GO:0043560 insulin receptor substrate binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0043560 (insulin receptor substrate binding) is a molecular function describing the binding of a protein to an insulin receptor substrate (IRS) adaptor protein.
• IRS proteins are phosphorylated by activated insulin and IGF-1 receptors and then recruit SH2 domain-containing signaling molecules to form a productive signaling complex.
• The IRS family evolved in vertebrates and includes IRS1, IRS2, IRS4, and IRS6, each with distinct tissue distributions and signaling roles.
• Akt-mediated phosphorylation of IRS proteins provides negative feedback that limits PI3K-mediated PIP3 synthesis, a key regulatory node in insulin signaling.
• Dysregulated IRS binding and signaling are linked to type 2 diabetes, obesity-related insulin resistance, and cancer.
• CRISPR knockout, point-mutation, knock-in, and overexpression models enable causal dissection of IRS binding interactions in disease-relevant cell types.
Description
GO:0043560, insulin receptor substrate binding, is a molecular function term that captures the physical interaction between a protein and an insulin receptor substrate (IRS) family member. IRS proteins are adaptor molecules that bind to the transphosphorylated insulin and insulin-like growth factor receptors, become phosphorylated themselves, and then recruit SH2 domain-containing signaling molecules to assemble a productive signaling complex. This function is central to insulin and IGF-1 signal transduction, linking receptor tyrosine kinase activity to downstream pathways such as PI3K-Akt and MAPK. Researchers study this term to understand how metabolic and growth signals are transmitted, and how disruptions in these interactions contribute to diseases including type 2 diabetes and cancer. The IRS gene family expanded in vertebrates, with IRS1 and IRS2 being the most widely expressed and functionally characterized members. Because IRS proteins are not enzymes but scaffolds, binding interactions define their biological output, making GO:0043560 a critical annotation for interpreting signaling experiments.
insulin receptor substrate binding At A Glance
| GO ID | GO:0043560 |
|---|---|
| GO term | insulin receptor substrate binding |
| Ontology | molecular_function |
| Synonym | insulin receptor substrate [protein] binding; IRS binding; IRS [protein] binding |
| Major function | Binding to IRS adaptor proteins to facilitate assembly of insulin/IGF-1 receptor signaling complexes |
| Definition source | QuickGO |
| Related pathways | Insulin signaling, IGF-1 signaling, PI3K-Akt signaling, MAPK signaling |
| Key domains involved | PTB domain, SH2 domain, phosphotyrosine motifs |
| Disease relevance | Type 2 diabetes, obesity-related insulin resistance, cancer |
What Is GO:0043560?
According to the QuickGO definition, insulin receptor substrate binding (GO:0043560) is the binding to an insulin receptor substrate (IRS) protein, an adaptor protein that binds to the transphosphorylated insulin and insulin-like growth factor receptors, is itself phosphorylated, and in turn recruits SH2 domain-containing signaling molecules to form a productive signaling complex. In other words, this term describes any protein-protein interaction where one molecule physically associates with an IRS family member, typically through a phosphotyrosine-binding (PTB) domain, SH2 domain, or other modular interaction domain, to propagate or regulate insulin/IGF-1 signaling.
Why Is insulin receptor substrate binding Important in Cell Biology?
Insulin receptor substrate binding is important because it is the first committed step that converts insulin and IGF-1 receptor activation into downstream cellular responses. Without IRS binding and subsequent phosphorylation, the receptor tyrosine kinase cannot efficiently recruit PI3K, Grb2, or other SH2 domain-containing effectors, and metabolic and growth signals fail to propagate. This function is therefore central to glucose homeostasis, lipid metabolism, cell growth, and survival, and its dysregulation is implicated in insulin resistance, type 2 diabetes, and tumorigenesis.
• Mediates the initial assembly of insulin and IGF-1 receptor signaling complexes.
• Links receptor tyrosine kinase activity to PI3K-Akt and MAPK pathways.
