GO:0120560 phosphatidylserine lysophospholipase A1 activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0120560 defines phosphatidylserine lysophospholipase A1 activity, a phospholipase A1-type enzymatic activity that hydrolyzes 1-acyl-sn-glycero-3-phospho-L-serine to sn-glycero-3-phospho-L-serine, a fatty acid, and a proton.
• The activity is catalyzed by phosphatidylserine-specific phospholipase A1 (PS-PLA1), encoded by the human gene PLA1A (also known as PS-PLA1), which was first characterized as an alternative splicing form with lysophosphatidylserine-specific lysophospholipase activity.
• PS-PLA1 is secreted into the circulation and is recognized as a laboratory biomarker for lysophospholipid-related disorders, including liver disease and atherosclerosis.
• The enzyme product lysophosphatidylserine (LysoPS) is a bioactive lipid that can modulate immune cell function and platelet activation, linking GO:0120560 to thrombosis and inflammation.
• PLA1A/PS-PLA1 can activate fibroblast-like synoviocytes through the autotaxin-lysophosphatidic acid receptor axis, implicating the activity in arthritic joint pathology.
• CRISPR-based knockout, point-mutation, knock-in, and overexpression models are essential to dissect the causal role of PLA1A and related phospholipases in disease.
Description
Phosphatidylserine lysophospholipase A1 activity (GO:0120560) is a molecular function that catalyzes the hydrolysis of the sn-1 acyl ester bond of phosphatidylserine, releasing a fatty acid and generating lysophosphatidylserine (LysoPS). This activity is attributed to phosphatidylserine-specific phospholipase A1 (PS-PLA1), a secreted enzyme encoded by the PLA1A gene in humans. The reaction is distinct from phospholipase A2 and phospholipase D activities because it specifically targets the sn-1 position of phosphatidylserine and requires water as a co-substrate. Researchers study GO:0120560 because its product, LysoPS, is a potent lipid mediator involved in immune regulation, platelet activation, and inflammatory signaling. The enzyme was initially identified as an alternative splicing form of PS-PLA1 that exhibits lysophosphatidylserine-specific lysophospholipase activity, converting LysoPS to glycerophosphoserine. Subsequent work has shown that PS-PLA1 circulates in plasma and serves as a clinical biomarker for conditions such as liver dysfunction and cardiovascular risk. The activity is also linked to the autotaxin-lysophosphatidic acid (LPA) axis, where LysoPS produced by PS-PLA1 can influence LPA receptor signaling in fibroblast-like synoviocytes. Given its role in lipid mediator production, GO:0120560 is a focal point for understanding how phospholipid remodeling contributes to disease. Knockout and knock-in models of PLA1A and related phospholipases have been used to probe the physiological impact of this activity in vivo. This article synthesizes the current knowledge of GO:0120560, its catalytic mechanism, key genes, disease associations, and the CRISPR-based methods used to study it.
phosphatidylserine lysophospholipase A1 activity At A Glance
| GO ID | GO:0120560 |
|---|---|
| GO term | phosphatidylserine lysophospholipase A1 activity |
| Ontology | molecular_function |
| Synonym | phosphatidylserine-specific phospholipase A1; phosphatidylserine sn-1 acylhydrolase; phosphatidylserine lysophospholipase A1-type activity |
| Major function | Hydrolysis of the sn-1 acyl ester bond of phosphatidylserine to release a fatty acid and lysophosphatidylserine |
| Reaction | 1-acyl-sn-glycero-3-phospho-L-serine + H2O = sn-glycero-3-phospho-L-serine + a fatty acid + H+ |
| Representative enzyme | Phosphatidylserine-specific phospholipase A1 (PS-PLA1), encoded by PLA1A in humans |
| Subcellular context | Secreted enzyme; acts in the extracellular space and circulation |
| Related activity | Lysophospholipase activity toward lysophosphatidylserine (LysoPS) |
What Is GO:0120560?
GO:0120560, phosphatidylserine lysophospholipase A1 activity, is defined as the catalysis of the reaction: a 1-acyl-sn-glycero-3-phospho-L-serine + H2O = sn-glycero-3-phospho-L-serine + a fatty acid + H+. In other words, it is a phospholipase A1-type activity that removes the fatty acid from the sn-1 position of phosphatidylserine, producing lysophosphatidylserine and a free fatty acid. The term is a molecular function in the Gene Ontology and is synonymous with phosphatidylserine-specific phospholipase A1, phosphatidylserine sn-1 acylhydrolase, and phosphatidylserine lysophospholipase A1-type activity.
Why Is phosphatidylserine lysophospholipase A1 activity Important in Cell Biology?
