GO:0102545 B-type glycerophospholipase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0102545 (B-type glycerophospholipase activity) is a molecular function that removes both fatty acyl chains from the sn-1 and sn-2 positions of glycerophospholipids such as phosphatidylcholine and phosphatidylethanolamine.
• The activity is also known as phospholipase B activity and is distinguished from phospholipase A1/A2 by its dual deacylation capability.
• B-type glycerophospholipase activity is involved in membrane lipid remodeling and the release of free fatty acids, including arachidonic acid, which can serve as precursors for eicosanoid signaling.
• Dysregulation of phospholipase B enzymes has been linked to inflammatory diseases, cancer progression, and pathogen virulence.
• Key genes encoding B-type glycerophospholipases include PLB1, PLB2, and related fungal and mammalian homologs, which are studied using knockout, knock-in, and overexpression models.
• CRISPR-based gene editing enables precise dissection of B-type glycerophospholipase function in health and disease, from single point mutations to whole-gene knockouts.
Description
B-type glycerophospholipase activity (GO:0102545) is a molecular function that catalyzes the hydrolysis of both fatty acyl ester bonds at the sn-1 and sn-2 positions of glycerophospholipids, yielding a glycerophosphodiester and two free fatty acids. This dual deacylation distinguishes it from phospholipase A1 or A2, which remove only one acyl chain. The activity is widely distributed across species, from fungi to mammals, and plays critical roles in membrane homeostasis, lipid signaling, and pathogenesis. Researchers study this activity to understand how cells remodel membranes, generate lipid mediators, and respond to environmental cues. In recent years, the availability of CRISPR-Cas9 tools has accelerated functional studies of genes encoding B-type glycerophospholipases, enabling precise genetic perturbations in diverse model systems.
B-type glycerophospholipase activity At A Glance
| GO ID | GO:0102545 |
|---|---|
| GO term | B-type glycerophospholipase activity |
| Ontology | molecular_function |
| Synonym | B-type phospholipase activity; phosphatidyl phospholipase B activity; phospholipase B activity |
| Definition | A glycerophospholipase activity that cleaves both fatty acids attached to the sn-1 and sn-2 positions of the glycerol group of a glycerophospholipid. Substrates include phosphatidylcholine and phosphatidylethanolamine. |
| Major function | Hydrolysis of both acyl chains from glycerophospholipids, releasing free fatty acids and glycerophosphodiesters. |
| Substrates | Phosphatidylcholine, phosphatidylethanolamine, and other glycerophospholipids. |
| Products | Glycerophosphodiesters and free fatty acids (e.g., arachidonic acid). |
| Cellular location | Membrane-associated, often secreted or localized to the cell surface. |
What Is GO:0102545?
According to the Gene Ontology, GO:0102545 (B-type glycerophospholipase activity) is defined as a glycerophospholipase activity that cleaves both fatty acids attached to the sn-1 and sn-2 positions of the glycerol group of a glycerophospholipid. Substrates include phosphatidylcholine and phosphatidylethanolamine. This activity is synonymous with B-type phospholipase activity, phosphatidyl phospholipase B activity, and phospholipase B activity.
Why Is B-type glycerophospholipase activity Important in Cell Biology?
B-type glycerophospholipase activity is essential for membrane lipid turnover, providing free fatty acids for energy production and signaling. Its products, such as arachidonic acid, are precursors to prostaglandins and leukotrienes, which regulate inflammation and immunity. In pathogenic fungi like Candida albicans and Cryptococcus neoformans, secreted phospholipase B contributes to virulence by degrading host cell membranes. In humans, dysregulated phospholipase B activity has been implicated in cancer, atherosclerosis, and respiratory diseases. Thus, understanding this activity offers insights into basic cell biology and potential therapeutic targets.
• Maintains membrane phospholipid asymmetry and turnover.
• Generates lipid second messengers like arachidonic acid for eicosanoid synthesis.
