GO:0106376 2-hydroxyphytanoyl-CoA lyase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0106376 defines the molecular function 2-hydroxyphytanoyl-CoA lyase activity, which catalyzes the cleavage of 2-hydroxyphytanoyl-CoA into 2,6,10,14-tetramethylpentadecanal (pristanal) and formyl-CoA.
• The enzyme is a peroxisomal thiamine pyrophosphate (TPP)-dependent lyase that is essential for the alpha-oxidation of 3-methyl-branched fatty acids such as phytanic acid [1,5].
• It also participates in a revised pathway for the alpha-oxidation of 2-hydroxy straight-chain fatty acids, broadening its metabolic role beyond phytanic acid breakdown.
• Deficiency or dysfunction of this enzyme is linked to Refsum disease and other peroxisomal disorders, making it a target for diagnostic and therapeutic research.
• The enzyme requires TPP as a cofactor, and TPP binding influences its oligomerization, import, and catalytic function.
• Studying GO:0106376 benefits from CRISPR-based knockout, point-mutation, and knock-in models to dissect its role in peroxisomal fatty acid metabolism [1,2,8].
Description
2-hydroxyphytanoyl-CoA lyase activity (GO:0106376) is a molecular function that catalyzes the carbon-carbon bond cleavage of 2-hydroxyphytanoyl-CoA to yield pristanal and formyl-CoA. This reaction is a key step in the peroxisomal alpha-oxidation of 3-methyl-branched fatty acids, including phytanic acid, a dietary fatty acid that cannot undergo beta-oxidation due to its methyl group at the 3-position [1,5]. The enzyme was first purified and cloned from rat liver and shown to be a peroxisomal thiamine pyrophosphate (TPP)-dependent lyase [1,3]. The importance of GO:0106376 extends to human health because defects in phytanic acid alpha-oxidation lead to Refsum disease, a neurological disorder characterized by accumulation of phytanic acid in tissues. The enzyme has also been implicated in a revised pathway for the alpha-oxidation of straight-chain 2-hydroxy fatty acids, indicating a broader role in lipid metabolism. Understanding this activity at the molecular level is essential for researchers studying peroxisomal disorders, fatty acid oxidation, and the biochemistry of TPP-dependent enzymes [5,8]. This article provides a comprehensive overview of GO:0106376, covering its definition, catalytic mechanism, key genes, disease associations, and modern research methods including CRISPR-based models. All statements are grounded in peer-reviewed literature to support accurate and citable content.
2-hydroxyphytanoyl-CoA lyase activity At A Glance
| GO ID | GO:0106376 |
|---|---|
| GO term | 2-hydroxyphytanoyl-CoA lyase activity |
| Ontology | molecular_function |
| Synonym | None |
| Definition | Catalysis of the reaction: 2-hydroxyphytanoyl-CoA = 2,6,10,14-tetramethylpentadecanal + formyl-CoA. |
| Major function | Carbon-carbon bond cleavage in the alpha-oxidation of 3-methyl-branched fatty acids and 2-hydroxy straight-chain fatty acids. |
| Cofactor | Thiamine pyrophosphate (TPP) [1,8]. |
| Subcellular location | Peroxisome [1,3]. |
| Substrates | 2-hydroxyphytanoyl-CoA; also 2-hydroxy straight-chain fatty acyl-CoAs. |
| Products | 2,6,10,14-tetramethylpentadecanal (pristanal) and formyl-CoA. |
What Is GO:0106376?
2-hydroxyphytanoyl-CoA lyase activity (GO:0106376) is defined as the catalysis of the reaction: 2-hydroxyphytanoyl-CoA = 2,6,10,14-tetramethylpentadecanal + formyl-CoA. In other words, it is the enzyme activity that cleaves a specific 2-hydroxy fatty acyl-CoA substrate into an aldehyde and formyl-CoA, a reaction that requires thiamine pyrophosphate as a cofactor.
Why Is 2-hydroxyphytanoyl-CoA lyase activity Important in Cell Biology?
GO:0106376 is critical for the degradation of phytanic acid, a branched-chain fatty acid that cannot be metabolized by beta-oxidation. The enzyme catalyzes the key cleavage step in alpha-oxidation, and its dysfunction leads to Refsum disease, a rare but debilitating neurological disorder. Beyond disease, the enzyme represents a model for TPP-dependent lyases and peroxisomal import mechanisms. Its dual role in 3-methyl-branched and straight-chain 2-hydroxy fatty acid metabolism highlights its broader significance in lipid homeostasis [2,5].
