GO:0031994 insulin-like growth factor I binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0031994 (insulin-like growth factor I binding) is a molecular function defined as binding to insulin-like growth factor I (IGF-I), a key growth and survival peptide.
• IGF-I binding is mediated by the IGF-I receptor (IGF1R) and modulated by IGF-binding proteins (IGFBPs), which control IGF-I bioavailability and signaling.
• IGF-I binding influences diverse biological processes including growth, metabolism, cell proliferation, survival, and migration.
• Dysregulated IGF-I binding is implicated in cancers (e.g., prostate, melanoma), asthma, type 1 diabetes, and infectious diseases.
• Research on IGF-I binding employs binding assays, structural biology, cell signaling readouts, and CRISPR-based gene editing to dissect gene function.
• Understanding IGF-I binding at the molecular level informs therapeutic strategies targeting IGF-I/IGF1R signaling in disease.
Description
Insulin-like growth factor I (IGF-I) is a peptide hormone structurally related to insulin that regulates growth, development, and metabolism. The molecular function of insulin-like growth factor I binding (GO:0031994) refers to the selective interaction of proteins with IGF-I, a critical step in initiating IGF-I-mediated cellular responses. This binding event is essential for the bioavailability, transport, and signaling of IGF-I in various physiological contexts. Researchers study IGF-I binding to understand how growth factors control cell fate, tissue homeostasis, and disease progression. The binding of IGF-I to its receptor (IGF1R) triggers autophosphorylation and downstream signaling cascades, while IGF-binding proteins (IGFBPs) sequester IGF-I, modulating its activity. Dysregulation of IGF-I binding is associated with cancer, metabolic disorders, and inflammatory conditions, making it a target for therapeutic intervention. This article explores the mechanisms, key genes, and research methodologies related to GO:0031994, providing a comprehensive resource for biomedical researchers.
insulin-like growth factor I binding At A Glance
| GO ID | GO:0031994 |
|---|---|
| GO term | insulin-like growth factor I binding |
| Ontology | molecular_function |
| Synonym | IGF-I binding |
| Definition | Binding to insulin-like growth factor I. |
| Major function | Mediates IGF-I recognition, transport, and signaling initiation |
| Related ligands | IGF-I (insulin-like growth factor I) |
| Key interacting proteins | IGF1R, IGFBPs, insulin receptor (INSR) |
| Cellular context | Extracellular space, cell membrane, endosomes |
What Is GO:0031994?
Insulin-like growth factor I binding (GO:0031994) is the molecular function of selectively interacting with insulin-like growth factor I (IGF-I). This binding can occur via specific receptors, binding proteins, or other IGF-I-interacting molecules, and it is a prerequisite for IGF-I-mediated signal transduction and regulation.
Why Is insulin-like growth factor I binding Important in Cell Biology?
IGF-I binding is fundamental to growth, development, and metabolic regulation, and its dysregulation contributes to major human diseases including cancer, diabetes, and inflammatory disorders. Understanding the molecular details of IGF-I binding enables the design of targeted therapies and diagnostic tools.
• Regulates cell proliferation, differentiation, and survival through IGF1R signaling.
• Modulates glucose uptake and metabolism, linking to type 1 diabetes and insulin resistance.
• Influences cancer progression by promoting tumor growth and metastasis in prostate cancer and melanoma.
• Plays a role in immune responses and inflammation, as seen in asthma and leishmaniasis.
• Affects muscle hypertrophy and repair, with implications for resistance exercise and aging.
• Serves as a biomarker for chemotherapy response in acute lymphoblastic leukemia.
• Provides a target for therapeutic antibodies and small molecules in oncology.
• Guides development of IGF-I analogs and binding protein inhibitors.
• Enables structural studies of ligand-receptor interactions.
• Facilitates CRISPR-based functional genomics of IGF pathway genes.
What Happens During insulin-like growth factor I binding?
Ligand recognition and binding
In simple terms: IGF-I binds to specific proteins on the cell surface or in circulation.
IGF-I binding begins with the recognition of IGF-I by high-affinity receptors such as IGF1R or by IGF-binding proteins (IGFBPs). This interaction is highly specific and can be influenced by the local environment, including pH and the presence of other binding partners.
