GO:0004686 elongation factor-2 kinase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0004686 (elongation factor-2 kinase activity) catalyzes the ATP-dependent phosphorylation of elongation factor 2 (eEF2), a reaction that inhibits eEF2 and suppresses global protein synthesis.
• The enzyme responsible, eEF2K, is a calcium/calmodulin-dependent kinase that is also regulated by mTOR, AMPK and other stress-responsive pathways.
• eEF2K activity is a key node in translational control and is implicated in cancer, neurological disease, metabolic stress and skeletal muscle atrophy.
• Small-molecule inhibitors of eEF2K are under active preclinical investigation as anticancer and other therapeutic strategies.
• eEF2K function is conserved across species; in C. elegans, EFK-1/eEF2K promotes starvation resistance by preventing oxidative damage.
• CRISPR-based knockout, point-mutation, knock-in and overexpression models are essential tools for dissecting eEF2K biology and validating drug targets.
Description
Elongation factor-2 kinase activity (GO:0004686) is a molecular function that catalyzes the transfer of a phosphate group from ATP to elongation factor 2 (eEF2), producing ADP and phosphorylated eEF2. This phosphorylation event is a well-established mechanism for suppressing the elongation step of protein synthesis, allowing cells to rapidly adjust translation in response to stress, nutrient availability and calcium signaling. The kinase responsible for this activity, eEF2K, is a calcium/calmodulin-dependent enzyme and a member of the alpha-kinase family. Because protein synthesis is tightly linked to cell growth, proliferation and survival, eEF2K activity has emerged as a focal point in cancer biology, neuroscience and metabolic research. Understanding GO:0004686 is therefore essential for researchers studying translational control, drug resistance and stress adaptation. This article integrates the QuickGO definition with verified PubMed literature to provide a research-grade overview of eEF2K activity, its regulatory network, its role in disease, and the experimental models used to study it.
elongation factor-2 kinase activity At A Glance
| GO ID | GO:0004686 |
|---|---|
| GO term | elongation factor-2 kinase activity |
| Ontology | molecular_function |
| Synonym | eEF2K; eEF-2 kinase activity; CaM kinase III; calmodulin-dependent protein kinase III; STK19 |
| Major function | Phosphorylation of elongation factor 2 (eEF2) at Thr56/Thr58, leading to inhibition of translational elongation |
| Reaction | ATP + [elongation factor 2] = ADP + [elongation factor 2] phosphate |
| Cofactor | Calcium/calmodulin |
| Regulatory input | mTOR, AMPK, S6K1, stress-activated pathways |
| Subcellular location | Cytoplasm; associated with ribosomes and cytoskeleton |
What Is GO:0004686?
According to the Gene Ontology, GO:0004686 (elongation factor-2 kinase activity) is defined as the catalysis of the reaction: ATP + [elongation factor 2] = ADP + [elongation factor 2] phosphate. In other words, it is the enzymatic activity that phosphorylates eEF2 using ATP as the phosphate donor. This activity is synonymous with eEF2K, CaM kinase III, and calmodulin-dependent protein kinase III, reflecting its dependence on calcium/calmodulin for activation. The reaction directly inhibits eEF2, thereby reducing the rate of translational elongation.
Why Is elongation factor-2 kinase activity Important in Cell Biology?
GO:0004686 is a central node in the control of protein synthesis, acting as a brake on translational elongation under conditions of stress, nutrient limitation or calcium flux. Because eEF2K activity directly affects cell growth, survival and metabolic adaptation, it is implicated in a wide range of human diseases, including multiple cancers, neurological disorders, and skeletal muscle atrophy. Pharmacological inhibition of eEF2K has shown promise in preclinical models of ovarian cancer, peritoneal metastasis and other malignancies. Moreover, eEF2K is conserved across evolution, and studies in C. elegans have revealed a role in starvation resistance and oxidative stress protection. Thus, understanding this activity is critical for both basic biology and therapeutic development.
• eEF2K activity suppresses global protein synthesis by phosphorylating eEF2, conserving energy under stress.
• It is a downstream target of mTOR and AMPK, integrating nutrient and energy signals.
• eEF2K is overexpressed or hyperactivated in many cancers and promotes tumor growth and metastasis.
• Inhibition of eEF2K sensitizes cancer cells to chemotherapy and targeted therapies.
• eEF2K dysfunction is linked to neurological disorders such as Alzheimer's disease and depression.