• Regulates glucose uptake, glycogen synthesis, and lipid metabolism.
• Akt-mediated phosphorylation of IRS proteins provides negative feedback on PI3K signaling.
• IRS polymorphisms are associated with type 2 diabetes susceptibility.
• Endoplasmic reticulum stress impairs insulin action and contributes to type 2 diabetes.
• IRS1 is a novel member of EGFR signaling in pancreatic cells, expanding its role beyond insulin signaling.
• The vertebrate IRS gene family evolved to fine-tune metabolic and growth signaling.
• IRS binding interactions are targets for therapeutic modulation in metabolic disease and cancer.
• CRISPR-based models enable causal testing of IRS binding variants in disease-relevant cells.
Molecular Mechanism of insulin receptor substrate binding
Receptor Activation and IRS Recruitment
In simple terms: Insulin or IGF-1 binds the receptor, which then phosphorylates itself and attracts IRS proteins.
Insulin or insulin-like growth factor 1 (IGF-1) binding to the insulin receptor or IGF-1 receptor induces receptor autophosphorylation on tyrosine residues. The transphosphorylated receptor then binds IRS proteins through their phosphotyrosine-binding (PTB) domain, bringing IRS molecules into the active signaling complex. This recruitment is the defining event of GO:0043560 and is required for subsequent IRS tyrosine phosphorylation.
IRS Phosphorylation and SH2 Domain Recruitment
In simple terms: Once bound, IRS proteins are phosphorylated and then grab other signaling proteins.
After binding to the activated receptor, IRS proteins are phosphorylated on multiple tyrosine residues. These phosphotyrosine motifs serve as docking sites for SH2 domain-containing signaling molecules such as the p85 regulatory subunit of PI3K and the adaptor Grb2. This step converts the receptor signal into a branched downstream cascade, including PI3K-Akt and MAPK pathways.
Negative Feedback by Akt
In simple terms: A downstream kinase, Akt, puts a brake on the system by phosphorylating IRS proteins.
Akt phosphorylates insulin receptor substrate proteins to limit PI3K-mediated PIP3 synthesis, providing a negative feedback loop that prevents excessive signaling. This regulation is critical for maintaining insulin sensitivity and is often disrupted in insulin-resistant states.
IRS Family Diversity and Tissue-Specific Functions
In simple terms: Different IRS proteins do similar jobs but in different tissues and contexts.
The vertebrate IRS gene family includes IRS1, IRS2, IRS4, and IRS6, which show distinct tissue distributions and signaling properties. IRS1 is widely expressed and primarily linked to peripheral insulin action, while IRS2 is important in liver and pancreatic beta cells. This diversity allows fine-tuning of metabolic and growth responses, and individual IRS proteins can be differentially engaged by insulin versus IGF-1 receptors.
Crosstalk with Other Receptor Systems
In simple terms: IRS proteins can also be used by other receptors, not just insulin receptors.
IRS1 is a novel member of EGFR signaling in pancreatic cells, indicating that IRS binding interactions are not exclusive to insulin and IGF-1 receptors. This crosstalk expands the biological scope of GO:0043560 and has implications for cancer and pancreatic biology.
Key Genes Involved in GO:0043560 insulin receptor substrate binding
The following genes and proteins are central to insulin receptor substrate binding and its downstream signaling.
