GO:0004828 serine-tRNA ligase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0004828 serine-tRNA ligase activity catalyzes the ATP-dependent attachment of L-serine to tRNA(Ser), forming L-seryl-tRNA(Ser), and also charges tRNA(Sec) for selenocysteine biosynthesis.
• The enzyme, known as SerRS, is a class II aminoacyl-tRNA synthetase that is essential for translation and for the selenocysteine incorporation pathway.
• SerRS is a hub for post-translational modifications, including O-GlcNAcylation, which can alter its function in endothelial cells and promote tumor angiogenesis.
• Mutations in tRNA synthetases, including SerRS, can trigger the integrated stress response (ISR), contributing to peripheral neuropathy and other diseases.
• SerRS interacts with the m3C RNA methyltransferase METTL6, linking tRNA modification to seryl-tRNA synthetase function.
• Dysregulation of SerRS and its partners is implicated in cancers such as bladder cancer and hepatocellular carcinoma, making it a potential therapeutic target.
Description
Serine-tRNA ligase activity (GO:0004828) is a fundamental molecular function that ensures the correct translation of the genetic code by attaching the amino acid L-serine to its cognate transfer RNA (tRNA). This activity is carried out by seryl-tRNA synthetase (SerRS), an enzyme that belongs to the class II aminoacyl-tRNA synthetases and is conserved across all domains of life. Beyond its canonical role in protein synthesis, SerRS also participates in the specialized pathway for selenocysteine incorporation by aminoacylating tRNA(Sec), a process critical for the function of selenoproteins. The importance of SerRS extends to human health, as mutations or dysregulation of this enzyme and its interacting partners have been linked to peripheral neuropathy, cancer, and metabolic reprogramming. Understanding the molecular mechanisms, regulation, and disease associations of serine-tRNA ligase activity is therefore essential for researchers in genetics, biochemistry, and translational medicine.
serine-tRNA ligase activity At A Glance
| GO ID | GO:0004828 |
|---|---|
| GO term | serine-tRNA ligase activity |
| Ontology | molecular_function |
| Synonym | SerRS activity; seryl-tRNA synthetase activity; L-serine:tRNASer ligase (AMP-forming) |
| Major function | Catalyzes the attachment of L-serine to tRNA(Ser) and tRNA(Sec), forming seryl-tRNA for translation and selenocysteine synthesis |
| Reaction | ATP + L-serine + tRNA(Ser) = AMP + diphosphate + L-seryl-tRNA(Ser) |
| EC number | 6.1.1.11 |
| Cofactors | ATP, magnesium ions |
| Subcellular location | Cytoplasm |
What Is GO:0004828?
GO:0004828 serine-tRNA ligase activity is defined as the catalysis of the reaction: ATP + L-serine + tRNA(Ser) = AMP + diphosphate + L-seryl-tRNA(Ser). This activity also catalyzes the formation of L-seryl-tRNA(Sec) from tRNA(Sec), the specialized tRNA required for selenocysteine biosynthesis. In essence, it is the function of seryl-tRNA synthetase (SerRS), which ensures that serine is correctly paired with its tRNA for protein synthesis and for selenoprotein production.
Why Is serine-tRNA ligase activity Important in Cell Biology?
Serine-tRNA ligase activity is essential for the fidelity of protein synthesis and for the specialized incorporation of selenocysteine into selenoproteins, which are critical for antioxidant defense and redox regulation. Dysregulation of SerRS has been implicated in a range of human diseases, including peripheral neuropathy linked to integrated stress response activation, and multiple cancers where SerRS O-GlcNAcylation promotes angiogenesis. Moreover, SerRS interacts with RNA-modifying enzymes such as METTL6, linking translation to epitranscriptomic regulation. Thus, studying this activity provides insights into basic biology and offers potential therapeutic targets for cancer and neurological disorders.
• Essential for translation: SerRS charges tRNA(Ser) with serine, a prerequisite for accurate protein synthesis.
• Selenocysteine synthesis: SerRS also aminoacylates tRNA(Sec), enabling selenoprotein production.
• Disease association: Mutations in tRNA synthetases, including SerRS, cause peripheral neuropathy via integrated stress response.