• In skeletal muscle, eEF2K activity contributes to disuse-induced atrophy.
• eEF2K inhibitors such as A484954 have shown cardiovascular and diuretic effects in animal models.
• The kinase is a potential target for anti-aging and stress-resistance interventions.
• CRISPR screens have identified eEF2K as a modulator of drug response and immune evasion.
• eEF2K activity can be monitored by phospho-eEF2 (Thr56) antibodies, enabling translational research.
Molecular Mechanism of elongation factor-2 kinase activity
Substrate recognition and binding
In simple terms: eEF2K finds and grabs onto its target, eEF2, so it can add a phosphate tag.
eEF2K specifically recognizes elongation factor 2 (eEF2) as its only known physiological substrate. The kinase domain of eEF2K binds to a region of eEF2 that includes the critical threonine residues Thr56 and Thr58. This interaction is facilitated by the unique alpha-kinase fold of eEF2K, which is distinct from conventional protein kinases. Structural studies and biochemical assays have shown that eEF2K activity is highly specific and does not phosphorylate other translation factors.
Calcium/calmodulin-dependent activation
In simple terms: Calcium acts like a switch that turns on eEF2K by binding to calmodulin.
eEF2K is a calcium/calmodulin-dependent kinase, meaning its activity requires the binding of calcium-loaded calmodulin (Ca2+/CaM) to its calmodulin-binding domain. Upon calcium influx, Ca2+/CaM binds to eEF2K, relieving autoinhibition and allowing the kinase to adopt an active conformation. This mechanism links eEF2K activity to calcium signaling pathways, such as those triggered by neurotransmitters or growth factors.
Catalytic phosphorylation of eEF2
In simple terms: The kinase transfers a phosphate from ATP onto eEF2, which stops eEF2 from doing its job.
Once activated, eEF2K catalyzes the transfer of the gamma-phosphate of ATP to the threonine 56 and 58 residues of eEF2. This phosphorylation event locks eEF2 in an inactive state, preventing it from participating in the translocation step of translational elongation. As a result, global protein synthesis is rapidly downregulated. The reaction is reversible; phosphatases such as PP2A can remove the phosphate and restore eEF2 activity.
Regulation by mTOR and AMPK signaling
In simple terms: Other cellular sensors can dial eEF2K up or down depending on nutrient and energy levels.
eEF2K activity is inhibited by mTORC1 via phosphorylation at Ser366 (by S6K1) and other sites, which suppresses eEF2K when nutrients are plentiful. Conversely, AMPK activates eEF2K by phosphorylating it at Ser398, promoting translation elongation arrest during energy stress. This integration of mTOR and AMPK signals allows eEF2K to act as a metabolic switch.
Feedback and crosstalk with translation machinery
In simple terms: When protein synthesis slows, cells can adapt by changing which proteins are made.
Phosphorylation of eEF2 by eEF2K not only reduces global translation but also selectively enhances the translation of certain stress-responsive mRNAs, such as ATF4. This feedback loop helps cells survive stress by reprogramming gene expression. Additionally, eEF2K activity can affect ribosome transit and mRNA decoding fidelity.
Key Genes Involved in GO:0004686 elongation factor-2 kinase activity
The following genes and proteins are central to the study of elongation factor-2 kinase activity (GO:0004686) and its regulatory network.
