GO:0018272 protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine: Post-Translational Modification, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0018272 describes the biological process in which a peptidyl-lysine residue is modified to form N6-pyridoxal phosphate-L-lysine, a covalent protein-pyridoxal-5-phosphate linkage.
• This process is a post-translational modification that attaches pyridoxal 5'-phosphate (PLP), the active form of vitamin B6, to specific lysine residues in proteins.
• The modification is distinct from non-covalent PLP binding and represents a stable covalent linkage that can influence protein function, stability, and interactions.
• Proteins undergoing this modification are often enzymes or regulatory proteins, and the linkage may serve roles in catalysis, redox sensing, or protein targeting.
• Research into GO:0018272 benefits from proteomics, site-specific mutagenesis, and CRISPR-based models to dissect its physiological relevance.
• Dysregulation of PLP-dependent processes has been linked to neurological and metabolic disorders, making this modification a potential area of disease research.
Description
The Gene Ontology term GO:0018272, protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine, defines a specific post-translational modification in which a lysine residue within a protein is covalently modified to form N6-pyridoxal phosphate-L-lysine. This process is part of the broader class of protein modifications that regulate enzyme activity, protein stability, and molecular interactions. Pyridoxal 5'-phosphate (PLP), the active form of vitamin B6, is a versatile cofactor involved in many enzymatic reactions, and its covalent attachment to proteins represents a unique regulatory mechanism. Understanding this modification is important because it can alter the chemical properties of the target protein, potentially affecting its catalytic activity or ability to interact with other molecules. Researchers studying this term are often interested in how PLP-dependent enzymes and other proteins are regulated in health and disease. The modification may also serve as a marker for specific cellular states or as a target for therapeutic intervention. Given the central role of PLP in metabolism, investigating GO:0018272 can provide insights into metabolic regulation, neurobiology, and disease mechanisms.
protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine At A Glance
| GO ID | GO:0018272 |
|---|---|
| GO term | protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine |
| Ontology | biological_process |
| Synonym | None |
| Major function | Covalent attachment of pyridoxal 5'-phosphate to a lysine residue in a protein, forming N6-pyridoxal phosphate-L-lysine |
| Definition | The modification of peptidyl-lysine to form N6-pyridoxal phosphate-L-lysine |
| Related molecules | Pyridoxal 5'-phosphate (PLP), lysine residues, target proteins |
| Biological context | Post-translational modification, cofactor attachment, enzyme regulation |
What Is GO:0018272?
GO:0018272 is defined as the modification of a peptidyl-lysine residue to form N6-pyridoxal phosphate-L-lysine. In other words, it is the covalent attachment of pyridoxal 5'-phosphate (PLP) to the epsilon-amino group of a lysine residue within a protein, resulting in a stable protein-PLP linkage. This process is a type of post-translational modification and is distinct from the non-covalent binding of PLP as a cofactor. The term is classified under the biological_process ontology aspect, indicating it is a biological process rather than a molecular function or cellular component.
Why Is protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine Important in Cell Biology?
GO:0018272 is important because it represents a specific and stable post-translational modification that can modulate protein function beyond the classic role of PLP as a non-covalent cofactor. Covalent PLP attachment can influence enzyme catalysis, protein stability, and interactions with other biomolecules, thereby impacting metabolic pathways and cellular signaling. Understanding this modification may reveal new regulatory mechanisms in vitamin B6 biology and provide insights into diseases linked to PLP metabolism, such as neurological disorders and metabolic syndromes.
• Provides a mechanism for covalent regulation of protein function by PLP.
• May affect enzyme activity and substrate specificity in PLP-dependent enzymes.
• Could serve as a marker for specific cellular metabolic states.
• Potential link to vitamin B6-related neurological and metabolic disorders.
• Offers a target for therapeutic intervention in diseases involving PLP dysregulation.
• Enables researchers to study protein-PLP interactions with site-specific precision.
• May influence protein-protein interactions and subcellular localization.
• Contributes to the diversity of post-translational modifications beyond phosphorylation and acetylation.
What Happens During protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine?
Recognition of Target Lysine Residues
In simple terms: The process starts when a specific lysine in a protein is chosen for modification.
The first step in GO:0018272 involves the recognition of a target lysine residue within a protein substrate. This recognition is likely mediated by the local sequence context and structural features that position the lysine for modification. The specificity of this process ensures that only certain proteins or specific lysine residues undergo covalent PLP attachment.
Activation and Attachment of Pyridoxal 5'-Phosphate
In simple terms: PLP, a form of vitamin B6, is chemically attached to the lysine.
Once the target lysine is recognized, pyridoxal 5'-phosphate (PLP) is covalently linked to the epsilon-amino group of the lysine, forming a Schiff base intermediate that can be stabilized as N6-pyridoxal phosphate-L-lysine. This step may require enzymatic catalysis or occur spontaneously under certain conditions, but the result is a stable protein-PLP adduct.
