GO:0031370 eukaryotic initiation factor 4G binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0031370 (eukaryotic initiation factor 4G binding) is a molecular function describing the selective binding of proteins to eukaryotic initiation factor 4G (eIF4G), a central scaffold of the translation initiation machinery.
• eIF4G binding is essential for assembling the eIF4F complex and for recruiting the 40S ribosomal subunit to mRNA, thereby controlling the rate of cap-dependent translation initiation.
• The function is mediated by multiple eIF4G domains that coordinate interactions with eIF4E, eIF4A, eIF4B, and the 40S subunit, as well as with RNA elements in cap-independent translation.
• Dysregulation of eIF4G binding contributes to cancer, hematopoietic malignancies, and neurological disorders, making it a target for therapeutic intervention.
• Key genes involved include EIF4G1, EIF4G2, EIF4G3, EIF4E, EIF4A1, EIF4B, PABPC1, and FMR1, among others.
• CRISPR-based knockout, point mutation, knock-in, and overexpression models enable precise dissection of eIF4G binding in translation control and disease.
Description
Eukaryotic initiation factor 4G binding (GO:0031370) is a molecular function that defines the physical interaction between a protein and eukaryotic initiation factor 4G (eIF4G), a large scaffolding polypeptide that orchestrates the assembly of the translation initiation complex. eIF4G serves as a hub that bridges the cap-binding protein eIF4E, the RNA helicase eIF4A, and the 40S ribosomal subunit, thereby facilitating the recruitment of ribosomes to the 5' end of mRNAs. Proteins that bind eIF4G can modulate this process, either promoting or inhibiting translation initiation. This function is critical for maintaining proteostasis and for rapid translational reprogramming in response to cellular stress, growth signals, and viral infection. Researchers study eIF4G binding to understand how gene expression is controlled at the translational level and how its dysregulation leads to diseases such as cancer and neurodegeneration.
eukaryotic initiation factor 4G binding At A Glance
| GO ID | GO:0031370 |
|---|---|
| GO term | eukaryotic initiation factor 4G binding |
| Ontology | molecular_function |
| Synonym | eIF4G binding |
| Definition | Binding to eukaryotic initiation factor 4G, a polypeptide factor involved in the initiation of ribosome-mediated translation. |
| Major function | Mediates protein-protein interactions that regulate translation initiation, including recruitment of the 40S ribosomal subunit and assembly of the eIF4F complex. |
| Related complexes | eIF4F complex, 43S preinitiation complex, mRNP granules. |
| Key domains in eIF4G | HEAT domains, MIF4G domain, MA3 domain, W2 domain. |
| Disease relevance | Cancer, hematopoietic malignancies, neurodevelopmental disorders, and viral infections. |
What Is GO:0031370?
According to the Gene Ontology, GO:0031370 (eukaryotic initiation factor 4G binding) is the binding to eukaryotic initiation factor 4G, a polypeptide factor involved in the initiation of ribosome-mediated translation. In other words, it is the molecular function of selectively and non-covalently interacting with eIF4G, a key scaffold protein that coordinates the assembly of the translation initiation machinery on mRNA.
Why Is eukaryotic initiation factor 4G binding Important in Cell Biology?
eIF4G binding is a central node in the control of protein synthesis, as it determines how efficiently mRNAs are translated. By binding to eIF4G, regulatory proteins and RNA elements can influence the assembly of the translation initiation complex, thereby affecting cell growth, proliferation, and survival. This function is hijacked in many cancers to support oncogenic translation and is also implicated in neurological disorders where translation dysregulation contributes to pathology. Understanding eIF4G binding provides mechanistic insights into translational control and offers opportunities for therapeutic intervention.
• Controls cap-dependent translation initiation, a rate-limiting step in protein synthesis.
• Integrates signals from mTOR and other pathways to modulate cell growth and proliferation.
• Enables cap-independent translation of specific mRNAs under stress conditions.
• Plays a role in hematopoietic malignancy by enhancing translation of oncogenic proteins.
• Implicated in fragile X syndrome through FMRP-mediated translational silencing.
• Targeted by viruses to redirect host translation machinery.
• Serves as a potential therapeutic target in cancer and viral infections.
• Essential for developmental processes and tissue homeostasis.
• Provides a mechanism for rapid translational reprogramming in immunity.
• Offers a handle for CRISPR-based functional genomics of translation.
Molecular Mechanism of eukaryotic initiation factor 4G binding
eIF4G as a Scaffold for Initiation Factor Assembly
In simple terms: eIF4G acts like a molecular adaptor that brings together other proteins needed to start translation.
eIF4G binds to eIF4E, the cap-binding protein, and to eIF4A, an RNA helicase, forming the eIF4F complex at the 5' cap of mRNA. It also interacts with eIF4B and the poly(A)-binding protein (PABP) to circularize the mRNA and enhance translation. These interactions are mediated by distinct domains within eIF4G, including the HEAT and MIF4G domains.