| Gene | Major Role | Research Relevance |
|---|---|---|
| IRS1 | Primary IRS adaptor in peripheral tissues; binds activated insulin/IGF-1 receptors and recruits PI3K | Most studied IRS family member; linked to insulin resistance and type 2 diabetes |
| IRS2 | IRS adaptor important in liver and pancreatic beta cells | Critical for beta-cell survival and glucose homeostasis |
| IRS4 | IRS family member with tissue-specific expression | Less characterized; potential roles in development and cancer |
| IRS6 | IRS family member identified in vertebrates | Understudied; may modulate insulin/IGF-1 signaling |
| INSR | Insulin receptor tyrosine kinase that phosphorylates IRS proteins | Direct upstream activator of IRS binding |
| IGF1R | IGF-1 receptor tyrosine kinase that also binds and phosphorylates IRS proteins | Mediates growth and survival signaling |
| PIK3R1 | p85 regulatory subunit of PI3K; binds phosphotyrosine motifs on IRS proteins | Key effector recruited by IRS |
| PIK3CA | p110 catalytic subunit of PI3K | Downstream of IRS-PI3K complex |
| AKT1 | Serine/threonine kinase that phosphorylates IRS proteins as negative feedback | Regulates IRS signaling amplitude |
| GRB2 | SH2 domain adaptor that binds IRS proteins and links to MAPK pathway | Connects IRS to Ras-MAPK signaling |
| SOS1 | Guanine nucleotide exchange factor recruited via Grb2 | Activates Ras downstream of IRS |
| PTPN1 | Protein tyrosine phosphatase that dephosphorylates IRS proteins | Negative regulator of IRS signaling |
| EGFR | Receptor tyrosine kinase that can signal through IRS1 in pancreatic cells | Expands IRS1 roles beyond insulin signaling |
| INS | Insulin ligand that activates the insulin receptor | Initiates IRS binding cascade |
| IGF1 | IGF-1 ligand that activates IGF-1 receptor | Stimulates IRS-mediated growth signaling |
| FOXO1 | Transcription factor inhibited by Akt downstream of IRS-PI3K | Mediates metabolic gene expression changes |
| SLC2A4 | GLUT4 glucose transporter translocated in response to IRS-PI3K-Akt signaling | Functional readout of insulin action |
How Is insulin receptor substrate binding Regulated?
Insulin receptor substrate binding and signaling are regulated at multiple levels. Receptor autophosphorylation is the initial trigger, and phosphatase activity can reverse it. Akt-mediated phosphorylation of IRS proteins provides a negative feedback loop that limits PI3K-mediated PIP3 synthesis. Endoplasmic reticulum stress can impair insulin action and contribute to insulin resistance, indirectly affecting IRS function. Additionally, IRS gene polymorphisms have been associated with altered signaling and type 2 diabetes risk. The evolutionary diversification of the IRS family also suggests tissue-specific regulatory mechanisms.
insulin receptor substrate binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| IRS1 | Type 2 diabetes, insulin resistance | IRS1 knockout and point-mutation cell models in hepatocytes and myotubes |
| IRS2 | Type 2 diabetes, beta-cell dysfunction | IRS2 knockout pancreatic beta-cell lines |
| IRS1 | Pancreatic cancer, EGFR crosstalk | IRS1 knockout in pancreatic cancer cell lines |
| AKT1 | Insulin resistance, cancer | AKT1 point-mutation knock-in to study IRS feedback |
| INSR | Insulin resistance, diabetes | INSR knockout and knock-in models |
Type 2 Diabetes and Insulin Resistance
Insulin receptor substrate binding is central to insulin action, and its dysfunction contributes to insulin resistance and type 2 diabetes. Endoplasmic reticulum stress links obesity, insulin action, and type 2 diabetes, in part by impairing IRS signaling. IRS polymorphisms have been associated with type 2 diabetes mellitus in human genetic studies.
Cancer and Growth Signaling
IRS proteins mediate IGF-1 and insulin signaling, which can promote cell growth and survival. IRS1 is a novel member of EGFR signaling in pancreatic cells, suggesting roles in pancreatic cancer and other malignancies. Dysregulated IRS-PI3K-Akt signaling is a common feature of many cancers.
Metabolic Syndrome and Obesity
Obesity-related insulin resistance involves impaired IRS binding and downstream signaling. The IRS family's role in glucose and lipid metabolism makes it a key node in metabolic syndrome.
