GO:0016155 formyltetrahydrofolate dehydrogenase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0016155 describes the molecular function of formyltetrahydrofolate dehydrogenase (FTHFD/ALDH1L1), which catalyzes the NADP+-dependent oxidation of 10-formyltetrahydrofolate to tetrahydrofolate, CO2, and NADPH.
• The enzyme is a multidomain protein: an N-terminal hydrolase domain, a central carrier domain, and a C-terminal aldehyde dehydrogenase domain; the dehydrogenase activity resides in the C-terminal domain and requires an intact interdomain interface.
• Cysteine 707 in the rat enzyme is essential for dehydrogenase catalysis, and mutation of this residue abolishes NADP+-dependent activity.
• The enzyme also exhibits hydrolase activity toward 10-formyl-5,8-dideazafolate, demonstrating bifunctionality of the recombinant protein.
• Acetaldehyde inhibits 10-formyltetrahydrofolate dehydrogenase activity in vitro, linking folate metabolism to alcohol-related perturbations.
• Knockdown of 10-formyltetrahydrofolate dehydrogenase in zebrafish increases oxidative stress and impairs embryogenesis by obstructing morphogenetic movements.
Description
Formyltetrahydrofolate dehydrogenase activity (GO:0016155) is a molecular function that removes the formyl group from 10-formyltetrahydrofolate, producing tetrahydrofolate, carbon dioxide, and NADPH. This reaction sits at a critical branch point in one-carbon metabolism, influencing the availability of tetrahydrofolate for nucleotide biosynthesis and the cellular redox balance through NADPH generation. Researchers study this activity to understand how folate-dependent pathways are rewired in cancer, developmental disorders, and alcohol-related pathologies. The enzyme responsible, 10-formyltetrahydrofolate dehydrogenase (ALDH1L1 in humans), is a multidomain protein whose catalytic mechanism and regulation have been dissected using recombinant mutants and domain-deletion constructs. Because the dehydrogenase step is irreversible and consumes a formyl donor that would otherwise support purine synthesis, its activity is a key determinant of folate flux. This article summarizes the authoritative GO definition, the structural and mechanistic basis of the activity, the genes and proteins involved, and the experimental models and methods used to study it.
formyltetrahydrofolate dehydrogenase activity At A Glance
| GO ID | GO:0016155 |
|---|---|
| GO term | formyltetrahydrofolate dehydrogenase activity |
| Ontology | molecular_function |
| Synonym | 10-formyl-H2PtGlu:NADP oxidoreductase activity; 10-formyl-H4folate dehydrogenase activity; 10-formyltetrahydrofolate dehydrogenase activity; 10-formyl tetrahydrofolate:NADP oxidoreductase activity; 10-formyltetrahydrofolate:NADP+ oxidoreductase activity; N10-formyltetrahydrofolate dehydrogenase activity |
| Major function | Catalyzes the NADP+-dependent oxidation of 10-formyltetrahydrofolate to tetrahydrofolate, CO2, and NADPH |
| Reaction | 10-formyltetrahydrofolate + H2O + NADP+ = (6S)-5,6,7,8-tetrahydrofolate + CO2 + H+ + NADPH |
| Cofactor | NADP+ (nicotinamide adenine dinucleotide phosphate, oxidized) |
| Substrate | 10-formyltetrahydrofolate |
| Product | (6S)-5,6,7,8-tetrahydrofolate, CO2, H+, NADPH |
| Representative enzyme | 10-formyltetrahydrofolate dehydrogenase (ALDH1L1 in humans; Fthfd/Aldh1l1 in rodents) |
| Key residue | Cysteine 707 in rat 10-formyltetrahydrofolate dehydrogenase is essential for dehydrogenase activity |
| Inhibitor | Acetaldehyde inhibits the activity in vitro |
What Is GO:0016155?
According to the Gene Ontology, GO:0016155 (formyltetrahydrofolate dehydrogenase activity) is defined as the catalysis of the reaction: 10-formyltetrahydrofolate + H2O + NADP+ = (6S)-5,6,7,8-tetrahydrofolate + CO2 + H+ + NADPH. In other words, the enzyme uses NADP+ as an electron acceptor to oxidize 10-formyltetrahydrofolate, releasing CO2 and generating NADPH while regenerating tetrahydrofolate. This activity is distinct from the hydrolase reaction that the same protein can catalyze on synthetic substrates, although both reactions are carried out by the recombinant enzyme.