Receptor activation and signaling
In simple terms: Binding turns on signals inside the cell that tell it to grow or survive.
Upon IGF-I binding, IGF1R undergoes autophosphorylation, leading to activation of downstream pathways such as PI3K/AKT and MAPK, which drive cell proliferation, survival, and metabolism. This signaling is tightly regulated by IGFBPs, which can either enhance or inhibit IGF-I action.
Modulation by IGF-binding proteins
In simple terms: Helper proteins can grab IGF-I and change how much is available to bind receptors.
IGFBPs bind IGF-I with high affinity, sequestering it in the extracellular space and prolonging its half-life. Some IGFBPs can also deliver IGF-I to target tissues or modulate its interaction with IGF1R, thereby fine-tuning the biological response.
Internalization and degradation
In simple terms: After binding, the IGF-I-receptor complex can be taken into the cell and broken down.
Following activation, the IGF-I/IGF1R complex is internalized via endocytosis, leading to signal termination and receptor recycling or degradation. This process is essential for maintaining cellular responsiveness to IGF-I.
Key Genes Involved in GO:0031994 insulin-like growth factor I binding
The following genes encode proteins that directly or indirectly participate in insulin-like growth factor I binding and its regulation.
| Gene | Major Role | Research Relevance |
|---|---|---|
| IGF1 | Encodes IGF-I, the ligand for GO:0031994 | Central to growth, cancer, and metabolism studies |
| IGF1R | Receptor tyrosine kinase that binds IGF-I | Mediates IGF-I signaling; target in oncology |
| IGFBP1 | Binds IGF-I, modulates bioavailability | Linked to metabolic disorders and cancer |
| IGFBP2 | Binds IGF-I, affects cell growth | Implicated in cancer progression |
| IGFBP3 | Major circulating IGF-I carrier | Therapeutic target in asthma and cancer |
| IGFBP4 | Modulates IGF-I action in tissues | Role in development and cancer |
| IGFBP5 | Binds IGF-I, influences bone and muscle | Studied in growth and fibrosis |
| IGFBP6 | Regulates IGF-I availability | Potential tumor suppressor |
| IGFBP7 | Binds IGF-I and insulin | Involved in senescence and cancer |
| INSR | Insulin receptor, cross-reacts with IGF-I | Metabolic signaling and diabetes research |
| INS | Insulin, related ligand | Comparative studies with IGF-I |
| IGF2 | IGF-II, related growth factor | Cross-talk with IGF-I binding |
| IGF2R | Mannose-6-phosphate receptor, binds IGF-II | Clearance of IGFs |
| IRS1 | Docking protein downstream of IGF1R | Mediates IGF-I signaling |
| IRS2 | Docking protein downstream of IGF1R | Metabolic and growth signaling |
| AKT1 | Serine/threonine kinase in IGF-I pathway | Cell survival and proliferation |
| MAPK1 | ERK2, downstream of IGF-I signaling | Proliferation and differentiation |
How Is insulin-like growth factor I binding Regulated?
Insulin-like growth factor I binding is regulated at multiple levels. The availability of IGF-I is controlled by IGF-binding proteins (IGFBPs), which can sequester IGF-I and prevent receptor binding. Additionally, the expression of IGF1R and its downstream signaling components is modulated by hormones such as growth hormone and insulin. Nutritional status, exercise, and inflammation also influence IGF-I levels and binding. At the molecular level, post-translational modifications of IGF1R and IGFBPs, as well as proteolytic cleavage of IGFBPs, can alter binding affinity and specificity.
insulin-like growth factor I binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| IGF1 | Acute lymphoblastic leukemia, growth disorders | Knockout mice, leukemia cell lines |
| IGF1R | Prostate cancer, melanoma | Xenograft models, CRISPR KO in cancer cells |
| IGFBP3 | Asthma, cancer | Airway epithelial cells, KO mice |
| IGFBP1 | Type 1 diabetes, metabolic syndrome | Diabetic animal models, hepatocyte KO |
| IGF2 | Overgrowth syndromes, cancer | Transgenic mice, cell lines |
Cancer
Dysregulated IGF-I binding is implicated in several cancers. Elevated circulating free IGF-I is associated with increased prostate cancer risk. In melanoma, targeting IGF-I and extracellular matrix interactions reduces tumor progression. IGF1R overexpression and increased IGF-I binding promote proliferation and survival in many tumor types, making this pathway a therapeutic target.