• Contributes to fungal and bacterial pathogenesis by degrading host membranes.
• Plays a role in intestinal lipid absorption and lipoprotein metabolism.
• Involved in inflammatory responses and immune cell activation.
• Linked to cancer cell proliferation and survival through lipid signaling.
• Potential target for antifungal and anti-inflammatory drugs.
• Serves as a model for studying enzyme kinetics and substrate specificity.
What Happens During B-type glycerophospholipase activity?
Substrate Binding and Orientation
In simple terms: The enzyme grabs a phospholipid molecule and positions it for cutting.
B-type glycerophospholipases bind glycerophospholipids such as phosphatidylcholine or phosphatidylethanolamine at the membrane interface. The enzyme's active site accommodates the glycerol backbone, positioning the sn-1 and sn-2 ester bonds for hydrolysis.
Catalytic Hydrolysis of sn-1 Acyl Chain
In simple terms: The enzyme first cuts the fatty acid at the first position.
A catalytic serine or aspartate residue attacks the sn-1 ester bond, releasing the fatty acid and forming an acyl-enzyme intermediate. This step is often rate-limiting and can be influenced by substrate acyl chain length and saturation.
Catalytic Hydrolysis of sn-2 Acyl Chain
In simple terms: Then it cuts the second fatty acid, completing the deacylation.
Following sn-1 hydrolysis, the enzyme repositions the lysophospholipid intermediate to cleave the sn-2 ester bond. This second hydrolysis yields a glycerophosphodiester and a second free fatty acid. The dual cleavage is the hallmark of B-type activity.
Product Release and Membrane Recycling
In simple terms: The products are released and the enzyme resets for another round.
The glycerophosphodiester and free fatty acids diffuse away or are channeled to downstream pathways. The enzyme undergoes conformational changes to release products and return to its active state, ready for another catalytic cycle.
Key Genes Involved in GO:0102545 B-type glycerophospholipase activity
The following genes encode enzymes with demonstrated or predicted B-type glycerophospholipase activity across species.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PLB1 (Candida albicans) | Secreted phospholipase B; virulence factor | Studied for antifungal drug discovery and host-pathogen interactions. |
| PLB2 (Candida albicans) | Phospholipase B involved in cell wall integrity | Model for enzyme regulation and secretion. |
| PLB1 (Cryptococcus neoformans) | Virulence factor; promotes brain invasion | Target for antifungal therapy. |
| PLB1 (Saccharomyces cerevisiae) | Lipid remodeling and stress response | Model for phospholipase B trafficking. |
| PLA2G15 (human) | Lysosomal phospholipase A2 with B-type activity | Linked to lipid metabolism disorders. |
| PNPLA6 (human) | Neuropathy target esterase; phospholipase B-like | Mutations cause motor neuron disease. |
| PNPLA7 (human) | Phospholipase B domain-containing protein | Role in lipid droplet metabolism. |
| LPLA2 (human) | Lysosomal phospholipase A2 | Involved in surfactant catabolism. |
| PLB1 (Aspergillus fumigatus) | Allergen and virulence factor | Asthma and invasive aspergillosis research. |
| PLB1 (Mycobacterium tuberculosis) | Phospholipase B for host membrane degradation | Tuberculosis pathogenesis studies. |
| PLB1 (Toxoplasma gondii) | Host cell invasion | Parasitology and drug target. |
| PLB1 (Leishmania major) | Virulence and survival in macrophages | Leishmaniasis research. |
| PLB1 (Schistosoma mansoni) | Host immune modulation | Schistosomiasis vaccine development. |
| PLB1 (Candida glabrata) | Adhesion and biofilm formation | Nosocomial infection models. |
| PLB1 (Histoplasma capsulatum) | Intracellular survival | Fungal pathogenesis. |
| PLB1 (Paracoccidioides brasiliensis) | Tissue invasion | Endemic mycoses research. |
| PLB1 (Blastomyces dermatitidis) | Virulence factor | Dimorphic fungal studies. |
| PLB1 (Coccidioides immitis) | Host cell lysis | Valley fever research. |
How Is B-type glycerophospholipase activity Regulated?
