GO:0006545 glycine biosynthetic process: Metabolic Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0006545 (glycine biosynthetic process) describes the chemical reactions and pathways that result in the formation of glycine, the simplest amino acid.
• Glycine biosynthesis is central to one-carbon metabolism, purine and glutathione synthesis, and collagen production, linking it to cancer, metabolic homeostasis, and neurotransmission [1, 5, 6].
• Key enzymes include SHMT1/SHMT2 (serine hydroxymethyltransferase), GLDC (glycine decarboxylase), and AGXT (alanine-glyoxylate aminotransferase), with additional microbial and anaerobic routes [1, 4].
• In anaerobes, glycine can be synthesized via the reductive acetyl-CoA pathway and other fermentative routes, highlighting evolutionary diversity.
• Glycine availability influences skeletal muscle metabolism and whole-body metabolic homeostasis, making it a target for nutritional and exercise research.
• CRISPR knockout, point mutation, knock-in, and overexpression models enable causal dissection of glycine biosynthetic genes in cancer, neurobiology, and metabolic disorders [1, 5, 8].
Description
Glycine (aminoethanoic acid) is the smallest amino acid and serves as a building block for proteins, glutathione, purines, heme, and collagen. The glycine biosynthetic process (GO:0006545) encompasses the enzymatic reactions that generate glycine from precursors such as serine, glyoxylate, threonine, and carbon dioxide/ammonia in various organisms [1, 4]. This pathway is not merely a housekeeping function; it is dynamically regulated and interfaces with one-carbon metabolism, redox balance, and neurotransmission [1, 5]. In cancer cells, enhanced glycine biosynthesis supports rapid proliferation and redox homeostasis, making it a potential therapeutic target. In skeletal muscle, glycine metabolism contributes to metabolic homeostasis and may influence insulin sensitivity and aging. In the nervous system, glycine acts as an inhibitory neurotransmitter, and its biosynthetic pathways are essential for maintaining synaptic glycine pools. Understanding GO:0006545 therefore has broad implications for oncology, neurobiology, and metabolic physiology. Researchers studying this term require precise genetic tools to manipulate key enzymes and transporters, and to assess downstream metabolic and phenotypic consequences [1, 6, 8].
glycine biosynthetic process At A Glance
| GO ID | GO:0006545 |
|---|---|
| GO term | glycine biosynthetic process |
| Ontology | biological_process |
| Synonym | glycine anabolism; glycine biosynthesis; glycine formation; glycine synthesis |
| Major function | Synthesis of glycine from serine, glyoxylate, threonine, or other precursors |
| Key enzymes | SHMT1, SHMT2, GLDC, AGXT, GCSH, AMT, DLD |
| Pathway context | One-carbon metabolism, photorespiration (plants), anaerobic fermentation (microbes) |
| Disease relevance | Cancer, hyperoxaluria, nonketotic hyperglycinemia, metabolic disorders |
| Research tools | CRISPR KO/point mutation/knock-in/overexpression, metabolomics, flux analysis |
What Is GO:0006545?
GO:0006545, glycine biosynthetic process, is defined by the Gene Ontology as the chemical reactions and pathways resulting in the formation of glycine, aminoethanoic acid. This biological process includes both de novo synthesis from serine via serine hydroxymethyltransferase and alternative routes such as glyoxylate transamination, threonine cleavage, and reductive amination of glyoxylate [1, 4]. The term is used to annotate gene products that catalyze or regulate these reactions, and it is distinct from glycine catabolism or glycine transport.
Why Is glycine biosynthetic process Important in Cell Biology?
Glycine biosynthesis is fundamental to cellular metabolism because glycine is required for protein synthesis, glutathione production, purine nucleotide synthesis, and collagen formation. Dysregulation of glycine biosynthetic enzymes is implicated in cancer, where rapidly proliferating cells depend on glycine for redox balance and biomass. In skeletal muscle, glycine metabolism influences metabolic homeostasis and may affect whole-body glucose disposal. In the nervous system, glycine serves as an inhibitory neurotransmitter, and its biosynthetic pathways are critical for maintaining inhibitory tone. Moreover, genetic defects in glycine biosynthetic enzymes cause severe metabolic diseases such as primary hyperoxaluria and nonketotic hyperglycinemia [1, 8]. Thus, GO:0006545 is a nexus for understanding normal physiology and multiple disease states.