| Gene | Major Role | Research Relevance |
|---|---|---|
| EEF2K | Encodes the kinase responsible for GO:0004686; phosphorylates eEF2 | Primary target for knockout, point mutation and inhibitor studies |
| EEF2 | Substrate of eEF2K; mediates ribosomal translocation | Phospho-eEF2 (Thr56) is a readout of eEF2K activity |
| MTOR | Upstream kinase that inhibits eEF2K via S6K1 | mTOR inhibitors affect eEF2K activity and translation |
| RPS6KB1 | Phosphorylates eEF2K at Ser366 to inhibit it | Links growth signaling to translation elongation |
| PRKAA1 | AMPK catalytic subunit; activates eEF2K by phosphorylation | Energy stress response and metabolic regulation |
| CALM1 | Calmodulin; binds Ca2+ and activates eEF2K | Calcium-dependent regulation of eEF2K |
| PPP2CA | Protein phosphatase 2A; dephosphorylates eEF2 | Counteracts eEF2K activity |
| ATF4 | Transcription factor whose translation is enhanced when eEF2 is phosphorylated | Integrated stress response readout |
| EFK-1 | C. elegans ortholog of eEF2K | Model for starvation resistance and oxidative stress |
| Eef2k | Mouse ortholog of EEF2K | Knockout mice used in muscle atrophy and cancer studies |
| A484954 | Small-molecule eEF2K inhibitor | Pharmacological tool; induces diuresis in hypertensive rats |
| EEF2K (STK19) | Alternative synonym for eEF2K | Used in some databases and literature |
| CAMK3 | Historical name for eEF2K (CaM kinase III) | Reflects calcium/calmodulin dependence |
| eEF2K (Ser366) | Phosphorylation site targeted by S6K1 | Marker of mTOR pathway activity |
| eEF2K (Ser398) | Phosphorylation site targeted by AMPK | Marker of energy stress |
| eEF2 (Thr56) | Phosphorylation site modified by eEF2K | Direct measure of eEF2K activity |
| eEF2 (Thr58) | Secondary phosphorylation site | Contributes to eEF2 inhibition |
| EEF2K mRNA | Transcript levels of eEF2K | Expression analysis in cancer and other diseases |
How Is elongation factor-2 kinase activity Regulated?
eEF2K activity is regulated by multiple signaling pathways. mTORC1, via its downstream effector S6K1, phosphorylates eEF2K at Ser366, leading to inhibition of eEF2K and thus promoting translation elongation when nutrients are abundant. In contrast, AMPK phosphorylates eEF2K at Ser398, activating it during energy stress and suppressing translation. Calcium/calmodulin binding is also a critical activator, linking eEF2K to calcium signaling. Additionally, eEF2K is subject to autophosphorylation and regulation by other kinases such as PKA and CDK1. This complex regulation allows eEF2K to integrate diverse cellular cues and fine-tune protein synthesis.
elongation factor-2 kinase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| EEF2K | Ovarian cancer growth and peritoneal metastasis | EEF2K knockout ovarian cancer cell lines; xenograft mouse models |
| EEF2K | Chemoresistance in breast and pancreatic cancer | CRISPR knockout or point-mutation models; drug sensitivity assays |
| EEF2K | Alzheimer's disease and synaptic dysfunction | Neuronal cultures with eEF2K knockout or overexpression; phospho-eEF2 readouts |
| EEF2K | Skeletal muscle atrophy | Mouse models of hindlimb unloading; Eef2k knockout mice |
| EFK-1 | Starvation resistance and oxidative stress in C. elegans | C. elegans efk-1 mutants; lifespan and stress assays |
eEF2K in Cancer
eEF2K is overexpressed or hyperactivated in many human cancers, including ovarian, breast, glioma and pancreatic cancer, where it promotes cell survival, proliferation and metastasis. High eEF2K activity is associated with poor prognosis and resistance to chemotherapy and targeted therapies. Preclinical studies have shown that genetic knockout or pharmacological inhibition of eEF2K suppresses tumor growth and peritoneal metastasis in ovarian cancer models. Small-molecule inhibitors of eEF2K are being developed as potential anticancer agents.
eEF2K in Neurological Disorders
Dysregulated eEF2K activity has been implicated in neurological and psychiatric disorders, including Alzheimer's disease, depression and synaptic plasticity defects. Excessive eEF2 phosphorylation leads to reduced synthesis of synaptic proteins, impairing memory and cognitive function. Modulating eEF2K activity is considered a potential therapeutic strategy for restoring translation in neurons.
eEF2K in Skeletal Muscle Atrophy
Disuse-induced skeletal muscle atrophy is associated with increased eEF2K activity and elevated phospho-eEF2 levels, contributing to reduced protein synthesis. Studies in animal models have shown that eEF2K expression and activity are upregulated during unloading, and targeting this pathway may help preserve muscle mass.
eEF2K in Metabolic and Cardiovascular Biology
eEF2K plays a role in metabolic stress responses and has been linked to cardiovascular function. In spontaneously hypertensive rats, the eEF2K inhibitor A484954 induced diuresis via nitric oxide production, suggesting a role in renal and cardiovascular regulation. In C. elegans, eEF2K promotes starvation resistance by preventing oxidative damage, highlighting its conserved role in stress adaptation.
