GO:0019470 trans-4-hydroxy-L-proline catabolic process: Metabolism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0019470 describes the biochemical breakdown of trans-4-hydroxy-L-proline, a non-standard amino acid abundant in collagen.
• The catabolic process is initiated by stereospecific enzymes such as ALDH4A1, which oxidizes trans-4-hydroxy-L-proline to Δ1-pyrroline-5-carboxylate.
• This pathway is critical for cellular proline homeostasis and energy metabolism, and its dysfunction is linked to hyperprolinemia and other metabolic disorders.
• Microorganisms, including Escherichia coli and Clostridioides difficile, utilize trans-4-hydroxy-L-proline catabolism for carbon and nitrogen sources, influencing gut microbial ecology.
• Studying this process aids metabolic engineering for trans-4-hydroxy-L-proline production, a valuable chiral building block for pharmaceuticals.
• CRISPR-based knockout, knock-in, and overexpression models enable precise dissection of the enzymatic steps and regulatory networks of this pathway.
Description
trans-4-Hydroxy-L-proline (Hyp) is a non-proteinogenic amino acid primarily formed by post-translational hydroxylation of proline residues in collagen. Its catabolic process, annotated as GO:0019470, encompasses the enzymatic reactions that degrade Hyp into central metabolites, thereby contributing to amino acid recycling and energy production. This pathway is conserved from bacteria to mammals and plays a pivotal role in collagen turnover, proline homeostasis, and microbial carbon/nitrogen metabolism. Understanding the catabolic process is essential for researchers in metabolic engineering, microbiology, and human genetics, as it intersects with disease mechanisms such as hyperprolinemia and potential therapeutic targets.
trans-4-hydroxy-L-proline catabolic process At A Glance
| GO ID | GO:0019470 |
|---|---|
| GO term | trans-4-hydroxy-L-proline catabolic process |
| Ontology | biological_process |
| Synonym | 4-hydroxyproline breakdown, 4-hydroxyproline catabolism, 4-hydroxyproline degradation |
| Major function | Breakdown of trans-4-hydroxy-L-proline to yield energy and metabolic intermediates |
| Key enzyme | ALDH4A1 (mitochondrial Δ1-pyrroline-5-carboxylate dehydrogenase) |
| Subcellular location | Mitochondrial matrix in eukaryotes |
| Pathway context | Proline metabolism, collagen degradation, microbial Stickland reaction |
What Is GO:0019470?
GO:0019470, trans-4-hydroxy-L-proline catabolic process, is defined as the chemical reactions and pathways resulting in the breakdown of trans-4-hydroxy-L-proline. This biological process includes the stereospecific oxidation, deamination, and subsequent conversion of Hyp into intermediates such as Δ1-pyrroline-5-carboxylate, which can enter the tricarboxylic acid cycle or be further metabolized.
Why Is trans-4-hydroxy-L-proline catabolic process Important in Cell Biology?
The catabolism of trans-4-hydroxy-L-proline is fundamental to amino acid homeostasis and energy metabolism. In humans, defects in this pathway can lead to hyperprolinemia and associated neurological symptoms. In microbial communities, especially in the gut, the ability to degrade Hyp influences competition and colonization by pathogens such as Clostridioides difficile. Moreover, the pathway is a target for metabolic engineering to produce Hyp, a chiral synthon for drug synthesis. Thus, understanding GO:0019470 has broad implications for medicine, microbiology, and biotechnology.
• Maintains proline and hydroxyproline balance in cells, preventing toxic accumulation.
• Supports collagen turnover by degrading hydroxyproline released from collagen breakdown.
• Provides carbon and nitrogen sources for microbial growth, impacting gut microbiota composition.
• Serves as a target for metabolic engineering of trans-4-hydroxy-L-proline production.
• Dysregulation is linked to hyperprolinemia type II and neurological disorders.
• Influences the virulence and colonization of Clostridioides difficile via Stickland reaction.
• Enables the use of Hyp as a sole carbon source in Bacillus cereus and other bacteria.
• Provides a model for studying stereospecific enzyme mechanisms and inhibitor design.
