GO:0070179 D-serine biosynthetic process: Neurotransmitter Synthesis Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0070179 describes the biochemical formation of D-serine, the D-enantiomer of serine, which in mammals occurs mainly through racemization of L-serine by serine racemase.
• D-serine is a co-agonist of the NMDA receptor and is essential for synaptic plasticity, learning, and memory.
• Astrocytic L-serine production feeds D-serine synthesis, and impairment of this pathway contributes to cognitive deficits in Alzheimer's disease models.
• D-serine biosynthetic enzymes are expressed in peripheral tissues as well as the brain, where they influence immune and metabolic functions.
• Recent work shows that D-serine levels are sensitive to sleep deprivation and modulate intestinal reactive oxygen species accumulation.
• CRISPR knockout, point-mutation, and knock-in models are powerful tools to dissect the causal roles of D-serine biosynthetic genes in health and disease.
Description
D-serine biosynthetic process (GO:0070179) is the set of chemical reactions and pathways that produce D-serine, the D-enantiomer of the amino acid serine. In mammals, the predominant route is the racemization of L-serine to D-serine, catalyzed by serine racemase (SRR). This process is critical because D-serine serves as an endogenous co-agonist of the N-methyl-D-aspartate (NMDA) receptor, a key mediator of synaptic plasticity and excitotoxicity. Beyond the central nervous system, D-serine is also synthesized in peripheral tissues, where it participates in immune regulation and metabolic signaling. Recent studies have linked D-serine biosynthesis to sleep deprivation-induced intestinal oxidative stress, highlighting its broader physiological relevance. Understanding the molecular players and regulatory mechanisms of D-serine biosynthesis is therefore essential for researchers in neuroscience, immunology, and metabolism.
D-serine biosynthetic process At A Glance
| GO ID | GO:0070179 |
|---|---|
| GO term | D-serine biosynthetic process |
| Ontology | biological_process |
| Synonym | D-serine anabolism; D-serine biosynthesis; D-serine formation; D-serine synthesis |
| Major function | Production of D-serine, a co-agonist of NMDA receptors and a signaling molecule in peripheral tissues |
| Key enzyme | Serine racemase (SRR) catalyzes the racemization of L-serine to D-serine |
| Substrate | L-serine |
| Product | D-serine |
| Cofactors | Pyridoxal 5'-phosphate (PLP) is required by serine racemase |
What Is GO:0070179?
GO:0070179, D-serine biosynthetic process, is defined as the chemical reactions and pathways resulting in the formation of D-serine, the D-enantiomer of serine, i.e. (2R)-2-amino-3-hydroxypropanoic acid. D-serine is often formed by racemization of L-serine. This biological process encompasses the enzymatic conversion of L-serine to D-serine, primarily via serine racemase, as well as any alternative biosynthetic routes that generate D-serine from other precursors.
Why Is D-serine biosynthetic process Important in Cell Biology?
D-serine biosynthesis is essential for normal brain function because D-serine is a mandatory co-agonist at the NMDA receptor glycine site, and its availability directly controls NMDA receptor activity, synaptic plasticity, and cognitive processes. Dysregulation of D-serine production has been implicated in neuropsychiatric and neurodegenerative disorders, including Alzheimer's disease, where impaired astrocytic L-serine supply leads to reduced D-serine and cognitive deficits. Moreover, D-serine synthesized in peripheral tissues influences immune responses and intestinal homeostasis, as shown by its role in sleep deprivation-induced ROS accumulation. Thus, understanding GO:0070179 is crucial for developing therapeutic strategies targeting NMDA receptor hypofunction and related pathologies.
• D-serine is a co-agonist of the NMDA receptor, which is central to synaptic plasticity and memory formation.
• Impaired D-serine biosynthesis contributes to cognitive decline in Alzheimer's disease models.
• D-serine levels are modulated by sleep and affect intestinal ROS accumulation, linking the pathway to gut physiology.
• Peripheral D-serine plays roles in immune regulation and tissue homeostasis.
• Serine racemase, the key enzyme, is a potential drug target for schizophrenia and cognitive disorders.
• D-serine biosynthetic enzymes are expressed in astrocytes, neurons, and peripheral tissues, indicating broad physiological importance.
• Alterations in D-serine metabolism have been observed in aging and neurodegenerative conditions.
• The pathway intersects with glycolysis and one-carbon metabolism, influencing cellular redox and methylation.
• D-serine dehydratase activity of serine hydroxymethyltransferases can degrade D-serine, adding another layer of regulation.
• CRISPR-based editing of SRR and related genes enables precise dissection of D-serine functions in vivo.
What Happens During D-serine biosynthetic process?