GO:0120560 is important because it generates lysophosphatidylserine (LysoPS), a bioactive lipid that regulates immune cell function, platelet activation, and inflammatory signaling. The enzyme responsible, PS-PLA1, is a circulating biomarker for liver disease and cardiovascular risk, and its activity is linked to the autotaxin-LPA axis in arthritis and thrombosis. Understanding this activity at the molecular level can inform therapeutic strategies targeting lipid mediator production in inflammatory and metabolic disorders.
• Produces lysophosphatidylserine (LysoPS), a lipid mediator that modulates immune cell recruitment and activation.
• PS-PLA1 is measured in clinical laboratories as a biomarker for liver dysfunction and atherosclerosis.
• The activity is implicated in platelet activation and thrombosis through the autotaxin-LPA receptor axis.
• PLA1A/PS-PLA1 can activate fibroblast-like synoviocytes, contributing to synovial inflammation in arthritis.
• Phospholipase A1 enzymes are conserved in fungi and may influence fungal cell wall remodeling and virulence.
• Lysophospholipase D activity from scorpion venom can mimic or intersect with lysophospholipid signaling pathways.
• The activity is a potential drug target for modulating LysoPS levels in inflammatory diseases.
• CRISPR knockout of PLA1A enables causal testing of its role in lipid metabolism and disease.
• Point mutations in the catalytic site can separate enzyme activity from non-catalytic functions.
• Overexpression models can reveal how excess PS-PLA1 activity affects circulating LysoPS and LPA levels.
Molecular Mechanism of phosphatidylserine lysophospholipase A1 activity
Substrate recognition and binding
In simple terms: The enzyme grabs a phosphatidylserine molecule and positions it for cutting.
Phosphatidylserine lysophospholipase A1 activity specifically recognizes phosphatidylserine (1-acyl-sn-glycero-3-phospho-L-serine) as its substrate. The enzyme binds the polar headgroup and the sn-1 acyl chain, positioning the ester bond for hydrolysis. This specificity distinguishes it from phospholipase A2, which cleaves the sn-2 position, and from phospholipase D, which removes the headgroup.
Catalytic hydrolysis of the sn-1 ester bond
In simple terms: Water is used to break the bond holding the fatty acid, releasing it along with a proton.
The catalytic mechanism involves nucleophilic attack by water on the sn-1 ester carbonyl, leading to the release of a free fatty acid and the formation of sn-glycero-3-phospho-L-serine (lysophosphatidylserine) plus a proton. This reaction is characteristic of phospholipase A1-type enzymes, which use a serine hydrolase catalytic triad. The human PS-PLA1 was shown to exhibit lysophosphatidylserine-specific lysophospholipase activity, meaning it can further hydrolyze LysoPS to glycerophosphoserine.
Product formation and release
In simple terms: The cut products, a fatty acid and lysophosphatidylserine, are released to act elsewhere.
The immediate products of GO:0120560 are a fatty acid and lysophosphatidylserine (LysoPS). LysoPS is a bioactive lipid that can be released from the enzyme and act on neighboring cells or circulate in plasma. In humans, PS-PLA1 is secreted and its activity contributes to the pool of circulating LysoPS, which is measured in laboratory medicine as a biomarker.
Regulation by alternative splicing and secretion
In simple terms: Different versions of the enzyme can be made, and it is exported from cells to work outside.
An alternative splicing form of PS-PLA1 was identified that exhibits lysophosphatidylserine-specific lysophospholipase activity, indicating that splicing can modulate substrate preference. The enzyme is secreted, allowing it to act in the extracellular space and circulation, where it can interact with other lipid-metabolizing enzymes such as autotaxin.
Cofactors and metal dependence
In simple terms: The enzyme does not appear to require a metal cofactor for its basic cutting activity.
Phosphatidylserine lysophospholipase A1 activity is catalyzed by a serine hydrolase-type mechanism and does not require a metal ion cofactor for catalysis. However, the activity can be influenced by the lipid environment and by interactions with other proteins, such as autotaxin, which can couple LysoPS production to LPA signaling.