B-type glycerophospholipase activity is regulated at multiple levels. Transcriptional control responds to lipid availability and stress signals. Post-translational modifications, including phosphorylation and glycosylation, modulate enzyme activity and secretion. In pathogenic fungi, secretion is regulated by the secretory pathway and environmental pH. In mammals, lysosomal phospholipase A2 (LPLA2) is regulated by lipid substrates and cofactors. Calcium ions can influence membrane binding and catalysis.
B-type glycerophospholipase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PLB1 (Candida albicans) | Candidiasis | Mouse model of systemic infection; CRISPR knockout strains. |
| PLB1 (Cryptococcus neoformans) | Cryptococcal meningitis | Rabbit meningitis model; gene deletion mutants. |
| PNPLA6 (human) | Hereditary spastic paraplegia | Patient iPSC-derived neurons; knock-in mice. |
| PLA2G15 (human) | Lysosomal acid lipase deficiency | Hepatocyte cell lines; knockout mice. |
| PLB1 (Aspergillus fumigatus) | Invasive aspergillosis | Neutropenic mouse model; CRISPR mutants. |
Infectious Diseases
Secreted B-type glycerophospholipases from Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus degrade host cell membranes, facilitating invasion and immune evasion. Inhibitors of these enzymes are being explored as antifungal agents.
Inflammatory Disorders
In mammals, phospholipase B activity releases arachidonic acid, a precursor to pro-inflammatory eicosanoids. Dysregulation contributes to asthma, arthritis, and atherosclerosis.
Cancer
Elevated phospholipase B activity has been observed in several cancers, promoting cell proliferation and survival through lipid signaling pathways. Targeting these enzymes may offer therapeutic benefits.
Neurodegeneration
Mutations in PNPLA6, which has phospholipase B-like activity, cause hereditary spastic paraplegia and motor neuron disease, highlighting its role in neuronal maintenance.
From B-type glycerophospholipase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does PLB1 knockout reduce fungal virulence? | CRISPR knockout in Candida albicans; mouse infection model. |
| What is the effect of a catalytic point mutation on enzyme activity? | Point mutation knock-in in Saccharomyces cerevisiae. |
| Can a tagged PLB1 reveal subcellular localization? | Knock-in of GFP tag in Cryptococcus neoformans. |
| Does overexpression of human PNPLA6 cause neurodegeneration? | Transgenic mouse or AAV-mediated overexpression. |
| Which genes regulate phospholipase B secretion? | CRISPR library screening in Aspergillus fumigatus. |
| How does PLB1 contribute to biofilm formation? | Knockout and overexpression in Candida glabrata. |
How to Study the B-type glycerophospholipase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorogenic substrate assay | Enzymatic activity | High-throughput inhibitor screening. |
| LC-MS lipidomics | Lipid species changes | Membrane remodeling studies. |
| CRISPR knockout screen | Gene essentiality and modifiers | Identifying regulators of phospholipase B. |
| Western blot | Protein expression and secretion | Validating knockout or overexpression. |
| Immunofluorescence | Subcellular localization | Tracking enzyme trafficking. |
| qRT-PCR | Transcript levels | Gene expression analysis. |
| Site-directed mutagenesis | Catalytic residue function | Mechanistic studies. |
| Animal infection model | Virulence contribution | Antifungal target validation. |
Enzymatic Activity Assays
Phospholipase B activity is measured using fluorogenic or radiolabeled substrates, such as phosphatidylcholine with labeled fatty acids. Released fatty acids are quantified by chromatography or fluorescence.
Lipidomics and Mass Spectrometry
Mass spectrometry-based lipidomics profiles changes in glycerophospholipid species and free fatty acids upon enzyme modulation, providing a systems-level view of B-type glycerophospholipase function.