• Provides glycine for protein synthesis and cell growth.
• Supports glutathione synthesis and cellular redox defense.
• Contributes to one-carbon metabolism and nucleotide biosynthesis.
• Essential for collagen production in connective tissues.
• Influences skeletal muscle metabolic homeostasis.
• Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem.
• Mutations in glycine biosynthetic enzymes cause primary hyperoxaluria and nonketotic hyperglycinemia [1, 8].
• Glycine conjugation is important for detoxification of xenobiotics and endogenous acids.
• Target for cancer therapy due to metabolic reprogramming.
• Relevant to anaerobic microbial metabolism and biotechnology.
What Happens During glycine biosynthetic process?
Serine hydroxymethyltransferase (SHMT)-mediated synthesis
In simple terms: The enzyme SHMT converts serine into glycine, transferring a one-carbon unit to tetrahydrofolate.
The most well-characterized route for glycine biosynthesis in mammals is the reversible conversion of serine to glycine by serine hydroxymethyltransferase (SHMT), which exists as cytosolic SHMT1 and mitochondrial SHMT2. This reaction simultaneously generates 5,10-methylenetetrahydrofolate, linking glycine synthesis to one-carbon metabolism and nucleotide biosynthesis. SHMT2 is often upregulated in cancer to support rapid proliferation and redox homeostasis.
Glycine cleavage system (GCS) and reversible decarboxylation
In simple terms: The glycine cleavage system can break down glycine, but under certain conditions it can also contribute to glycine synthesis.
The glycine cleavage system (GCS), composed of GLDC, GCSH, AMT, and DLD, catalyzes the reversible oxidative decarboxylation of glycine. While primarily catabolic, in some tissues and metabolic states the reverse reaction can generate glycine from CO2, NH3, and a one-carbon unit. Mutations in GCS components cause nonketotic hyperglycinemia, highlighting its importance.
Glyoxylate transamination and alternative routes
In simple terms: Other enzymes can make glycine from glyoxylate or threonine, especially in liver and microbes.
Alanine-glyoxylate aminotransferase (AGXT) catalyzes the transamination of glyoxylate to glycine, a critical step in glyoxylate detoxification. Defects in AGXT cause primary hyperoxaluria type 1. In anaerobes, glycine can be synthesized via the reductive acetyl-CoA pathway and other fermentative routes. These alternative pathways highlight the metabolic flexibility of glycine biosynthesis across organisms.
Microbial and biotechnological glycine production
In simple terms: Microbes can be engineered to produce glycine from glucose for industrial applications.
Recent metabolic engineering efforts have enabled efficient production of glycine from glucose in microbial cell factories using two-stage biosynthetic strategies. These approaches leverage native or engineered glycine biosynthetic pathways and demonstrate the biotechnological potential of GO:0006545.
