
| NGF | Pain, neuropathy | NGF transgenic mice |
Alzheimer's Disease
In Alzheimer's disease, amyloid-beta binds p75NTR and induces dendritic spine pathology, contributing to synaptic loss and cognitive decline. p75NTR also mediates amyloid-beta-induced apoptosis, linking neurotrophin signaling to neurodegeneration.
Neurodegenerative Disorders
p75NTR is implicated in motor neuron disease, Parkinson's disease, and glaucoma, where it can promote neuronal death through retrograde apoptotic signaling. Its role in modulating Trk signaling also affects neuroprotection.
Cancer
p75NTR is expressed in various cancers and can act as a tumor suppressor or oncogene depending on context. It influences stem cell biology, including proliferation and differentiation, and is a marker for cancer stem cells.
Stem Cell Biology
p75NTR regulates stem cell behavior beyond being a marker, affecting survival, proliferation, and differentiation in neural and non-neural tissues.
From neurotrophin p75 receptor binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does p75NTR mediate amyloid-beta-induced spine loss? | p75NTR knockout mice crossed with APP transgenic mice |
| How does p75NTR modulate TrkB signaling? | Conditional p75NTR knockout in hippocampal neurons |
| What is the role of p75NTR in retrograde apoptosis? | Sympathetic neuron cultures from p75NTR-/- mice |
| Does p75NTR regulate stem cell differentiation? | p75NTR knockout embryonic stem cells |
| What is the structural basis of neurotrophin binding? | Recombinant p75NTR ectodomain for crystallography |
| Can p75NTR be targeted for neuroprotection? | p75NTR antagonist in animal models of neurodegeneration |
How to Study the neurotrophin p75 receptor binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Surface plasmon resonance (SPR) | Binding affinity and kinetics | Measuring neurotrophin-p75NTR interactions |
| Isothermal titration calorimetry (ITC) | Thermodynamics of binding | Characterizing binding affinity |
| X-ray crystallography | 3D structure of protein complexes | Determining binding interface |
| Western blot | Protein phosphorylation and expression | Assessing downstream signaling |
| Immunofluorescence | Protein localization and morphology | Visualizing p75NTR and synaptic markers |
| Co-immunoprecipitation | Protein-protein interactions | Detecting p75NTR-Trk complexes |
| Apoptosis assays (TUNEL, caspase-3) | Cell death | Measuring p75NTR-mediated apoptosis |
| Behavioral tests | Cognitive and motor function | Evaluating neurodegeneration in vivo |
Binding Assays
Surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) can measure the affinity and kinetics of neurotrophin binding to p75NTR. These methods provide quantitative data on binding constants and stoichiometry.
Structural Biology
X-ray crystallography and cryo-electron microscopy have been used to determine the structure of the p75NTR ectodomain and its complexes with neurotrophins, revealing the molecular basis of binding.
Cell-Based Signaling Assays
Neuronal cultures treated with neurotrophins and p75NTR inhibitors can be used to study downstream signaling, such as JNK phosphorylation, NF-kB activation, and apoptosis, using Western blotting and immunofluorescence.
Animal Models
Transgenic mice with p75NTR knockout or overexpression are used to study the role of p75NTR in development, neurodegeneration, and behavior.
How CRISPR Can Be Used to Study GO:0005166 neurotrophin p75 receptor binding
Knockout
CRISPR-Cas9 knockout of NGFR (p75NTR) in cell lines or primary neurons can abolish neurotrophin binding and downstream signaling, providing a clean background to study p75NTR-specific functions. Knockout mice are valuable for in vivo studies of development and disease.
Point Mutation
Introducing point mutations in the neurotrophin-binding domain of p75NTR can dissect the structural requirements for ligand binding and signaling. For example, mutations in cysteine-rich repeats can disrupt neurotrophin binding.
Knock-in
Knock-in of tagged p75NTR (e.g., HA or GFP) allows for visualization and purification of the receptor in its endogenous context. This can be used to study receptor trafficking and complex formation.
Overexpression
Overexpression of p75NTR in cell lines or neurons can enhance neurotrophin-induced signaling and apoptosis, useful for gain-of-function studies. It can also sensitize cells to neurotrophin-mediated effects.
How EDITGENE Supports neurotrophin p75 receptor binding Research
Researchers studying neurotrophin p75 receptor binding-related genes often need to determine whether a candidate gene is causally involved in receptor function, signaling, or disease. EDITGENE provides comprehensive CRISPR-based services to create precise genetic models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for neurotrophin p75 receptor binding research.
Frequently Asked Questions About neurotrophin p75 receptor binding
What is GO:0005166 neurotrophin p75 receptor binding?
It is a Gene Ontology molecular function term describing the binding of a neurotrophin ligand to the p75 neurotrophin receptor (p75NTR).
What genes are involved in neurotrophin p75 receptor binding?
Key genes include NGFR (encoding p75NTR), neurotrophins (NGF, BDNF, NTF3, NTF4), and co-receptors like NTRK1, NTRK2, and SORT1.
How does p75NTR bind neurotrophins?
p75NTR binds neurotrophins through its extracellular cysteine-rich domain with low affinity, initiating conformational changes and signaling.
What is the role of p75NTR in Alzheimer's disease?
p75NTR mediates amyloid-beta-induced dendritic spine pathology and apoptosis, contributing to neurodegeneration.
Can p75NTR signaling be targeted for therapy?
Yes, p75NTR antagonists or modulators are being explored for neuroprotection in neurodegenerative diseases.
What are the downstream effects of neurotrophin p75 receptor binding?
It can activate JNK, NF-kB, and caspase pathways, leading to either survival or apoptosis depending on context.
How is p75NTR expression regulated?
p75NTR expression is regulated transcriptionally and post-translationally, including by proteolytic cleavage and co-receptor interactions.
What research methods are used to study p75NTR binding?
Methods include SPR, ITC, X-ray crystallography, cell signaling assays, and animal models.
What diseases are associated with p75NTR?
Alzheimer's disease, motor neuron disease, cancer, and stem cell disorders.
How can CRISPR be used to study p75NTR function?
CRISPR knockout, point mutation, knock-in, and overexpression models allow precise dissection of p75NTR signaling in vitro and in vivo.
Conclusion
GO:0005166 neurotrophin p75 receptor binding is a fundamental molecular function that governs diverse neuronal processes, from survival to apoptosis. Its dysregulation is linked to major neurodegenerative diseases and cancer, making it a critical research focus. Understanding the structural and signaling mechanisms of p75NTR binding provides opportunities for therapeutic intervention. Advanced CRISPR models and bioinformatics tools are essential for unraveling the complexities of this interaction.
References
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- 3. Zanin JP et al.. 2019. The p75 Neurotrophin Receptor Facilitates TrkB Signaling and Function in Rat Hippocampal Neurons.. Front Cell Neurosci 13:485 PMID: 31736712
- 4. Pathak A et al.. 2017. Retrograde apoptotic signaling by the p75 neurotrophin receptor.. Neuronal Signal 1(1):NS20160007 PMID: 32714573
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- 7. Tomellini E et al.. 2014. Role of p75 neurotrophin receptor in stem cell biology: more than just a marker.. Cell Mol Life Sci 71(13):2467-81 PMID: 24481864
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