L-serine availability and transport
In simple terms: The cell must first have enough L-serine, the starting material for making D-serine.
D-serine biosynthesis depends on the availability of L-serine, which is synthesized from glycolytic intermediates or taken up from the extracellular space. In astrocytes, L-serine production is tightly linked to glycolysis, and impairment of this supply reduces D-serine levels, contributing to cognitive deficits in Alzheimer's disease models. A lactate-dependent shift in glycolysis can also influence serine metabolism and synaptic processes.
Racemization of L-serine to D-serine
In simple terms: An enzyme called serine racemase flips L-serine into its mirror-image form, D-serine.
The central step in D-serine biosynthesis is the racemization of L-serine to D-serine, catalyzed by serine racemase (SRR). This pyridoxal 5'-phosphate (PLP)-dependent enzyme is expressed in astrocytes and neurons and is the principal source of D-serine in the mammalian brain. The reaction is reversible, but under physiological conditions it favors D-serine formation to supply the NMDA receptor co-agonist pool.
Alternative routes and degradation
In simple terms: D-serine can also be made or broken down by other enzymes, keeping its levels balanced.
Beyond serine racemase, D-serine can be produced by other pathways, and its degradation is mediated by D-amino acid oxidase (DAAO) and by a recently discovered tetrahydrofolate-dependent D-serine dehydratase activity of serine hydroxymethyltransferases (SHMTs). This alternative catabolic route highlights the interplay between D-serine biosynthesis and one-carbon metabolism.
Compartmentalization and release
In simple terms: D-serine is made in specific cells and then released to act on nearby neurons.
D-serine is synthesized primarily in astrocytes, which are positioned to support neuronal NMDA receptor function. After synthesis, D-serine is released into the synaptic cleft, where it acts as a co-agonist at the NMDA receptor glycine site. The journey of D-serine between astrocytes and synapses is dynamically regulated and essential for synaptic transmission.
Key Genes Involved in GO:0070179 D-serine biosynthetic process
The following genes and proteins are experimentally implicated in D-serine biosynthetic process and its regulation.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SRR | Serine racemase; converts L-serine to D-serine | Central enzyme of the pathway; knockout models show reduced D-serine and NMDA receptor hypofunction |
| DAO | D-amino acid oxidase; degrades D-serine | Regulates D-serine levels; polymorphisms linked to schizophrenia |
| SHMT1 | Serine hydroxymethyltransferase 1; can degrade D-serine via dehydratase activity | Connects D-serine catabolism to one-carbon metabolism |
| SHMT2 | Serine hydroxymethyltransferase 2; mitochondrial isoform with D-serine dehydratase activity | Potential regulator of D-serine in mitochondria |
| PHGDH | Phosphoglycerate dehydrogenase; first step of L-serine synthesis | Provides L-serine for D-serine production; implicated in Alzheimer's disease |
| PSAT1 | Phosphoserine aminotransferase; L-serine synthesis | Supports L-serine supply for D-serine biosynthesis |
| PSPH | Phosphoserine phosphatase; L-serine synthesis | Contributes to L-serine pool |
| GOT1 | Glutamate oxaloacetate transaminase 1; links metabolism to serine synthesis | May influence L-serine availability |
| GOT2 | Glutamate oxaloacetate transaminase 2; mitochondrial | Supports metabolic flux for serine synthesis |
| LDHA | Lactate dehydrogenase A; lactate-dependent shift of glycolysis | Modulates glycolytic flux affecting serine synthesis |
| SLC1A4 | Glutamate transporter; may influence synaptic D-serine | Indirectly affects D-serine signaling |
| GRIN1 | NMDA receptor subunit 1; target of D-serine | D-serine is a co-agonist; receptor activity depends on D-serine |
| GRIN2A | NMDA receptor subunit 2A; binds D-serine | D-serine modulates receptor function |
| GRIN2B | NMDA receptor subunit 2B; binds D-serine | D-serine modulates receptor function |
| GLS | Glutaminase; provides glutamate for NMDA receptor | Indirectly affects D-serine signaling |
| SLC7A11 | Cystine/glutamate antiporter; affects redox and D-serine | Links D-serine to oxidative stress |
| NOS1 | Neuronal nitric oxide synthase; downstream of NMDA receptor | D-serine influences NO signaling |
| CAMK2A | Calcium/calmodulin-dependent protein kinase II; downstream of NMDA receptor | D-serine modulates synaptic plasticity via CaMKII |
How Is D-serine biosynthetic process Regulated?