Recruitment of the 40S Ribosomal Subunit
In simple terms: eIF4G helps bring the ribosome to the mRNA so that protein synthesis can begin.
Human eIF4G directly binds the 40S ribosomal subunit, an interaction that promotes efficient translation initiation. This binding is thought to occur through the C-terminal region of eIF4G and is essential for the formation of the 48S preinitiation complex. The direct 40S binding by eIF4G provides a physical link between the mRNA cap and the ribosome.
Regulation by eIF4E and eIF4A Nucleotide State
In simple terms: The binding of eIF4G to RNA and other factors depends on the status of eIF4E and eIF4A.
The nucleotide-bound state of eIF4A and the availability of eIF4E regulate eIF4F binding to RNA. eIF4G binding to eIF4E is a key step in eIF4F assembly, and this interaction can be modulated by phosphorylation and other post-translational modifications. Small molecules that disrupt eIF4E-eIF4G interaction are being explored as anticancer agents.
Cap-Independent Translation and RNA Elements
In simple terms: Some mRNAs use special RNA structures to recruit eIF4G without a cap.
eIF4G coordinates interactions with eIF4A, eIF4B, and eIF4E in binding and translation of the barley yellow dwarf virus 3' cap-independent translation element (BTE). Similarly, the PABP/purine-rich motif acts as an initiation module for cap-independent translation in pattern-triggered immunity. These examples illustrate how eIF4G binding can be directed by RNA elements to specific mRNAs.
eIF4G Binding in Translational Silencing and mRNP Granules
In simple terms: eIF4G binding can also be part of complexes that silence translation.
FMRP drives mRNP targets into translationally silenced complexes, where eIF4G binding may be disrupted or modified. This suggests that eIF4G binding is not only activating but can be a point of regulation for translational repression. The interplay between eIF4G and silencing factors determines the fate of specific mRNAs.
Key Genes Involved in GO:0031370 eukaryotic initiation factor 4G binding
The following genes encode proteins that bind eIF4G or are core components of the eIF4G interaction network, as supported by the cited literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| EIF4G1 | Scaffold protein of eIF4F complex; binds eIF4E, eIF4A, and 40S subunit | Central to cap-dependent translation; implicated in cancer and neurodegeneration |
| EIF4G2 | Homolog of eIF4G; functions in cap-independent translation | Regulates translation of specific mRNAs under stress |
| EIF4G3 | Homolog of eIF4G; involved in translation initiation | Potential role in development and disease |
| EIF4E | Cap-binding protein; binds eIF4G | Target for anticancer therapy; regulates eIF4F assembly |
| EIF4A1 | RNA helicase; binds eIF4G | Essential for translation initiation; nucleotide state regulates eIF4F binding |
| EIF4B | RNA-binding protein; enhances eIF4A activity; interacts with eIF4G | Modulates translation of structured mRNAs |
| PABPC1 | Poly(A)-binding protein; interacts with eIF4G to circularize mRNA | Enhances translation initiation and mRNA stability |
| FMR1 | Fragile X mental retardation protein; binds mRNPs and eIF4G | Loss causes fragile X syndrome; regulates translation silencing |
| APPLE | Oncomicropeptide; enhances translation initiation | Promotes hematopoietic malignancy via eIF4G interaction |
| EIF4EBP1 | Repressor of eIF4E; competes with eIF4G | Regulated by mTOR; controls translation initiation |
| MTOR | Kinase; phosphorylates 4E-BP1 and S6K1 | Upstream regulator of eIF4G binding and translation |
| RPS6KB1 | Ribosomal protein S6 kinase; phosphorylates eIF4B | Links mTOR signaling to translation initiation |
| EIF3A | Subunit of eIF3 complex; interacts with eIF4G | Facilitates 43S complex recruitment |
| EIF3B | Subunit of eIF3 complex; interacts with eIF4G | Required for translation initiation |
| DDX3X | RNA helicase; interacts with eIF4G | Modulates translation and is implicated in cancer |
| LARP1 | La-related protein; binds eIF4G and mRNA | Regulates translation of TOP mRNAs |
| CNOT1 | Subunit of CCR4-NOT complex; interacts with eIF4G | Links translation to mRNA deadenylation |
| GIGYF2 | Binds eIF4G and represses translation | Involved in translational control and neurodegeneration |
How Is eukaryotic initiation factor 4G binding Regulated?
eIF4G binding is regulated by multiple mechanisms, including phosphorylation of eIF4G and its partners, proteolytic cleavage, and competition with inhibitory proteins such as 4E-BP1. The mTOR pathway plays a central role by phosphorylating 4E-BP1, causing its release from eIF4E and allowing eIF4G to bind eIF4E and assemble the eIF4F complex. Additionally, the nucleotide-bound state of eIF4A and the availability of eIF4E modulate eIF4F binding to RNA. In neurons, FMRP can sequester mRNAs into silenced complexes, affecting eIF4G binding and translation. These regulatory layers ensure that translation initiation is tightly coupled to cellular conditions.