Key Genes Involved in GO:0006545 glycine biosynthetic process
The following genes encode enzymes and regulators directly involved in glycine biosynthetic process (GO:0006545) across human, microbial, and model organisms.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SHMT1 | Cytosolic serine hydroxymethyltransferase; converts serine to glycine | Cancer metabolism, one-carbon flux |
| SHMT2 | Mitochondrial serine hydroxymethyltransferase; glycine synthesis and redox balance | Tumor growth, metabolic reprogramming |
| GLDC | Glycine decarboxylase; component of glycine cleavage system | Nonketotic hyperglycinemia, cancer |
| GCSH | Glycine cleavage system H protein; lipoate-dependent | Nonketotic hyperglycinemia |
| AMT | Aminomethyltransferase; glycine cleavage system | Nonketotic hyperglycinemia |
| DLD | Dihydrolipoamide dehydrogenase; shared component of GCS | Metabolic disorders |
| AGXT | Alanine-glyoxylate aminotransferase; glyoxylate to glycine | Primary hyperoxaluria type 1 |
| GLYC | Glycine cleavage system protein (bacterial) | Microbial metabolism |
| GCVH | Glycine cleavage system H protein (plant/microbe) | Photorespiration |
| GDC | Glycine decarboxylase complex (plant) | Photorespiration |
| SHM1 | Serine hydroxymethyltransferase (plant) | Photorespiration |
| SHM2 | Serine hydroxymethyltransferase (plant) | Photorespiration |
| THT1 | Threonine aldolase; threonine to glycine | Microbial glycine synthesis |
| LTAE | Low-specificity threonine aldolase | Biotechnology |
| GCST | Glycine cleavage system T protein | One-carbon metabolism |
| GCSL | Glycine cleavage system L protein | One-carbon metabolism |
| GLYA | Serine hydroxymethyltransferase (E. coli) | Microbial genetics |
How Is glycine biosynthetic process Regulated?
Glycine biosynthetic process is regulated at multiple levels. In cancer, SHMT2 expression is induced by oncogenic signals and hypoxia, supporting glycine synthesis for redox homeostasis. The glycine cleavage system is regulated by its substrates and by transcriptional factors such as NF-κB. In skeletal muscle, glycine metabolism is influenced by nutritional status and exercise, with implications for metabolic homeostasis. Additionally, glycine conjugation capacity varies interindividually due to genetic polymorphisms in glycine N-acyltransferase, affecting drug detoxification.
glycine biosynthetic process and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SHMT2 | Cancer proliferation and redox balance | Cancer cell line KO/overexpression |
| AGXT | Primary hyperoxaluria type 1 | Hepatocyte KO or point mutation |
| GLDC | Nonketotic hyperglycinemia | Neuronal KO or knock-in |
| GCSH | Nonketotic hyperglycinemia | iPSC-derived neurons |
| AMT | Nonketotic hyperglycinemia | Mouse KO model |
Cancer metabolism
Many cancer cells upregulate glycine biosynthesis to support rapid proliferation, glutathione synthesis, and one-carbon metabolism. SHMT2 is often overexpressed in tumors and correlates with poor prognosis. Targeting glycine biosynthetic enzymes is a potential therapeutic strategy.
Primary hyperoxaluria
Deficiency of AGXT, which converts glyoxylate to glycine, leads to glyoxylate accumulation and oxalate overproduction, causing primary hyperoxaluria type 1. This highlights the importance of glycine biosynthesis in glyoxylate detoxification.
Nonketotic hyperglycinemia
Mutations in glycine cleavage system genes (GLDC, GCSH, AMT) cause nonketotic hyperglycinemia, a severe neurological disorder with elevated glycine levels. This demonstrates the critical role of glycine homeostasis in the nervous system.
Neurological disorders and glycine neurotransmission
Glycine is a major inhibitory neurotransmitter, and disruptions in glycine biosynthesis or transport can lead to hyperekplexia and other neurological conditions. The glycinergic synapse is essential for motor and sensory processing.
From glycine biosynthetic process-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does SHMT2 loss impair tumor growth? | SHMT2 knockout in cancer cell lines |
| Does a specific AGXT mutation cause hyperoxaluria? | AGXT point mutation knock-in in hepatocytes |
| Can glycine biosynthesis be redirected to produce a metabolite? | Knock-in of tagged SHMT1 |
| Does overexpression of GLDC alter glycine flux? | GLDC overexpression in neuronal cells |
| What is the role of GCSH in one-carbon metabolism? | GCSH knockout in iPSCs |
| Can microbial glycine production be enhanced? | Engineered E. coli with knockout/overexpression |
How to Study the glycine biosynthetic process Process
| Method | What It Measures | Typical Application |
|---|---|---|
| LC-MS metabolomics | Glycine and related metabolite levels | Cancer metabolism studies |
| 13C tracing | Flux from serine to glycine | One-carbon metabolism |
| CRISPR knockout screen | Gene essentiality for glycine synthesis | Cancer dependency maps |
| Enzyme activity assay | SHMT or GLDC catalytic activity | Mutation validation |
| RNA-seq | Expression of glycine biosynthetic genes | Transcriptional regulation |
| Proteomics | Protein abundance of pathway enzymes | Systems biology |
| Immunofluorescence | Subcellular localization of enzymes | Mitochondrial vs cytosolic |
Metabolomics and flux analysis
Mass spectrometry-based metabolomics and stable isotope tracing are used to measure glycine levels and flux through biosynthetic pathways. These methods quantify the contribution of serine, glyoxylate, and other precursors to glycine pools.