D-serine biosynthesis is regulated at multiple levels. The expression and activity of serine racemase (SRR) are modulated by factors such as glutamate, growth factors, and inflammatory cytokines. In astrocytes, L-serine supply from glycolysis is a rate-limiting factor, and a lactate-dependent shift in glycolysis can alter serine metabolism and synaptic function. Additionally, D-serine degradation by D-amino acid oxidase (DAAO) and by the D-serine dehydratase activity of serine hydroxymethyltransferases (SHMTs) provides a counterbalance, influencing steady-state D-serine levels. Sleep deprivation has been shown to affect D-serine levels and intestinal ROS accumulation, indicating systemic regulation. The pathway is also influenced by the metabolic state of the cell, including one-carbon metabolism and redox balance.
D-serine biosynthetic process and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SRR | Schizophrenia, cognitive deficits | SRR knockout mouse; point mutation of catalytic residue |
| PHGDH | Alzheimer's disease, serine deficiency | Astrocyte-specific PHGDH knockout; knock-in of patient mutations |
| DAO | Schizophrenia, D-serine levels | DAO knockout; overexpression of DAO |
| SHMT1/2 | One-carbon metabolism, D-serine catabolism | SHMT1/2 knockout; point mutation of dehydratase active site |
| SLC7A11 | Oxidative stress, sleep deprivation | SLC7A11 knockout; overexpression in intestinal cells |
Alzheimer's disease
Impairment of glycolysis-derived L-serine production in astrocytes reduces D-serine synthesis and contributes to cognitive deficits in Alzheimer's disease models. This suggests that boosting D-serine biosynthesis could be a therapeutic strategy.
Schizophrenia
D-serine is a co-agonist of the NMDA receptor, and NMDA receptor hypofunction is a leading hypothesis for schizophrenia. Alterations in serine racemase and D-amino acid oxidase activity have been linked to the disorder.
Sleep deprivation and intestinal oxidative stress
Sleep deprivation leads to intestinal ROS accumulation, and D-serine plays a role in this process, linking D-serine biosynthesis to gut redox homeostasis.
Peripheral inflammatory diseases
D-serine is synthesized in peripheral tissues and modulates immune responses, suggesting a role in inflammatory conditions.
From D-serine biosynthetic process-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does SRR knockout reduce D-serine and impair NMDA receptor function? | SRR knockout mouse or human iPSC-derived astrocytes |
| Does a point mutation in SRR catalytic site abolish racemase activity? | CRISPR point mutation knock-in of SRR active-site residue |
| Can knock-in of a disease-associated PHGDH variant recapitulate Alzheimer's phenotypes? | PHGDH knock-in mouse or cell model |
| Does overexpression of DAO lower D-serine and affect behavior? | DAO overexpression transgenic mouse |
| What is the role of SHMT2 D-serine dehydratase activity in vivo? | SHMT2 knockout and point mutation models |
| Does D-serine biosynthesis regulate intestinal ROS after sleep deprivation? | Intestinal epithelial cell-specific SRR knockout |
How to Study the D-serine biosynthetic process Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Expression of D-serine biosynthetic genes | Tissue-specific and disease-related expression profiling |
| LC-MS/MS metabolomics | D-serine and L-serine concentrations | Quantification in brain, plasma, and peripheral tissues |
| Stable isotope tracing | Flux from glucose/L-serine to D-serine | Metabolic pathway activity |
| Enzyme activity assay | Serine racemase and SHMT dehydratase activity | Functional characterization of variants |
| D-serine biosensor imaging | Real-time D-serine release | Synaptic D-serine dynamics |
| Electrophysiology | NMDA receptor currents | Functional impact of D-serine levels |
| CRISPR screening | Genes required for D-serine production | Unbiased discovery of pathway regulators |
Genomic and transcriptomic profiling
RNA-seq and single-cell RNA-seq can quantify expression of D-serine biosynthetic genes (SRR, PHGDH, PSAT1, PSPH, SHMT1/2) across tissues and cell types, revealing cell-type-specific contributions.
Metabolomics and flux analysis
Targeted metabolomics using mass spectrometry can measure D-serine and L-serine levels, while stable isotope tracing can quantify flux through the biosynthetic pathway.
Enzymatic activity assays
Recombinant serine racemase and SHMT proteins can be assayed for racemase and dehydratase activities using chiral chromatography or coupled enzymatic assays.
Imaging and electrophysiology
D-serine biosensors and electrophysiological recordings of NMDA receptor currents can assess real-time D-serine dynamics and synaptic function.
How CRISPR Can Be Used to Study GO:0070179 D-serine biosynthetic process
Knockout
CRISPR knockout of SRR, PHGDH, or SHMT1/2 can abolish or reduce D-serine biosynthesis, enabling studies of its role in NMDA receptor function, cognition, and peripheral physiology.
Point Mutation
Point mutations in the catalytic residues of serine racemase (e.g., lysine 56) or in SHMT dehydratase active sites can dissect enzymatic mechanisms and separate racemase from dehydratase activities.