CRISPR-Cas9 Genetic Screens
Genome-wide CRISPR knockout or activation screens can identify genes that regulate phospholipase B activity or mediate its downstream effects, using phenotypic readouts like lipid accumulation or cell viability.
Imaging and Localization Studies
Fluorescent tagging of phospholipase B enzymes enables live-cell imaging to track localization, secretion, and membrane association dynamics.
How CRISPR Can Be Used to Study GO:0102545 B-type glycerophospholipase activity
Knockout
CRISPR-Cas9 knockout of genes encoding B-type glycerophospholipases, such as PLB1 in Candida albicans, abolishes enzyme activity and attenuates virulence in infection models. Knockout cell lines are used to study lipid remodeling and signaling pathways.
Point Mutation
Introducing point mutations in catalytic residues (e.g., serine to alanine) via CRISPR base editing or homology-directed repair allows precise dissection of enzymatic activity versus non-catalytic functions.
Knock-in
Knock-in of epitope tags (e.g., GFP, FLAG) or reporter genes enables real-time tracking of phospholipase B expression, localization, and secretion in live cells.
Overexpression
CRISPR activation (CRISPRa) or transgenic overexpression of phospholipase B genes can model gain-of-function phenotypes, such as increased lipid mediator production or enhanced virulence.
How EDITGENE Supports B-type glycerophospholipase activity Research
Researchers studying B-type glycerophospholipase activity-related genes often need to determine whether a candidate gene is causally involved in lipid metabolism, infection, or disease. EDITGENE provides a comprehensive suite of CRISPR services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for B-type glycerophospholipase activity research.
Frequently Asked Questions About B-type glycerophospholipase activity
What is B-type glycerophospholipase activity?
It is a molecular function (GO:0102545) that cleaves both fatty acids from the sn-1 and sn-2 positions of glycerophospholipids, such as phosphatidylcholine and phosphatidylethanolamine.
What genes are involved in B-type glycerophospholipase activity?
Genes include PLB1 and PLB2 in fungi, and PNPLA6, PNPLA7, PLA2G15, and LPLA2 in humans, among others.
What is the difference between phospholipase A and B?
Phospholipase A removes one fatty acid, while phospholipase B removes both, producing a glycerophosphodiester and two free fatty acids.
Which diseases are linked to B-type glycerophospholipase activity?
Infectious diseases (candidiasis, cryptococcosis), inflammatory disorders, cancer, and neurodegeneration.
How is B-type glycerophospholipase activity measured?
Using fluorogenic or radiolabeled substrates, lipidomics, and mass spectrometry.
What model systems are used to study B-type glycerophospholipase activity?
Yeast, Candida albicans, Cryptococcus neoformans, mouse infection models, and human cell lines.
Can CRISPR be used to study B-type glycerophospholipase activity?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models enable precise functional studies.
What are the substrates of B-type glycerophospholipase?
Phosphatidylcholine, phosphatidylethanolamine, and other glycerophospholipids.
What are the products of B-type glycerophospholipase activity?
Glycerophosphodiesters and free fatty acids, including arachidonic acid.
Why is B-type glycerophospholipase activity important for drug discovery?
It is a virulence factor in fungi and a mediator of inflammation, making it a potential drug target.
Conclusion
B-type glycerophospholipase activity (GO:0102545) is a fundamental enzymatic function with broad biological and clinical significance. From fungal pathogenesis to human inflammatory diseases, this activity influences membrane dynamics and lipid signaling. CRISPR-based models are indispensable for dissecting its roles and identifying therapeutic opportunities. EDITGENE's comprehensive gene editing services empower researchers to explore this activity with precision and efficiency.
References
- 1. Morris NR et al.. 2023. Exercise-based rehabilitation programmes for pulmonary hypertension.. Cochrane Database Syst Rev 3(3):CD011285 PMID: 36947725