From elongation factor-2 kinase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of eEF2K affect tumor growth? | EEF2K knockout cancer cell lines and xenografts |
| How does eEF2K phosphorylation of eEF2 regulate translation? | Point-mutation of eEF2 at Thr56/Thr58 to non-phosphorylatable residues |
| What is the effect of eEF2K activation on neuronal function? | Knock-in of phospho-mimetic eEF2K or eEF2 mutants in neurons |
| Can eEF2K be targeted by small molecules? | Overexpression of eEF2K for inhibitor screening; CRISPR knockout for target validation |
| How does eEF2K contribute to muscle atrophy? | Muscle-specific Eef2k knockout or overexpression in mice |
| What is the role of eEF2K in stress resistance? | C. elegans efk-1 knockout and rescue with wild-type or mutant eEF2K |
How to Study the elongation factor-2 kinase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| In vitro kinase assay | Phosphorylation of eEF2 by eEF2K | Enzyme kinetics and inhibitor testing |
| Western blot with phospho-eEF2 (Thr56) | eEF2K activity in cells/tissues | Monitoring pathway activation |
| Polysome profiling | Global translation efficiency | Assessing eEF2K impact on protein synthesis |
| Ribo-seq | Ribosome occupancy and codon resolution | Detecting elongation pausing |
| CRISPR knockout | Loss-of-function of EEF2K | Target validation in cancer and other diseases |
| Overexpression | Gain-of-function of eEF2K | Studying downstream effects and drug screening |
| Immunofluorescence | Subcellular localization of eEF2K/eEF2 | Visualizing co-localization with ribosomes |
| Mouse xenograft | Tumor growth and metastasis | Preclinical testing of eEF2K inhibitors |
Measuring eEF2K Activity
eEF2K activity can be measured using in vitro kinase assays with recombinant eEF2 as substrate and [gamma-32P]ATP, followed by SDS-PAGE and autoradiography. Alternatively, phospho-specific antibodies against eEF2 (Thr56) are widely used in Western blotting to monitor eEF2K activity in cells and tissues. These methods are essential for validating inhibitors and genetic models.
Translational Profiling
Polysome profiling and ribosome footprinting (Ribo-seq) can assess the impact of eEF2K activity on global translation and codon-specific elongation rates. These techniques reveal how eEF2 phosphorylation alters the translation of specific mRNAs, such as ATF4. They are powerful for studying the downstream consequences of eEF2K modulation.
Genetic and Pharmacological Perturbation
CRISPR/Cas9 knockout, siRNA knockdown, and overexpression of wild-type or mutant eEF2K are standard approaches to manipulate eEF2K activity. Small-molecule inhibitors such as A484954 provide acute pharmacological control. Combining genetic and pharmacological tools helps distinguish on-target effects.
In Vivo Models
Mouse models, including Eef2k knockout mice and xenograft tumors, are used to study eEF2K in cancer, muscle atrophy and metabolism. C. elegans efk-1 mutants serve as a model for stress resistance and aging. These in vivo systems provide physiological context for eEF2K function.
How CRISPR Can Be Used to Study GO:0004686 elongation factor-2 kinase activity
Knockout
CRISPR/Cas9-mediated knockout of EEF2K is widely used to study loss of eEF2K activity in cancer cells, neurons and muscle cells. Knockout models have demonstrated that eEF2K is required for tumor growth and metastasis in ovarian cancer. These models are also valuable for validating the specificity of small-molecule inhibitors.
Point Mutation
Point mutations can be introduced into EEF2K to abrogate its kinase activity (e.g., catalytic dead mutants) or to mimic phosphorylation at regulatory sites (Ser366, Ser398). Similarly, point mutations in EEF2 at Thr56/Thr58 can prevent phosphorylation, allowing researchers to dissect the specific contribution of eEF2 phosphorylation to translation control.
Knock-in
Knock-in of tagged EEF2K (e.g., FLAG, GFP) enables affinity purification, imaging and proteomic studies. Knock-in of phospho-mimetic or phospho-deficient EEF2 variants provides insights into the physiological consequences of eEF2 phosphorylation. These models are particularly useful for studying eEF2K in vivo.
Overexpression
Overexpression of wild-type or mutant EEF2K in cell lines is used to study gain-of-function phenotypes, such as increased stress resistance or altered translation. Overexpression models are also employed in high-throughput drug screens to identify eEF2K inhibitors.
