GO:0071890 bicarbonate binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0071890 (bicarbonate binding) is a molecular function defined as binding to bicarbonate ions (CHO3-), also called hydrogencarbonate [QuickGO].
• Bicarbonate binding is essential for enzymes such as phosphoenolpyruvate carboxylase, carbonic anhydrases, and vitamin K-dependent carboxylase.
• Transport proteins like Band 3 and pendrin rely on bicarbonate binding for anion exchange and pH regulation.
• Bicarbonate binding modulates metal transfer by transferrin and photosynthetic electron transfer in photosystem II.
• Dysregulation of bicarbonate-binding proteins is linked to cancer, metabolic disorders, and cardiovascular disease.
• CRISPR knockout, point mutation, knock-in, and overexpression models enable functional dissection of bicarbonate-binding sites.
Description
Bicarbonate (CHO3-) is a ubiquitous anion that participates in pH homeostasis, carbon fixation, and ion transport. The Gene Ontology term GO:0071890, bicarbonate binding, describes the molecular function of selectively binding this ion [QuickGO]. This function is critical for enzymes that use bicarbonate as a substrate or cofactor, such as phosphoenolpyruvate carboxylase (PEPC) and vitamin K-dependent carboxylase. Bicarbonate binding also underlies the transport cycle of anion exchangers like Band 3 and pendrin. Understanding bicarbonate binding is therefore central to fields ranging from plant carbon metabolism to human physiology. Researchers study this term to identify binding sites, quantify affinity, and link mutations to disease. The availability of high-resolution structures and CRISPR models has accelerated discovery, making GO:0071890 a focal point for both basic and translational science.
bicarbonate binding At A Glance
| GO ID | GO:0071890 |
|---|---|
| GO term | bicarbonate binding |
| Ontology | molecular_function |
| Synonym | CHO3- ion binding, hydrogencarbonate binding |
| Major function | Binding to bicarbonate ions (CHO3-) |
| Definition | Binding to bicarbonate ions (CHO3-). |
| Related proteins | Phosphoenolpyruvate carboxylase, carbonic anhydrase, Band 3, pendrin, vitamin K-dependent carboxylase |
| Disease relevance | Cancer, metabolic disorders, cardiovascular disease, renal tubular acidosis |
What Is GO:0071890?
GO:0071890 is a molecular function term defined as the binding to bicarbonate ions (CHO3-). It encompasses non-covalent interactions that selectively recognize bicarbonate, often via hydrogen bonding, electrostatic, or metal-coordinated mechanisms. This term is synonymous with hydrogencarbonate binding and CHO3- ion binding. It does not describe catalysis or transport per se, but rather the binding event that enables downstream biological processes such as carboxylation, anion exchange, or pH sensing [QuickGO].
Why Is bicarbonate binding Important in Cell Biology?
Bicarbonate binding is a fundamental molecular event that underpins carbon fixation, pH regulation, and ion transport across membranes. It is essential for the catalytic activity of enzymes like PEPC and vitamin K-dependent carboxylase, and for the function of anion exchangers such as Band 3 and pendrin. Defects in bicarbonate binding can lead to metabolic acidosis, cancer progression, and impaired photosynthesis. Thus, studying this term provides insights into both normal physiology and disease mechanisms.
• Enables carbon fixation in plants and bacteria via PEPC.
• Supports vitamin K-dependent carboxylation of clotting factors.
• Regulates intracellular pH through Band 3 and pendrin anion exchange.
• Modulates metal transfer by transferrin.
• Influences photosynthetic electron transfer in photosystem II.
• Linked to cancer metabolism and tumor growth.
• Implicated in renal tubular acidosis and hearing loss.
• Provides targets for drug design in metabolic and cardiovascular diseases.
• Essential for bacterial carbonic anhydrase function.
• Facilitates structural studies of membrane transporters.
Molecular Mechanism of bicarbonate binding
Bicarbonate recognition by phosphoenolpyruvate carboxylase
In simple terms: PEPC grabs bicarbonate to help fix carbon.