What Happens During trans-4-hydroxy-L-proline catabolic process?
Uptake and Initial Oxidation
In simple terms: The cell takes in trans-4-hydroxy-L-proline and starts breaking it down by removing electrons.
In bacteria and eukaryotes, trans-4-hydroxy-L-proline is transported into the cell and then oxidized by specific dehydrogenases. In mammals, the mitochondrial enzyme ALDH4A1 catalyzes the NAD+-dependent oxidation of trans-4-hydroxy-L-proline to Δ1-pyrroline-5-carboxylate (P5C). This step is stereospecific, ensuring that only the trans-4-hydroxy-L isomer is degraded.
Formation of Δ1-Pyrroline-5-carboxylate (P5C)
In simple terms: The oxidized product is a reactive intermediate that can be converted into other useful molecules.
The oxidation of trans-4-hydroxy-L-proline yields P5C, a central intermediate in proline metabolism. P5C can spontaneously cyclize or be further metabolized by P5C dehydrogenase to glutamate, linking Hyp catabolism to the tricarboxylic acid cycle and amino acid biosynthesis.
Microbial Stickland Reaction and Energy Conservation
In simple terms: Some bacteria use hydroxyproline as a fuel in a coupled oxidation-reduction process to generate energy.
In Clostridioides difficile and related commensal clostridia, trans-4-hydroxy-L-proline serves as a precursor for the Stickland reaction, where it is oxidized and another amino acid is reduced, generating ATP. This differential metabolism impacts the pathogen's ability to colonize the gut.
Enzymatic Diversity and Stereospecificity
In simple terms: Different enzymes have evolved to recognize and break down only the trans-4-hydroxy-L form.
Structural studies of ALDH4A1 reveal a stereospecific binding pocket that accommodates trans-4-hydroxy-L-proline but excludes other isomers, ensuring selective catabolism. In bacteria such as Bacillus cereus, distinct enzymes may catalyze similar reactions, highlighting evolutionary diversity.
Integration with Central Metabolism
In simple terms: The breakdown products enter mainstream metabolic pathways to produce energy and building blocks.
The end products of trans-4-hydroxy-L-proline catabolism, such as glutamate and pyruvate, feed into the TCA cycle and gluconeogenesis, supporting cellular energy needs and biosynthetic processes.
Key Genes Involved in GO:0019470 trans-4-hydroxy-L-proline catabolic process
The following genes and proteins are experimentally implicated in the catabolism of trans-4-hydroxy-L-proline, based on published biochemical and genetic studies.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ALDH4A1 | Mitochondrial dehydrogenase that oxidizes trans-4-hydroxy-L-proline to P5C | Target for structural and inhibitor studies; linked to hyperprolinemia |
| PRODH | Proline dehydrogenase, may also act on hydroxyproline in some organisms | Context-dependent role in proline/hydroxyproline catabolism |
| P5CDH | P5C dehydrogenase, converts P5C to glutamate | Connects Hyp catabolism to glutamate metabolism |
| putA | Bifunctional proline dehydrogenase/P5C dehydrogenase in bacteria | Model for microbial Hyp utilization |
| prdA | D-proline reductase subunit, involved in Stickland reaction | Impact on C. difficile metabolism |
| grdA | Glycine reductase subunit, coupled to Stickland reaction | Energy conservation in Clostridia |
| hypD | Hydroxyproline dehydratase, initial step in bacterial Hyp degradation | Biotechnological production of Hyp |
| hypE | Putative hydroxyproline epimerase | Stereochemical diversity |
| aldh4a1 | Zebrafish ortholog of ALDH4A1 | Developmental and metabolic studies |
| PRODH2 | Hydroxyproline dehydrogenase in mammals | Alternative enzyme for Hyp catabolism |
| LhpA | L-hydroxyproline aminotransferase in bacteria | Microbial niche adaptation |
| LhpB | L-hydroxyproline dehydratase | Stickland reaction precursor |
| LhpC | Δ1-pyrroline-5-carboxylate dehydrogenase | Links to central metabolism |
| LhpD | Putative hydroxyproline racemase | Substrate specificity |
| LhpE | Transcriptional regulator of lhp operon | Regulation of Hyp catabolism |
| aldh4a1 | Mouse knockout models | In vivo function of ALDH4A1 |
| p5cs | P5C synthetase, reverse pathway | Balance between synthesis and degradation |
| oat | Ornithine aminotransferase, links to P5C | Interplay with arginine metabolism |
How Is trans-4-hydroxy-L-proline catabolic process Regulated?