How EDITGENE Supports elongation factor-2 kinase activity Research
Researchers studying elongation factor-2 kinase activity-related genes often need to determine whether a candidate gene is causally involved in translation control, disease progression or drug response. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell and animal models, enabling rigorous functional validation of eEF2K and its regulatory network.
Contact EDITGENE today to design your custom CRISPR model for elongation factor-2 kinase activity research.
Frequently Asked Questions About elongation factor-2 kinase activity
What is elongation factor-2 kinase activity?
Elongation factor-2 kinase activity (GO:0004686) is the enzymatic activity that phosphorylates elongation factor 2 (eEF2) using ATP, thereby inhibiting protein synthesis.
What gene encodes elongation factor-2 kinase?
The EEF2K gene encodes the kinase responsible for this activity.
What is the function of eEF2K?
eEF2K phosphorylates eEF2 at Thr56/Thr58, leading to suppression of translational elongation, especially under stress conditions.
How is eEF2K regulated?
eEF2K is regulated by calcium/calmodulin, mTORC1-S6K1 (inhibitory phosphorylation at Ser366), and AMPK (activating phosphorylation at Ser398).
What diseases are associated with eEF2K?
eEF2K is implicated in cancer, neurological disorders, skeletal muscle atrophy and metabolic stress responses.
What are eEF2K inhibitors?
Small-molecule inhibitors such as A484954 target eEF2K activity and are being explored for cancer therapy and other conditions.
How can I measure eEF2K activity?
eEF2K activity can be measured by in vitro kinase assays or by Western blotting for phospho-eEF2 (Thr56).
Is eEF2K conserved across species?
Yes, eEF2K is conserved; the C. elegans ortholog EFK-1 regulates starvation resistance and oxidative stress.
What are the research tools for studying eEF2K?
CRISPR knockout, point mutation, knock-in, overexpression, Ribo-seq, polysome profiling and phospho-specific antibodies are commonly used.
Why is eEF2K a drug target?
eEF2K promotes tumor growth and survival, and its inhibition sensitizes cancer cells to therapy, making it an attractive target.
Conclusion
Elongation factor-2 kinase activity (GO:0004686) is a critical molecular function that controls protein synthesis by phosphorylating eEF2. Its regulation by calcium, mTOR and AMPK integrates diverse cellular signals, and its dysregulation contributes to cancer, neurological disease and muscle atrophy. Continued research using CRISPR models and pharmacological tools will further illuminate its therapeutic potential.
References
- 1. Wang X et al.. 2017. Eukaryotic Elongation Factor 2 Kinase (eEF2K) in Cancer.. Cancers (Basel) 9(12) PMID: 29186827
- 2. Wang H et al.. 2024. Targeting eukaryotic elongation factor 2 kinase (eEF2K) with small-molecule inhibitors for cancer therapy.. Drug Discov Today 29(10):104155 PMID: 39214495
- 3. Yan J et al.. 2025. Eukaryotic Elongation Factor 2 Kinase EFK-1/eEF2K promotes starvation resistance by preventing oxidative damage in C. elegans.. Nat Commun 16(1):1752 PMID: 39966347
- 4. Karakas D et al.. 2020. Eukaryotic elongation factor-2 kinase (eEF2K) signaling in tumor and microenvironment as a novel molecular target.. J Mol Med (Berl) 98(6):775-787 PMID: 32377852
- 5. Erdogan MA et al.. 2021. Targeting eukaryotic elongation factor-2 kinase suppresses the growth and peritoneal metastasis of ovarian cancer.. Cell Signal 81:109938 PMID: 33539938
- 6. Beretta S et al.. 2020. Eukaryotic Elongation Factor 2 Kinase a Pharmacological Target to Regulate Protein Translation Dysfunction in Neurological Diseases.. Neuroscience 445:42-49 PMID: 32088293
- 7. Kodama T et al.. 2023. Eukaryotic elongation factor 2 kinase inhibitor, A484954 induced diuresis via nitric oxide production in spontaneously hypertensive rats.. J Vet Med Sci 85(12):1314-1318 PMID: 37853639
- 8. Vilchinskaya N et al.. 2023. Investigating Eukaryotic Elongation Factor 2 Kinase/Eukaryotic Translation Elongation Factor 2 Pathway Regulation and Its Role in Protein Synthesis Impairment during Disuse-Induced Skeletal Muscle Atrophy.. Am J Pathol 193(6):813-828 PMID: 36871751
