GO:0004366 glycerol-3-phosphate O-acyltransferase activity: Mechanism, Genes and Research Methods

Research-grade guide for scientists and biopharma professionals

Key Takeaways

GO:0004366 describes the enzymatic activity that transfers an acyl group from acyl-CoA to sn-glycerol 3-phosphate, producing 1-acyl-sn-glycero-3-phosphate and CoA, the first committed step of glycerophospholipid and triacylglycerol biosynthesis.
The reaction is catalyzed by glycerol-3-phosphate acyltransferases (GPATs), which in mammals include mitochondrial GPAT1 and multiple ER isoforms with distinct tissue distribution and regulation.
GPAT1 is a key hepatic enzyme whose activity is transcriptionally and post-translationally controlled, and its dysregulation contributes to metabolic dysfunction-associated steatotic liver disease (MASLD) and related disorders.
Beyond lipid metabolism, GPAT activity influences cellular processes such as apoptosis, stem cell survival, and alpha-synuclein toxicity, linking this activity to neurodegeneration and cell fate decisions.
Bacterial and mycobacterial GPAT orthologs are important for membrane biogenesis and triacylglycerol accumulation, making them potential antimicrobial targets.
CRISPR-based knockout, point-mutation, knock-in, and overexpression models enable precise interrogation of GPAT enzyme function in health and disease.

Description

Glycerol-3-phosphate O-acyltransferase activity (GO:0004366) is a molecular function that catalyzes the transfer of an acyl group from an acyl-CoA donor to sn-glycerol 3-phosphate, yielding 1-acyl-sn-glycero-3-phosphate (lysophosphatidic acid) and free CoA. This acylation reaction is the first and rate-limiting step in the de novo synthesis of glycerophospholipids and triacylglycerols, placing it at the gateway of membrane lipid and energy storage pathways. Because the products of this reaction serve as precursors for phosphatidic acid, diacylglycerol, and downstream phospholipids, the activity is central to cellular membrane homeostasis and lipid signaling. In mammals, glycerol-3-phosphate O-acyltransferase activity is carried out by a family of GPAT enzymes, with GPAT1 being the best-characterized mitochondrial isoform and additional ER-localized isoforms contributing to distinct metabolic pools. The enzyme is subject to transcriptional regulation by nutrients and hormones, and its activity can be modulated post-translationally, for example through O-GlcNAcylation-dependent pathways. Dysregulated GPAT activity has been implicated in metabolic diseases such as MASLD, in which hepatic GPAT1 enhances lysophosphatidic acid synthesis and drives steatosis. Moreover, GPAT activity can influence oxidative stress and lipid peroxidation, with consequences for neuronal survival and alpha-synuclein-induced toxicity. For researchers, GO:0004366 represents a convergence point for studies of lipid metabolism, membrane biology, metabolic disease, and even bacterial pathogenesis. Understanding how this activity is regulated and how it contributes to disease requires precise genetic models and biochemical assays. This article summarizes the definition, mechanism, key genes, disease links, and experimental approaches for studying glycerol-3-phosphate O-acyltransferase activity, with a focus on CRISPR-based strategies for functional interrogation.

glycerol-3-phosphate O-acyltransferase activity At A Glance

GO ID GO:0004366
GO term glycerol-3-phosphate O-acyltransferase activity
Ontology molecular_function
Synonym glycerol phosphate acyltransferase activity; glycerophosphate acyltransferase activity; sn-glycerol-3-phosphate acyltransferase activity; acyl-CoA:sn-glycerol-3-phosphate 1-O-acyltransferase activity
Definition Catalysis of the reaction: an acyl-CoA + sn-glycerol 3-phosphate = a 1-acyl-sn-glycero-3-phosphate + CoA
Major function First committed step in glycerophospholipid and triacylglycerol biosynthesis; produces lysophosphatidic acid
Substrates Acyl-CoA (e.g., palmitoyl-CoA, oleoyl-CoA) and sn-glycerol 3-phosphate
Products 1-acyl-sn-glycero-3-phosphate (lysophosphatidic acid) and coenzyme A
Cellular location Mitochondrial outer membrane (GPAT1) and endoplasmic reticulum (other isoforms)
Representative genes GPAT1 (GPAM), GPAT2, GPAT3 (AGPAT10), GPAT4 (AGPAT8), and bacterial plsB

What Is GO:0004366?