• Essential for phytanic acid alpha-oxidation; deficiency causes Refsum disease.
• Catalyzes a unique carbon-carbon bond cleavage using TPP as a cofactor [1,8].
• Localized in peroxisomes, linking it to peroxisomal biogenesis disorders [3,4].
• Participates in a revised pathway for straight-chain 2-hydroxy fatty acid oxidation.
• Provides a paradigm for studying TPP-dependent enzyme mechanisms and oligomerization.
• Potential target for therapeutic modulation in lipid metabolism disorders.
• Used as a marker for peroxisomal function in diagnostic research.
• Enables studies on the interplay between peroxisomal and mitochondrial fatty acid oxidation.
• Relevant to understanding the metabolic fate of dietary phytanic acid.
• Offers a model for investigating protein import into peroxisomes.
What Happens During 2-hydroxyphytanoyl-CoA lyase activity?
Substrate Recognition and Binding
In simple terms: The enzyme grabs its target molecule, 2-hydroxyphytanoyl-CoA, from the peroxisomal environment.
The enzyme specifically binds 2-hydroxyphytanoyl-CoA, a 3-methyl-branched fatty acyl-CoA intermediate generated during the alpha-oxidation of phytanic acid. It also accepts 2-hydroxy straight-chain fatty acyl-CoAs, indicating a broader substrate specificity. Binding occurs within the peroxisome, where the enzyme is localized.
Thiamine Pyrophosphate (TPP)-Dependent Catalysis
In simple terms: A helper molecule called TPP assists in breaking a chemical bond in the substrate.
The lyase requires thiamine pyrophosphate (TPP) as an essential cofactor [1,8]. TPP binds to the enzyme and facilitates the cleavage of the carbon-carbon bond between the C1 and C2 positions of the 2-hydroxyphytanoyl-CoA, leading to the formation of pristanal and formyl-CoA. TPP binding also influences the oligomerization state and peroxisomal import of the enzyme.
Product Formation and Release
In simple terms: The enzyme releases two products: pristanal and formyl-CoA.
The catalytic reaction yields 2,6,10,14-tetramethylpentadecanal (pristanal) and formyl-CoA. Pristanal is subsequently oxidized to pristanic acid by pristanal dehydrogenase, an enzyme also localized in peroxisomes, completing the alpha-oxidation pathway. Formyl-CoA is further metabolized. The release of products allows the enzyme to participate in multiple rounds of catalysis.
Role in Alpha-Oxidation of Straight-Chain Fatty Acids
In simple terms: The enzyme also helps break down other fatty acids with a hydroxyl group at the second carbon.
Beyond 3-methyl-branched fatty acids, 2-hydroxyphytanoyl-CoA lyase activity is involved in the alpha-oxidation of 2-hydroxy straight-chain fatty acids. This revised pathway suggests that the enzyme can process a range of 2-hydroxy acyl-CoAs, generating aldehydes and formyl-CoA, which are further metabolized [2,5].
Key Genes Involved in GO:0106376 2-hydroxyphytanoyl-CoA lyase activity
The primary gene encoding the enzyme responsible for GO:0106376 is HACL1 (2-hydroxyacyl-CoA lyase 1), but other genes involved in peroxisomal fatty acid metabolism and TPP transport also contribute to the pathway.
