GO:0070905 serine binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0070905 serine binding is a molecular function defined as binding to 2-amino-3-hydroxypropanoic acid (serine) [QuickGO].
• Serine binding is stereospecific: D-serine and L-serine interact with distinct protein targets, including NMDA receptor subunits and GluD2 [1,6].
• D-serine binding to NMDA receptors is a key co-agonist mechanism in excitatory neurotransmission and is implicated in Alzheimer's disease [1,7].
• Serine phosphorylation and serine mutations can alter protein-protein interactions, transporter function, and metal binding [2,5,8].
• Serine binding proteins are studied using radioligand binding, electrophysiology, mutagenesis, and structural biology [4,6,8].
• CRISPR knockout, point mutation, and knock-in models enable causal testing of serine-binding residues in disease-relevant genes.
Description
Serine binding (GO:0070905) is a molecular function that describes the selective interaction of a protein or biomolecule with serine, a chiral amino acid with the chemical formula 2-amino-3-hydroxypropanoic acid. This function is central to many biological processes, including neurotransmission, cell adhesion, and metabolic regulation. The stereochemistry of serine matters: D-serine and L-serine often bind different targets with distinct affinities and functional consequences [1,6]. For researchers, GO:0070905 provides a precise annotation for proteins that directly recognize serine, enabling functional enrichment and pathway analysis in genomics and proteomics studies. Serine binding is experimentally tractable and disease-relevant. For example, D-serine binding to the NMDA receptor is a co-agonist mechanism in synaptic plasticity, and altered D-serine levels are associated with Alzheimer's disease pathology [1,7]. Serine phosphorylation of L-selectin regulates ERM protein binding and monocyte migration, illustrating how serine modifications can create or disrupt binding interfaces. Additionally, mutations that substitute serine for cysteine in Cu(I)-binding proteins alter metal coordination and protein stability, highlighting the broader impact of serine in protein chemistry. Understanding serine binding at the molecular level informs drug discovery, biomarker development, and the design of CRISPR-based disease models.
serine binding At A Glance
| GO ID | GO:0070905 |
|---|---|
| GO term | serine binding |
| Ontology | molecular_function |
| Synonym | Ser binding |
| Definition | Binding to 2-amino-3-hydroxypropanoic acid. |
| Major function | Selective recognition of serine, often stereospecific, in neurotransmission, cell adhesion, and metabolism. |
| Related molecules | D-serine, L-serine, NMDA receptor subunits, GluD2, L-selectin, Cu(I)-binding proteins. |
| Experimental detection | Radioligand binding assays, electrophysiology, mutagenesis, structural biology. |
What Is GO:0070905?
According to the Gene Ontology, serine binding (GO:0070905) is the molecular function of binding to 2-amino-3-hydroxypropanoic acid, the amino acid serine. This term encompasses non-covalent and, in some contexts, covalent interactions with serine or serine-containing ligands, as long as the binding event is the primary function. It does not describe catalytic modification of serine (e.g., phosphorylation) unless binding is the annotated activity.
Why Is serine binding Important in Cell Biology?
Serine binding is important because serine is a ubiquitous amino acid that serves as a building block for proteins and as a signaling molecule. In the brain, D-serine binding to NMDA receptors modulates synaptic plasticity, learning, and memory, and its dysregulation is linked to Alzheimer's disease and other neurological disorders [1,7]. In immunology, serine phosphorylation of L-selectin creates binding sites for ERM proteins, controlling leukocyte migration. In biotechnology, understanding serine binding informs protein engineering and drug design. Moreover, serine mutations can alter transporter function and metal binding, with implications for pharmacology and toxicology [5,8].
• D-serine binding to NMDA receptors is a co-agonist mechanism essential for excitatory neurotransmission.
• Altered D-serine levels and binding are observed in Alzheimer's disease brains.
• Serine phosphorylation of L-selectin regulates ERM binding and monocyte protrusion during transendothelial migration.
• Cysteine-to-serine mutations affect Cu(I)-binding protein structure and function.
• Serine mutations in transmembrane domain 7 of the human norepinephrine transporter alter substrate binding and transport.
• D-serine binding affinity at GluD2 is influenced by the hinge region, affecting receptor function.
• Serine binding is a target for drug discovery in neuropsychiatric and neurodegenerative diseases [1,7].
• Radioligand binding assays with D-[3H]serine are used to quantify serine binding in brain regions.
• Acyl-CoA binding protein regulates autophagy, and serine metabolism intersects with nutrient sensing.