Phosphoenolpyruvate carboxylase (PEPC) binds bicarbonate as a substrate for the carboxylation of phosphoenolpyruvate. Computational and structural studies have identified key binding sites where bicarbonate is coordinated by conserved residues, facilitating the formation of oxaloacetate. This binding is essential for carbon fixation in C4 and CAM plants and in bacteria.
Bicarbonate binding in carbonic anhydrases
In simple terms: Carbonic anhydrases use bicarbonate to interconvert CO2 and bicarbonate.
Bacterial beta-carbonic anhydrases bind bicarbonate as part of their catalytic cycle, converting CO2 to bicarbonate and vice versa. Structural analyses reveal that bicarbonate is stabilized by zinc coordination and hydrogen bonding networks, which are critical for enzyme activity.
Anion exchange by Band 3 and pendrin
In simple terms: Band 3 and pendrin swap bicarbonate across cell membranes.
Band 3 (AE1) and pendrin (SLC26A4) are anion exchangers that bind bicarbonate to transport it across membranes. Molecular dynamics simulations and structural studies show that cholesterol modulates bicarbonate binding in Band 3, affecting its transport function. Pendrin utilizes a similar mechanism, with mutations in its bicarbonate-binding site linked to disease.
Bicarbonate in vitamin K-dependent carboxylase
In simple terms: Bicarbonate helps activate vitamin K-dependent carboxylase.
Human vitamin K-dependent carboxylase binds bicarbonate to mediate the carboxylation of glutamate residues in clotting factors. Recent structural insights reveal that bicarbonate is positioned to act as a base, facilitating the reaction.
Bicarbonate binding in transferrin and photosystem II
In simple terms: Bicarbonate also helps iron transport and photosynthesis.
Transferrin binds bicarbonate to facilitate zinc(II) transfer, with the bicarbonate ion stabilizing the metal-binding site. In photosystem II, bicarbonate binding to the PsbS/Psb27 complex activates monomeric photosystem II, influencing electron transfer.
Key Genes Involved in GO:0071890 bicarbonate binding
The following genes and proteins are directly implicated in bicarbonate binding, as supported by structural, biochemical, and genetic studies.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PPC | Phosphoenolpyruvate carboxylase; binds bicarbonate for carbon fixation | Target for improving crop yield and understanding C4 photosynthesis |
| CA | Carbonic anhydrase; binds bicarbonate in catalytic cycle | Antibacterial and anticancer drug target |
| SLC4A1 | Band 3 anion exchanger; binds bicarbonate for pH regulation | Mutations cause hereditary spherocytosis and renal acidosis |
| SLC26A4 | Pendrin; binds bicarbonate for anion exchange | Mutations linked to Pendred syndrome and hearing loss |
| GGCX | Vitamin K-dependent carboxylase; binds bicarbonate for carboxylation | Target for anticoagulant therapy |
| TF | Transferrin; binds bicarbonate for metal transport | Iron metabolism and zinc transfer studies |
| PsbS | Photosystem II subunit; binds bicarbonate for activation | Photosynthesis research |
| Psb27 | Photosystem II assembly factor; binds bicarbonate | Photosystem II regulation |
| AE1 | Anion exchanger 1; binds bicarbonate | Red blood cell physiology |
| AE2 | Anion exchanger 2; binds bicarbonate | Gastric acid secretion |
| AE3 | Anion exchanger 3; binds bicarbonate | Neuronal pH regulation |
| NBCe1 | Electrogenic sodium bicarbonate cotransporter; binds bicarbonate | Kidney and pancreatic function |
| NBCn1 | Electroneutral sodium bicarbonate cotransporter; binds bicarbonate | pH homeostasis |
| CAA | Carbonic anhydrase-related protein; binds bicarbonate | Cancer metabolism |
| SLC4A4 | Sodium bicarbonate cotransporter; binds bicarbonate | Proximal renal tubular acidosis |
| SLC4A7 | Sodium bicarbonate cotransporter; binds bicarbonate | Breast cancer and pH regulation |
How Is bicarbonate binding Regulated?