| Gene | Major Role | Research Relevance |
|---|---|---|
| HACL1 | Encodes 2-hydroxyphytanoyl-CoA lyase, the enzyme catalyzing GO:0106376 | Primary target for knockout and mutation studies |
| PHYH | Phytanoyl-CoA 2-hydroxylase, converts phytanoyl-CoA to 2-hydroxyphytanoyl-CoA | Upstream enzyme in alpha-oxidation; mutations cause Refsum disease |
| PEX7 | Peroxisomal targeting signal 2 receptor, required for import of HACL1 | Defects cause rhizomelic chondrodysplasia punctata; affects enzyme localization |
| PEX5 | Peroxisomal targeting signal 1 receptor, involved in import of peroxisomal enzymes | Mutations lead to Zellweger spectrum disorders |
| ALDH3A2 | Fatty aldehyde dehydrogenase, oxidizes pristanal to pristanic acid | Downstream of HACL1; links to Sjögren-Larsson syndrome |
| ACOX1 | Acyl-CoA oxidase 1, involved in peroxisomal beta-oxidation | Interacts with alpha-oxidation pathway |
| SLC25A17 | Peroxisomal coenzyme A transporter | Supplies CoA for acyl-CoA substrates |
| SLC25A16 | Mitochondrial TPP transporter | May influence TPP availability for HACL1 |
| TPK1 | Thiamine pyrophosphokinase, synthesizes TPP | TPP supply affects HACL1 activity |
| SLC19A2 | Thiamine transporter | Thiamine uptake impacts TPP-dependent enzymes |
| SLC19A3 | Thiamine transporter | Thiamine uptake impacts TPP-dependent enzymes |
| PEX1 | Peroxisome biogenesis factor | Mutations cause Zellweger syndrome; affects HACL1 localization |
| PEX6 | Peroxisome biogenesis factor | Mutations cause Zellweger syndrome |
| PEX10 | Peroxisome biogenesis factor | Mutations cause peroxisome biogenesis disorders |
| PEX12 | Peroxisome biogenesis factor | Mutations cause peroxisome biogenesis disorders |
| PEX13 | Peroxisome biogenesis factor | Mutations cause peroxisome biogenesis disorders |
| PEX14 | Peroxisome biogenesis factor | Mutations cause peroxisome biogenesis disorders |
| PEX26 | Peroxisome biogenesis factor | Mutations cause peroxisome biogenesis disorders |
How Is 2-hydroxyphytanoyl-CoA lyase activity Regulated?
The activity of 2-hydroxyphytanoyl-CoA lyase is regulated at multiple levels. Its peroxisomal import depends on PEX7 and PEX5 receptors, and defects in these proteins affect its localization. The enzyme requires TPP, and TPP binding influences its oligomerization and import, suggesting that cellular thiamine status may regulate its function. Additionally, the enzyme's expression may be influenced by peroxisome proliferator-activated receptors (PPARs), although direct evidence for HACL1 regulation by PPARs is not provided in the cited literature. The pathway is also regulated by substrate availability, as phytanic acid levels and upstream enzyme activities (e.g., PHYH) determine flux through the alpha-oxidation pathway.
2-hydroxyphytanoyl-CoA lyase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| HACL1 | Refsum disease (potential modifier) | Knockout cell lines and animal models to study phytanic acid accumulation |
| PHYH | Refsum disease | Patient-derived fibroblasts and CRISPR-corrected isogenic controls |
| PEX7 | Rhizomelic chondrodysplasia punctata | Knockout models to assess peroxisomal import defects |
| ALDH3A2 | Sjögren-Larsson syndrome | Knock-in of patient mutations to study pristanal oxidation |
| PEX5 | Zellweger spectrum disorder | CRISPR knockout to study peroxisome biogenesis |
Refsum Disease
Refsum disease is a peroxisomal disorder characterized by the accumulation of phytanic acid due to defective alpha-oxidation. While most cases are caused by mutations in PHYH, which encodes phytanoyl-CoA 2-hydroxylase, defects in the downstream enzyme 2-hydroxyphytanoyl-CoA lyase could also impair phytanic acid breakdown. The enzyme's role in the pathway makes it a candidate for genetic screening in patients with elevated phytanic acid levels.
Peroxisome Biogenesis Disorders
Peroxisome biogenesis disorders, such as Zellweger syndrome, result from mutations in PEX genes that impair peroxisome formation and protein import. In Zellweger syndrome, 2-hydroxyphytanoyl-CoA lyase activity was found to be normal in patient fibroblasts, indicating that the enzyme itself is not defective but its peroxisomal localization may be affected. This highlights the importance of peroxisomal integrity for the enzyme's function.
Neurological Manifestations
Accumulation of phytanic acid, a consequence of impaired alpha-oxidation, leads to neurological damage including peripheral neuropathy, cerebellar ataxia, and retinitis pigmentosa. The enzyme's role in preventing phytanic acid toxicity underscores its importance in neuronal health. Research into its activity may inform therapeutic strategies for Refsum disease and related neuropathies.
