GO:0042376 phylloquinone catabolic process: Vitamin K1 Breakdown, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0042376 phylloquinone catabolic process describes the biochemical breakdown of phylloquinone (vitamin K1), a quinone-derived compound synthesized by green plants.
• Phylloquinone is the primary dietary form of vitamin K and is essential for hepatic synthesis of clotting factors and bone-related proteins.
• The catabolic process involves oxidative cleavage of the phytyl side chain and the quinone ring, generating metabolites that can be measured in plasma and tissues.
• Phylloquinone catabolism is relevant to vitamin K status assessment, anticoagulation monitoring, and neonatal prophylaxis strategies.
• Emerging evidence links phylloquinone and its metabolites to ferroptosis inhibition and neuroprotection, expanding its biological roles beyond coagulation.
• CRISPR-based models (knockout, point mutation, knock-in, overexpression) enable precise dissection of genes involved in phylloquinone catabolic process.
Description
Phylloquinone (vitamin K1) is a lipid-soluble quinone synthesized by green plants and is the major dietary source of vitamin K in humans. The GO term GO:0042376, phylloquinone catabolic process, refers to the chemical reactions and pathways that result in the breakdown of this compound. Understanding this catabolic process is important because it determines the bioavailability, tissue distribution, and biological activity of vitamin K1 and its metabolites. The process is also relevant to clinical conditions such as vitamin K deficiency bleeding in infants, anticoagulant therapy, and emerging roles in neuronal protection. Research into phylloquinone catabolic process has gained momentum due to its implications in human health, particularly in coagulation, bone metabolism, and cellular redox regulation. The catabolic pathway involves enzymatic modifications that convert phylloquinone into more polar metabolites, which are excreted or recycled. These steps are critical for maintaining vitamin K homeostasis and preventing toxicity. In this article, we integrate the QuickGO definition with verified PubMed literature to provide a comprehensive overview of the phylloquinone catabolic process, its genetic players, regulatory mechanisms, disease associations, and state-of-the-art research methods including CRISPR-based models.
phylloquinone catabolic process At A Glance
| GO ID | GO:0042376 |
|---|---|
| GO term | phylloquinone catabolic process |
| Ontology | biological_process |
| Synonym | phylloquinone breakdown; phylloquinone catabolism; phylloquinone degradation; phytomenadione catabolic process; phytomenadione catabolism; phytonadione catabolic process; phytonadione catabolism; phytylmenaquinone catabolic process; phytylmenaquinone catabolism; vitamin K1 catabolic process; vitamin K1 catabolism |
| Major function | Breakdown of phylloquinone (vitamin K1) to maintain vitamin K homeostasis and generate metabolites for excretion or recycling |
| Compounds involved | Phylloquinone (vitamin K1), phytyl side chain, quinone ring, oxidative enzymes |
| Biological context | Occurs in plants, animals, and humans; essential for vitamin K metabolism |
| Related pathways | Vitamin K cycle, menaquinone biosynthesis, oxidative degradation of quinones |
What Is GO:0042376?
The phylloquinone catabolic process (GO:0042376) is defined as the chemical reactions and pathways resulting in the breakdown of phylloquinone, also known as vitamin K1, a quinone-derived compound synthesized by green plants. This process encompasses enzymatic steps that modify the phytyl side chain and the quinone ring, leading to the formation of catabolic intermediates and excretable metabolites.
Why Is phylloquinone catabolic process Important in Cell Biology?
The phylloquinone catabolic process is critical for regulating vitamin K1 levels in the body, preventing accumulation of potentially toxic quinone intermediates, and ensuring adequate supply of vitamin K for coagulation and bone health. Dysregulation of this process has been linked to vitamin K deficiency, which can cause bleeding disorders, and to altered vitamin K status in infants and adults. Moreover, recent studies suggest that phylloquinone and its catabolites may influence ferroptosis and neuronal survival, highlighting broader physiological roles.
• Maintains vitamin K homeostasis by preventing excessive accumulation of phylloquinone.
• Generates metabolites that can be measured to assess vitamin K status in clinical settings.
• Plays a role in the vitamin K cycle, which is essential for gamma-carboxylation of clotting factors.
• Impacts neonatal health, as vitamin K1 catabolism influences prophylaxis strategies for vitamin K deficiency bleeding.
• May modulate ferroptosis through the xCT/GPX4 pathway, offering neuroprotective insights.
• Relevant to anticoagulant therapy, as warfarin and other drugs affect vitamin K metabolism.
• Provides targets for genetic studies using CRISPR to dissect catabolic enzyme functions.
• Contributes to plant physiology, as phylloquinone is synthesized and degraded in photosynthetic organisms.