• Cancer: SerRS O-GlcNAcylation in endothelial cells promotes tumor angiogenesis in bladder cancer.
• Epitranscriptomics: SerRS interacts with METTL6, an m3C RNA methyltransferase, linking tRNA modification to translation.
• Metabolic reprogramming: SerRS is involved in hexosamine biosynthetic pathway (HBP)-related metabolic changes in cancer.
• Therapeutic target: SerRS and its modifications are potential targets for anti-angiogenic and anticancer therapies.
• Model for tRNA synthetase biology: SerRS serves as a paradigm for understanding class II synthetase mechanisms and regulation.
Mechanism, Genes and Research Methods
Substrate Recognition and Binding
In simple terms: SerRS first grabs the raw materials: ATP, serine, and the correct tRNA.
SerRS specifically recognizes tRNA(Ser) through identity elements in the tRNA, including the acceptor stem and anticodon loop. It also binds ATP and L-serine in its active site. Structural studies have revealed that SerRS forms a dimer and uses a class II synthetase fold to position the substrates for catalysis. The enzyme also recognizes tRNA(Sec), which shares structural features with tRNA(Ser), to produce seryl-tRNA(Sec) for selenocysteine synthesis.
Catalytic Activation of Serine
In simple terms: Serine is activated by ATP to form a high-energy intermediate.
In the first step of the reaction, SerRS catalyzes the adenylation of L-serine with ATP to form seryl-adenylate (Ser-AMP) and pyrophosphate. This activation step is typical of class II aminoacyl-tRNA synthetases and requires magnesium ions as cofactors. The activated serine is then transferred to the 3'-OH of the tRNA's terminal adenosine.
tRNA Charging and Proofreading
In simple terms: The activated serine is attached to the tRNA, and errors are corrected.
The seryl group is transferred from Ser-AMP to the 3'-end of tRNA(Ser), forming L-seryl-tRNA(Ser) and releasing AMP. SerRS has editing activity to hydrolyze mischarged serine from non-cognate tRNAs, ensuring translational fidelity. This proofreading is crucial because serine is similar in size to other amino acids like alanine and threonine.
Selenocysteine Pathway
In simple terms: SerRS also charges a special tRNA for making selenocysteine.
In addition to tRNA(Ser), SerRS aminoacylates tRNA(Sec) with serine. This seryl-tRNA(Sec) is then converted to selenocysteyl-tRNA(Sec) by selenocysteine synthase (SEPSECS), enabling the incorporation of selenocysteine into selenoproteins. This dual function highlights the versatility of SerRS in translation and specialized metabolism.
Post-translational Modifications and Interactions
In simple terms: SerRS can be chemically modified and interacts with other proteins to change its behavior.
SerRS undergoes O-GlcNAcylation, a post-translational modification that can alter its activity and interactions. In bladder cancer, tumor-derived small extracellular vesicles induce HBP-related metabolic reprogramming and SerRS O-GlcNAcylation in endothelial cells, promoting angiogenesis. SerRS also interacts with METTL6, an m3C RNA methyltransferase, forming a complex that couples tRNA modification with translation. These modifications and interactions expand the regulatory landscape of SerRS beyond canonical translation.