Conformational and Functional Consequences
In simple terms: The attachment changes the protein's shape or activity.
The formation of the covalent linkage can induce conformational changes in the target protein, potentially altering its catalytic activity, stability, or interactions with other molecules. This modification may also affect the protein's ability to bind substrates or cofactors, thereby modulating its biological function.
Reversibility and Regulation
In simple terms: The modification might be reversible or controlled by other factors.
While the covalent PLP-lysine linkage is generally stable, there may be mechanisms for its removal or regulation. Enzymes such as phosphatases or specific proteases could potentially reverse the modification, although this is not well characterized. The process may also be regulated by cellular PLP levels, which are influenced by vitamin B6 availability and metabolic state.
Key Genes Involved in GO:0018272 protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine
The following genes and proteins are relevant to the study of GO:0018272, either as targets of the modification or as enzymes that may catalyze or regulate the process.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PLPBP | Pyridoxal phosphate binding protein | May regulate PLP homeostasis and covalent attachment |
| PNPO | Pyridoxamine 5'-phosphate oxidase | Produces PLP, the substrate for the modification |
| PDXK | Pyridoxal kinase | Phosphorylates vitamin B6 to form PLP |
| ALAS1 | Delta-aminolevulinate synthase 1 | PLP-dependent enzyme, potential target of covalent modification |
| ALAS2 | Delta-aminolevulinate synthase 2 | PLP-dependent enzyme, potential target |
| GAD1 | Glutamate decarboxylase 1 | PLP-dependent enzyme, may undergo covalent PLP linkage |
| GAD2 | Glutamate decarboxylase 2 | PLP-dependent enzyme, potential target |
| AOX1 | Aldehyde oxidase 1 | PLP-binding protein, possible modification target |
| KYNU | Kynureninase | PLP-dependent enzyme, potential covalent modification |
| SHMT1 | Serine hydroxymethyltransferase 1 | PLP-dependent enzyme, may form covalent adduct |
| SHMT2 | Serine hydroxymethyltransferase 2 | PLP-dependent enzyme, potential target |
| CBS | Cystathionine beta-synthase | PLP-dependent enzyme, possible covalent linkage |
| CTH | Cystathionine gamma-lyase | PLP-dependent enzyme, potential target |
| ODC1 | Ornithine decarboxylase 1 | PLP-dependent enzyme, may undergo modification |
| GPT | Glutamic--pyruvic transaminase | PLP-dependent enzyme, potential target |
| GOT1 | Glutamic--oxaloacetic transaminase 1 | PLP-dependent enzyme, potential target |
| GOT2 | Glutamic--oxaloacetic transaminase 2 | PLP-dependent enzyme, potential target |
How Is protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine Regulated?
The regulation of GO:0018272 is likely tied to cellular levels of pyridoxal 5'-phosphate (PLP), which are controlled by vitamin B6 metabolism, including enzymes such as pyridoxal kinase (PDXK) and pyridoxamine 5'-phosphate oxidase (PNPO). Additionally, the modification may be influenced by the availability of target lysine residues and the presence of regulatory proteins that recognize specific sequence motifs. While direct regulatory mechanisms are not well defined, it is plausible that this process is subject to feedback regulation based on metabolic demand and PLP availability.
protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PDXK | Neurological disorders, vitamin B6 metabolism | Knockout cell lines, point mutations |
| PNPO | Pyridoxine-dependent epilepsy | Knock-in of patient mutations |
| GAD1 | Epilepsy, neurotransmitter imbalance | Overexpression and knockout models |
| SHMT1 | Cancer metabolism | CRISPR knockout in cancer cell lines |
| CBS | Homocystinuria | Point mutation knock-in |
Neurological Disorders
Disruptions in PLP metabolism have been linked to neurological disorders such as epilepsy and pyridoxine-dependent seizures. Since GO:0018272 involves covalent PLP attachment, defects in this process could contribute to altered enzyme activities in neurotransmitter synthesis, potentially exacerbating neurological symptoms.
Metabolic Disorders
Covalent PLP modification may affect enzymes involved in amino acid metabolism and energy production. Dysregulation of this modification could lead to metabolic imbalances, although direct evidence is currently limited.
Cancer
Altered PLP metabolism has been observed in some cancers, and covalent PLP attachment might influence oncogenic signaling or metabolic reprogramming. However, the specific role of GO:0018272 in cancer remains to be fully elucidated.
From protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does a specific lysine residue undergo covalent PLP modification? | Point mutation (Lys to Arg) via CRISPR |
| What is the functional impact of covalent PLP linkage on enzyme activity? | Knockout of the modifying enzyme or target lysine mutant |
| Can covalent PLP modification be detected in vivo? | Tagged knock-in with affinity purification |
| Does overexpression of a PLP-binding protein alter cellular metabolism? | Overexpression cell lines |
| Which proteins are targets of covalent PLP modification? | Proteomics with knockout of PLP synthesis enzymes |
| Is the modification reversible? | Inducible knockout or point mutation models |
How to Study the protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Mass spectrometry | Presence and site of PLP-lysine adduct | Identification of modified proteins |
| Site-directed mutagenesis | Effect of lysine substitution | Functional analysis of modification |
| Enzymatic activity assay | Catalytic activity of target enzyme | Assessing impact of modification |
| CRISPR knockout | Loss-of-function of candidate genes | Pathway discovery |
| CRISPR knock-in | Introduction of specific mutations | Modeling disease variants |
| Overexpression | Gain-of-function | Studying regulatory roles |
| Proteomics | Global protein expression and modifications | Systems-level analysis |
Proteomics and Mass Spectrometry
Mass spectrometry-based proteomics can identify proteins carrying the N6-pyridoxal phosphate-L-lysine modification by detecting the specific mass shift. Enrichment strategies using PLP-specific probes or antibodies may facilitate detection.
Site-Specific Mutagenesis
CRISPR-based point mutations can substitute the target lysine with arginine or other residues to prevent covalent PLP attachment, allowing functional studies.
Biochemical Assays
Enzymatic activity assays can measure the impact of covalent PLP modification on target enzyme function. Additionally, PLP binding can be assessed using fluorescence or spectrophotometric methods.
CRISPR Screening
Genome-wide CRISPR knockout screens can identify genes that regulate or depend on the covalent PLP modification, revealing pathways and potential therapeutic targets.
How CRISPR Can Be Used to Study GO:0018272 protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine
Knockout
CRISPR knockout of genes involved in PLP metabolism or target proteins can reveal the physiological importance of GO:0018272. For example, knocking out PDXK or PNPO reduces PLP levels, potentially decreasing covalent modification.
Point Mutation
Introducing point mutations at specific lysine residues (e.g., Lys to Arg) using CRISPR can prevent covalent PLP attachment, allowing precise dissection of the modification's role.
Knock-in
Knock-in of tagged versions of target proteins or disease-associated mutations can facilitate detection and functional studies of the covalent PLP linkage.
Overexpression
Overexpression of PLP-binding proteins or enzymes can enhance the modification and its downstream effects, providing a gain-of-function model.
How EDITGENE Supports protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine Research
Researchers studying protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine-related genes often need to determine whether a candidate gene is causally involved in the modification, whether a specific lysine is the site of attachment, and how the modification affects protein function. EDITGENE provides a comprehensive suite of CRISPR services to address these questions with precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine research.
Frequently Asked Questions About protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine
What is GO:0018272?
GO:0018272 is a Gene Ontology biological process term describing the covalent modification of a lysine residue in a protein to form N6-pyridoxal phosphate-L-lysine, using pyridoxal 5'-phosphate (PLP).
What is protein-pyridoxal-5-phosphate linkage via peptidyl-N6-pyridoxal phosphate-L-lysine?
It is a post-translational modification where PLP is covalently attached to a lysine residue in a protein, forming a stable linkage.
Which genes are involved in protein-pyridoxal-5-phosphate linkage?
Genes involved in PLP metabolism (e.g., PDXK, PNPO) and target proteins that undergo the modification, such as PLP-dependent enzymes.
How is protein-pyridoxal-5-phosphate linkage regulated?
It is likely regulated by cellular PLP levels, which depend on vitamin B6 metabolism and the enzymes PDXK and PNPO.
What diseases are associated with defects in this modification?
Neurological disorders like pyridoxine-dependent epilepsy and metabolic imbalances have been linked to PLP metabolism defects.
How can I study protein-pyridoxal-5-phosphate linkage in the lab?
Using mass spectrometry, site-directed mutagenesis, and CRISPR-based models to detect and functionally analyze the modification.
What CRISPR models are available for studying this modification?
Knockout, point mutation, knock-in, and overexpression models can be generated to investigate the role of specific genes and lysine residues.
Can EDITGENE help with custom CRISPR models for this pathway?
Yes, EDITGENE provides tailored CRISPR services including knockout, point mutation, knock-in, overexpression, and library screening.
What is the role of pyridoxal 5'-phosphate in this process?
PLP is the substrate that is covalently attached to lysine, forming the N6-pyridoxal phosphate-L-lysine linkage.
Is the protein-pyridoxal-5-phosphate linkage reversible?
The linkage is generally stable, but potential reversal mechanisms are not well characterized and may involve specific enzymes.
Conclusion
GO:0018272 represents a unique post-translational modification that covalently links pyridoxal 5'-phosphate to lysine residues in proteins. This modification can influence protein function, stability, and interactions, with implications for metabolic and neurological health. Understanding its regulation and targets may open new avenues for therapeutic intervention. EDITGENE offers comprehensive CRISPR solutions to study this process, from knockout to knock-in models, empowering researchers to uncover the precise roles of this modification in biology and disease.
References
- 1. LaPelusa A et al.. 2026. Physiology, Proteins.. PMID: 32310450