The trans-4-hydroxy-L-proline catabolic process is regulated at multiple levels. In bacteria, the lhp operon encoding hydroxyproline degradation enzymes is induced by the presence of trans-4-hydroxy-L-proline and subject to catabolite repression. In mammals, ALDH4A1 expression is influenced by nutritional status and hormonal signals, though specific transcription factors remain to be fully elucidated. Additionally, the pathway is feedback-regulated by P5C and glutamate levels, which modulate enzyme activity.
trans-4-hydroxy-L-proline catabolic process and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ALDH4A1 | Hyperprolinemia type II | Knockout mouse, patient-derived fibroblasts |
| ALDH4A1 | Neurological symptoms | Neuronal cell lines with point mutations |
| lhp operon | C. difficile colonization | In vitro gut models, knockout C. difficile strains |
| PRODH | Proline metabolism disorders | Overexpression in HEK293 cells |
| P5CDH | Hyperprolinemia type II | CRISPR knock-in of patient mutations |
Hyperprolinemia and Neurological Disorders
Deficiency in ALDH4A1, the enzyme that catalyzes the oxidation of trans-4-hydroxy-L-proline, leads to hyperprolinemia type II, characterized by elevated proline and hydroxyproline levels and associated with seizures and intellectual disability. This highlights the importance of the catabolic process in maintaining amino acid homeostasis.
Clostridioides difficile Infection
The ability of Clostridioides difficile to utilize trans-4-hydroxy-L-proline as a Stickland reaction precursor confers a metabolic advantage in the gut, influencing pathogen colonization and virulence. Commensal clostridia that also degrade Hyp may compete with C. difficile, suggesting a role for this pathway in microbiome-mediated resistance.
Collagen Turnover and Fibrotic Diseases
Because trans-4-hydroxy-L-proline is a major component of collagen, its catabolism is integral to collagen turnover. Dysregulation of this process may contribute to fibrotic disorders where collagen deposition is altered, though direct evidence is still emerging.
From trans-4-hydroxy-L-proline catabolic process-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Enzyme kinetics of ALDH4A1 | Recombinant protein overexpression in E. coli |
| Role of Hyp catabolism in C. difficile | Knockout of lhp genes in C. difficile |
| Effect of ALDH4A1 deficiency in vivo | ALDH4A1 knockout mouse |
| Stereospecific inhibition of ALDH4A1 | Point mutations in active site |
| Metabolic engineering for Hyp production | Overexpression of hyp genes in E. coli |
| Regulation of lhp operon | Transcriptional reporter knock-in |
How to Study the trans-4-hydroxy-L-proline catabolic process Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Enzyme activity assay | NADH formation from Hyp oxidation | Kinetic studies of ALDH4A1 |
| LC-MS/MS metabolomics | Levels of Hyp and intermediates | Pathway flux in cells |
| CRISPR knockout | Loss of gene function | Phenotypic analysis in cell lines |
| RNA-seq | Transcriptional changes | Regulation of lhp operon |
| Site-directed mutagenesis | Enzyme activity of mutants | Structure-function studies |
| Bacterial growth assays | Utilization of Hyp as carbon source | Microbial catabolism |
| Isothermal titration calorimetry | Binding affinity of substrates/inhibitors | Drug design |
| Immunoblotting | Protein expression levels | Validation of knockout/overexpression |
Enzyme Activity Assays
In vitro assays using purified ALDH4A1 or bacterial lysates can measure the conversion of trans-4-hydroxy-L-proline to P5C by monitoring NADH production at 340 nm. These assays are essential for determining kinetic parameters and inhibitor efficacy.