Bicarbonate binding is regulated by factors such as pH, cholesterol, and post-translational modifications. For example, cholesterol modulates bicarbonate binding in Band 3, affecting anion exchange. In photosystem II, bicarbonate binding is regulated by light and assembly factors. Additionally, phosphorylation of pendrin may alter its bicarbonate affinity.
bicarbonate binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLC4A1 | Hereditary spherocytosis, renal tubular acidosis | Knockout mouse, point mutation knock-in |
| SLC26A4 | Pendred syndrome, hearing loss | Knockout mouse, overexpression |
| GGCX | Vitamin K-dependent clotting factor deficiency | Point mutation knock-in, knockout |
| PPC | Cancer metabolism | Overexpression, knockout in cancer cell lines |
| CA | Bacterial infections, cancer | Knockout, point mutation |
Bicarbonate binding in cancer
Altered bicarbonate binding by enzymes like PEPC and carbonic anhydrases contributes to tumor metabolic reprogramming. PEPC binds bicarbonate to support anaplerosis in cancer cells, while carbonic anhydrases regulate pH and promote invasion.
Bicarbonate binding in renal and cardiovascular disease
Mutations in bicarbonate-binding proteins such as Band 3 and pendrin cause renal tubular acidosis, hearing loss, and cardiovascular complications. Defective bicarbonate binding impairs pH homeostasis and ion transport.
Bicarbonate binding in metabolic disorders
Vitamin K-dependent carboxylase binds bicarbonate to activate clotting factors; impaired binding leads to bleeding disorders. Transferrin bicarbonate binding affects iron and zinc metabolism, linking to anemia and neurodegeneration.
From bicarbonate binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does mutation in bicarbonate-binding site affect enzyme activity? | Point mutation knock-in |
| What is the effect of bicarbonate-binding protein knockout on pH regulation? | Knockout cell line or mouse |
| Can overexpression of bicarbonate-binding protein rescue disease phenotype? | Overexpression |
| How does cholesterol modulate bicarbonate binding? | Point mutation, tagged knock-in |
| What is the role of bicarbonate binding in photosynthesis? | Knockout, point mutation in plants |
| Can CRISPR library screening identify novel bicarbonate-binding regulators? | CRISPR library screening |
How to Study the bicarbonate binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| X-ray crystallography | Atomic structure of bicarbonate-binding site | PEPC, carbonic anhydrase |
| Cryo-EM | Structure of membrane transporters | Band 3, pendrin |
| Molecular dynamics | Binding dynamics and cholesterol effects | Band 3 |
| Isothermal titration calorimetry | Binding affinity (Kd) | Carbonic anhydrase |
| CRISPR knockout | Loss-of-function phenotype | SLC4A1, SLC26A4 |
| CRISPR point mutation | Effect of specific residue on binding | GGCX, PEPC |
| CRISPR overexpression | Gain-of-function phenotype | GGCX |
| CRISPR library screening | Identify novel regulators | Cancer metabolism |
Structural biology
X-ray crystallography and cryo-EM reveal bicarbonate-binding sites in proteins like PEPC and Band 3. These methods provide atomic-level details of coordination and conformational changes.
Molecular dynamics simulations
MD simulations elucidate the dynamics of bicarbonate binding, including the effect of cholesterol on Band 3 and the stability of binding pockets.
Biochemical assays
Isothermal titration calorimetry and fluorescence-based assays measure bicarbonate-binding affinity and kinetics. These are used to validate mutations and screen inhibitors.
CRISPR-based functional genomics
CRISPR knockout, point mutation, and overexpression models enable functional dissection of bicarbonate-binding proteins in cells and organisms.
How CRISPR Can Be Used to Study GO:0071890 bicarbonate binding
Knockout
CRISPR knockout of bicarbonate-binding genes such as SLC4A1 or SLC26A4 abolishes bicarbonate transport, leading to pH imbalance and disease phenotypes. These models are used to study loss-of-function effects.
Point Mutation
Point mutations in bicarbonate-binding residues (e.g., in PEPC or GGCX) allow precise testing of binding affinity and catalytic activity. CRISPR-mediated point mutation knock-in models mimic human disease alleles.
Knock-in
Knock-in of tagged bicarbonate-binding proteins (e.g., GFP-tagged Band 3) enables live-cell imaging and proteomic analysis. This approach helps track protein localization and interactions.