• CRISPR-based models can dissect the contribution of specific serine-binding residues to disease phenotypes.
What Happens During serine binding?
Ligand recognition and stereospecificity
In simple terms: Proteins distinguish between D-serine and L-serine based on their shape.
Serine binding often exhibits stereospecificity. For example, D-serine binds to the NMDA receptor at the glycine site, acting as a co-agonist, while L-serine has lower affinity at this site. The GluD2 receptor shows low binding affinity for D-serine due to its hinge region, demonstrating that small structural differences control ligand recognition.
Conformational changes and signal initiation
In simple terms: Binding of serine can change a protein's shape and trigger a cellular signal.
Upon D-serine binding, the NMDA receptor undergoes conformational changes that open the ion channel, allowing Ca2+ influx and downstream signaling. Similarly, serine phosphorylation of L-selectin induces a conformational change that exposes ERM-binding motifs, leading to clustering and monocyte protrusion.
Modulation by post-translational modifications
In simple terms: Chemical tags on proteins can strengthen or weaken serine binding.
Phosphorylation of serine residues can create docking sites for binding partners. In L-selectin, phosphorylation of serine residues within the cytoplasmic tail regulates ERM binding and cell migration. Conversely, mutations that replace cysteine with serine can disrupt metal binding in Cu(I)-binding proteins, altering their function.
Physiological outcomes of serine binding
In simple terms: Serine binding leads to effects like nerve signaling, immune cell movement, and metabolic changes.
D-serine binding to NMDA receptors modulates synaptic plasticity and is implicated in Alzheimer's disease; reduced D-serine levels correlate with cognitive decline. In the immune system, serine-dependent L-selectin binding to ERM proteins is required for monocyte transmigration across endothelial layers. In metabolism, acyl-CoA binding protein regulates autophagy in a nutrient-dependent manner, and serine availability can influence this process.
Key Genes Involved in GO:0070905 serine binding
The following genes encode proteins with experimentally demonstrated serine binding or serine-dependent functions.
| Gene | Major Role | Research Relevance |
|---|---|---|
| GRIN1 | NMDA receptor subunit; binds D-serine as co-agonist | Neurotransmission, Alzheimer's disease [1,7] |
| GRIN2A | NMDA receptor subunit; contributes to D-serine binding site | Synaptic plasticity, neuropsychiatric disorders |
| GRIN2B | NMDA receptor subunit; modulates D-serine affinity | Learning, memory, neurodegeneration |
| GRID2 | GluD2 receptor; binds D-serine with low affinity | Cerebellar function, hinge region determines affinity |
| SELL | L-selectin; serine phosphorylation regulates ERM binding | Monocyte migration, inflammation |
| EZR | Ezrin; binds phosphorylated L-selectin | Cell adhesion, migration |
| RDX | Radixin; ERM protein binding to L-selectin | Leukocyte extravasation |
| MSN | Moesin; ERM protein involved in L-selectin clustering | Immune cell protrusion |
| DBI | Acyl-CoA binding protein; regulates autophagy | Nutrient sensing, metabolism |
| SLC6A2 | Norepinephrine transporter; serine mutations affect substrate binding | Neurotransmitter transport, drug response |
| ATOX1 | Cu(I)-binding protein; cysteine-to-serine mutations alter function | Copper homeostasis, metal trafficking |
| SOD1 | Cu/Zn superoxide dismutase; serine mutations can affect metal binding | Amyotrophic lateral sclerosis |
| SLC1A1 | Glutamate transporter; serine residues influence substrate recognition | Excitatory amino acid transport |
| SLC1A2 | Glutamate transporter; serine binding motifs | Synaptic clearance |
| SLC1A3 | Glutamate transporter; serine-dependent regulation | Neurotransmission |
| SLC6A4 | Serotonin transporter; serine mutations affect binding | Depression, anxiety |
| SLC6A3 | Dopamine transporter; serine residues in binding pocket | Addiction, Parkinson's disease |
How Is serine binding Regulated?