Why Is formyltetrahydrofolate dehydrogenase activity Important in Cell Biology?
GO:0016155 is important because it controls a key node in one-carbon metabolism that determines whether formyl groups are used for purine biosynthesis or are oxidized to CO2 with concomitant NADPH production. By regulating tetrahydrofolate availability and redox balance, this activity influences cell proliferation, developmental morphogenesis, and the cellular response to oxidative stress. Its inhibition by acetaldehyde links it to alcohol-related metabolic disturbances, and its domain architecture makes it a model system for understanding interdomain communication in multidomain enzymes.
• Regulates the balance between folate-dependent purine synthesis and oxidative folate catabolism.
• Generates NADPH, contributing to cellular antioxidant defense and reductive biosynthesis.
• Essential for normal embryogenesis; knockdown in zebrafish causes oxidative stress and defective morphogenetic movements.
• Inhibited by acetaldehyde, providing a mechanistic link to alcohol-related folate deficiency.
• Cysteine 707 is a critical catalytic residue, making it a target for site-directed mutagenesis studies.
• The enzyme is bifunctional, catalyzing both dehydrogenase and hydrolase reactions on synthetic substrates.
• Domain-domain interactions are required for dehydrogenase activity, as disruption of a calmodulin-like central region uncouples the functional domains.
• Provides a paradigm for understanding how multidomain proteins coordinate sequential reactions.
• Relevant to cancer metabolism because altered folate flux supports tumor proliferation.
• Serves as a biomarker and potential therapeutic target in conditions of folate imbalance.
Molecular Mechanism of formyltetrahydrofolate dehydrogenase activity
Substrate binding and domain architecture
In simple terms: The enzyme has three parts that work together to grab the substrate and perform the reaction.
10-formyltetrahydrofolate dehydrogenase is a multidomain protein composed of an N-terminal hydrolase domain, a central carrier domain, and a C-terminal aldehyde dehydrogenase domain. The substrate 10-formyltetrahydrofolate binds to the carrier domain, which then transfers the formyl group to the active site of the C-terminal domain for oxidation. Disruption of the central calmodulin-like region impairs dehydrogenase activity by uncoupling the functional domains, indicating that interdomain communication is essential.
Catalytic role of cysteine 707
In simple terms: A specific cysteine residue acts as the key catalytic switch for the dehydrogenase reaction.
Cysteine 707 in the rat enzyme is directly involved in the dehydrogenase activity site; mutation of this residue abolishes NADP+-dependent dehydrogenase activity. This cysteine is located in the C-terminal aldehyde dehydrogenase domain and is conserved in the human enzyme, highlighting its importance for catalysis.
NADP+ cofactor and hydride transfer
In simple terms: The enzyme uses NADP+ to accept electrons, producing NADPH.
The reaction requires NADP+ as the electron acceptor, which is reduced to NADPH during the oxidation of the formyl group to CO2. The dehydrogenase activity is strictly NADP+-dependent, and the reaction produces (6S)-5,6,7,8-tetrahydrofolate, CO2, H+, and NADPH.
Bifunctionality: dehydrogenase and hydrolase activities
In simple terms: The same enzyme can also act as a hydrolase on a synthetic substrate.
Recombinant 10-formyltetrahydrofolate dehydrogenase catalyzes both dehydrogenase and hydrolase reactions utilizing the synthetic substrate 10-formyl-5,8-dideazafolate. This bifunctionality suggests that the enzyme can hydrolyze the formyl group in the absence of NADP+, although the physiological relevance of the hydrolase activity remains to be fully established.
Inhibition by acetaldehyde
In simple terms: Acetaldehyde, a breakdown product of alcohol, blocks the enzyme's activity.
In vitro studies show that acetaldehyde inhibits 10-formyltetrahydrofolate dehydrogenase activity. This inhibition may contribute to the folate deficiency and metabolic disturbances observed in chronic alcohol consumption.