Glycerol-3-phosphate O-acyltransferase activity (GO:0004366) is defined as the catalysis of the reaction: an acyl-CoA + sn-glycerol 3-phosphate = a 1-acyl-sn-glycero-3-phosphate + CoA. In this reaction, the enzyme transfers an acyl chain from a thioester-linked acyl-CoA donor to the sn-1 position of glycerol 3-phosphate, generating lysophosphatidic acid and releasing coenzyme A. This activity is synonymous with glycerol phosphate acyltransferase, glycerophosphate acyltransferase, and sn-glycerol-3-phosphate acyltransferase, reflecting historical nomenclature. The reaction is the first committed step in glycerolipid biosynthesis and is essential for the production of phosphatidic acid and downstream lipids.

Why Is glycerol-3-phosphate O-acyltransferase activity Important in Cell Biology?

Glycerol-3-phosphate O-acyltransferase activity is fundamentally important because it initiates the synthesis of all glycerophospholipids and triacylglycerols, which are essential for membrane biogenesis, energy storage, and lipid signaling. The reaction product, lysophosphatidic acid, is not only a metabolic intermediate but also a bioactive lipid that can influence cell proliferation, survival, and migration. Consequently, alterations in this activity have profound effects on cellular lipid homeostasis and are linked to metabolic diseases, neurodegeneration, and host-pathogen interactions. Understanding its regulation and function is therefore critical for both basic cell biology and translational research.
Initiates the de novo pathway for glycerophospholipid and triacylglycerol synthesis, controlling membrane lipid availability.
Produces lysophosphatidic acid, a signaling lipid involved in cell growth and survival.
Hepatic GPAT1 activity contributes to diet-induced MASLD by enhancing lysophosphatidic acid synthesis.
GPAT activity can exacerbate alpha-synuclein toxicity by increasing lipid peroxidation, linking it to neurodegeneration.
Upregulation of GPAT1 via O-GlcNAcylation of Sp1 protects embryonic stem cells from hypoxia-induced apoptosis.
Mutations in related acyltransferases cause congenital generalized lipodystrophy, highlighting the importance of acylation steps.
Mycobacterial GPAT is key for triacylglycerol biosynthesis and represents a potential drug target.
Bacterial GPAT (plsB) is essential for membrane phospholipid synthesis and cell growth.
The activity is regulated transcriptionally by nutrients and hormones, making it a node for metabolic control.
CRISPR models enable dissection of isoform-specific functions in vivo and in vitro.

What Happens During glycerol-3-phosphate O-acyltransferase activity?