From insulin receptor substrate binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of IRS1 impair insulin-stimulated glucose uptake? | IRS1 knockout cell line (e.g., hepatocytes or myotubes) |
| Does a specific IRS1 polymorphism alter PI3K recruitment? | IRS1 point-mutation knock-in cell model |
| Can tagged IRS1 be used to map binding partners? | Knock-in of epitope-tagged IRS1 |
| Does IRS2 overexpression rescue beta-cell survival? | IRS2 overexpression in pancreatic beta cells |
| Does Akt-mediated IRS phosphorylation limit PIP3 synthesis? | AKT1 knockout or point-mutation models |
| Does EGFR signaling require IRS1 in pancreatic cells? | IRS1 knockout in EGFR-expressing pancreatic cells |
How to Study the insulin receptor substrate binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Co-immunoprecipitation | Physical interaction between IRS and binding partners | Validate IRS-receptor or IRS-PI3K binding |
| GST pull-down | Direct binding of recombinant proteins to IRS | Map interaction domains |
| Phosphoproteomics | Tyrosine phosphorylation sites on IRS proteins | Identify signaling nodes |
| CRISPR knockout screen | Genes required for IRS-mediated signaling | Discover novel regulators |
| FRET biosensor imaging | Real-time PIP3 synthesis and IRS recruitment | Measure signaling dynamics |
| Western blot | IRS phosphorylation and downstream Akt activation | Assess pathway activity |
| qRT-PCR | IRS gene expression levels | Evaluate transcriptional regulation |
| Immunofluorescence | Subcellular localization of IRS proteins | Study trafficking and complex assembly |
Co-Immunoprecipitation and Pull-Down Assays
Co-immunoprecipitation and GST pull-down assays are used to detect physical binding between IRS proteins and their partners, directly assaying GO:0043560. These methods can be combined with phosphotyrosine immunoblotting to confirm receptor-IRS interactions.
Phosphoproteomics and Mass Spectrometry
Phosphoproteomics can map tyrosine phosphorylation sites on IRS proteins and identify SH2 domain-containing proteins recruited to these sites. Mass spectrometry-based interactomics can reveal the composition of IRS signaling complexes.
CRISPR-Based Genetic Screens
CRISPR knockout and activation screens can identify genes that regulate IRS binding and downstream signaling. These screens are useful for discovering novel modulators of insulin and IGF-1 signaling.
Live-Cell Imaging and FRET Biosensors
FRET-based biosensors and live-cell imaging can monitor IRS recruitment and PIP3 production in real time. These approaches provide spatial and temporal resolution of IRS binding dynamics.
How CRISPR Can Be Used to Study GO:0043560 insulin receptor substrate binding
Knockout
CRISPR knockout of IRS1, IRS2, or other IRS family genes can abolish insulin receptor substrate binding and downstream signaling, providing a clean background to test causality. Knockout models are essential for distinguishing the roles of individual IRS proteins in metabolic and growth responses.
Point Mutation
Point mutations can be introduced into IRS genes to disrupt specific phosphotyrosine motifs or binding domains, allowing precise dissection of which residues are required for PI3K or Grb2 recruitment. Such models are valuable for studying disease-associated polymorphisms.
Knock-in
Knock-in of epitope-tagged or fluorescently tagged IRS proteins enables endogenous-level tracking of IRS binding interactions and complex assembly. Knock-in of disease-relevant IRS variants can model human genetic risk.
Overexpression
Overexpression of IRS proteins or their binding partners can amplify signaling and reveal rate-limiting steps in insulin/IGF-1 pathways. Overexpression models are useful for biochemical purification of IRS complexes.
How EDITGENE Supports insulin receptor substrate binding Research
Researchers studying insulin receptor substrate binding-related genes often need to determine whether a candidate gene is causally involved in insulin/IGF-1 signaling, metabolic regulation, or disease. EDITGENE provides CRISPR-based cell model services to enable these causal experiments in relevant cell types.
