GO:0048009 insulin-like growth factor receptor signaling pathway: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0048009 describes the molecular signaling cascade initiated when an insulin-like growth factor (IGF) ligand binds to an IGF receptor on the cell surface, culminating in regulation of downstream cellular processes such as transcription.
• The pathway is mediated by the type 1 IGF receptor (IGF1R), a receptor tyrosine kinase that autophosphorylates upon ligand binding and recruits adaptor proteins including IRS1/2 and SHC.
• IGF receptor signaling is essential for normal growth, development, and metabolism, but its dysregulation is implicated in many cancers, including breast, liver, and hematological malignancies.
• Oncogenic fusion proteins can hijack the IGF signaling pathway, driving tumorigenesis and chemoresistance.
• Key downstream effectors include the PI3K-AKT-mTOR and RAS-MAPK cascades, which control cell proliferation, survival, and metabolism.
• CRISPR-based models (knockout, point mutation, knock-in, overexpression) are powerful tools for dissecting the causal roles of IGF pathway components in disease.
Description
The insulin-like growth factor receptor signaling pathway (GO:0048009) is a fundamental biological process that transmits signals from IGF ligands to the interior of the cell, ultimately regulating gene expression, cell growth, and survival. This pathway is initiated by the binding of IGF1 or IGF2 to the type 1 IGF receptor (IGF1R), a receptor tyrosine kinase, leading to receptor autophosphorylation and activation of downstream signaling cascades. The pathway plays critical roles in normal physiology, including embryonic development, tissue growth, and metabolic homeostasis. Dysregulation of IGF receptor signaling is a hallmark of many human diseases, particularly cancer, where it promotes proliferation, metastasis, and resistance to therapy. Understanding the molecular mechanisms of this pathway is therefore essential for developing targeted therapeutic strategies. This article provides a comprehensive overview of the IGF receptor signaling pathway, covering its definition, key genes, regulatory mechanisms, disease associations, and research methodologies, with a focus on CRISPR-based approaches for functional studies.
insulin-like growth factor receptor signaling pathway At A Glance
| GO ID | GO:0048009 |
|---|---|
| GO term | insulin-like growth factor receptor signaling pathway |
| Ontology | biological_process |
| Synonym | IGF receptor signaling pathway; IGF receptor signalling pathway |
| Major function | Transmits signals from IGF ligands to regulate transcription and cellular processes |
| Key receptors | IGF1R, IGF2R, insulin receptor (INSR) isoforms |
| Major ligands | IGF1, IGF2, insulin |
| Downstream pathways | PI3K-AKT-mTOR, RAS-MAPK |
| Disease relevance | Cancer, growth disorders, metabolic diseases |
What Is GO:0048009?
GO:0048009, insulin-like growth factor receptor signaling pathway, is defined as the series of molecular signals initiated by a ligand binding to an insulin-like growth factor receptor on the surface of a target cell, and ending with the regulation of a downstream cellular process, e.g. transcription. This process encompasses ligand-receptor interaction, receptor activation, and the propagation of signals through intracellular second messengers and protein phosphorylation cascades, ultimately leading to changes in gene expression, cell proliferation, differentiation, or survival.
Why Is insulin-like growth factor receptor signaling pathway Important in Cell Biology?
The insulin-like growth factor receptor signaling pathway is critically important because it governs fundamental cellular processes such as growth, proliferation, survival, and metabolism. In normal physiology, it mediates the effects of growth hormone and nutritional status on tissue development. In disease, aberrant activation of this pathway contributes to cancer progression, metastasis, and resistance to chemotherapy and targeted therapies. Moreover, oncogenic fusion proteins can constitutively activate IGF signaling, highlighting its central role in tumorigenesis. Therefore, understanding this pathway is essential for identifying therapeutic targets and developing precision medicine approaches.
• Regulates normal growth and development from embryogenesis to adulthood.