Key Genes Involved in GO:0016155 formyltetrahydrofolate dehydrogenase activity
The following genes and proteins are directly implicated in formyltetrahydrofolate dehydrogenase activity or its regulation, based on published biochemical and genetic studies.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ALDH1L1 (human) | Encodes 10-formyltetrahydrofolate dehydrogenase, the enzyme responsible for GO:0016155 | Target for cancer metabolism and folate flux studies |
| Aldh1l1 (mouse) | Ortholog of human ALDH1L1; catalyzes the same reaction | Model for knockout and knockdown studies in development |
| Fthfd (rat) | Rat ortholog used in early biochemical characterization | Source of recombinant enzyme for mechanistic studies |
| MTHFD1 | Mitochondrial methylenetetrahydrofolate dehydrogenase, methenyltetrahydrofolate cyclohydrolase, and formyltetrahydrofolate synthetase | Provides 10-formyltetrahydrofolate for the dehydrogenase reaction |
| MTHFD2 | Mitochondrial bifunctional enzyme in one-carbon metabolism | Supplies formyl groups for folate-dependent processes |
| MTHFD1L | Mitochondrial formyltetrahydrofolate synthetase | Generates 10-formyltetrahydrofolate in mitochondria |
| SHMT1 | Serine hydroxymethyltransferase, cytosolic | Feeds one-carbon units into the folate pool |
| SHMT2 | Serine hydroxymethyltransferase, mitochondrial | Contributes to mitochondrial one-carbon metabolism |
| MTHFR | Methylenetetrahydrofolate reductase | Regulates folate distribution between methylation and nucleotide synthesis |
| GART | Phosphoribosylglycinamide formyltransferase | Competes for 10-formyltetrahydrofolate in purine synthesis |
| ATIC | AICAR transformylase/IMP cyclohydrolase | Uses 10-formyltetrahydrofolate in purine biosynthesis |
| NUDT5 | Nudix hydrolase 5; non-enzymatic role in repressing purine de novo synthesis | Linked to folate-dependent purine synthesis regulation |
| ALDH1L2 | Mitochondrial aldehyde dehydrogenase 1 family member L2 | Mitochondrial paralog with potential formyltetrahydrofolate dehydrogenase activity |
| CYP2E1 | Cytochrome P450 2E1; generates acetaldehyde | Indirect regulator via acetaldehyde production |
| ADH1B | Alcohol dehydrogenase 1B; produces acetaldehyde | Indirect regulator of enzyme activity through acetaldehyde |
| ALDH2 | Aldehyde dehydrogenase 2; detoxifies acetaldehyde | Modulates acetaldehyde levels that inhibit the enzyme |
How Is formyltetrahydrofolate dehydrogenase activity Regulated?
The activity of 10-formyltetrahydrofolate dehydrogenase is regulated at multiple levels. The enzyme requires an intact interdomain interface for dehydrogenase activity, and disruption of the central calmodulin-like region uncouples the functional domains, leading to loss of activity. Cysteine 707 is essential for catalysis, and its oxidation or modification could affect enzyme function. Acetaldehyde directly inhibits the enzyme in vitro, suggesting that metabolic states with high acetaldehyde, such as alcohol consumption, can downregulate this activity. Additionally, the availability of the substrate 10-formyltetrahydrofolate, which is produced by mitochondrial and cytosolic one-carbon enzymes such as MTHFD1 and MTHFD1L, indirectly regulates the flux through this reaction. The expression of ALDH1L1 is also subject to transcriptional regulation, although specific transcription factors are not detailed in the cited literature.
formyltetrahydrofolate dehydrogenase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ALDH1L1 | Alcohol-related folate deficiency | Hepatocyte cell lines treated with acetaldehyde; Aldh1l1 knockout mice |
| ALDH1L1 | Developmental defects and oxidative stress | Zebrafish knockdown or knockout models |
| ALDH1L1 | Cancer metabolism | Cancer cell lines with ALDH1L1 overexpression or knockout |
| MTHFD1 | Folate-responsive developmental anomalies | Mouse models with Mthfd1 mutations |
| MTHFD2 | Cancer proliferation | Cancer cell lines with MTHFD2 knockdown |
Alcohol-related folate deficiency
Acetaldehyde, the primary metabolite of ethanol, inhibits 10-formyltetrahydrofolate dehydrogenase activity in vitro. This inhibition may contribute to the folate deficiency and altered one-carbon metabolism observed in chronic alcoholics, potentially exacerbating liver damage and impairing nucleotide synthesis.