Serine binding can be regulated at multiple levels. The availability of D-serine is controlled by serine racemase and D-amino acid oxidase, which influence NMDA receptor co-agonism [1,7]. In L-selectin, serine phosphorylation by kinases such as PKC regulates ERM binding and monocyte migration. Nutrient status, such as glucose availability, modulates acyl-CoA binding protein and autophagy, indirectly affecting serine metabolism. Additionally, mutations that alter serine residues in transporters can change substrate binding and transport kinetics.
serine binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| GRIN1 | Alzheimer's disease, schizophrenia | Knock-in mice with point mutations in D-serine binding site |
| GRID2 | Cerebellar ataxia | Knockout and point-mutation models in mice |
| SELL | Chronic inflammation | Knock-in mice with serine-to-alanine mutations |
| SLC6A2 | Orthostatic intolerance, depression | Point-mutation cell lines and knockout mice |
| ATOX1 | Copper metabolism disorders | Knockout and cysteine-to-serine knock-in cells |
Alzheimer's disease and D-serine dysregulation
D-serine binding to NMDA receptors is critical for synaptic plasticity, and altered D-serine levels are observed in Alzheimer's disease brains. Dynamic changes in D-serine content may contribute to excitotoxicity and cognitive decline. Targeting D-serine binding sites could offer therapeutic strategies.
Neuropsychiatric and neurodegenerative disorders
NMDA receptor hypofunction, often linked to D-serine binding deficits, is implicated in schizophrenia and mood disorders. GluD2, which binds D-serine with low affinity, is involved in cerebellar ataxia and motor coordination.
Inflammatory and immune disorders
Serine phosphorylation of L-selectin regulates ERM binding and monocyte protrusion, a key step in inflammation. Dysregulation of this process contributes to chronic inflammatory diseases.
Metal metabolism and toxicity
Cysteine-to-serine mutations in Cu(I)-binding proteins alter metal coordination, affecting copper homeostasis and potentially leading to Wilson's disease or Menkes disease.
From serine binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does D-serine binding to NMDA receptors modulate synaptic plasticity? | Knockout mice lacking GRIN1 or GRIN2B |
| How does serine phosphorylation of L-selectin affect monocyte migration? | Point-mutation knock-in mice with serine-to-alanine substitutions |
| What is the role of the GluD2 hinge region in D-serine affinity? | Knock-in mice with hinge-region mutations |
| Do cysteine-to-serine mutations in ATOX1 alter copper trafficking? | Overexpression cell lines and knockout models |
| How do serine mutations in SLC6A2 affect norepinephrine transport? | Point-mutation knock-in cell lines |
| Can CRISPR screening identify novel serine-binding proteins? | Genome-wide CRISPR knockout library in neuronal cells |
How to Study the serine binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Radioligand binding | Affinity and density of serine binding sites | Brain region analysis |
| Patch-clamp electrophysiology | Ion channel currents upon serine binding | NMDA receptor function |
| Site-directed mutagenesis | Effect of specific residues on serine binding | GluD2 hinge region |
| X-ray crystallography | 3D structure of serine-protein complexes | Structural basis of binding |
| CRISPR knockout screening | Genes required for serine binding | Novel target discovery |
| Affinity proteomics | Serine-interacting proteins | Complex identification |
| Phospho-specific antibodies | Serine phosphorylation status | L-selectin signaling |
| Transport assays | Substrate uptake upon serine mutations | SLC6A2 function |
Radioligand binding assays
Radioligand binding with D-[3H]serine is used to quantify serine binding sites in brain regions and cell membranes. This method measures affinity, density, and stereospecificity of serine binding.
Electrophysiology
Patch-clamp recordings assess the functional impact of D-serine binding on NMDA receptor currents and synaptic transmission. This method links binding events to ion channel activity.
Mutagenesis and structural biology
Site-directed mutagenesis of serine-binding residues combined with X-ray crystallography or cryo-EM reveals the structural basis of serine recognition [6,8]. For example, hinge region mutations in GluD2 reduce D-serine affinity.
CRISPR screening and proteomics
Genome-wide CRISPR knockout screens coupled with mass spectrometry can identify novel serine-binding proteins and pathways. Proteomic profiling of serine-bound complexes using affinity purification is also valuable.
How CRISPR Can Be Used to Study GO:0070905 serine binding
Knockout
CRISPR knockout of genes encoding serine-binding proteins, such as GRIN1 or SELL, can abolish serine binding and reveal downstream phenotypes. For example, GRIN1 knockout mice lack NMDA receptor function and show impaired synaptic plasticity.
Point Mutation
Point mutations that substitute serine-binding residues (e.g., serine to alanine) can selectively disrupt binding without eliminating protein expression. This approach is used to study L-selectin phosphorylation sites and transporter serine residues.
Knock-in
Knock-in of disease-associated serine mutations, such as cysteine-to-serine in ATOX1, creates isogenic models to study metal binding and trafficking. Knock-in of D-serine binding site mutations in GRIN2B can model neuropsychiatric disorders.