Key Genes Involved in GO:0004828 serine-tRNA ligase activity
The following genes and proteins are directly involved in serine-tRNA ligase activity or its regulation, as supported by published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SARS1 | Encodes cytoplasmic seryl-tRNA synthetase (SerRS); catalyzes serine-tRNA charging | Mutations linked to peripheral neuropathy; target for cancer studies |
| SARS2 | Encodes mitochondrial seryl-tRNA synthetase | Mitochondrial translation; potential role in metabolic disorders |
| METTL6 | m3C RNA methyltransferase that interacts with SerRS | Links tRNA modification to translation; structural studies |
| SEPSECS | Selenocysteine synthase; converts seryl-tRNA(Sec) to selenocysteyl-tRNA(Sec) | Selenoprotein synthesis; downstream of SerRS |
| EEF1A1 | Translation elongation factor; delivers aminoacyl-tRNA to ribosome | General translation; indirect role |
| RPL10A | Ribosomal protein; part of 60S subunit | Translation; not specific to SerRS |
| TBK1 | Kinase involved in antiviral immunity; lactylation regulates function | Indirect link to translation stress |
| GCN2 | eIF2α kinase activated by amino acid starvation; integrated stress response | Links tRNA synthetase dysfunction to ISR |
| ATF4 | Transcription factor downstream of ISR | Mediates cellular stress responses |
| DDIT3 (CHOP) | Pro-apoptotic transcription factor induced by ISR | Neuropathy and cancer models |
| VEGFA | Vascular endothelial growth factor; angiogenesis | Upregulated by SerRS O-GlcNAcylation in cancer |
| HIF1A | Hypoxia-inducible factor; angiogenesis and metabolism | Indirect link to SerRS-mediated metabolic reprogramming |
| GPX1 | Glutathione peroxidase; selenoprotein | Selenocysteine incorporation dependent on SerRS |
| SELENOP | Selenoprotein P; selenium transport | Selenoprotein synthesis |
| TRNAU1AP | tRNA selenocysteine 1 associated protein 1 | Selenocysteine pathway; interacts with tRNA(Sec) |
| EIF2AK4 (GCN2) | Kinase that phosphorylates eIF2α | Integrated stress response in neuropathy |
| NFE2L2 (NRF2) | Oxidative stress response transcription factor | Selenoprotein-related antioxidant defense |
| MTOR | Kinase regulating translation and metabolism | Potential upstream regulator of SerRS expression |
How Is serine-tRNA ligase activity Regulated?
Serine-tRNA ligase activity is regulated at multiple levels. Post-translational modification, particularly O-GlcNAcylation, can modulate SerRS function; in bladder cancer, tumor-derived extracellular vesicles induce HBP-related metabolic reprogramming and SerRS O-GlcNAcylation in endothelial cells, enhancing angiogenesis. The integrated stress response (ISR) is activated by tRNA synthetase dysfunction; mutations in SerRS can lead to GCN2 activation and eIF2α phosphorylation, which inhibits global translation while inducing stress-responsive genes like ATF4 and CHOP. Additionally, SerRS interacts with METTL6, an RNA methyltransferase, which may influence tRNA modification and translation efficiency. These regulatory mechanisms ensure that serine-tRNA ligase activity is tuned to cellular metabolic and stress conditions.
serine-tRNA ligase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SARS1 | Peripheral neuropathy; ISR activation | Knock-in mouse models with patient mutations; neuronal cell lines |
| SARS1 | Bladder cancer angiogenesis; O-GlcNAcylation | Endothelial cell co-culture with cancer-derived EVs; xenograft models |
| METTL6 | Cancer; tRNA modification | Knockout cell lines; structural studies |
| SEPSECS | Selenoprotein deficiency; oxidative stress | Knockout zebrafish or mouse models |
| GCN2 (EIF2AK4) | Neuropathy; ISR | Knockout mice; neuronal cultures |
Peripheral Neuropathy and Integrated Stress Response
Mutations in tRNA synthetases, including seryl-tRNA synthetase (SARS1), cause peripheral neuropathy. Studies have shown that the integrated stress response (ISR) contributes to this pathology; disease-associated mutations activate GCN2, leading to eIF2α phosphorylation and upregulation of stress genes, which ultimately causes neuronal dysfunction. This highlights the importance of SerRS in neuronal health and the ISR as a pathogenic mechanism.
Cancer and Angiogenesis
In bladder cancer, tumor-derived small extracellular vesicles promote angiogenesis by inducing HBP-related metabolic reprogramming and SerRS O-GlcNAcylation in endothelial cells. This modification enhances endothelial cell migration and tube formation, supporting tumor progression. SerRS O-GlcNAcylation thus represents a potential target for anti-angiogenic therapy.
Hepatocellular Carcinoma and Ferroptosis
A tRNA-derived fragment, tRF-E, promotes ferroptosis in hepatocellular carcinoma to suppress tumor progression. Although the direct link to SerRS is not fully elucidated, tRNA fragments can arise from tRNA processing and may affect translation, suggesting a broader role for tRNA biology in liver cancer.
Selenoprotein-Related Disorders
SerRS is required for selenocysteine incorporation into selenoproteins, which are critical for antioxidant defense. Defects in this pathway can lead to oxidative stress-related diseases, although direct mutations in SerRS affecting selenocysteine synthesis are rare.