Key Genes Involved in GO:0120560 phosphatidylserine lysophospholipase A1 activity
The following genes and proteins are directly or functionally linked to phosphatidylserine lysophospholipase A1 activity (GO:0120560) and its downstream lipid mediator pathways.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PLA1A | Encodes phosphatidylserine-specific phospholipase A1 (PS-PLA1), the enzyme responsible for GO:0120560 | Primary target for knockout, point mutation, and overexpression studies of the activity |
| ENPP2 | Encodes autotaxin, a lysophospholipase D that produces lysophosphatidic acid (LPA) | Interacts with PS-PLA1 in the autotaxin-LPA axis; relevant to thrombosis and arthritis |
| LPAR1 | Lysophosphatidic acid receptor 1 | Mediates downstream signaling of LPA generated in the autotaxin pathway |
| LPAR2 | Lysophosphatidic acid receptor 2 | Contributes to LPA receptor signaling in fibroblast-like synoviocytes |
| LPAR3 | Lysophosphatidic acid receptor 3 | Part of the LPA receptor family that can be activated downstream of PS-PLA1 activity |
| GPR34 | Lysophosphatidylserine receptor | Potential receptor for LysoPS produced by GO:0120560 |
| PLA2G | Phospholipase A2 family enzymes | Related phospholipases that cleave the sn-2 position, providing contrast to A1 activity |
| PLD1 | Phospholipase D1 | Related phospholipase that removes the headgroup, distinct from A1 activity |
| LCAT | Lecithin-cholesterol acyltransferase | Lipid-modifying enzyme in plasma that can influence lysophospholipid levels |
| LPL | Lipoprotein lipase | Lipid hydrolase that contributes to fatty acid release and lipid metabolism |
| ALPL | Alkaline phosphatase | Can dephosphorylate lysophospholipids, affecting LysoPS stability |
| ABHD12 | Lysophosphatidylserine lipase | Degrades LysoPS, opposing the activity of PS-PLA1 |
| ABHD16A | Phosphatidylserine lipase | Produces LysoPS from phosphatidylserine, similar to GO:0120560 |
| SLC1A1 | Glutamate transporter | Not directly linked; included as a control for lipid signaling studies |
| TLR2 | Toll-like receptor 2 | Can be modulated by lysophospholipids in inflammation |
| TLR4 | Toll-like receptor 4 | Involved in lipid-mediated inflammatory signaling |
| NFKB1 | NF-kB subunit 1 | Transcription factor downstream of inflammatory lipid signaling |
| IL6 | Interleukin 6 | Cytokine induced by inflammatory lipid mediators |
How Is phosphatidylserine lysophospholipase A1 activity Regulated?
The activity of phosphatidylserine lysophospholipase A1 is regulated at multiple levels. Alternative splicing of PLA1A produces isoforms with different substrate specificities, including a form with lysophosphatidylserine-specific lysophospholipase activity. Secretion of PS-PLA1 into the circulation places the enzyme under systemic regulation, where it can be measured as a biomarker. The activity is also functionally coupled to the autotaxin-LPA axis, meaning that changes in autotaxin expression or integrin binding can indirectly modulate the downstream effects of PS-PLA1. In inflammatory conditions, cytokines and growth factors may influence PLA1A expression, although specific transcriptional regulators remain to be fully defined.
phosphatidylserine lysophospholipase A1 activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PLA1A | Cardiovascular disease, thrombosis | PLA1A knockout mouse; platelet aggregation assays |
| PLA1A | Arthritis, synovial inflammation | Fibroblast-like synoviocyte cultures with PLA1A overexpression or knockout |
| ENPP2 | Thrombosis, inflammation | Autotaxin knockout or inhibitor-treated models |
| ABHD12 | Neuroinflammation, LysoPS degradation | ABHD12 knockout mice to assess LysoPS accumulation |
| GPR34 | Immune regulation by LysoPS | GPR34 knockout models to test LysoPS signaling |
Cardiovascular disease and thrombosis
PS-PLA1 activity contributes to the production of lysophosphatidylserine, which can influence platelet activation and thrombosis. The binding of autotaxin to integrins mediates hyperhomocysteinemia-potentiated platelet activation and thrombosis, and PS-PLA1 can feed into this axis by generating LysoPS. Circulating PS-PLA1 is recognized as a laboratory biomarker for cardiovascular risk and atherosclerosis.
Arthritis and synovial inflammation
Phospholipase A1 member A (PLA1A) activates fibroblast-like synoviocytes through the autotaxin-lysophosphatidic acid receptor axis, suggesting that GO:0120560 contributes to synovial inflammation in arthritic joints. LysoPS produced by PS-PLA1 may act on synoviocytes to promote inflammatory cytokine release and joint destruction.
Liver disease and metabolic disorders
PS-PLA1 is measured in clinical laboratories as a marker of liver function, and altered lysophospholipid metabolism is associated with hepatic disorders. The activity of GO:0120560 may influence the balance of circulating lysophospholipids that are used in diagnostic panels for liver disease.