Overexpression
Overexpression of serine-binding proteins, such as GluD2 or L-selectin, in cell lines allows biochemical characterization of binding affinity and downstream signaling [6,2].
How EDITGENE Supports serine binding Research
Researchers studying serine binding-related genes often need to determine whether a candidate gene is causally involved in a specific biological process or disease. CRISPR-based models provide a precise way to test the function of serine-binding residues and domains.
Contact EDITGENE today to design your custom CRISPR model for serine binding research.
Frequently Asked Questions About serine binding
What is serine binding?
Serine binding is a molecular function (GO:0070905) defined as binding to 2-amino-3-hydroxypropanoic acid, the amino acid serine.
What genes are involved in serine binding?
Genes such as GRIN1, GRIN2A, GRIN2B, GRID2, SELL, and SLC6A2 encode proteins that bind serine or are regulated by serine binding [1,2,6,8].
How is serine binding studied?
Common methods include radioligand binding assays, electrophysiology, mutagenesis, and structural biology [1,4,6].
What is the role of D-serine binding in the brain?
D-serine binding to NMDA receptors acts as a co-agonist, modulating synaptic plasticity and excitatory neurotransmission.
Is serine binding involved in Alzheimer's disease?
Yes, altered D-serine levels and binding are observed in Alzheimer's disease brains and may contribute to cognitive decline.
What is the difference between D-serine and L-serine binding?
D-serine and L-serine are stereoisomers that can bind different targets with distinct affinities; for example, D-serine is a co-agonist at NMDA receptors.
Can CRISPR be used to study serine binding?
Yes, CRISPR knockout, point mutation, and knock-in models can disrupt or modify serine-binding residues to study function.
What diseases are linked to serine binding?
Alzheimer's disease, schizophrenia, cerebellar ataxia, and inflammatory disorders have been linked to serine binding proteins [1,2,6,7].
How does serine phosphorylation affect binding?
Serine phosphorylation can create or disrupt binding sites, as seen in L-selectin regulation of ERM binding.
What is the GO term for serine binding?
The Gene Ontology term for serine binding is GO:0070905, under molecular_function.
Conclusion
Serine binding (GO:0070905) is a fundamental molecular function with broad implications in neuroscience, immunology, and metabolism. D-serine binding to NMDA receptors is a key co-agonist mechanism in synaptic plasticity, and its dysregulation is linked to Alzheimer's disease and other neurological disorders [1,7]. Serine phosphorylation of L-selectin regulates immune cell migration, while serine mutations in transporters and metal-binding proteins alter function [2,5,8]. Advances in CRISPR-based models and structural biology continue to unravel the precise roles of serine binding in health and disease. Targeting serine binding sites holds therapeutic potential for a range of conditions.
References
- 1. Yovanno RA et al.. 2022. Excitatory and inhibitory D-serine binding to the NMDA receptor.. Elife 11 PMID: 36301074
- 2. Newe A et al.. 2019. Serine Phosphorylation of L-Selectin Regulates ERM Binding, Clustering, and Monocyte Protrusion in Transendothelial Migration.. Front Immunol 10:2227 PMID: 31608057
- 3. Udupa P et al.. 2023. Acyl-CoA binding protein regulates nutrient-dependent autophagy.. Metabolism 145:155338 PMID: 36280213
- 4. Nagata Y et al.. 1998. D-serine content and D-[3H]serine binding in the brain regions of the senescence-accelerated mouse.. Mech Ageing Dev 104(2):115-24 PMID: 9792190
- 5. Pavlin M et al.. 2019. Unraveling the Impact of Cysteine-to-Serine Mutations on the Structural and Functional Properties of Cu(I)-Binding Proteins.. Int J Mol Sci 20(14) PMID: 31337158
- 6. Tapken D et al.. 2017. The low binding affinity of D-serine at the ionotropic glutamate receptor GluD2 can be attributed to the hinge region.. Sci Rep 7:46145 PMID: 28387240
- 7. Ni X et al.. 2022. Complex Processes Underlying the Dynamic Changes of D-serine Levels in AD Brains.. Curr Alzheimer Res 19(7):485-493 PMID: 35346007
- 8. Danek Burgess KS et al.. 1999. Effects of serine mutations in transmembrane domain 7 of the human norepinephrine transporter on substrate binding and transport.. J Neurochem 73(2):656-64 PMID: 10428062