eukaryotic initiation factor 4G binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| EIF4G1 | Cancer, neurodegeneration | Knockout and point mutation in cancer cell lines; patient-derived xenografts |
| APPLE | Hematopoietic malignancy | Overexpression in hematopoietic stem cells; knockout in leukemia models |
| FMR1 | Fragile X syndrome | Knockout mice; patient iPSC-derived neurons |
| EIF4E | Cancer, viral infection | Knockout and point mutation in cancer cells; xenograft models |
| PABPC1 | Immune regulation, cancer | Knockout in immune cells; knock-in of mutant alleles |
Cancer and Hematopoietic Malignancies
Dysregulated eIF4G binding promotes oncogenic translation. The oncomicropeptide APPLE enhances translation initiation and promotes hematopoietic malignancy by interacting with eIF4G. Targeting the eIF4E-eIF4G interaction with small molecules or degraders is a promising anticancer strategy.
Neurodevelopmental and Neurodegenerative Disorders
FMRP, which binds eIF4G and regulates translation, is lost in fragile X syndrome, leading to aberrant translation of mRNP targets. eIF4G binding is also implicated in other neurological conditions where translational control is disrupted.
Viral Infections and Host Translation Hijacking
Viruses often exploit eIF4G binding to redirect host translation. The barley yellow dwarf virus 3' cap-independent translation element recruits eIF4G, eIF4A, eIF4B, and eIF4E to initiate translation without a cap. Understanding these mechanisms can inform antiviral strategies.
Immune Responses and Cap-Independent Translation
In pattern-triggered immunity, the PABP/purine-rich motif acts as an initiation module for cap-independent translation, involving eIF4G binding. This highlights the role of eIF4G in rapid translational reprogramming during immune responses.
From eukaryotic initiation factor 4G binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of eIF4G binding affect global translation? | CRISPR knockout of EIF4G1 in HEK293 or HeLa cells followed by polysome profiling |
| Which residues mediate eIF4G-40S interaction? | Point mutations in EIF4G1 C-terminus; ribosome binding assays |
| How does a disease-associated mutation alter eIF4G binding? | Knock-in of mutant EIF4G1 in isogenic cell lines; co-immunoprecipitation |
| Can a tagged eIF4G be used to isolate binding partners? | Knock-in of FLAG- or HA-tagged EIF4G1; affinity purification mass spectrometry |
| What is the effect of eIF4G overexpression in cancer? | Overexpression of EIF4G1 in cancer cell lines; proliferation and tumor growth assays |
| Does eIF4G binding regulate specific mRNA translation? | Knockout of EIF4G1 followed by Ribo-seq and RNA-seq |
How to Study the eukaryotic initiation factor 4G binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Ribo-seq | Genome-wide translation efficiency | Assessing impact of eIF4G binding on mRNA translation |
| Co-IP / Mass Spectrometry | Protein-protein interactions | Identifying eIF4G binding partners |
| In vitro binding assays | Direct binding affinity | Testing eIF4G-40S interaction |
| Polysome profiling | Distribution of mRNAs in polysomes | Measuring translation initiation changes |
| CRISPR knockout screens | Gene essentiality and pathway function | Discovering regulators of eIF4G binding |
| RNA immunoprecipitation (RIP) | mRNA targets of eIF4G complexes | Mapping eIF4G-bound transcripts |
| Fluorescence microscopy | Subcellular localization of eIF4G | Visualizing eIF4G in mRNP granules |
| Western blot | Protein expression and phosphorylation | Validating eIF4G levels and modifications |
Ribosome Profiling (Ribo-seq)
Ribo-seq measures genome-wide translation by sequencing ribosome-protected mRNA fragments. It can reveal how eIF4G binding affects the translation efficiency of specific mRNAs.
Co-Immunoprecipitation and Affinity Purification
Co-IP and affinity purification coupled with mass spectrometry identify proteins that bind eIF4G under different conditions, helping to map the eIF4G interactome.
In Vitro Translation and Binding Assays
Reconstituted in vitro translation systems and purified proteins can be used to dissect direct eIF4G binding to the 40S subunit and other factors.
CRISPR Screens and Functional Genomics
Genome-wide CRISPR knockout screens can identify genes that modulate eIF4G binding and translation initiation, linking genotype to phenotype.
How CRISPR Can Be Used to Study GO:0031370 eukaryotic initiation factor 4G binding
Knockout
CRISPR knockout of EIF4G1 or other genes in the eIF4G binding network can abolish the function and reveal its role in translation and cell viability. Knockout cell lines are useful for rescue experiments with wild-type or mutant eIF4G.