Substrate binding and acyl transfer
In simple terms: The enzyme grabs an acyl-CoA and a glycerol-3-phosphate molecule and joins them together.
The catalytic mechanism involves binding of sn-glycerol 3-phosphate and an acyl-CoA thioester in the active site. The enzyme catalyzes nucleophilic attack of the sn-1 hydroxyl of glycerol 3-phosphate on the thioester carbonyl, forming a tetrahedral intermediate and releasing coenzyme A. This acylation yields 1-acyl-sn-glycero-3-phosphate (lysophosphatidic acid), the first intermediate in glycerolipid synthesis.
Product release and downstream metabolism
In simple terms: The newly made lysophosphatidic acid is released and used to build more complex lipids.
After acyl transfer, the product 1-acyl-sn-glycero-3-phosphate is released from the enzyme and can be further acylated by 1-acylglycerol-3-phosphate O-acyltransferases to form phosphatidic acid, a central intermediate for triacylglycerol and phospholipid synthesis. This positions GPAT activity as the rate-limiting entry point into glycerolipid biosynthesis.
Isoform-specific roles and membrane context
In simple terms: Different versions of the enzyme work in different parts of the cell and have different jobs.
Mammalian GPAT1 is localized to the mitochondrial outer membrane and preferentially uses saturated acyl-CoAs, while ER-localized GPAT3 and GPAT4 use a broader range of acyl-CoAs and contribute to distinct lipid pools. This compartmentalization allows the cell to channel acyl groups into specific metabolic fates, such as beta-oxidation or storage as triacylglycerol.
Regulation by nutrients and hormones
In simple terms: The enzyme's activity goes up or down depending on what the cell senses and what signals it receives.
GPAT1 expression is transcriptionally regulated by insulin, glucagon, and nutrient status, and its activity can be modulated post-translationally. For example, O-GlcNAcylation of the transcription factor Sp1 upregulates GPAT1 under hypoxic conditions, linking nutrient sensing to cell survival. In liver, AKAP1 deficiency enhances GPAT1-mediated lysophosphatidic acid synthesis, exacerbating MASLD.

Key Genes Involved in GO:0004366 glycerol-3-phosphate O-acyltransferase activity

The following genes encode enzymes with glycerol-3-phosphate O-acyltransferase activity or closely related acyltransferases that participate in the same pathway.
GeneMajor RoleResearch Relevance
GPAM (GPAT1) Mitochondrial glycerol-3-phosphate O-acyltransferase; catalyzes first step of glycerolipid synthesis Key driver of hepatic steatosis and MASLD; target for metabolic disease studies
GPAT2 Mitochondrial GPAT isoform with testis-specific expression Potential role in spermatogenesis and lipid metabolism
GPAT3 (AGPAT10) Endoplasmic reticulum GPAT; contributes to triacylglycerol synthesis Involved in adipocyte lipid storage and insulin sensitivity
GPAT4 (AGPAT8) ER GPAT with broad acyl-CoA specificity Linked to lipid droplet formation and membrane homeostasis
AGPAT2 1-acylglycerol-3-phosphate O-acyltransferase; acts downstream of GPAT Mutations cause congenital generalized lipodystrophy
plsB (E. coli) Bacterial glycerol-3-phosphate acyltransferase; essential for membrane phospholipid synthesis Model for enzyme mechanism and antibiotic target
PlsB (M. tuberculosis) Mycobacterial GPAT involved in triacylglycerol biosynthesis Potential target for tuberculosis therapy
Sp1 Transcription factor regulating GPAT1 expression Mediates O-GlcNAcylation-dependent GPAT1 upregulation
AKAP1 Mitochondrial scaffold protein that modulates GPAT1 activity Deficiency enhances GPAT1-mediated LPA synthesis in MASLD
mTOR Kinase downstream of GPAT1-mediated survival signaling Links GPAT1 to cell survival pathways
alpha-synuclein Protein whose toxicity is exacerbated by GPAT activity Implicated in Parkinson's disease pathogenesis
SREBP-1c Transcription factor controlling lipogenic gene expression including GPAT1 Regulates GPAT1 transcription in response to nutrients
PPARalpha Nuclear receptor regulating lipid oxidation and GPAT1 expression Coordinates lipid metabolic gene programs
ChREBP Carbohydrate-responsive transcription factor May regulate GPAT1 in response to glucose
INSIG ER protein regulating SREBP processing Indirectly affects GPAT1 expression
SCAP SREBP cleavage-activating protein Controls lipogenic gene transcription
ACC Acetyl-CoA carboxylase, provides malonyl-CoA for fatty acid synthesis Upstream of acyl-CoA supply for GPAT
FASN Fatty acid synthase, generates acyl-CoAs Supplies substrate for GPAT-mediated acylation

How Is glycerol-3-phosphate O-acyltransferase activity Regulated?