Metabolic and endocrine disorders
In type 1 diabetes, the growth hormone/IGF-I axis is altered, affecting IGF-I binding and action. IGF-I binding proteins are also linked to insulin resistance and obesity, highlighting the role of GO:0031994 in metabolic regulation.
Inflammatory and infectious diseases
IGF-I binding modulates immune responses. In asthma, targeting IGF-I and IGFBP-3 signaling reduces airway inflammation and remodeling. In visceral leishmaniasis, IGF-I levels correlate with disease progression and anemia, suggesting a role for IGF-I binding in infection outcomes.
Leukemia
In children with acute lymphoblastic leukemia, chemotherapy upregulates IGF-I, which may influence treatment response and disease progression through IGF-I binding and signaling.
From insulin-like growth factor I binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does IGF1R mediate IGF-I binding and signaling? | IGF1R knockout cell lines (e.g., CRISPR KO) |
| How do point mutations in IGF1 affect binding affinity? | Point-mutation knock-in mice or cells |
| What is the effect of IGFBP3 overexpression on IGF-I binding? | IGFBP3 overexpression cell models |
| Can tagged IGF-I be used to track binding in live cells? | Tagged knock-in of IGF1 with fluorescent protein |
| Which genes regulate IGF-I bioavailability? | CRISPR library screening in relevant cell types |
| How does IGF-I binding change in cancer? | Patient-derived xenografts and organoids |
How to Study the insulin-like growth factor I binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Surface plasmon resonance (SPR) | Binding affinity and kinetics | Characterizing IGF-I/IGF1R interactions |
| Western blot | Protein phosphorylation and expression | IGF-I signaling activation |
| RNA-seq | Transcriptional changes | Gene expression profiling after IGF-I stimulation |
| CRISPR knockout screening | Gene function in IGF-I binding | Identifying novel regulators |
| Immunoprecipitation | Protein-protein interactions | Detecting IGF-I/IGFBP complexes |
| ELISA | Quantification of IGF-I and IGFBPs | Clinical biomarker studies |
| Fluorescence microscopy | Subcellular localization | Tracking IGF-I internalization |
| Proteomics | Global protein changes | Mapping IGF-I signaling networks |
Binding assays
Radioligand binding assays, surface plasmon resonance (SPR), and isothermal titration calorimetry (ITC) are used to measure the affinity and kinetics of IGF-I binding to receptors and binding proteins. These methods provide quantitative data on interaction strength and specificity.
Cell signaling analysis
Western blotting for phosphorylated IGF1R, AKT, and MAPK, as well as luciferase reporter assays, assess downstream signaling upon IGF-I binding. These techniques are essential for linking binding events to functional outcomes.
Structural biology
X-ray crystallography and cryo-electron microscopy reveal the atomic details of IGF-I in complex with IGF1R or IGFBPs, informing drug design. NMR can study conformational changes upon binding.
Genomic and proteomic approaches
RNA-seq, proteomics, and CRISPR screens identify genes and proteins that regulate IGF-I binding and signaling. These high-throughput methods uncover novel components of the pathway.
How CRISPR Can Be Used to Study GO:0031994 insulin-like growth factor I binding
Knockout
CRISPR knockout of IGF1, IGF1R, or IGFBP genes in cell lines and animal models ablates IGF-I binding and signaling, enabling loss-of-function studies. For example, IGF1R knockout cells fail to respond to IGF-I, confirming its essential role.
Point Mutation
Introducing point mutations in the IGF-I binding domain of IGF1R or in IGF-I itself via CRISPR base editing or HDR can dissect residues critical for binding affinity and specificity. Such models help validate structural predictions.
Knock-in
Knock-in of tagged IGF-I (e.g., GFP or HA) allows real-time tracking of ligand binding and trafficking in live cells. Knock-in of disease-associated variants can model altered IGF-I binding in human diseases.
