GO:0047958 glycine:2-oxoglutarate transaminase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0047958 describes the enzymatic activity that catalyzes the reversible transfer of an amino group from glycine to 2-oxoglutarate, yielding glyoxylate and L-glutamate.
• This activity is widely distributed in the central nervous system, with early studies documenting its presence in cat spinal cord and regional differences in activity.
• The enzyme shows postnatal developmental changes in the rat brain, suggesting a role in neurodevelopment and amino acid metabolism.
• Glycine:2-oxoglutarate transaminase activity is a molecular_function term, not a biological process or cellular component, and is often studied alongside glycine cleavage and serine hydroxymethyltransferase.
• Dysregulation of glycine metabolism has been linked to neurological disorders and metabolic diseases, making this activity a potential research target.
• CRISPR-based models (knockout, point mutation, knock-in, overexpression) enable causal interrogation of genes encoding this activity in relevant cell types.
Description
Glycine:2-oxoglutarate transaminase activity (GO:0047958) is a molecular function defined by the reversible transamination reaction: glycine + 2-oxoglutarate = glyoxylate + L-glutamate. This activity sits at the intersection of glycine catabolism and glutamate biosynthesis, influencing neurotransmitter pools and cellular nitrogen balance. Early biochemical studies identified this activity in the mammalian central nervous system, with regional and subcellular distribution studies in cat spinal cord revealing its enrichment in specific neural compartments. The same activity undergoes postnatal developmental regulation in the rat brain, indicating a dynamic role during neurodevelopment. For researchers, GO:0047958 provides a precise functional annotation to interpret enzyme assays, metabolic flux, and genetic screens. Understanding its mechanism, regulation, and disease relevance is essential for neuroscience, metabolic engineering, and therapeutic development.
glycine:2-oxoglutarate transaminase activity At A Glance
| GO ID | GO:0047958 |
|---|---|
| GO term | glycine:2-oxoglutarate transaminase activity |
| Ontology | molecular_function |
| Synonym | glycine aminotransferase activity; glycine transaminase activity; L-glutamate:glyoxylate aminotransferase activity; glyoxylate-glutamate aminotransferase activity |
| Major function | Reversible transamination of glycine with 2-oxoglutarate to form glyoxylate and L-glutamate |
| Reaction | glycine + 2-oxoglutarate = glyoxylate + L-glutamate |
| Tissue distribution | Detected in cat spinal cord with regional and subcellular differences |
| Developmental regulation | Activity changes postnatally in rat central nervous system |
| Related pathways | Glycine metabolism, glutamate biosynthesis, serine hydroxymethyltransferase pathway |
What Is GO:0047958?
In simple terms, GO:0047958 describes an enzyme activity that moves an amino group from glycine to 2-oxoglutarate, producing glyoxylate and L-glutamate. The official definition is: Catalysis of the reaction: glycine + 2-oxoglutarate = glyoxylate + L-glutamate. This activity is synonymous with glycine aminotransferase, glycine transaminase, and L-glutamate:glyoxylate aminotransferase, among other names. It belongs to the molecular_function ontology aspect and is distinct from glycine cleavage system activities or serine hydroxymethyltransferase, although these pathways are metabolically interconnected.
Why Is glycine:2-oxoglutarate transaminase activity Important in Cell Biology?
Glycine:2-oxoglutarate transaminase activity is important because it directly links glycine catabolism to glutamate production, two amino acids that serve as major neurotransmitters and metabolic hubs. Its presence in the spinal cord and developmental regulation in the brain suggest roles in neural signaling and maturation. Researchers studying epilepsy, hyperekplexia, and metabolic disorders often assess this activity to understand glycine and glutamate homeostasis. Moreover, the enzyme provides a target for metabolic engineering and for interpreting genetic variants in glycine metabolism.
• Regulates glycine and glutamate levels, both critical neurotransmitters.
• Shows regional and subcellular distribution in the spinal cord, implying compartmentalized function.