Overexpression
Overexpression of bicarbonate-binding proteins like GGCX or carbonic anhydrases can rescue deficiency phenotypes or drive cancer metabolism. These models are useful for gain-of-function studies.
How EDITGENE Supports bicarbonate binding Research
Researchers studying bicarbonate binding-related genes often need to determine whether a candidate gene is causally involved in a specific biological process or disease. This requires precise genetic models that can knockout, mutate, or overexpress the gene of interest.
Contact EDITGENE today to design your custom CRISPR model for bicarbonate binding research.
Frequently Asked Questions About bicarbonate binding
What is bicarbonate binding?
Bicarbonate binding is a molecular function (GO:0071890) defined as the binding to bicarbonate ions (CHO3-), also known as hydrogencarbonate [QuickGO].
What genes are involved in bicarbonate binding?
Key genes include PPC, CA, SLC4A1, SLC26A4, GGCX, TF, PsbS, and Psb27, among others.
What is the GO ID for bicarbonate binding?
The GO ID is GO:0071890.
How does bicarbonate binding affect enzyme activity?
Bicarbonate binding is required for catalysis in enzymes like PEPC and vitamin K-dependent carboxylase, where it acts as a substrate or base.
What diseases are linked to bicarbonate binding?
Diseases include renal tubular acidosis, hereditary spherocytosis, Pendred syndrome, cancer, and clotting disorders.
How can I study bicarbonate binding using CRISPR?
CRISPR knockout, point mutation, knock-in, and overexpression models allow functional analysis of bicarbonate-binding proteins.
What methods measure bicarbonate binding affinity?
Isothermal titration calorimetry, fluorescence assays, and molecular dynamics simulations are commonly used.
Is bicarbonate binding important for photosynthesis?
Yes, bicarbonate binding to photosystem II proteins like PsbS and Psb27 activates electron transfer.
What is the role of bicarbonate binding in Band 3?
Band 3 binds bicarbonate to exchange anions across the red blood cell membrane, regulating pH and CO2 transport.
Can bicarbonate binding be targeted for drug discovery?
Yes, inhibitors of carbonic anhydrases and anion exchangers that block bicarbonate binding are in development for cancer and metabolic diseases.
Conclusion
Bicarbonate binding (GO:0071890) is a fundamental molecular function that enables carbon fixation, pH regulation, and ion transport. Its dysregulation is linked to cancer, metabolic disorders, and cardiovascular disease. Advances in structural biology and CRISPR technologies continue to illuminate the mechanisms and therapeutic potential of bicarbonate-binding proteins. EDITGENE offers comprehensive CRISPR services to accelerate research in this field.
References
- 1. Chéron N. 2024. Binding Sites of Bicarbonate in Phosphoenolpyruvate Carboxylase.. J Chem Inf Model 64(8):3375-3385 PMID: 38533570
- 2. Ferraroni M. 2024. Bacterial β-carbonic anhydrases.. Enzymes 55:65-91 PMID: 39222999
- 3. Lv H et al.. 2024. Molecular Insights into the Effect of Cholesterol on the Binding of Bicarbonate Ions in Band 3 Protein.. Langmuir 40(21):10908-10915 PMID: 38739034
- 4. Martínez-Crespo L et al.. 2021. Transmembrane Transport of Bicarbonate Unravelled*.. Chemistry 27(26):7367-7375 PMID: 33932059
- 5. Wu K et al.. 2025. Structural insight into bicarbonate-mediated carboxylation by human vitamin K-dependent carboxylase.. Nat Commun 16(1):10480 PMID: 41290650
- 6. Fantuzzi A et al.. 2023. Bicarbonate activation of the monomeric photosystem II-PsbS/Psb27 complex.. Plant Physiol 192(4):2656-2671 PMID: 37202365
- 7. Harris WR et al.. 1988. The bicarbonate-dependence of zinc(II)-transferrin binding.. J Inorg Biochem 33(3):211-23 PMID: 2843602
- 8. Wang L et al.. 2024. Mechanism of anion exchange and small-molecule inhibition of pendrin.. Nat Commun 15(1):346 PMID: 38184688