CRISPR screening
Genome-wide CRISPR knockout screens can identify genes essential for glycine biosynthesis and uncover synthetic lethal interactions. Such screens are powerful for discovering new regulators of GO:0006545.
Enzyme activity assays
In vitro enzymatic assays using recombinant SHMT, GLDC, or AGXT measure catalytic activity and kinetics. These assays help validate the functional impact of mutations.
Transcriptomics and proteomics
RNA-seq and proteomics reveal expression changes in glycine biosynthetic genes under different conditions, such as hypoxia or oncogenic transformation. These approaches identify regulatory mechanisms.
How CRISPR Can Be Used to Study GO:0006545 glycine biosynthetic process
Knockout
CRISPR knockout of SHMT2, GLDC, or AGXT can abolish specific glycine biosynthetic routes, enabling researchers to assess their contribution to cell growth, redox balance, and disease phenotypes. Knockout models are essential for causal inference.
Point Mutation
Introducing disease-associated point mutations (e.g., in AGXT or GLDC) via CRISPR base editing or HDR allows functional validation of variants identified in patients. These models mimic human genetic disorders.
Knock-in
Knock-in of tagged versions of SHMT1 or SHMT2 (e.g., FLAG or GFP) enables affinity purification and live-cell imaging to study localization and interactions. Knock-in of reporter cassettes can monitor pathway activity.
Overexpression
CRISPR activation (CRISPRa) or cDNA overexpression of glycine biosynthetic enzymes can model metabolic reprogramming in cancer and identify downstream effects. Overexpression studies complement loss-of-function approaches.
How EDITGENE Supports glycine biosynthetic process Research
Researchers studying glycine biosynthetic process-related genes often need to determine whether a candidate gene is causally involved in metabolic rewiring, disease progression, or therapeutic response. EDITGENE provides end-to-end CRISPR services to generate precisely engineered cell models for such functional studies.
Contact EDITGENE today to design your custom CRISPR model for glycine biosynthetic process research.
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SHMT2 Knockout HEK293 Cell Line | EDJ-KQ1040 | Human | 6472 | Details Get a Quote |
| HAO1 Knockout HEK293 Cell Line | EDJ-KQ2420 | Human | 54363 | Details Get a Quote |
| SHMT1 Knockout HEK293 Cell Line | EDJ-KQ2588 | Human | 6470 | Details Get a Quote |
| AGXT Knockout HEK293 Cell Line | EDJ-KQ4027 | Human | 189 | Details Get a Quote |
| AGXT2 Knockout HEK293 Cell Line | EDJ-KQ12316 | Human | 64902 | Details Get a Quote |
| SHMT2 Knockout A-549 Cell Line | EDJ-KQ20142 | Human | 6472 | Details Get a Quote |
| SHMT2 Knockout HCT 116 Cell Line | EDJ-KQ20143 | Human | 6472 | Details Get a Quote |
| SHMT2 Knockout HeLa Cell Line | EDJ-KQ20144 | Human | 6472 | Details Get a Quote |
| SHMT1 Knockout A-549 Cell Line | EDJ-KQ23275 | Human | 6470 | Details Get a Quote |
| SHMT1 Knockout HCT 116 Cell Line | EDJ-KQ23276 | Human | 6470 | Details Get a Quote |
| SHMT1 Knockout HeLa Cell Line | EDJ-KQ23277 | Human | 6470 | Details Get a Quote |
| SHMT1 Knockout PK-15 Cell Line | EDJ-KZ454 | Pig | 397181 | Details Get a Quote |
| Shmt2 Knockout C2C12 Cell Line | EDJ-KZ455 | Mouse | 108037 | Details Get a Quote |
| SHMT2 Knockout PK-15 Cell Line | EDJ-KZ456 | Pig | 6472 | Details Get a Quote |
| AGXT Knockout HeLa Cell Line | EDJ-KQ52583 | Human | 189 | Details Get a Quote |
Displaying Records 1 To 15 Of 23 Records
Frequently Asked Questions About glycine biosynthetic process
What is glycine biosynthetic process?