Developmental disorders and oxidative stress
Knocking down 10-formyltetrahydrofolate dehydrogenase in zebrafish increased oxidative stress and impeded embryogenesis by obstructing morphogenetic movement. This suggests that loss of enzyme activity can disrupt developmental processes through redox imbalance and impaired cell migration.
Cancer metabolism
Altered folate metabolism is a hallmark of cancer, and the dehydrogenase activity competes with purine biosynthesis for 10-formyltetrahydrofolate. Loss of ALDH1L1 expression has been observed in several cancers, but the cited literature does not provide specific cancer statistics; further studies are needed to establish causal links.
From formyltetrahydrofolate dehydrogenase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of ALDH1L1 affect folate flux and NADPH levels? | ALDH1L1 knockout cell lines (e.g., HepG2, HEK293) |
| Is cysteine 707 required for dehydrogenase activity? | Point mutation (C707A) knock-in in cell lines |
| Does ALDH1L1 overexpression protect against oxidative stress? | Overexpression cell models (e.g., stable transfection) |
| How does acetaldehyde inhibit the enzyme? | In vitro enzyme assays with purified recombinant protein |
| Does ALDH1L1 knockdown impair embryogenesis? | Zebrafish morpholino or CRISPR knockout |
| Can ALDH1L1 be used as a metabolic biomarker? | Tagged knock-in for live-cell imaging (e.g., GFP-ALDH1L1) |
How to Study the formyltetrahydrofolate dehydrogenase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| NADPH absorbance assay | Dehydrogenase activity | Enzyme kinetics with purified protein |
| Site-directed mutagenesis | Role of specific residues | C707A mutant characterization |
| Western blot | Protein expression levels | ALDH1L1 knockdown validation |
| RNA-seq | Transcriptome changes | Pathway analysis after ALDH1L1 knockout |
| 13C metabolic tracing | Folate flux | One-carbon metabolism studies |
| Zebrafish morpholino knockdown | Developmental phenotypes | Embryogenesis and oxidative stress |
| Immunofluorescence | Subcellular localization | Tagged ALDH1L1 imaging |
Enzymatic activity assays
Dehydrogenase activity is typically measured spectrophotometrically by monitoring NADPH production at 340 nm using purified enzyme or cell lysates. Synthetic substrates such as 10-formyl-5,8-dideazafolate can be used to distinguish dehydrogenase and hydrolase activities.
Site-directed mutagenesis and domain mapping
Recombinant mutants, such as C707A, are generated to identify catalytic residues and domain requirements. Domain-deletion constructs help map the roles of the N-terminal, central, and C-terminal domains in catalysis.
Gene expression analysis
RNA-seq and qPCR are used to quantify ALDH1L1 mRNA levels in tissues or cell lines under different conditions, such as oxidative stress or alcohol exposure.
Metabolic flux analysis
Stable isotope tracing with 13C-labeled serine or formate can measure flux through the folate pathway and assess the contribution of formyltetrahydrofolate dehydrogenase to one-carbon metabolism.
How CRISPR Can Be Used to Study GO:0016155 formyltetrahydrofolate dehydrogenase activity
Knockout
CRISPR-Cas9 knockout of ALDH1L1 can be used to eliminate formyltetrahydrofolate dehydrogenase activity, enabling studies of its role in folate metabolism, oxidative stress, and cell proliferation. Knockout cell lines are valuable for metabolic flux analysis and drug sensitivity testing.
Point Mutation
Point mutations such as C707A can be introduced into the endogenous ALDH1L1 locus to specifically abolish dehydrogenase activity while preserving protein structure. This allows dissection of the dehydrogenase function from other potential roles of the protein.
Knock-in
Knock-in of tagged ALDH1L1 (e.g., GFP or FLAG) enables live-cell imaging and affinity purification of the enzyme complex. Knock-in of disease-associated variants can model human mutations affecting folate metabolism.
Overexpression
Overexpression of ALDH1L1 in cell lines can increase NADPH production and reduce oxidative stress, providing a gain-of-function model to study the enzyme's protective effects. Overexpression models are also useful for testing inhibitors such as acetaldehyde.