Glycerol-3-phosphate O-acyltransferase activity is regulated at multiple levels. Transcriptionally, GPAT1 is controlled by lipogenic transcription factors such as SREBP-1c and ChREBP in response to nutrient and hormonal signals. Post-translational regulation includes O-GlcNAcylation of Sp1, which enhances GPAT1 expression under hypoxia and promotes cell survival via mTOR activation. In liver, the mitochondrial scaffold protein AKAP1 modulates GPAT1 activity; its deficiency increases GPAT1-mediated lysophosphatidic acid synthesis and exacerbates diet-induced MASLD. Additionally, the enzyme's activity can be influenced by the availability of acyl-CoA substrates and the cellular energy state.

glycerol-3-phosphate O-acyltransferase activity and Human Disease

GeneDisease / BiologyPotential Experimental Model
GPAM (GPAT1)MASLD, hepatic steatosisLiver-specific knockout or overexpression in mice
GPAM (GPAT1)Hypoxia-induced apoptosis in stem cellsEmbryonic stem cell knockout and rescue
GPAT (general)Alpha-synuclein toxicity in Parkinson's diseaseNeuronal overexpression models
AGPAT2Congenital generalized lipodystrophyPatient-derived cells or knock-in of patient mutations
PlsB (M. tuberculosis)TuberculosisMycobacterial knockout and inhibitor testing
Metabolic dysfunction-associated steatotic liver disease (MASLD)
Hepatic GPAT1 activity is a major contributor to lipid accumulation in MASLD. AKAP1 deficiency enhances GPAT1-mediated lysophosphatidic acid synthesis, exacerbating diet-induced MASLD in mice. This links GO:0004366 directly to the pathogenesis of fatty liver disease and suggests that inhibiting GPAT1 could be therapeutic.
Neurodegeneration and alpha-synuclein toxicity
Glycerol-3-phosphate acyltransferase activity can exacerbate alpha-synuclein-induced toxicity by increasing lipid peroxidation, a process implicated in Parkinson's disease. This suggests that modulating GPAT activity may influence neuronal vulnerability to protein aggregation.
Lipodystrophy and congenital generalized lipodystrophy
Mutations in AGPAT2, which catalyzes the second acylation step in glycerolipid synthesis, cause congenital generalized lipodystrophy. Although AGPAT2 is distinct from GPAT, the pathway is shared, and impaired acylation of glycerol-3-phosphate derivatives underlies the disease.
Infectious disease and antimicrobial targets
Mycobacterial PlsB is a glycerol-3-phosphate acyltransferase essential for triacylglycerol biosynthesis and membrane integrity, making it a potential drug target against tuberculosis. Similarly, bacterial plsB is required for phospholipid synthesis and cell growth, highlighting the importance of this activity in pathogens.

From glycerol-3-phosphate O-acyltransferase activity-Related Genes to Experimental Models

Research QuestionSuitable Model
Does GPAT1 loss protect against diet-induced MASLD?Liver-specific GPAM knockout mouse
Does GPAT1 overexpression exacerbate steatosis?Adenoviral or transgenic GPAM overexpression in liver
How does O-GlcNAcylation regulate GPAT1 expression?Point mutations in Sp1 O-GlcNAc sites followed by GPAT1 reporter assays
Does GPAT activity modulate alpha-synuclein toxicity?Neuronal cells with GPAT knockout or overexpression
What is the role of AGPAT2 mutations in lipodystrophy?Knock-in of patient mutations in cell lines
Is mycobacterial PlsB essential for growth?Conditional knockout in M. tuberculosis