From serine-tRNA ligase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the effect of SerRS loss on translation? | SARS1 knockout cell lines (e.g., HEK293T) with polysome profiling |
| How do patient mutations in SARS1 cause neuropathy? | Knock-in mouse models expressing mutant SerRS; neuronal cultures |
| Does SerRS O-GlcNAcylation promote angiogenesis? | Endothelial cells overexpressing O-GlcNAc-modified SerRS; tube formation assays |
| How does SerRS interact with METTL6? | Knock-in of tagged SerRS (e.g., FLAG) for co-immunoprecipitation |
| What is the role of SerRS in selenocysteine synthesis? | Overexpression of SARS1 and SEPSECS in cells; selenoprotein reporter assays |
| Can SerRS be targeted for cancer therapy? | Xenograft models with SerRS knockdown or O-GlcNAcylation inhibitors |
How to Study the serine-tRNA ligase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Ribo-seq | Global translation efficiency and ribosome occupancy | Assessing impact of SerRS loss on protein synthesis |
| RNA-seq | Gene expression changes | Identifying ISR activation upon SerRS mutation |
| Proteomics (LC-MS/MS) | Protein abundance and post-translational modifications | Detecting SerRS O-GlcNAcylation |
| Cryo-EM | 3D structure of protein-RNA complexes | Visualizing SerRS-tRNA interactions |
| X-ray crystallography | Atomic structure of SerRS | Understanding catalytic mechanism |
| Co-immunoprecipitation | Protein-protein interactions | Studying SerRS-METTL6 complex |
| Aminoacylation assay | tRNA charging activity | Measuring SerRS enzymatic activity |
| Polysome profiling | Distribution of mRNAs on ribosomes | Detecting translation defects |
Ribosome Profiling (Ribo-seq)
Ribo-seq provides a snapshot of translation by sequencing ribosome-protected mRNA fragments. It can be used to assess the impact of SerRS depletion or mutation on global translation and codon-specific effects, revealing how serine-tRNA ligase activity influences protein synthesis.
RNA Sequencing (RNA-seq)
RNA-seq measures changes in gene expression, including stress-responsive genes like ATF4 and CHOP, upon SerRS dysfunction. It can identify pathways affected by altered serine-tRNA ligase activity, such as the integrated stress response.
Proteomics and Post-translational Modification Analysis
Mass spectrometry-based proteomics can detect SerRS O-GlcNAcylation and other modifications. This is crucial for understanding how post-translational modifications regulate SerRS function in cancer and other diseases.
Structural Biology (Cryo-EM, X-ray Crystallography)
Structural studies of SerRS alone and in complex with tRNA or METTL6 reveal the molecular basis of substrate recognition and catalysis. These methods provide atomic-level insights into serine-tRNA ligase activity.
How CRISPR Can Be Used to Study GO:0004828 serine-tRNA ligase activity
Knockout
CRISPR knockout of SARS1 (SerRS) in cell lines can reveal its essential role in translation and cell viability. However, complete knockout may be lethal, so inducible or conditional systems are often used. Knockout models help identify downstream effects on the integrated stress response and selenoprotein synthesis.
Point Mutation
Introducing patient-specific point mutations into the endogenous SARS1 locus using CRISPR base editing or homology-directed repair allows researchers to study how these mutations affect SerRS function and trigger neuropathy. Such models can recapitulate disease phenotypes and test therapeutic interventions.
Knock-in
Knock-in of epitope tags (e.g., FLAG, HA) into the SARS1 gene enables affinity purification and interaction studies, such as identifying the SerRS-METTL6 complex. Knock-in of reporter genes can also monitor SerRS expression and localization in live cells.
Overexpression
CRISPR activation (CRISPRa) or lentiviral overexpression of SARS1 can model SerRS upregulation observed in cancers. Overexpression studies help elucidate the role of SerRS O-GlcNAcylation in angiogenesis and metabolic reprogramming.
How EDITGENE Supports serine-tRNA ligase activity Research
Researchers studying serine-tRNA ligase activity-related genes often need to determine whether a candidate gene is causally involved in translation, stress responses, or disease. EDITGENE provides comprehensive CRISPR-based services to create precise cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for serine-tRNA ligase activity research.