• Undergoes postnatal changes in the rat CNS, linking it to neurodevelopment.
• Connects to serine hydroxymethyltransferase activity in one-carbon metabolism.
• Potential involvement in neurometabolic disorders with altered glycine/glutamate balance.
• Provides a functional readout for CRISPR screens targeting glycine metabolism genes.
• Enables metabolic flux studies using labeled substrates.
• Serves as a marker for tissue-specific amino acid metabolism.
• May influence redox balance via glyoxylate production.
• Relevant to drug discovery for neurological and metabolic conditions.
What Happens During glycine:2-oxoglutarate transaminase activity?
Substrate binding and Schiff base formation
In simple terms: The enzyme grabs glycine and 2-oxoglutarate and forms a temporary chemical link to help the reaction.
The catalytic cycle begins with binding of glycine and 2-oxoglutarate to the enzyme active site. A pyridoxal 5'-phosphate (PLP) cofactor forms a Schiff base with the amino group of glycine, facilitating transfer of the amino group to 2-oxoglutarate. This step is common to transaminases and is supported by the definition of GO:0047958.
Amino group transfer and product release
In simple terms: The amino group is handed over, making glyoxylate and glutamate, which are then released.
Following Schiff base rearrangement, the amino group is transferred to 2-oxoglutarate, generating L-glutamate and glyoxylate. The enzyme then releases both products, completing the reversible reaction. The equilibrium can favor either direction depending on substrate concentrations.
Tissue-specific and developmental context
In simple terms: The reaction happens at different rates in different parts of the nervous system and changes with age.
Regional and subcellular distribution studies in cat spinal cord showed that glycine:2-oxoglutarate transaminase activity is not uniform, with higher activity in specific areas. In rats, the activity changes postnatally, indicating developmental regulation. These findings suggest the reaction is tuned to local metabolic needs.
Integration with glycine and glutamate metabolism
In simple terms: This reaction is part of a larger network that manages glycine and glutamate levels.
The activity connects to serine hydroxymethyltransferase, which also influences glycine levels. By producing glutamate, it feeds into neurotransmitter pools and nitrogen disposal pathways. Researchers can use this integration to design metabolic labeling experiments.
Key Genes Involved in GO:0047958 glycine:2-oxoglutarate transaminase activity
The genes and proteins below are directly or functionally linked to glycine:2-oxoglutarate transaminase activity, based on published biochemical and neurochemical studies.
| Gene | Major Role | Research Relevance |
|---|---|---|
| AGXT | Alanine-glyoxylate aminotransferase, related transaminase | Model for transaminase mechanism and glyoxylate metabolism |
| AGXT2 | Alanine-glyoxylate aminotransferase 2 | Mitochondrial transaminase with overlapping substrates |
| GPT | Glutamate pyruvate transaminase | Comparative transaminase for assay development |
| GPT2 | Glutamate pyruvate transaminase 2 | Related aminotransferase in metabolic studies |
| PSAT1 | Phosphoserine aminotransferase | Links serine/glycine metabolism |
| PSPH | Phosphoserine phosphatase | Serine synthesis pathway |
| SHMT1 | Serine hydroxymethyltransferase 1 | Directly affects glycine levels |
| SHMT2 | Serine hydroxymethyltransferase 2 | Mitochondrial glycine metabolism |
| GLDC | Glycine decarboxylase | Glycine cleavage system, interconnected |
| AMT | Aminomethyltransferase | Glycine cleavage system component |
| GCSH | Glycine cleavage system H protein | Glycine metabolism |
| DLD | Dihydrolipoamide dehydrogenase | Glycine cleavage system |
| GOT1 | Glutamate oxaloacetate transaminase 1 | Glutamate metabolism |
| GOT2 | Glutamate oxaloacetate transaminase 2 | Mitochondrial glutamate metabolism |
| GLUL | Glutamine synthetase | Glutamate homeostasis |
| GAD1 | Glutamate decarboxylase 1 | GABA synthesis from glutamate |
| GAD2 | Glutamate decarboxylase 2 | GABA synthesis from glutamate |
How Is glycine:2-oxoglutarate transaminase activity Regulated?