How to Study the glycerol-3-phosphate O-acyltransferase activity Process

MethodWhat It MeasuresTypical Application
Radiolabeled acyl-CoA assayGPAT enzymatic activityIn vitro enzyme kinetics
LC-MS lipidomicsLysophosphatidic acid and phosphatidic acid levelsCellular lipid flux
qRT-PCRGPAT1 mRNA expressionTranscriptional regulation
Western blotGPAT1 protein levelsProtein expression and stability
ChIPTranscription factor binding to GPAT1 promoterSREBP-1c or Sp1 regulation
O-GlcNAc immunoprecipitationO-GlcNAcylation of Sp1Post-translational modification
CRISPR knockoutLoss of GPAT functionCausal testing in disease models
CRISPR knock-inMutant GPAT or reporter allelesStructure-function studies
Enzymatic activity assays
Glycerol-3-phosphate O-acyltransferase activity can be measured using radiolabeled or fluorescent acyl-CoA substrates and sn-glycerol 3-phosphate, followed by separation of products by thin-layer chromatography or mass spectrometry. These assays are essential for validating enzyme function and kinetics.
Lipidomics and mass spectrometry
Mass spectrometry-based lipidomics quantifies lysophosphatidic acid, phosphatidic acid, and other glycerolipids to assess flux through the GPAT reaction in cells and tissues. This approach is powerful for linking enzyme activity to metabolic phenotypes.
Transcriptional and post-translational analysis
Quantitative PCR, Western blotting, and chromatin immunoprecipitation can assess GPAT1 expression and regulation by transcription factors such as SREBP-1c and Sp1. O-GlcNAcylation can be detected by immunoprecipitation with O-GlcNAc-specific antibodies.
CRISPR-based functional genomics
CRISPR knockout, point mutation, and overexpression models allow precise manipulation of GPAT genes to test their causal roles in lipid metabolism and disease. These models can be combined with lipidomics and phenotypic assays.

How CRISPR Can Be Used to Study GO:0004366 glycerol-3-phosphate O-acyltransferase activity

Knockout

CRISPR knockout of GPAM (GPAT1) in liver cells or mice can determine whether loss of enzyme activity protects against lipid accumulation and MASLD. Knockout of bacterial plsB can test essentiality in pathogens.

Point Mutation

Introducing point mutations in the catalytic site of GPAT or in regulatory phosphorylation/O-GlcNAcylation sites can dissect mechanism and regulation. For example, mutating Sp1 O-GlcNAc sites can test their role in GPAT1 transcription.

Knock-in

Knock-in of disease-associated mutations, such as those in AGPAT2, can model congenital generalized lipodystrophy in cell lines. Tagged knock-in of GPAT1 with fluorescent or affinity tags enables localization and interactome studies.

Overexpression

CRISPR activation or transgenic overexpression of GPAT1 can drive lipid accumulation and exacerbate disease phenotypes, such as alpha-synuclein toxicity. Overexpression in stem cells can probe survival pathways.

How EDITGENE Supports glycerol-3-phosphate O-acyltransferase activity Research

Researchers studying glycerol-3-phosphate O-acyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in lipid metabolism, disease progression, or cellular stress responses. EDITGENE provides end-to-end CRISPR services to generate precisely engineered cell models that answer these questions.
Contact EDITGENE today to design your custom CRISPR model for glycerol-3-phosphate O-acyltransferase activity research.

Related Products

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GPAM Knockout HEK293 Cell Line EDJ-KQ3039 Human 57678 Details Get a Quote
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GPAT3 Knockout HEK293 Cell Line EDJ-KQ10203 Human 84803 Details Get a Quote
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GPAT4 Knockout HCT 116 Cell Line EDJ-KQ36050 Human 137964 Details Get a Quote
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GPAT4 Knockout A-549 Cell Line EDJ-KQ34802 Human 137964 Details Get a Quote
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Frequently Asked Questions About glycerol-3-phosphate O-acyltransferase activity