• Influences bone health through vitamin K-dependent proteins like osteocalcin.
• Serves as a model for quinone catabolism in general, with implications for drug metabolism.
What Happens During phylloquinone catabolic process?
Initial oxidation of the phytyl side chain
In simple terms: The first step in breaking down vitamin K1 involves adding oxygen to its long tail.
The catabolic process begins with oxidative modification of the phytyl side chain of phylloquinone, which is a polyunsaturated isoprenoid chain. Enzymes such as cytochrome P450 monooxygenases catalyze the introduction of hydroxyl groups, making the molecule more polar and preparing it for further cleavage. This step is crucial for initiating the degradation pathway and is conserved across species.
Cleavage of the quinone ring
In simple terms: The core ring structure of vitamin K1 is broken open.
Following side-chain oxidation, the quinone ring of phylloquinone undergoes enzymatic cleavage, likely via dioxygenases or peroxidases. This step generates smaller metabolites such as phthalic acid derivatives and other aromatic fragments. The ring cleavage is essential for the complete breakdown of phylloquinone and for the formation of excretable products.
Formation of water-soluble metabolites
In simple terms: The breakdown products become water-soluble so they can be excreted.
The oxidized and cleaved products are further conjugated with glucuronic acid or sulfate, increasing their water solubility. These conjugated metabolites are then transported to the kidneys and excreted in urine, or to the bile for fecal excretion. This phase is critical for the elimination of vitamin K1 catabolites and for maintaining vitamin K balance.
Regulation by vitamin K status and enzymes
In simple terms: The speed of vitamin K1 breakdown depends on how much vitamin K is in the body and which enzymes are active.
The catabolic process is regulated by vitamin K status; high intake can induce catabolic enzymes, while deficiency may slow breakdown. Key enzymes involved include CYP4F2 and other cytochrome P450 family members, which are subject to genetic polymorphisms that affect vitamin K metabolism. Additionally, the process is interconnected with the vitamin K cycle, which recycles vitamin K for gamma-carboxylation.
Tissue-specific catabolism
In simple terms: Different organs break down vitamin K1 at different rates.
The liver is the primary site of phylloquinone catabolism, but extrahepatic tissues such as bone, brain, and kidneys also contribute. In the brain, phylloquinone catabolites may play a role in neuronal protection by inhibiting ferroptosis. Tissue-specific expression of catabolic enzymes determines local vitamin K1 levels and influences physiological outcomes.
Key Genes Involved in GO:0042376 phylloquinone catabolic process
The following genes and proteins are involved in or regulate the phylloquinone catabolic process, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CYP4F2 | Cytochrome P450 enzyme that oxidizes vitamin K1; involved in catabolism and vitamin K cycle | Genetic variants affect warfarin dose and vitamin K status |
| VKORC1 | Vitamin K epoxide reductase; recycles vitamin K and influences catabolism | Target of anticoagulants; mutations cause vitamin K-dependent clotting defects |
| GGCX | Gamma-glutamyl carboxylase; uses reduced vitamin K for protein carboxylation | Defects cause bleeding disorders; linked to vitamin K metabolism |
| CYP2C9 | Metabolizes vitamin K and drugs; contributes to catabolic oxidation | Polymorphisms affect warfarin metabolism |
| UGT1A1 | Glucuronosyltransferase; conjugates vitamin K metabolites for excretion | Important for phase II metabolism of quinones |
| SULT1A1 | Sulfotransferase; sulfates vitamin K catabolites | Contributes to detoxification and excretion |
| ABCB1 | Transporter; may efflux vitamin K metabolites | Affects bioavailability and tissue distribution |
| APOE | Lipoprotein; transports vitamin K in plasma | Isoforms influence vitamin K status |
| GPX4 | Glutathione peroxidase; protects against lipid peroxidation; linked to phylloquinone neuroprotection | Target for ferroptosis research |
| SLC7A11 (xCT) | Cystine/glutamate antiporter; involved in ferroptosis inhibition by phylloquinone | Modulates oxidative stress responses |
| NQO1 | Quinone oxidoreductase; may reduce quinones and affect catabolism | Detoxifies quinones; relevant to vitamin K metabolism |
| CYP3A4 | Cytochrome P450; oxidizes vitamin K and other lipids | Major drug-metabolizing enzyme |
| CYP2C19 | Cytochrome P450; contributes to vitamin K oxidation | Genetic polymorphisms affect drug metabolism |
| EPHX1 | Epoxide hydrolase; may hydrolyze vitamin K epoxides | Involved in detoxification pathways |
| GSTP1 | Glutathione S-transferase; conjugates quinones for excretion | Polymorphisms affect xenobiotic metabolism |
| NQO2 | Quinone reductase; reduces quinones | Potential role in vitamin K catabolism |
How Is phylloquinone catabolic process Regulated?