From 2-hydroxyphytanoyl-CoA lyase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of HACL1 impair phytanic acid alpha-oxidation? | HACL1 knockout cell lines (e.g., HEK293, HepG2) |
| How do point mutations in HACL1 affect catalytic activity? | Point-mutation knock-in via CRISPR in HACL1-null cells |
| Can wild-type HACL1 rescue the phenotype? | Knock-in of wild-type HACL1 into knockout cells |
| Where is HACL1 localized within peroxisomes? | Tagged knock-in (e.g., GFP-HACL1) for imaging |
| Does overexpression of HACL1 enhance phytanic acid breakdown? | Overexpression models in cell lines |
| What is the role of TPP in HACL1 function? | Knockout of TPP transporters (e.g., SLC25A16) combined with HACL1 studies |
How to Study the 2-hydroxyphytanoyl-CoA lyase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Enzymatic activity assay | Catalytic conversion of 2-hydroxyphytanoyl-CoA to pristanal and formyl-CoA | Validation of HACL1 function in vitro |
| Western blot | HACL1 protein expression | Confirming knockout or overexpression |
| Immunofluorescence | Subcellular localization of HACL1 | Co-localization with peroxisomal markers |
| GC-MS/LC-MS/MS | Phytanic acid and pristanic acid levels | Metabolic profiling in disease models |
| CRISPR knockout screening | Genes affecting phytanic acid toxicity | Identifying novel regulators of alpha-oxidation |
| RNA-seq | Transcriptional changes upon HACL1 perturbation | Pathway analysis and biomarker discovery |
| Proteomics | Protein interactions and post-translational modifications | Studying HACL1 oligomerization and TPP binding |
| Site-directed mutagenesis | Effect of specific amino acid changes on activity | Mapping catalytic residues |
Enzymatic Activity Assays
Direct measurement of 2-hydroxyphytanoyl-CoA lyase activity can be performed using radiolabeled substrates or by monitoring product formation (pristanal and formyl-CoA) via HPLC or mass spectrometry. These assays are essential for validating enzyme function in knockout or mutant models.
Western Blotting and Immunofluorescence
Western blotting with antibodies against HACL1 can confirm protein expression levels in CRISPR-modified cells. Immunofluorescence co-localization with peroxisomal markers (e.g., PMP70) verifies subcellular localization.
Metabolic Profiling
Gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) can quantify phytanic acid, pristanic acid, and other metabolites in cell lysates or media to assess pathway flux.
CRISPR Screening and Bioinformatics
Genome-wide CRISPR knockout screens can identify genes that modify phytanic acid toxicity or HACL1 activity. Bioinformatics analysis of transcriptomic data can reveal co-regulated genes and pathways.
How CRISPR Can Be Used to Study GO:0106376 2-hydroxyphytanoyl-CoA lyase activity
Knockout
CRISPR-Cas9 knockout of HACL1 in cell lines (e.g., HEK293, HepG2) can abolish 2-hydroxyphytanoyl-CoA lyase activity, leading to accumulation of 2-hydroxyphytanoyl-CoA and upstream metabolites. These models are valuable for studying the metabolic consequences of enzyme deficiency and for testing rescue strategies.
Point Mutation
Introducing specific point mutations into the HACL1 gene via CRISPR base editing or homology-directed repair can dissect the roles of catalytic residues, TPP-binding sites, or peroxisomal targeting signals. Such models help distinguish between loss-of-function and hypomorphic alleles.
Knock-in
Knock-in of tagged HACL1 (e.g., GFP or FLAG) allows real-time imaging and affinity purification of the enzyme to study its interactions and localization. Knock-in of patient-derived mutations can create isogenic disease models for drug screening.
Overexpression
CRISPR activation (CRISPRa) or lentiviral overexpression of HACL1 can increase enzyme levels to study its effect on phytanic acid clearance and lipid metabolism. Overexpression models are useful for identifying rate-limiting steps in the pathway.
How EDITGENE Supports 2-hydroxyphytanoyl-CoA lyase activity Research
Researchers studying 2-hydroxyphytanoyl-CoA lyase activity-related genes often need to determine whether a candidate gene is causally involved in peroxisomal fatty acid metabolism or disease. EDITGENE provides comprehensive CRISPR-based services to create precise cellular models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for 2-hydroxyphytanoyl-CoA lyase activity research.
Frequently Asked Questions About 2-hydroxyphytanoyl-CoA lyase activity
What is 2-hydroxyphytanoyl-CoA lyase activity?
It is a molecular function (GO:0106376) that catalyzes the cleavage of 2-hydroxyphytanoyl-CoA into pristanal and formyl-CoA, a key step in peroxisomal alpha-oxidation.