• Controls glucose uptake and metabolism, linking to diabetes and metabolic syndrome.
• Promotes cell proliferation and survival, often hijacked in cancer.
• Mediates resistance to chemotherapy and targeted therapies in multiple cancers.
• Involved in hematological malignancies through aberrant IGF1R signaling.
• Oncogenic fusion proteins can activate IGF signaling in sarcomas and other tumors.
• Serves as a therapeutic target for monoclonal antibodies and tyrosine kinase inhibitors.
• Plays a role in liver cancer reactivation of IGF-II signaling.
• Impacts immune cell function and tumor microenvironment.
• Provides a model for studying receptor tyrosine kinase signaling specificity.
What Happens During insulin-like growth factor receptor signaling pathway?
Ligand Binding and Receptor Activation
In simple terms: An IGF ligand binds to the IGF receptor on the cell surface, switching it on.
The pathway begins when insulin-like growth factor 1 (IGF1) or IGF2 binds to the extracellular domain of the type 1 IGF receptor (IGF1R), a receptor tyrosine kinase. This binding induces a conformational change that leads to receptor autophosphorylation on tyrosine residues within the intracellular kinase domain. The activated receptor then serves as a docking site for adaptor proteins such as insulin receptor substrate 1 (IRS1) and IRS2, and SHC.
Intracellular Signal Transduction
In simple terms: The activated receptor triggers a chain of molecular switches inside the cell.
Phosphorylated IRS proteins recruit and activate downstream effectors, primarily the PI3K-AKT-mTOR and RAS-MAPK pathways. PI3K activation leads to AKT phosphorylation, which promotes cell survival, growth, and metabolism. The RAS-MAPK cascade, through GRB2-SOS-RAS-RAF-MEK-ERK, regulates gene expression and proliferation. These signaling branches are tightly regulated by phosphatases and negative feedback loops.
Regulation of Downstream Cellular Processes
In simple terms: The signal reaches the nucleus and changes which genes are turned on or off.
Activated AKT and ERK translocate to the nucleus and phosphorylate transcription factors such as FOXO, CREB, and MYC, leading to changes in gene expression that drive cell cycle progression, survival, and differentiation. The pathway also regulates protein synthesis via mTOR and ribosomal biogenesis. Ultimately, these molecular events culminate in the regulation of cellular processes such as proliferation, growth, and apoptosis.
Crosstalk and Feedback Regulation
In simple terms: The pathway talks to other signaling systems and can shut itself down.
IGF receptor signaling intersects with other pathways, including insulin receptor signaling, EGFR, and integrin signaling, allowing integration of diverse environmental cues. Negative feedback mechanisms, such as phosphorylation of IRS1 by mTORC1 or ERK, attenuate the signal to prevent overactivation. Dysregulation of these feedback loops can lead to sustained signaling and oncogenesis.
Key Genes Involved in GO:0048009 insulin-like growth factor receptor signaling pathway
The following genes and proteins are central to the insulin-like growth factor receptor signaling pathway, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| IGF1 | Ligand that binds IGF1R to initiate signaling | Growth, development, cancer |
| IGF2 | Ligand with high affinity for IGF1R and IGF2R | Embryonic growth, liver cancer |
| IGF1R | Receptor tyrosine kinase that mediates IGF signaling | Cancer, growth disorders |
| IGF2R | Mannose-6-phosphate receptor that clears IGF2 | Tumor suppression, growth |
| INSR | Insulin receptor, forms hybrid receptors with IGF1R | Metabolism, diabetes, cancer |
| IRS1 | Adaptor protein that recruits PI3K and GRB2 | Insulin resistance, cancer |
| IRS2 | Adaptor protein with overlapping functions | Beta-cell survival, cancer |
| SHC1 | Adaptor that activates RAS-MAPK pathway | Proliferation, cancer |
| PIK3CA | Catalytic subunit of PI3K, activates AKT | Cancer, growth |
| AKT1 | Serine/threonine kinase, promotes survival | Cancer, metabolism |
| MTOR | Kinase that regulates protein synthesis | Growth, cancer |
| GRB2 | Adaptor linking IRS to RAS | Proliferation, cancer |
| SOS1 | Guanine nucleotide exchange factor for RAS | RAS-MAPK activation |
| HRAS | Small GTPase that activates RAF | Cancer, growth |
| RAF1 | Kinase that activates MEK | Cancer, proliferation |
| MAP2K1 | MEK, activates ERK | Cancer, proliferation |
| MAPK1 | ERK, regulates transcription | Cancer, proliferation |
How Is insulin-like growth factor receptor signaling pathway Regulated?