The phylloquinone catabolic process is regulated at multiple levels. Vitamin K status itself modulates enzyme expression; high vitamin K intake can induce catabolic enzymes such as CYP4F2, while deficiency may downregulate them. Genetic polymorphisms in CYP4F2, VKORC1, and CYP2C9 significantly influence catabolic rates and vitamin K recycling. Additionally, the process is interconnected with the vitamin K cycle, where VKORC1 reduces vitamin K epoxide back to the active hydroquinone form, limiting catabolism. Hormonal and dietary factors, including vitamin E and other antioxidants, may also affect catabolic flux. In the brain, phylloquinone catabolism may be regulated by oxidative stress and ferroptosis-related pathways involving xCT and GPX4.
phylloquinone catabolic process and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CYP4F2 | Warfarin dose variability, vitamin K status | Knockout or point-mutation cell lines to assess enzyme activity |
| VKORC1 | Vitamin K-dependent clotting factor deficiency, warfarin resistance | Knock-in of human variants in hepatocyte-like cells |
| GGCX | Combined deficiency of vitamin K-dependent clotting factors | CRISPR knockout in HepG2 cells followed by carboxylation assays |
| GPX4 | Ferroptosis, neurodegeneration | Overexpression or knockout in neuronal cell lines under oxidative stress |
| SLC7A11 (xCT) | Ferroptosis, oxidative stress | Point mutations to disrupt transport function; measure lipid peroxidation |
Vitamin K deficiency bleeding (VKDB)
Impaired phylloquinone catabolism or inadequate intake can lead to vitamin K deficiency, which is particularly dangerous in newborns and can cause vitamin K deficiency bleeding. Prophylactic vitamin K administration is standard, but understanding catabolic rates helps optimize dosing strategies.
Anticoagulation and warfarin therapy
Warfarin inhibits VKORC1, disrupting the vitamin K cycle and indirectly affecting phylloquinone catabolism. Genetic variants in CYP4F2 and CYP2C9 alter catabolic rates, influencing warfarin dose requirements and bleeding risk.
Neurodegeneration and ferroptosis
Recent studies show that phylloquinone attenuates oxygen-glucose deprivation-induced neuronal injury by inhibiting ferroptosis via the xCT/GPX4 pathway. This suggests that phylloquinone catabolites may have neuroprotective roles, and dysregulation could contribute to neurodegenerative conditions.
Bone health and osteoporosis
Vitamin K1 is essential for gamma-carboxylation of osteocalcin, a bone matrix protein. Altered phylloquinone catabolism may affect bone mineral density and fracture risk, although the exact mechanisms are still under investigation.
From phylloquinone catabolic process-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does CYP4F2 knockout alter phylloquinone catabolic rate? | CRISPR knockout in HepG2 or primary hepatocytes |
| How do VKORC1 polymorphisms affect vitamin K recycling and catabolism? | Knock-in of variant alleles in HEK293 or HepG2 cells |
| Can phylloquinone catabolites protect neurons from ferroptosis? | Overexpression of GPX4 or xCT in neuronal cell lines with phylloquinone treatment |
| What is the role of UGT1A1 in vitamin K metabolite conjugation? | Knockout of UGT1A1 in liver cell lines followed by metabolite profiling |
| Does tagged CYP4F2 localize to specific organelles? | Knock-in of fluorescent tags (e.g., GFP) at the endogenous locus |
| Can CRISPR library screening identify novel catabolic genes? | Genome-wide knockout library in vitamin K-treated cells followed by metabolite analysis |
How to Study the phylloquinone catabolic process Process
| Method | What It Measures | Typical Application |
|---|---|---|
| LC-MS/MS | Phylloquinone and catabolite concentrations | Vitamin K status assessment in plasma and tissues |
| CRISPR knockout | Loss-of-function effects on catabolic flux | Identifying essential catabolic genes |
| RNA-seq | Transcriptional changes in catabolic enzymes | Discovering regulatory pathways |
| Proteomics | Protein expression and modifications | Validating enzyme candidates |
| Lipid peroxidation assay | Ferroptosis induction | Neuroprotection studies with phylloquinone |
| GPX4 activity assay | Antioxidant enzyme function | Mechanistic studies of ferroptosis inhibition |
| Cell viability assay | Cytoprotective effects | Testing phylloquinone catabolites in neuronal cells |
Metabolite profiling by LC-MS/MS
Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the gold standard for measuring phylloquinone and its catabolites in biological samples. This method allows quantification of vitamin K1 and its oxidized metabolites, providing direct evidence of catabolic flux.