How EDITGENE Supports formyltetrahydrofolate dehydrogenase activity Research
Researchers studying formyltetrahydrofolate dehydrogenase activity-related genes often need to determine whether a candidate gene is causally involved in folate metabolism, oxidative stress, or developmental processes. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for formyltetrahydrofolate dehydrogenase activity research.
Frequently Asked Questions About formyltetrahydrofolate dehydrogenase activity
What is formyltetrahydrofolate dehydrogenase activity?
It is the molecular function defined by GO:0016155, catalyzing the NADP+-dependent oxidation of 10-formyltetrahydrofolate to tetrahydrofolate, CO2, and NADPH.
What genes are involved in formyltetrahydrofolate dehydrogenase activity?
The primary gene is ALDH1L1 in humans, with orthologs Aldh1l1 in mouse and Fthfd in rat; related one-carbon genes include MTHFD1, MTHFD2, and MTHFD1L.
What is the reaction catalyzed by GO:0016155?
10-formyltetrahydrofolate + H2O + NADP+ = (6S)-5,6,7,8-tetrahydrofolate + CO2 + H+ + NADPH.
Which residue is critical for dehydrogenase activity?
Cysteine 707 in the rat enzyme is essential; mutation abolishes dehydrogenase activity.
How is formyltetrahydrofolate dehydrogenase activity inhibited?
Acetaldehyde inhibits the activity in vitro, linking it to alcohol metabolism.
What is the role of ALDH1L1 in development?
Knockdown in zebrafish increases oxidative stress and impairs embryogenesis by obstructing morphogenetic movement.
Can formyltetrahydrofolate dehydrogenase act as a hydrolase?
Yes, recombinant enzyme catalyzes both dehydrogenase and hydrolase reactions on synthetic substrates.
What domains make up 10-formyltetrahydrofolate dehydrogenase?
It has an N-terminal hydrolase domain, a central carrier domain, and a C-terminal aldehyde dehydrogenase domain.
How can I study formyltetrahydrofolate dehydrogenase activity in cells?
Use CRISPR knockout, point mutation, or overexpression models combined with NADPH assays and metabolic tracing.
What diseases are associated with altered formyltetrahydrofolate dehydrogenase activity?
Alcohol-related folate deficiency, developmental defects, and cancer metabolism have been linked to this activity.
Conclusion
Formyltetrahydrofolate dehydrogenase activity (GO:0016155) is a central reaction in one-carbon metabolism that controls tetrahydrofolate availability and NADPH production. Its multidomain architecture, essential cysteine residue, and inhibition by acetaldehyde make it a fascinating target for biochemical and disease research. CRISPR-based models, including knockouts, point mutations, and tagged knock-ins, provide powerful tools to dissect its physiological roles and therapeutic potential.
References
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- 3. Krupenko SA et al.. 1995. Cysteine 707 is involved in the dehydrogenase activity site of rat 10-formyltetrahydrofolate dehydrogenase.. J Biol Chem 270(2):519-22 PMID: 7822273
- 4. Krupenko SA et al.. 1995. Recombinant 10-formyltetrahydrofolate dehydrogenase catalyses both dehydrogenase and hydrolase reactions utilizing the synthetic substrate 10-formyl-5,8-dideazafolate.. Biochem J 306 ( Pt 3)(Pt 3):651-5 PMID: 7702556
- 5. Reuland SN et al.. 2003. Disruption of a calmodulin central helix-like region of 10-formyltetrahydrofolate dehydrogenase impairs its dehydrogenase activity by uncoupling the functional domains.. J Biol Chem 278(25):22894-900 PMID: 12684508
- 6. Christensen KE et al.. 2008. Mitochondrial methylenetetrahydrofolate dehydrogenase, methenyltetrahydrofolate cyclohydrolase, and formyltetrahydrofolate synthetases.. Vitam Horm 79:393-410 PMID: 18804703
- 7. Schirch D et al.. 1994. Domain structure and function of 10-formyltetrahydrofolate dehydrogenase.. J Biol Chem 269(40):24728-35 PMID: 7929148
- 8. Chang WN et al.. 2014. Knocking down 10-Formyltetrahydrofolate dehydrogenase increased oxidative stress and impeded zebrafish embryogenesis by obstructing morphogenetic movement.. Biochim Biophys Acta 1840(7):2340-50 PMID: 24747731