Fungal pathogenesis and venom biology
Phospholipase B/lysophospholipases from Saccharomyces cerevisiae have been characterized, and related activities are found in pathogenic fungi, where they may affect cell wall lipids and dimorphism. Scorpion venom contains a dermonecrotic toxin with lysophospholipase D activity, highlighting the broader biological importance of lysophospholipid-metabolizing enzymes.
From phosphatidylserine lysophospholipase A1 activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of PLA1A reduce circulating LysoPS? | PLA1A knockout cell line or mouse |
| Does a catalytic-site mutation abolish enzyme activity? | Point-mutation knock-in of PLA1A catalytic serine |
| Can tagged PS-PLA1 be used to track secretion? | Knock-in of a fluorescent or epitope tag at the PLA1A locus |
| Does overexpression of PLA1A increase LPA production? | PLA1A overexpression in fibroblast-like synoviocytes |
| Which genes are required for LysoPS-mediated platelet activation? | CRISPR library screening in platelet-like cells |
| Does PS-PLA1 interact with autotaxin in vivo? | Knock-in of interaction tags or proximity labeling |
How to Study the phosphatidylserine lysophospholipase A1 activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorescent phospholipase A1 assay | Enzymatic hydrolysis of phosphatidylserine | Measuring PS-PLA1 activity in cell lysates or plasma |
| LC-MS lipidomics | Levels of LysoPS, LPA, and fatty acids | Profiling lipid changes after PLA1A knockout or overexpression |
| CRISPR knockout screening | Genes required for LysoPS production or signaling | Identifying modifiers of GO:0120560 in immune cells |
| Co-immunoprecipitation | Protein-protein interactions of PS-PLA1 | Testing interaction with autotaxin or integrins |
| ELISA for PS-PLA1 | Circulating PS-PLA1 protein levels | Clinical biomarker studies in liver disease |
| Platelet aggregation assay | Platelet activation and thrombosis | Assessing LysoPS effects on platelet function |
| Synoviocyte activation assay | Inflammatory cytokine release | Testing PLA1A-driven synovial inflammation |
| Site-directed mutagenesis | Catalytic activity of mutant PS-PLA1 | Mapping the active site serine residue |
Enzymatic activity assays
Phosphatidylserine lysophospholipase A1 activity can be measured using fluorescent or radioactive phosphatidylserine substrates, followed by separation of products by thin-layer chromatography or high-performance liquid chromatography. These assays quantify the release of fatty acid and LysoPS, providing direct evidence of GO:0120560 activity.
Lipidomics and mass spectrometry
Mass spectrometry-based lipidomics enables comprehensive profiling of lysophospholipids, including LysoPS and LPA, in cells and plasma. This approach is used to assess how changes in PLA1A expression or activity alter the lipid mediator landscape in disease models.
CRISPR-based genetic screens
Genome-wide CRISPR knockout or activation screens can identify genes that regulate phosphatidylserine lysophospholipase A1 activity or its downstream effects. Such screens are particularly useful for uncovering modifiers of LysoPS production and signaling in immune cells.
Protein interaction and secretion studies
Co-immunoprecipitation, proximity labeling, and ELISA-based secretion assays can determine how PS-PLA1 interacts with partners such as autotaxin and how it is secreted into the extracellular space. These methods help link GO:0120560 to systemic lipid signaling pathways.
How CRISPR Can Be Used to Study GO:0120560 phosphatidylserine lysophospholipase A1 activity
Knockout
CRISPR knockout of PLA1A can eliminate phosphatidylserine lysophospholipase A1 activity, allowing researchers to test its role in LysoPS production and downstream signaling. Knockout cell lines and mouse models are used to assess changes in platelet activation, synoviocyte inflammation, and circulating lipid biomarkers.
Point Mutation
Point mutations in the catalytic serine or other active-site residues of PLA1A can abolish enzymatic activity while preserving protein expression, enabling separation of catalytic and non-catalytic functions. Such models are valuable for determining whether disease phenotypes depend on the enzymatic activity of GO:0120560.
Knock-in
Knock-in of epitope tags, fluorescent proteins, or reporter cassettes at the PLA1A locus allows real-time tracking of PS-PLA1 expression, secretion, and localization. Knock-in models can also introduce disease-associated mutations to study their impact on enzyme function.
Overexpression
Overexpression of PLA1A in cell lines or transgenic animals increases phosphatidylserine lysophospholipase A1 activity, leading to elevated LysoPS and potentially LPA levels. These models are used to test whether excess activity is sufficient to drive inflammatory or thrombotic phenotypes.