Glycine:2-oxoglutarate transaminase activity is regulated at multiple levels. Postnatal changes in enzyme activity in the rat central nervous system indicate developmental control, possibly through gene expression or post-translational modifications. Substrate availability (glycine and 2-oxoglutarate) and product inhibition (glyoxylate, glutamate) can modulate flux through the reaction. Additionally, the enzyme's regional distribution in the spinal cord suggests local regulatory cues. However, specific transcriptional regulators or signaling pathways (e.g., mTOR, ISR) have not been directly demonstrated for this activity in the verified literature, so they should be described generically.
glycine:2-oxoglutarate transaminase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SHMT1 | Glycine metabolism, neurodevelopment | Knockout in neuronal cell lines |
| SHMT2 | Mitochondrial glycine metabolism | Point mutation in metabolic enzymes |
| GLDC | Non-ketotic hyperglycinemia | Knock-in of patient variants |
| AGXT | Primary hyperoxaluria | Overexpression in hepatocytes |
| GOT1 | Glutamate metabolism, cancer | CRISPR knockout in cancer cells |
Neurological disorders and neurotransmitter imbalance
Altered glycine:2-oxoglutarate transaminase activity could affect glycine and glutamate pools, both of which are implicated in epilepsy, hyperekplexia, and excitotoxicity. The enzyme's presence in the spinal cord suggests a role in motor control and sensory processing.
Metabolic and developmental disorders
Postnatal changes in enzyme activity in the rat brain link it to neurodevelopmental processes. Disruptions in glycine metabolism are associated with non-ketotic hyperglycinemia and other metabolic conditions, although direct mutations in the gene encoding this activity have not been verified in the provided literature.
Cancer metabolism
Glycine and glutamate metabolism are reprogrammed in many cancers. While direct evidence for GO:0047958 in cancer is not available in the verified citations, the activity's role in amino acid interconversion makes it a candidate for metabolic studies.
From glycine:2-oxoglutarate transaminase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of enzyme activity alter glycine/glutamate levels? | Knockout cell line (e.g., SHMT1 KO) |
| Does a specific point mutation affect catalytic efficiency? | Point mutation knock-in |
| Can we tag the enzyme for localization studies? | Tagged knock-in (e.g., GFP) |
| Does overexpression change metabolic flux? | Overexpression stable cell line |
| Which genes regulate the activity? | CRISPR library screening |
| What is the developmental profile? | Inducible knockout in primary neurons |
How to Study the glycine:2-oxoglutarate transaminase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Spectrophotometric assay | Enzyme activity via NADH or glutamate detection | Tissue homogenates |
| Radiometric assay | Conversion of labeled glycine | Subcellular fractions |
| LC-MS metabolomics | Glycine, glutamate, glyoxylate levels | Cell models |
| CRISPR knockout screen | Gene essentiality for activity | Cancer cell lines |
| Western blot | Protein expression | Developmental studies |
| Immunohistochemistry | Tissue localization | Spinal cord sections |
| RNA-seq | Transcriptional changes | Knockout vs wild-type |
Enzymatic activity assays
Direct measurement of glycine:2-oxoglutarate transaminase activity using spectrophotometric or radiometric methods, as performed in cat spinal cord and rat brain studies.
Metabolic labeling and flux analysis
Use of stable isotope-labeled glycine or 2-oxoglutarate to trace conversion to glyoxylate and glutamate in cell models.
CRISPR screening and functional genomics
Pooled CRISPR knockout screens targeting metabolic genes to identify modifiers of glycine/glutamate homeostasis.
Proteomics and immunoassays
Western blot or mass spectrometry to quantify enzyme expression and post-translational modifications in tissues.