The insulin-like growth factor receptor signaling pathway is tightly regulated at multiple levels. Ligand availability is controlled by IGF-binding proteins (IGFBPs), which sequester IGFs and modulate their interaction with receptors. Receptor activation is counterbalanced by protein tyrosine phosphatases (e.g., PTP1B) that dephosphorylate IGF1R and IRS proteins. Negative feedback loops, such as mTORC1-mediated phosphorylation of IRS1, desensitize the pathway. Additionally, crosstalk with other signaling pathways and microRNAs adds further complexity. Dysregulation of these regulatory mechanisms contributes to diseases such as cancer and diabetes.
insulin-like growth factor receptor signaling pathway and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| IGF1R | Breast cancer, growth disorders | Knockout, point mutation, overexpression |
| IGF2 | Hepatocellular carcinoma, Beckwith-Wiedemann syndrome | Knock-in, overexpression |
| IRS1 | Insulin resistance, cancer | Knockout, point mutation |
| AKT1 | Cancer, metabolic syndrome | Knock-in, overexpression |
| MTOR | Cancer, neurodegeneration | Knockout, point mutation |
IGF Signaling in Cancer
Aberrant activation of the IGF receptor signaling pathway is a common feature of many cancers. In breast cancer, IGF1R signaling promotes proliferation and survival, and combination therapies targeting this pathway are under investigation. In hematological malignancies, IGF1R signaling supports growth and survival of leukemic cells. Oncogenic fusion proteins, such as those involving NUP98 and IGF2BP3, can constitutively activate IGF signaling in sarcomas and other tumors. In hepatocellular carcinoma, reactivation of IGF-II signaling drives tumorigenesis. These findings underscore the therapeutic potential of targeting IGF signaling in cancer.
IGF Signaling in Metabolic and Growth Disorders
The IGF receptor signaling pathway is essential for normal growth and metabolism. Mutations in IGF1R or downstream components can cause growth retardation and insulin resistance. In type 2 diabetes, impaired IGF signaling contributes to beta-cell dysfunction and insulin resistance. The pathway also plays a role in aging and longevity, with reduced IGF signaling associated with extended lifespan in model organisms.
IGF Signaling in Chemoresistance
Activation of IGF receptor signaling is a mechanism of resistance to chemotherapy and targeted therapies. In breast cancer, IGF1R signaling confers resistance to HER2-targeted therapies. In hematological malignancies, IGF1R activation protects cells from apoptosis induced by chemotherapeutic agents. Targeting IGF signaling may therefore overcome chemoresistance and improve patient outcomes.