How EDITGENE Supports phosphatidylserine lysophospholipase A1 activity Research
Researchers studying phosphatidylserine lysophospholipase A1 activity-related genes often need to determine whether a candidate gene is causally involved in lipid mediator production, inflammation, or thrombosis. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell and animal models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for phosphatidylserine lysophospholipase A1 activity research.
Frequently Asked Questions About phosphatidylserine lysophospholipase A1 activity
What is phosphatidylserine lysophospholipase A1 activity?
It is a molecular function (GO:0120560) that catalyzes the hydrolysis of phosphatidylserine to release a fatty acid and lysophosphatidylserine, as defined by the Gene Ontology.
What genes are involved in phosphatidylserine lysophospholipase A1 activity?
The primary gene is PLA1A, which encodes phosphatidylserine-specific phospholipase A1 (PS-PLA1). Related genes include ENPP2 (autotaxin) and LPA receptors.
What is the reaction catalyzed by GO:0120560?
The reaction is: a 1-acyl-sn-glycero-3-phospho-L-serine + H2O = sn-glycero-3-phospho-L-serine + a fatty acid + H+.
How is phosphatidylserine lysophospholipase A1 activity measured?
It is typically measured using fluorescent or radioactive phosphatidylserine substrates, followed by chromatographic separation of products.
What diseases are associated with phosphatidylserine lysophospholipase A1 activity?
It has been linked to cardiovascular disease, thrombosis, arthritis, and liver disease through the production of lysophosphatidylserine and lysophosphatidic acid.
What is the role of PS-PLA1 in the autotaxin-LPA axis?
PS-PLA1 generates LysoPS, which can be converted by autotaxin to LPA, thereby feeding into LPA receptor signaling in cells such as fibroblast-like synoviocytes.
Can CRISPR be used to study phosphatidylserine lysophospholipase A1 activity?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models of PLA1A are widely used to dissect the function of this activity.
What is lysophosphatidylserine?
Lysophosphatidylserine (LysoPS) is the product of phosphatidylserine lysophospholipase A1 activity and acts as a bioactive lipid mediator.
Is phosphatidylserine lysophospholipase A1 activity the same as phospholipase A2?
No, phospholipase A1 cleaves the sn-1 position, while phospholipase A2 cleaves the sn-2 position of phospholipids.
How can I create a PLA1A knockout cell line?
EDITGENE provides custom CRISPR knockout services for PLA1A and related genes, delivering validated cell lines for functional studies.
Conclusion
Phosphatidylserine lysophospholipase A1 activity (GO:0120560) is a specialized phospholipase A1 function that produces lysophosphatidylserine, a lipid mediator with broad roles in immunity, thrombosis, and inflammation. The enzyme PS-PLA1, encoded by PLA1A, is a circulating biomarker and a potential therapeutic target in cardiovascular and arthritic diseases. CRISPR-based models are indispensable for establishing causal links between this activity and disease phenotypes. Continued research using knockout, point-mutation, knock-in, and overexpression approaches will clarify how GO:0120560 contributes to human health and disease.
References
- 1. Yatomi Y et al.. 2018. Lysophospholipids in laboratory medicine.. Proc Jpn Acad Ser B Phys Biol Sci 94(10):373-389 PMID: 30541965
- 2. Nagai Y et al.. 1999. An alternative splicing form of phosphatidylserine-specific phospholipase A1 that exhibits lysophosphatidylserine-specific lysophospholipase activity in humans.. J Biol Chem 274(16):11053-9 PMID: 10196188
- 4. Han L et al.. 2022. The binding of autotaxin to integrins mediates hyperhomocysteinemia-potentiated platelet activation and thrombosis in mice and humans.. Blood Adv 6(1):46-61 PMID: 34559203
- 5. Zhao Y et al.. 2021. Phospholipase A1 Member A Activates Fibroblast-like Synoviocytes through the Autotaxin-Lysophosphatidic Acid Receptor Axis.. Int J Mol Sci 22(23) PMID: 34884486
- 6. Merkel O et al.. 1999. Characterization and function in vivo of two novel phospholipases B/lysophospholipases from Saccharomyces cerevisiae.. J Biol Chem 274(40):28121-7 PMID: 10497163
- 7. Kitajma Y. 2000. [Structural and biochemical characteristics of pathogenic fungus: cell walls, lipids and dimorphism, and action modes of antifungal agents].. Nihon Ishinkin Gakkai Zasshi 41(4):211-7 PMID: 11064317
- 8. Borchani L et al.. 2013. The pathological effects of Heminecrolysin, a dermonecrotic toxin from Hemiscorpius lepturus scorpion venom are mediated through its lysophospholipase D activity.. Toxicon 68:30-9 PMID: 23562369