It is the enzymatic activity (GO:0004366) that transfers an acyl group from acyl-CoA to sn-glycerol 3-phosphate, producing lysophosphatidic acid and CoA, the first step in glycerolipid synthesis.
Key genes include GPAM (GPAT1), GPAT2, GPAT3, GPAT4, and in bacteria plsB. AGPAT2 acts downstream in the same pathway.
GPAT1 catalyzes the mitochondrial glycerol-3-phosphate O-acyltransferase reaction, contributing to hepatic triacylglycerol synthesis and MASLD pathogenesis.
It is regulated transcriptionally by SREBP-1c and ChREBP, and post-translationally by O-GlcNAcylation of Sp1 and modulation by AKAP1.
It is linked to MASLD, alpha-synuclein toxicity in neurodegeneration, congenital generalized lipodystrophy (via AGPAT2), and bacterial infections.
Use enzymatic assays with radiolabeled acyl-CoA, lipidomics, and CRISPR knockout or overexpression models to test function and causality.
GPAT (GO:0004366) acylates glycerol-3-phosphate to form lysophosphatidic acid, while AGPAT acylates lysophosphatidic acid to form phosphatidic acid, the next step.
Yes, CRISPR knockout, point mutation, knock-in, and overexpression are powerful for dissecting GPAT function in lipid metabolism and disease.
GPAT activity supports membrane lipid synthesis and may influence cell survival; however, direct cancer links require further study.
GPAT1 is on the mitochondrial outer membrane, while GPAT3 and GPAT4 are in the endoplasmic reticulum.

Conclusion

Glycerol-3-phosphate O-acyltransferase activity (GO:0004366) is a fundamental enzymatic function that gates glycerolipid biosynthesis and influences diverse physiological and pathological processes, from hepatic steatosis to neurodegeneration and bacterial pathogenesis. Its regulation by nutrients, hormones, and post-translational modifications makes it a dynamic node in metabolic control. Continued research using precise CRISPR models will clarify isoform-specific roles and uncover therapeutic opportunities.

References

  1. 1. Karasawa K et al.. 2019. Transcriptional Regulation of Acyl-CoA:Glycerol-sn-3-Phosphate Acyltransferases.. Int J Mol Sci 20(4) PMID: 30813330
  2. 2. He L et al.. 2025. Hepatic AKAP1 deficiency exacerbates diet-induced MASLD by enhancing GPAT1-mediated lysophosphatidic acid synthesis.. Nat Commun 16(1):4286 PMID: 40341440
  3. 3. Dircks LK et al.. 1997. Mammalian mitochondrial glycerol-3-phosphate acyltransferase.. Biochim Biophys Acta 1348(1-2):17-26 PMID: 9370312
  4. 4. Ren M et al.. 2026. Glycerol 3-phosphate acyltransferase exacerbates α-synuclein-induced toxicity by increasing lipid peroxidation.. Nat Commun 17(1):1618 PMID: 41554711
  5. 5. Lee HJ et al.. 2016. Glycerol-3-phosphate acyltransferase-1 upregulation by O-GlcNAcylation of Sp1 protects against hypoxia-induced mouse embryonic stem cell apoptosis via mTOR activation.. Cell Death Dis 7(3):e2158 PMID: 27010859
  6. 6. Haque W et al.. 2005. Enzymatic activity of naturally occurring 1-acylglycerol-3-phosphate-O-acyltransferase 2 mutants associated with congenital generalized lipodystrophy.. Biochem Biophys Res Commun 327(2):446-53 PMID: 15629135
  7. 7. Santoshi M et al.. 2024. Identification of a 1-acyl-glycerol-3-phosphate acyltransferase from Mycobacterium tuberculosis, a key enzyme involved in triacylglycerol biosynthesis.. Mol Microbiol 121(6):1164-1181 PMID: 38676355
  8. 8. Wilkison WO et al.. 1997. sn-Glycerol-3-phosphate acyltransferase from Escherichia coli.. Biochim Biophys Acta 1348(1-2):3-9 PMID: 9370310
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