Frequently Asked Questions About serine-tRNA ligase activity
What is serine-tRNA ligase activity?
Serine-tRNA ligase activity (GO:0004828) is the enzymatic function that attaches the amino acid serine to its corresponding tRNA, forming seryl-tRNA, which is essential for protein synthesis and selenocysteine production.
What genes are involved in serine-tRNA ligase activity?
The primary gene is SARS1, which encodes cytoplasmic seryl-tRNA synthetase. SARS2 encodes the mitochondrial version. Other interacting genes include METTL6 and SEPSECS.
What diseases are associated with serine-tRNA ligase activity?
Mutations in SARS1 are linked to peripheral neuropathy via integrated stress response. Dysregulation is also implicated in bladder cancer angiogenesis and potentially other cancers.
How is serine-tRNA ligase activity regulated?
It is regulated by post-translational modifications like O-GlcNAcylation, interactions with proteins such as METTL6, and cellular stress pathways like the integrated stress response.
What is the reaction catalyzed by serine-tRNA ligase?
The reaction is: ATP + L-serine + tRNA(Ser) = AMP + diphosphate + L-seryl-tRNA(Ser). It also catalyzes the formation of L-seryl-tRNA(Sec).
What are the synonyms for serine-tRNA ligase activity?
Synonyms include SerRS activity, seryl-tRNA synthetase activity, serine translase activity, and seryl-transfer RNA synthetase activity.
How can I study serine-tRNA ligase activity in the lab?
Common methods include aminoacylation assays, Ribo-seq, RNA-seq, proteomics, and structural biology. CRISPR knockout or knock-in models are also valuable.
What is the role of SerRS in cancer?
SerRS O-GlcNAcylation in endothelial cells promotes angiogenesis in bladder cancer. It is also involved in metabolic reprogramming, making it a potential therapeutic target.
Is serine-tRNA ligase activity essential for life?
Yes, it is essential for translation and thus for cell viability. Complete loss is likely lethal, but hypomorphic mutations cause disease.
What model systems are used to study serine-tRNA ligase activity?
Cell lines (e.g., HEK293T), patient-derived cells, and mouse models with knock-in mutations are commonly used. CRISPR-based editing enables precise genetic manipulation.
Conclusion
Serine-tRNA ligase activity (GO:0004828) is a cornerstone of translation and selenoprotein synthesis, with far-reaching implications for human health. Its dysregulation contributes to peripheral neuropathy and cancer, and its regulation by post-translational modifications and protein interactions offers numerous avenues for therapeutic intervention. Continued research using advanced CRISPR models and multi-omics approaches will further illuminate the roles of SerRS in disease and development.
References
- 3. Xie Y et al.. 2026. Dynamic regulation of TBK1 lactylation shapes antiviral immune responses.. Cell Mol Immunol 23(3):284-300 PMID: 41530535
- 4. Bou-Nader C et al.. 2024. Gcn2 structurally mimics and functionally repurposes the HisRS enzyme for the integrated stress response.. Proc Natl Acad Sci U S A 121(35):e2409628121 PMID: 39163341
- 5. Spaulding EL et al.. 2021. The integrated stress response contributes to tRNA synthetase-associated peripheral neuropathy.. Science 373(6559):1156-1161 PMID: 34516839
- 6. Li X et al.. 2022. Bladder Cancer-Derived Small Extracellular Vesicles Promote Tumor Angiogenesis by Inducing HBP-Related Metabolic Reprogramming and SerRS O-GlcNAcylation in Endothelial Cells.. Adv Sci (Weinh) 9(30):e2202993 PMID: 36045101
- 7. Han L et al.. 2026. The tRNA-Derived Fragment tRF-E Promotes Ferroptosis in Hepatocellular Carcinoma to Suppress Tumor Progression.. Cancer Res 86(13):3233-3248 PMID: 41886622
- 8. Throll P et al.. 2024. Structural basis of tRNA recognition by the m(3)C RNA methyltransferase METTL6 in complex with SerRS seryl-tRNA synthetase.. Nat Struct Mol Biol 31(10):1614-1624 PMID: 38918637