From insulin-like growth factor receptor signaling pathway-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does IGF1R kinase activity drive tumor growth? | Point mutation (kinase-dead) knock-in |
| What is the effect of IGF1R loss on development? | Knockout mouse or cell line |
| How does IGF2 overexpression contribute to liver cancer? | Overexpression cell model |
| Can a specific mutation in IRS1 disrupt PI3K binding? | Point mutation knock-in |
| What is the role of IGF1R in chemoresistance? | Knockout and overexpression in cancer cell lines |
| How does IGF1R signaling affect gene expression? | Tagged knock-in for ChIP-seq or RNA-seq |
How to Study the insulin-like growth factor receptor signaling pathway Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Global gene expression changes | Identify transcriptional targets of IGF signaling |
| Phosphoproteomics | Phosphorylation sites on proteins | Map signaling networks downstream of IGF1R |
| CRISPR knockout screen | Gene essentiality and pathway modifiers | Discover novel regulators of IGF signaling |
| Western blot | Protein expression and phosphorylation | Validate activation of AKT and ERK |
| Immunoprecipitation | Protein-protein interactions | Study IGF1R-IRS1 complex formation |
| Live-cell imaging | Real-time signaling dynamics | Monitor AKT translocation upon IGF stimulation |
| ChIP-seq | Transcription factor binding sites | Identify FOXO and CREB targets |
| Metabolic assays | Glucose uptake, lactate production | Assess metabolic effects of IGF signaling |
Transcriptomic Analysis
RNA sequencing (RNA-seq) is widely used to measure changes in gene expression upon activation or inhibition of IGF receptor signaling. This method can identify downstream transcriptional targets and reveal feedback mechanisms. For example, RNA-seq of cells treated with IGF1 can uncover genes involved in proliferation and survival.
Proteomic and Phosphoproteomic Approaches
Mass spectrometry-based proteomics and phosphoproteomics enable global profiling of protein expression and phosphorylation events downstream of IGF1R activation. These techniques can identify novel substrates and signaling nodes, providing a systems-level view of the pathway.
Functional Genomic Screens
CRISPR-Cas9 knockout screens are powerful for identifying genes that modulate IGF signaling or are required for cancer cell growth. Pooled screens with libraries targeting kinases or the entire genome can uncover synthetic lethal interactions and resistance mechanisms.
Imaging and Biosensor Approaches
Live-cell imaging with fluorescent biosensors can monitor real-time activation of AKT and ERK in response to IGF stimulation. These methods provide spatial and temporal resolution of signaling dynamics and can be combined with CRISPR knock-in of tagged proteins.
How CRISPR Can Be Used to Study GO:0048009 insulin-like growth factor receptor signaling pathway
Knockout
CRISPR-Cas9 knockout of IGF1R, IRS1, or AKT1 can abolish IGF signaling and reveal its role in cell proliferation, survival, and metabolism. Knockout cell lines are valuable for validating drug targets and studying pathway redundancy. For example, IGF1R knockout in cancer cells reduces tumor growth in xenograft models.
Point Mutation
Point mutations can be introduced to study specific residues critical for kinase activity or protein interactions. For instance, a kinase-dead mutation in IGF1R (K1003R) can distinguish kinase-dependent from scaffold functions. Similarly, mutations in IRS1 tyrosine phosphorylation sites can dissect downstream signaling branches.
Knock-in
Knock-in of tagged versions of IGF1R or downstream effectors (e.g., GFP-AKT1) allows real-time imaging and proteomic analysis. Knock-in of disease-associated mutations, such as those found in IGF1R in growth disorders, can model human phenotypes in cell lines or mice.
Overexpression
Overexpression of IGF1, IGF2, or IGF1R using CRISPR activation (CRISPRa) or lentiviral vectors can mimic the hyperactivation seen in cancer. Overexpression models are useful for studying oncogenic transformation and testing targeted therapies.
How EDITGENE Supports insulin-like growth factor receptor signaling pathway Research
Researchers studying insulin-like growth factor receptor signaling pathway-related genes often need to determine whether a candidate gene is causally involved in pathway activation, disease progression, or therapeutic response. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell models, enabling functional validation and mechanistic studies.
Contact EDITGENE today to design your custom CRISPR model for insulin-like growth factor receptor signaling pathway research.
Frequently Asked Questions About insulin-like growth factor receptor signaling pathway
What is the insulin-like growth factor receptor signaling pathway?