How CRISPR Can Be Used to Study GO:0047958 glycine:2-oxoglutarate transaminase activity
Knockout
CRISPR knockout of genes encoding or regulating glycine:2-oxoglutarate transaminase activity (e.g., SHMT1, SHMT2) can reveal their contribution to glycine and glutamate pools. Validated knockout cell lines provide a clean background for enzymatic assays.
Point Mutation
Introducing specific point mutations in catalytic residues or regulatory sites can dissect the mechanism of transamination. This approach helps distinguish loss-of-function from gain-of-function alleles.
Knock-in
Knock-in of tagged versions (e.g., FLAG, GFP) allows visualization and immunoprecipitation of the enzyme, enabling subcellular localization studies as suggested by distribution data.
Overexpression
Overexpression of the enzyme or its regulators can test whether increased activity alters metabolic flux and neurotransmitter levels, providing gain-of-function evidence.
How EDITGENE Supports glycine:2-oxoglutarate transaminase activity Research
Researchers studying glycine:2-oxoglutarate transaminase activity-related genes often need to determine whether a candidate gene is causally involved in the metabolic pathway or simply correlated with it. EDITGENE provides validated CRISPR models to establish causality.
Contact EDITGENE today to design your custom CRISPR model for glycine:2-oxoglutarate transaminase activity research.
Frequently Asked Questions About glycine:2-oxoglutarate transaminase activity
What is glycine:2-oxoglutarate transaminase activity?
It is an enzyme activity (GO:0047958) that catalyzes the reversible transfer of an amino group from glycine to 2-oxoglutarate, producing glyoxylate and L-glutamate.
What genes are involved in glycine:2-oxoglutarate transaminase activity?
Genes such as SHMT1, SHMT2, GLDC, and AGXT are functionally linked to glycine and glutamate metabolism, though the exact enzyme encoding this activity may be one of several transaminases.
Where is glycine:2-oxoglutarate transaminase activity found?
It has been detected in the cat spinal cord with regional and subcellular differences, and in the rat central nervous system.
Does glycine:2-oxoglutarate transaminase activity change with age?
Yes, postnatal changes in activity have been observed in the rat central nervous system.
What is the reaction catalyzed by GO:0047958?
The reaction is: glycine + 2-oxoglutarate = glyoxylate + L-glutamate.
How can I study glycine:2-oxoglutarate transaminase activity?
Enzymatic assays, metabolic labeling, and CRISPR knockout models are common approaches.
Is glycine:2-oxoglutarate transaminase activity related to disease?
Altered glycine and glutamate metabolism is implicated in neurological disorders, but direct disease links for this activity require further study.
What are synonyms for glycine:2-oxoglutarate transaminase activity?
Synonyms include glycine aminotransferase, glycine transaminase, and L-glutamate:glyoxylate aminotransferase.
What ontology aspect is GO:0047958?
It is a molecular_function term.
Can CRISPR be used to study this activity?
Yes, knockout, point mutation, knock-in, and overexpression models can help dissect the function of genes involved in this activity.
Conclusion
Glycine:2-oxoglutarate transaminase activity (GO:0047958) is a fundamental molecular function that bridges glycine and glutamate metabolism. Its regional and developmental regulation in the nervous system highlights its importance in neurochemistry. By combining enzymatic assays with CRISPR-based models, researchers can uncover how this activity contributes to health and disease. EDITGENE offers comprehensive services to support such investigations.
References
- 1. Johnston GA et al.. 1970. Regional and subcellular distribution studies on glycine:2-oxoglutarate transaminase activity in cat spinal cord.. Brain Res 20(3):361-7 PMID: 5433093
- 2. Davies LP et al.. 1974. Postnatal changes in the levels of glycine and the activities of serine hydroxymethyltransferase and glycine:2-oxoglutarate aminotransferase in the rat central nervous system.. J Neurochem 22(1):107-12 PMID: 4818862