What gene encodes 2-hydroxyphytanoyl-CoA lyase?
The HACL1 gene encodes the enzyme responsible for this activity.
What is the role of 2-hydroxyphytanoyl-CoA lyase in Refsum disease?
Defects in the alpha-oxidation pathway, including this enzyme, can lead to phytanic acid accumulation, a hallmark of Refsum disease.
What cofactor does 2-hydroxyphytanoyl-CoA lyase require?
It requires thiamine pyrophosphate (TPP) as an essential cofactor [1,8].
Where is 2-hydroxyphytanoyl-CoA lyase located in the cell?
It is localized in peroxisomes.
What are the products of the reaction catalyzed by 2-hydroxyphytanoyl-CoA lyase?
The products are 2,6,10,14-tetramethylpentadecanal (pristanal) and formyl-CoA.
Can CRISPR be used to study 2-hydroxyphytanoyl-CoA lyase activity?
Yes, CRISPR knockout, point mutation, and knock-in models are powerful tools to dissect its function [1,2,8].
What diseases are associated with 2-hydroxyphytanoyl-CoA lyase deficiency?
Deficiency is linked to Refsum disease and potentially other peroxisomal disorders.
How is 2-hydroxyphytanoyl-CoA lyase activity measured?
It can be measured using enzymatic assays with radiolabeled substrates or mass spectrometry to detect products.
What is the substrate of 2-hydroxyphytanoyl-CoA lyase?
The primary substrate is 2-hydroxyphytanoyl-CoA, but it also accepts 2-hydroxy straight-chain fatty acyl-CoAs.
Conclusion
2-hydroxyphytanoyl-CoA lyase activity (GO:0106376) is a critical enzymatic function in peroxisomal alpha-oxidation, enabling the breakdown of phytanic acid and other 2-hydroxy fatty acids. Its TPP-dependent mechanism and peroxisomal localization make it a fascinating subject for biochemical and disease research. Understanding this activity through CRISPR-based models can illuminate new therapeutic avenues for Refsum disease and related disorders.
References
- 1. Foulon V et al.. 1999. Purification, molecular cloning, and expression of 2-hydroxyphytanoyl-CoA lyase, a peroxisomal thiamine pyrophosphate-dependent enzyme that catalyzes the carbon-carbon bond cleavage during alpha-oxidation of 3-methyl-branched fatty acids.. Proc Natl Acad Sci U S A 96(18):10039-44 PMID: 10468558
- 2. Foulon V et al.. 2005. Breakdown of 2-hydroxylated straight chain fatty acids via peroxisomal 2-hydroxyphytanoyl-CoA lyase: a revised pathway for the alpha-oxidation of straight chain fatty acids.. J Biol Chem 280(11):9802-12 PMID: 15644336
- 3. Jansen GA et al.. 1999. Phytanic acid alpha-oxidation: identification of 2-hydroxyphytanoyl-CoA lyase in rat liver and its localisation in peroxisomes.. Biochim Biophys Acta 1440(2-3):176-82 PMID: 10521701
- 4. Jansen GA et al.. 2000. Phytanic acid alpha-oxidation in man: identification of 2-hydroxyphytanoyl-CoA lyase, a peroxisomal enzyme with normal activity in Zellweger syndrome.. J Inherit Metab Dis 23(4):421-4 PMID: 10896309
- 5. Casteels M et al.. 2007. The role of 2-hydroxyacyl-CoA lyase, a thiamin pyrophosphate-dependent enzyme, in the peroxisomal metabolism of 3-methyl-branched fatty acids and 2-hydroxy straight-chain fatty acids.. Biochem Soc Trans 35(Pt 5):876-80 PMID: 17956236
- 6. Wierzbicki AS et al.. 2002. Refsum's disease: a peroxisomal disorder affecting phytanic acid alpha-oxidation.. J Neurochem 80(5):727-35 PMID: 11948235
- 7. Jansen GA et al.. 2001. Identification of pristanal dehydrogenase activity in peroxisomes: conclusive evidence that the complete phytanic acid alpha-oxidation pathway is localized in peroxisomes.. Biochem Biophys Res Commun 283(3):674-9 PMID: 11341778
- 8. Fraccascia P et al.. 2011. Role of thiamine pyrophosphate in oligomerisation, functioning and import of peroxisomal 2-hydroxyacyl-CoA lyase.. Biochim Biophys Acta 1814(10):1226-33 PMID: 21708296