It is a biological process (GO:0048009) where IGF ligands bind to IGF receptors on the cell surface, triggering intracellular signals that regulate transcription and cellular processes such as growth and survival.
What genes are involved in insulin-like growth factor receptor signaling pathway?
Key genes include IGF1, IGF2, IGF1R, IGF2R, INSR, IRS1, IRS2, SHC1, PIK3CA, AKT1, MTOR, GRB2, SOS1, HRAS, RAF1, MAP2K1, and MAPK1.
How is IGF receptor signaling activated?
It is activated when IGF1 or IGF2 binds to IGF1R, causing receptor autophosphorylation and recruitment of adaptor proteins like IRS1 and SHC.
What diseases are associated with IGF receptor signaling?
Dysregulation is linked to cancers (breast, liver, hematological), growth disorders, diabetes, and chemoresistance.
What are the downstream pathways of IGF1R?
The main downstream pathways are PI3K-AKT-mTOR and RAS-MAPK, which control proliferation, survival, and metabolism.
How can CRISPR be used to study IGF signaling?
CRISPR can create knockout, point mutation, knock-in, and overexpression models to dissect gene function and validate drug targets.
What is the role of IGF2 in cancer?
IGF2 is often overexpressed in cancers like hepatocellular carcinoma, where it reactivates IGF signaling to promote tumor growth.
What are IGF-binding proteins?
IGFBPs are proteins that bind IGFs and modulate their availability to receptors, thereby regulating pathway activity.
How does IGF signaling contribute to chemoresistance?
Activation of IGF1R signaling can protect cancer cells from apoptosis induced by chemotherapy, leading to resistance.
What model systems are used to study IGF signaling?
Common models include CRISPR-engineered cell lines, mouse knockouts, and xenografts, as well as biochemical assays and omics approaches.
Conclusion
The insulin-like growth factor receptor signaling pathway (GO:0048009) is a central regulator of cell growth, survival, and metabolism, with profound implications for cancer, metabolic disorders, and development. Understanding its molecular mechanisms and regulatory networks is essential for identifying therapeutic targets and biomarkers. CRISPR-based models, combined with advanced omics and imaging techniques, offer powerful tools to dissect this pathway and translate findings into clinical applications. EDITGENE provides comprehensive services to support such research, from custom cell model generation to high-throughput screening and bioinformatics analysis.
References
- 1. Choi E et al.. 2025. Regulation and function of insulin and insulin-like growth factor receptor signalling.. Nat Rev Mol Cell Biol 26(7):558-580 PMID: 39930003
- 2. Galal MA et al.. 2023. Insulin Receptor Isoforms and Insulin Growth Factor-like Receptors: Implications in Cell Signaling, Carcinogenesis, and Chemoresistance.. Int J Mol Sci 24(19) PMID: 37834454
- 3. Dilawar M et al.. 2026. Insulin-like growth factor receptor signaling in physiology and disease.. Signal Transduct Target Ther 11(1) PMID: 42722676
- 4. Breuhahn K et al.. 2008. Reactivation of the insulin-like growth factor-II signaling pathway in human hepatocellular carcinoma.. World J Gastroenterol 14(11):1690-8 PMID: 18350600
- 5. Werner H et al.. 2018. Oncogenic fusion proteins adopt the insulin-like growth factor signaling pathway.. Mol Cancer 17(1):28 PMID: 29455671
- 6. Vishwamitra D et al.. 2017. Type I insulin-like growth factor receptor signaling in hematological malignancies.. Oncotarget 8(1):1814-1844 PMID: 27661006
- 7. Ochnik AM et al.. 2016. Combination therapy approaches to target insulin-like growth factor receptor signaling in breast cancer.. Endocr Relat Cancer 23(11):R513-R536 PMID: 27733416
- 8. Chitnis MM et al.. 2008. The type 1 insulin-like growth factor receptor pathway.. Clin Cancer Res 14(20):6364-70 PMID: 18927274