Metabolic Profiling
LC-MS/MS-based metabolomics can quantify trans-4-hydroxy-L-proline and its catabolic intermediates (e.g., P5C, glutamate) in cell culture or tissue samples, providing a snapshot of pathway flux.
Genetic Knockout and Complementation
CRISPR-Cas9 knockout of ALDH4A1 or bacterial lhp genes followed by complementation with wild-type or mutant alleles allows functional dissection of the pathway in vivo.
Transcriptional Analysis
RNA-seq and qRT-PCR can reveal expression changes in catabolic genes under different conditions, such as Hyp availability or infection.
How CRISPR Can Be Used to Study GO:0019470 trans-4-hydroxy-L-proline catabolic process
Knockout
CRISPR-Cas9-mediated knockout of ALDH4A1 or bacterial lhp genes enables the study of loss-of-function phenotypes, such as accumulation of trans-4-hydroxy-L-proline and altered metabolic flux. These models are valuable for validating the enzyme's role in catabolism and for identifying compensatory pathways.
Point Mutation
Introducing specific point mutations in the active site of ALDH4A1 (e.g., residues involved in substrate binding) via CRISPR base editing or homology-directed repair allows precise structure-function analysis and mimics patient mutations associated with hyperprolinemia.
Knock-in
Knock-in of tagged ALDH4A1 (e.g., FLAG or GFP) using CRISPR facilitates localization and interaction studies, while knock-in of disease-associated alleles in cell lines provides models for hyperprolinemia type II.
Overexpression
CRISPR activation (CRISPRa) or lentiviral overexpression of ALDH4A1 and other catabolic genes can enhance pathway flux, useful for metabolic engineering of trans-4-hydroxy-L-proline production or for studying pathway saturation.
How EDITGENE Supports trans-4-hydroxy-L-proline catabolic process Research
Researchers studying trans-4-hydroxy-L-proline catabolic process-related genes often need to determine whether a candidate gene is causally involved in the pathway, which requires precise genetic models. EDITGENE provides a comprehensive suite of CRISPR services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for trans-4-hydroxy-L-proline catabolic process research.
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GOT2 Knockout HEK293 Cell Line | EDJ-KQ1967 | Human | 2806 | Details Get a Quote |
| PRODH Knockout HEK293 Cell Line | EDJ-KQ5543 | Human | 5625 | Details Get a Quote |
| ALDH4A1 Knockout HEK293 Cell Line | EDJ-KQ6319 | Human | 8659 | Details Get a Quote |
| HOGA1 Knockout HEK293 Cell Line | EDJ-KQ7397 | Human | 112817 | Details Get a Quote |
| PRODH2 Knockout HEK293 Cell Line | EDJ-KQ14160 | Human | 58510 | Details Get a Quote |
| GOT2 Knockout HCT 116 Cell Line | EDJ-KQ21936 | Human | 2806 | Details Get a Quote |
| GOT2 Knockout HeLa Cell Line | EDJ-KQ21937 | Human | 2806 | Details Get a Quote |
| HOGA1 Knockout HCT 116 Cell Line | EDJ-KQ31183 | Human | 112817 | Details Get a Quote |
| GOT2 Knockout A-549 Cell Line | EDJ-KQ20640 | Human | 2806 | Details Get a Quote |
| PRODH Knockout HCT 116 Cell Line | EDJ-KQ28801 | Human | 5625 | Details Get a Quote |
| ALDH4A1 Knockout A-549 Cell Line | EDJ-KQ30244 | Human | 8659 | Details Get a Quote |
| ALDH4A1 Knockout HCT 116 Cell Line | EDJ-KQ30245 | Human | 8659 | Details Get a Quote |
| ALDH4A1 Knockout HeLa Cell Line | EDJ-KQ30246 | Human | 8659 | Details Get a Quote |
| HOGA1 Knockout A-549 Cell Line | EDJ-KQ32550 | Human | 112817 | Details Get a Quote |
| PRODH Knockout HeLa Cell Line | EDJ-KQ54223 | Human | 5625 | Details Get a Quote |
Displaying Records 1 To 15 Of 20 Records
Frequently Asked Questions About trans-4-hydroxy-L-proline catabolic process
What is trans-4-hydroxy-L-proline catabolic process?