Overexpression
CRISPR activation (CRISPRa) or transgenic overexpression of IGF-I, IGF1R, or IGFBPs increases binding capacity and signaling output, useful for studying gain-of-function effects in cancer and growth disorders.
How EDITGENE Supports insulin-like growth factor I binding Research
Researchers studying insulin-like growth factor I binding-related genes often need to determine whether a candidate gene is causally involved in IGF-I recognition, signaling, or disease progression. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell and animal models, accelerating functional validation and therapeutic development.
Contact EDITGENE today to design your custom CRISPR model for insulin-like growth factor I binding research.
Frequently Asked Questions About insulin-like growth factor I binding
What is insulin-like growth factor I binding?
Insulin-like growth factor I binding (GO:0031994) is the molecular function of selectively interacting with IGF-I, a peptide hormone that regulates growth and metabolism.
What genes are involved in insulin-like growth factor I binding?
Key genes include IGF1 (the ligand), IGF1R (the receptor), and IGFBP1-7 (binding proteins that modulate IGF-I availability).
How does IGF-I binding affect cancer?
Increased IGF-I binding and signaling can promote tumor cell proliferation and survival, and is implicated in prostate cancer and melanoma.
What diseases are associated with insulin-like growth factor I binding?
Dysregulated IGF-I binding is linked to cancers, type 1 diabetes, asthma, and infectious diseases like leishmaniasis.
How can I study insulin-like growth factor I binding in the lab?
Common methods include binding assays (SPR, ITC), Western blot for signaling, and CRISPR screens to identify regulators.
What is the role of IGFBP3 in IGF-I binding?
IGFBP3 binds IGF-I with high affinity, sequestering it and modulating its interaction with IGF1R; it is a therapeutic target in asthma and cancer.
Can CRISPR be used to study IGF-I binding?
Yes, CRISPR knockout, knock-in, and activation models enable precise manipulation of IGF pathway genes to study binding and function.
What is the clinical significance of free IGF-I levels?
Circulating free IGF-I is a biomarker for cancer risk and disease progression, as shown in prostate cancer and leukemia studies.
How does exercise affect IGF-I binding?
Chronic resistance exercise alters IGF-I distribution across blood, interstitial fluid, and muscle, influencing its binding and action.
What are the therapeutic strategies targeting IGF-I binding?
Antibodies against IGF1R, IGFBP inhibitors, and IGF-I analogs are being developed for cancer and inflammatory diseases.
Conclusion
Insulin-like growth factor I binding (GO:0031994) is a pivotal molecular function that governs IGF-I bioavailability and signaling, impacting growth, metabolism, and disease. Understanding its mechanisms and regulation offers opportunities for therapeutic intervention in cancer, diabetes, and inflammatory conditions. Advanced CRISPR tools and EDITGENE services empower researchers to dissect this pathway with precision.
References
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- 3. Chen H et al.. 2019. Insulin-like growth factor type I selectively binds to G-quadruplex structures.. Biochim Biophys Acta Gen Subj 1863(1):31-38 PMID: 30278241
- 4. Sterczala AJ et al.. 2022. Insulin-like growth factor-I biocompartmentalization across blood, interstitial fluid and muscle, before and after 3 months of chronic resistance exercise.. J Appl Physiol (1985) 133(1):170-182 PMID: 35678743
- 5. Lee H et al.. 2014. Targeting insulin-like growth factor-I and insulin-like growth factor-binding protein-3 signaling pathways. A novel therapeutic approach for asthma.. Am J Respir Cell Mol Biol 50(4):667-77 PMID: 24219511
- 6. Cheng TS et al.. 2024. Circulating free insulin-like growth factor-I and prostate cancer: a case-control study nested in the European prospective investigation into cancer and nutrition.. BMC Cancer 24(1):676 PMID: 38831273
- 7. Pinho FA et al.. 2019. Association between Insulin-Like Growth Factor-I Levels and the Disease Progression and Anemia in Visceral Leishmaniasis.. Am J Trop Med Hyg 100(4):808-815 PMID: 30761980
- 8. Murekatete B et al.. 2018. Targeting Insulin-Like Growth Factor-I and Extracellular Matrix Interactions in Melanoma Progression.. Sci Rep 8(1):583 PMID: 29330502