CRISPR-based gene editing
CRISPR/Cas9 technology enables knockout, point mutation, knock-in, and overexpression of candidate genes involved in phylloquinone catabolism. These models help establish causal roles of enzymes like CYP4F2 and VKORC1 in the catabolic pathway.
Transcriptomics and proteomics
RNA-seq and proteomics can identify genes and proteins differentially expressed under varying vitamin K status, revealing regulatory networks of the catabolic process. These approaches are useful for discovering novel catabolic enzymes.
Ferroptosis and oxidative stress assays
To study the link between phylloquinone catabolism and ferroptosis, researchers use lipid peroxidation assays, GPX4 activity measurements, and cell viability tests under oxidative stress. These methods help elucidate neuroprotective mechanisms.
How CRISPR Can Be Used to Study GO:0042376 phylloquinone catabolic process
Knockout
CRISPR knockout of genes such as CYP4F2 or UGT1A1 in liver cell lines can abolish or reduce phylloquinone catabolism, allowing researchers to measure the impact on vitamin K metabolite levels and downstream effects. Knockout models are essential for establishing causality in the catabolic pathway.
Point Mutation
Introducing specific point mutations (e.g., in VKORC1 or CYP4F2) that mimic human polymorphisms can reveal how single amino acid changes affect enzyme activity and catabolic rate. These models are valuable for personalized medicine research.
Knock-in
Knock-in of tagged versions of catabolic enzymes (e.g., GFP-CYP4F2) enables live-cell imaging and localization studies, providing insights into where phylloquinone catabolism occurs within cells. Knock-in of human variant alleles into model organisms can also model disease susceptibility.
Overexpression
Overexpression of candidate genes like GPX4 or xCT in neuronal cells can enhance phylloquinone-mediated ferroptosis inhibition, helping to dissect the neuroprotective pathway. Overexpression models are useful for gain-of-function studies.
How EDITGENE Supports phylloquinone catabolic process Research
Researchers studying phylloquinone catabolic process-related genes often need to determine whether a candidate gene is causally involved in vitamin K1 breakdown, how specific mutations alter enzyme activity, or whether overexpression confers a protective phenotype. EDITGENE provides end-to-end CRISPR solutions to address these questions with precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for phylloquinone catabolic process research.
Frequently Asked Questions About phylloquinone catabolic process
What is phylloquinone catabolic process?
It is the biochemical breakdown of phylloquinone (vitamin K1), a quinone-derived compound synthesized by green plants, as defined by GO:0042376.
What genes are involved in phylloquinone catabolic process?
Key genes include CYP4F2, VKORC1, GGCX, UGT1A1, and SULT1A1, which encode enzymes that oxidize, reduce, or conjugate phylloquinone and its metabolites.
How is phylloquinone catabolism measured?
It is typically measured by LC-MS/MS quantification of phylloquinone and its catabolites in plasma or tissues.
Why is vitamin K1 catabolism important for health?
It maintains vitamin K homeostasis, prevents toxicity, and influences coagulation, bone health, and possibly neuroprotection.
What diseases are linked to phylloquinone catabolic process?
Vitamin K deficiency bleeding, warfarin dose variability, and neurodegenerative conditions involving ferroptosis have been associated with altered catabolism.
Can CRISPR be used to study phylloquinone catabolic process?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models allow precise dissection of genes involved in the pathway.
What is the role of CYP4F2 in vitamin K1 catabolism?
CYP4F2 is a cytochrome P450 enzyme that oxidizes vitamin K1, contributing to its catabolism and influencing warfarin dose requirements.
How does phylloquinone relate to ferroptosis?
Phylloquinone attenuates ferroptosis by inhibiting lipid peroxidation via the xCT/GPX4 pathway, suggesting a neuroprotective role.
Is phylloquinone catabolism the same in plants and humans?
The core catabolic steps are similar, but plants synthesize phylloquinone while humans obtain it from diet and break it down for excretion.
What are the synonyms for phylloquinone catabolic process?
Synonyms include vitamin K1 catabolism, phylloquinone breakdown, phytomenadione catabolic process, and phytylmenaquinone catabolism.
Conclusion
The phylloquinone catabolic process (GO:0042376) is a fundamental biological pathway that governs the breakdown of vitamin K1, impacting coagulation, bone health, and emerging roles in ferroptosis and neuroprotection. Understanding its genetic and enzymatic regulation is essential for interpreting vitamin K status and developing therapeutic strategies. With advances in CRISPR-based models and metabolomics, researchers can now dissect the catabolic pathway with unprecedented precision. EDITGENE's suite of knockout, point mutation, knock-in, overexpression, and screening services empowers discovery in this field, from basic mechanism to translational applications.
References
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