Knock-in
Knock-in of disease-associated variants (e.g., PHGDH mutations) or tagged versions of SRR (e.g., HA-tag) allows tracking of protein localization and function in vivo.
Overexpression
Overexpression of SRR or DAO can elevate or deplete D-serine levels, respectively, providing gain-of-function models to study D-serine's impact on synaptic plasticity and behavior.
How EDITGENE Supports D-serine biosynthetic process Research
Researchers studying D-serine biosynthetic process-related genes often need to determine whether a candidate gene is causally involved in D-serine production, NMDA receptor function, or related diseases. EDITGENE provides end-to-end CRISPR services to generate precisely engineered cell and animal models, enabling rigorous functional validation.
Contact EDITGENE today to design your custom CRISPR model for D-serine biosynthetic process research.
Frequently Asked Questions About D-serine biosynthetic process
What is D-serine biosynthetic process?
D-serine biosynthetic process (GO:0070179) is the set of biochemical reactions that produce D-serine, primarily through the racemization of L-serine by serine racemase.
What genes are involved in D-serine biosynthetic process?
Key genes include SRR (serine racemase), PHGDH, PSAT1, PSPH (L-serine synthesis), and SHMT1/2 (D-serine catabolism).
Why is D-serine important for the brain?
D-serine is a co-agonist of the NMDA receptor, which is essential for synaptic plasticity, learning, and memory.
How is D-serine synthesized?
D-serine is mainly synthesized from L-serine by serine racemase, a pyridoxal 5'-phosphate-dependent enzyme.
What diseases are linked to D-serine biosynthesis?
Alzheimer's disease, schizophrenia, and sleep deprivation-induced intestinal oxidative stress have been linked to altered D-serine biosynthesis.
Can CRISPR be used to study D-serine biosynthesis?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models enable precise dissection of D-serine pathway genes.
What is the role of serine racemase in D-serine production?
Serine racemase catalyzes the conversion of L-serine to D-serine and is the principal enzyme for D-serine biosynthesis in mammals.
How is D-serine degraded?
D-serine is degraded by D-amino acid oxidase (DAAO) and by the D-serine dehydratase activity of serine hydroxymethyltransferases.
Is D-serine produced outside the brain?
Yes, D-serine is synthesized in peripheral tissues, where it plays roles in immune regulation and metabolism.
What methods are used to measure D-serine biosynthesis?
LC-MS/MS metabolomics, stable isotope tracing, enzyme activity assays, and D-serine biosensors are commonly used.
Conclusion
D-serine biosynthetic process (GO:0070179) is a fundamental metabolic pathway that supplies the NMDA receptor co-agonist D-serine, with critical roles in synaptic plasticity, cognition, and peripheral physiology. Dysregulation of this pathway is implicated in Alzheimer's disease, schizophrenia, and sleep-related oxidative stress. CRISPR-based models are invaluable for dissecting the causal roles of SRR, PHGDH, SHMT1/2, and other genes in D-serine production and related pathologies. EDITGENE offers comprehensive CRISPR services to accelerate research on this pathway and its therapeutic potential.
References
- 1. Zheng F et al.. 2025. Role of d-serine in intestinal ROS accumulation after sleep deprivation.. Sci Adv 11(29):eadr8592 PMID: 40680136
- 2. Le Douce J et al.. 2020. Impairment of Glycolysis-Derived l-Serine Production in Astrocytes Contributes to Cognitive Deficits in Alzheimer's Disease.. Cell Metab 31(3):503-517.e8 PMID: 32130882
- 3. Wolosker H. 2018. The Neurobiology of d-Serine Signaling.. Adv Pharmacol 82:325-348 PMID: 29413526
- 4. Fernández-Moncada I et al.. 2024. A lactate-dependent shift of glycolysis mediates synaptic and cognitive processes in male mice.. Nat Commun 15(1):6842 PMID: 39122700
- 5. Mountadem S et al.. 2025. D-Serine's Journey Between Stars and Synapses.. Neurochem Res 50(5):327 PMID: 41085755
- 6. Coyle JT et al.. 2020. D-Serine, the Shape-Shifting NMDA Receptor Co-agonist.. Neurochem Res 45(6):1344-1353 PMID: 32189130
- 7. Miyamoto T et al.. 2024. Novel tetrahydrofolate-dependent d-serine dehydratase activity of serine hydroxymethyltransferases.. FEBS J 291(2):308-322 PMID: 37700610
- 8. Montesinos Guevara C et al.. 2016. The role of D-serine in peripheral tissues.. Eur J Pharmacol 780:216-23 PMID: 27038518