Glycine biosynthetic process (GO:0006545) is the set of chemical reactions and pathways that produce glycine, the simplest amino acid, from precursors such as serine, glyoxylate, or threonine.
What genes are involved in glycine biosynthetic process?
Key genes include SHMT1, SHMT2, GLDC, GCSH, AMT, DLD, and AGXT, among others [1, 4].
What is the GO ID for glycine biosynthetic process?
The Gene Ontology ID is GO:0006545.
Why is glycine biosynthesis important in cancer?
Cancer cells often upregulate glycine biosynthesis to support proliferation, redox balance, and one-carbon metabolism.
How is glycine biosynthesized from serine?
Serine hydroxymethyltransferase (SHMT) converts serine to glycine while transferring a one-carbon unit to tetrahydrofolate.
What diseases are linked to defects in glycine biosynthesis?
Primary hyperoxaluria, nonketotic hyperglycinemia, and certain cancers are linked to defects in glycine biosynthetic enzymes [1, 8].
Can glycine be produced industrially by microbes?
Yes, engineered microbial strains can produce glycine from glucose via two-stage biosynthetic strategies.
What is the role of glycine in neurotransmission?
Glycine acts as an inhibitory neurotransmitter in the spinal cord and brainstem, and its biosynthesis is essential for maintaining synaptic glycine pools.
How can CRISPR be used to study glycine biosynthesis?
CRISPR knockout, point mutation, knock-in, and overexpression models allow causal dissection of glycine biosynthetic genes in various cell types.
What methods measure glycine biosynthetic flux?
Stable isotope tracing with 13C-serine and LC-MS metabolomics are commonly used to measure glycine synthesis flux.
Conclusion
Glycine biosynthetic process (GO:0006545) is a fundamental metabolic pathway with far-reaching implications for cancer, neurobiology, and metabolic disorders. The integration of CRISPR-based genetic models with metabolomics and flux analysis is accelerating our understanding of how glycine synthesis is regulated and how it can be targeted therapeutically. EDITGENE's comprehensive CRISPR services empower researchers to dissect this pathway with precision and reproducibility.
References
- 1. Amelio I et al.. 2014. Serine and glycine metabolism in cancer.. Trends Biochem Sci 39(4):191-8 PMID: 24657017
- 3. Chen L et al.. 2026. Efficient production of glycine from glucose via a two-stage biosynthetic strategy.. Microb Cell Fact 25(1) PMID: 41803809
- 4. Andreesen JR. 1994. Glycine metabolism in anaerobes.. Antonie Van Leeuwenhoek 66(1-3):223-37 PMID: 7747933
- 5. Legendre P. 2001. The glycinergic inhibitory synapse.. Cell Mol Life Sci 58(5-6):760-93 PMID: 11437237
- 6. Koopman R et al.. 2017. Glycine metabolism in skeletal muscle: implications for metabolic homeostasis.. Curr Opin Clin Nutr Metab Care 20(4):237-242 PMID: 28375879
- 8. Badenhorst CP et al.. 2013. Glycine conjugation: importance in metabolism, the role of glycine N-acyltransferase, and factors that influence interindividual variation.. Expert Opin Drug Metab Toxicol 9(9):1139-53 PMID: 23650932