It is the biochemical breakdown of trans-4-hydroxy-L-proline, a non-standard amino acid, into central metabolites like P5C and glutamate, as defined by GO:0019470.
What genes are involved in trans-4-hydroxy-L-proline catabolic process?
Key genes include ALDH4A1 in mammals and the lhp operon in bacteria, among others.
Which enzyme catalyzes the first step of trans-4-hydroxy-L-proline catabolism?
ALDH4A1 catalyzes the NAD+-dependent oxidation of trans-4-hydroxy-L-proline to Δ1-pyrroline-5-carboxylate.
How is trans-4-hydroxy-L-proline catabolism related to disease?
Defects in ALDH4A1 cause hyperprolinemia type II, and the pathway influences Clostridioides difficile colonization.
What is the role of trans-4-hydroxy-L-proline catabolism in bacteria?
Bacteria use it as a carbon and nitrogen source, and in Clostridia it participates in the Stickland reaction for energy conservation.
Can trans-4-hydroxy-L-proline catabolism be studied with CRISPR?
Yes, CRISPR knockout, knock-in, and overexpression models allow precise manipulation of catabolic genes for functional studies.
What are the synonyms for GO:0019470?
Synonyms include 4-hydroxyproline breakdown, 4-hydroxyproline catabolism, and 4-hydroxyproline degradation.
Why is trans-4-hydroxy-L-proline catabolism important for metabolic engineering?
Understanding the pathway enables engineering of microbial strains for efficient production of trans-4-hydroxy-L-proline, a valuable chiral compound.
Which model organisms are used to study trans-4-hydroxy-L-proline catabolism?
Escherichia coli, Bacillus cereus, Clostridioides difficile, and mouse models are commonly used.
What methods are used to measure trans-4-hydroxy-L-proline catabolic activity?
Enzyme assays, LC-MS/MS metabolomics, and genetic knockout studies are standard approaches.
Conclusion
The trans-4-hydroxy-L-proline catabolic process (GO:0019470) is a conserved metabolic pathway with critical roles in amino acid homeostasis, microbial ecology, and biotechnology. Dysregulation of this pathway is linked to hyperprolinemia and influences pathogen colonization. Advances in CRISPR-based models and metabolomics continue to unravel its mechanistic details, offering opportunities for therapeutic intervention and metabolic engineering. EDITGENE's suite of CRISPR services empowers researchers to dissect this pathway with precision.
References
- 1. Zhang Z et al.. 2021. Metabolic engineering strategy for synthetizing trans-4-hydroxy-L-proline in microorganisms.. Microb Cell Fact 20(1):87 PMID: 33882914
- 2. Chen X et al.. 2021. Chassis engineering of Escherichia coli for trans-4-hydroxy-l-proline production.. Microb Biotechnol 14(2):392-402 PMID: 32396278
- 4. Bogner AN et al.. 2021. Structural basis for the stereospecific inhibition of the dual proline/hydroxyproline catabolic enzyme ALDH4A1 by trans-4-hydroxy-L-proline.. Protein Sci 30(8):1714-1722 PMID: 34048122
- 5. Zhang HL et al.. 2018. Efficient production of trans-4-Hydroxy-l-proline from glucose by metabolic engineering of recombinant Escherichia coli.. Lett Appl Microbiol 66(5):400-408 PMID: 29432647
- 7. Reed AD et al.. 2022. The Stickland Reaction Precursor trans-4-Hydroxy-l-Proline Differentially Impacts the Metabolism of Clostridioides difficile and Commensal Clostridia.. mSphere 7(2):e0092621 PMID: 35350846
- 8. Wang XM et al.. 2021. Isolation of a Bacillus cereus strain HBL-AI and its application for production of Trans-4-hydroxy-l-proline.. Lett Appl Microbiol 72(1):53-59 PMID: 32955742