Contact EDITGENE today to design your custom CRISPR model for insulin receptor substrate binding research.
Frequently Asked Questions About insulin receptor substrate binding
What is insulin receptor substrate binding?
Insulin receptor substrate binding (GO:0043560) is the molecular function of binding to an IRS adaptor protein, which links activated insulin and IGF-1 receptors to downstream signaling complexes.
What genes are involved in insulin receptor substrate binding?
Key genes include IRS1, IRS2, IRS4, IRS6, INSR, IGF1R, PIK3R1, PIK3CA, AKT1, GRB2, and SOS1.
What is the GO ID for insulin receptor substrate binding?
The GO ID is GO:0043560.
How does insulin receptor substrate binding work?
Activated insulin or IGF-1 receptors phosphorylate themselves and bind IRS proteins via PTB domains; IRS proteins are then phosphorylated and recruit SH2 domain-containing effectors like PI3K.
Why is insulin receptor substrate binding important in diabetes?
Dysregulated IRS binding and signaling contribute to insulin resistance and type 2 diabetes, and IRS polymorphisms are associated with disease risk.
What diseases are linked to insulin receptor substrate binding?
Type 2 diabetes, obesity-related insulin resistance, metabolic syndrome, and cancers with IGF-1/insulin signaling dysregulation.
How can I study insulin receptor substrate binding in the lab?
Common methods include co-immunoprecipitation, GST pull-down, phosphoproteomics, CRISPR screens, and FRET biosensors.
What CRISPR models are available for IRS genes?
Knockout, point mutation, knock-in, and overexpression models can be generated for IRS1, IRS2, and related genes.
Does Akt regulate insulin receptor substrate binding?
Yes, Akt phosphorylates IRS proteins to limit PI3K-mediated PIP3 synthesis as a negative feedback mechanism.
Is IRS1 involved in cancer?
IRS1 is a novel member of EGFR signaling in pancreatic cells, suggesting roles in pancreatic cancer and other malignancies.
Conclusion
Insulin receptor substrate binding (GO:0043560) is a foundational molecular function that connects insulin and IGF-1 receptor activation to PI3K-Akt and MAPK signaling. Its dysregulation is implicated in type 2 diabetes, obesity-related insulin resistance, and cancer, making it a key area of biomedical research. CRISPR-based cell models, combined with biochemical and proteomic methods, provide powerful tools to dissect the causal roles of IRS proteins and their binding partners in health and disease.
References
- 1. Lee J et al.. 1994. The insulin receptor: structure, function, and signaling.. Am J Physiol 266(2 Pt 1):C319-34 PMID: 8141246
- 2. Mendoza C et al.. 2023. Insulin receptor-inspired soluble insulin binder.. Eur J Cell Biol 102(2):151293 PMID: 36739671
- 3. Kearney AL et al.. 2021. Akt phosphorylates insulin receptor substrate to limit PI3K-mediated PIP3 synthesis.. Elife 10 PMID: 34253290
- 4. Ozcan U et al.. 2004. Endoplasmic reticulum stress links obesity, insulin action, and type 2 diabetes.. Science 306(5695):457-61 PMID: 15486293
- 5. Sesti G. 2000. Insulin receptor substrate polymorphisms and type 2 diabetes mellitus.. Pharmacogenomics 1(3):343-57 PMID: 11256583
- 6. Al-Salam A et al.. 2017. Evolution of the vertebrate insulin receptor substrate (Irs) gene family.. BMC Evol Biol 17(1):148 PMID: 28645244
- 7. Takács T et al.. 2024. Insulin receptor substrate 1 is a novel member of EGFR signaling in pancreatic cells.. Eur J Cell Biol 103(4):151457 PMID: 39326351
- 8. Perz M et al.. 2001. Insulin receptor--structural and functional characteristics.. Med Sci Monit 7(1):169-77 PMID: 11208515