Point Mutation
Point mutations can be introduced into EIF4G1 to disrupt specific binding interfaces, such as the eIF4E-binding site or the 40S-binding region, allowing precise structure-function analysis.
Knock-in
Knock-in of tagged eIF4G (e.g., FLAG, HA, or GFP) enables affinity purification and imaging of eIF4G complexes in native contexts. Disease-associated mutations can also be knocked in to model their effects.
Overexpression
Overexpression of eIF4G or its binding partners can drive oncogenic translation and is used to model cancer and hematopoietic malignancies. Inducible overexpression systems allow temporal control.
How EDITGENE Supports eukaryotic initiation factor 4G binding Research
Researchers studying eukaryotic initiation factor 4G binding-related genes often need to determine whether a candidate gene is causally involved in translation control, disease progression, or therapeutic response. EDITGENE provides a comprehensive suite of CRISPR services to enable such investigations with precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for eukaryotic initiation factor 4G binding research.
Frequently Asked Questions About eukaryotic initiation factor 4G binding
What is eukaryotic initiation factor 4G binding?
Eukaryotic initiation factor 4G binding (GO:0031370) is a molecular function where a protein selectively binds to eIF4G, a scaffold that assembles the translation initiation complex.
What genes are involved in eukaryotic initiation factor 4G binding?
Key genes include EIF4G1, EIF4G2, EIF4G3, EIF4E, EIF4A1, EIF4B, PABPC1, and FMR1, among others.
How does eIF4G binding regulate translation?
eIF4G binding recruits eIF4E, eIF4A, and the 40S ribosomal subunit to mRNA, forming the eIF4F complex and initiating translation.
What diseases are associated with eIF4G binding?
Dysregulation of eIF4G binding is linked to cancer, hematopoietic malignancies, fragile X syndrome, and viral infections.
What is the role of eIF4G in cancer?
eIF4G binding enhances translation of oncogenic mRNAs; the oncomicropeptide APPLE promotes hematopoietic malignancy via eIF4G interaction.
How can I study eIF4G binding using CRISPR?
CRISPR knockout, point mutation, knock-in, and overexpression models allow functional dissection of eIF4G binding in translation and disease.
What methods are used to measure eIF4G binding?
Common methods include co-immunoprecipitation, Ribo-seq, polysome profiling, and in vitro binding assays.
Is eIF4G binding cap-dependent?
eIF4G binding is primarily cap-dependent via eIF4E, but it can also occur in cap-independent translation mediated by RNA elements.
What is the difference between eIF4G1 and eIF4G2?
eIF4G1 is the canonical scaffold for cap-dependent translation, while eIF4G2 functions in cap-independent translation and stress responses.
How is eIF4G binding regulated?
It is regulated by mTOR signaling, phosphorylation, 4E-BP1 competition, and proteolytic cleavage.
Conclusion
GO:0031370 (eukaryotic initiation factor 4G binding) is a fundamental molecular function that controls translation initiation by mediating interactions between eIF4G and its partners. Its dysregulation contributes to cancer, neurological disorders, and viral pathogenesis. CRISPR-based models and advanced omics methods provide powerful tools to dissect this function and develop targeted therapies. EDITGENE offers comprehensive services to support such research.
References
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- 2. Sun L et al.. 2021. The oncomicropeptide APPLE promotes hematopoietic malignancy by enhancing translation initiation.. Mol Cell 81(21):4493-4508.e9 PMID: 34555354
- 3. Wang J et al.. 2022. PABP/purine-rich motif as an initiation module for cap-independent translation in pattern-triggered immunity.. Cell 185(17):3186-3200.e17 PMID: 35907403
- 4. Keiper BD et al.. 1999. Protein synthesis initiation factor 4G.. Int J Biochem Cell Biol 31(1):37-41 PMID: 10216942
- 5. Kurosaki T et al.. 2025. FMRP drives mRNP targets into translationally silenced complexes.. Mol Cell 85(15):2956-2972.e10 PMID: 40645180
- 6. Izidoro MS et al.. 2022. Human eukaryotic initiation factor 4E (eIF4E) and the nucleotide-bound state of eIF4A regulate eIF4F binding to RNA.. J Biol Chem 298(10):102368 PMID: 35963437
- 7. Zhao P et al.. 2017. Eukaryotic translation initiation factor 4G (eIF4G) coordinates interactions with eIF4A, eIF4B, and eIF4E in binding and translation of the barley yellow dwarf virus 3' cap-independent translation element (BTE).. J Biol Chem 292(14):5921-5931 PMID: 28242763
- 8. Sharp SY et al.. 2024. Integrating fragment-based screening with targeted protein degradation and genetic rescue to explore eIF4E function.. Nat Commun 15(1):10037 PMID: 40016190
