GO:0004742 dihydrolipoyllysine-residue acetyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0004742 describes the enzymatic activity that transfers an acetyl group from acetyl-CoA to a dihydrolipoyl-lysine residue on a protein, producing S-acetyldihydrolipoyl-lysine and CoA.
• This activity is a core component of the pyruvate dehydrogenase complex (PDC), linking glycolysis to the tricarboxylic acid cycle and cellular energy production.
• The DLAT gene encodes the dihydrolipoyl acetyltransferase (E2) subunit of PDC, which harbors this catalytic activity.
• Dysregulation of this activity is implicated in primary biliary cholangitis, where PDC-E2 is the dominant autoantigen.
• In cancer, DLAT-mediated mitochondrial function supports hepatocellular carcinoma progression, and DLAT is a cuproptosis-related gene.
• Studying GO:0004742 requires integrated approaches such as CRISPR knockout, point mutation, and metabolic flux analysis.
Description
Dihydrolipoyllysine-residue acetyltransferase activity (GO:0004742) is a molecular function that catalyzes the transfer of an acetyl group from acetyl-CoA to a dihydrolipoyl-lysine residue on a protein, yielding S-acetyldihydrolipoyl-lysine and coenzyme A. This activity is essential for the oxidative decarboxylation of pyruvate within the pyruvate dehydrogenase complex (PDC), a multienzyme assembly that connects glycolysis to the tricarboxylic acid cycle. The reaction is carried out by the dihydrolipoyl acetyltransferase (E2) subunit, which in humans is encoded by the DLAT gene. Researchers study GO:0004742 because it sits at the crossroads of energy metabolism, mitochondrial function, and disease. Mutations in PDC components, including DLAT, cause pyruvate dehydrogenase complex deficiency, a severe neurometabolic disorder often presenting as Leigh syndrome. Beyond inherited disorders, the E2 subunit is the primary autoantigen in primary biliary cholangitis, making this activity a target of autoimmune attack. In cancer, DLAT expression and mitochondrial function are linked to tumor progression, and DLAT is recognized as a cuproptosis-related gene. Thus, understanding the regulation and structural basis of GO:0004742 offers insights into metabolic disease, autoimmunity, and oncology. This article integrates authoritative QuickGO annotation with verified PubMed literature to provide a research-grade overview of GO:0004742, covering its definition, mechanism, key genes, disease relevance, and experimental strategies for functional interrogation.
dihydrolipoyllysine-residue acetyltransferase activity At A Glance
| GO ID | GO:0004742 |
|---|---|
| GO term | dihydrolipoyllysine-residue acetyltransferase activity |
| Ontology | molecular_function |
| Synonym | dihydrolipoamide S-acetyltransferase activity; acetyl-CoA:dihydrolipoamide S-acetyltransferase activity; lipoate acetyltransferase activity |
| Major function | Catalyzes acetyl transfer from acetyl-CoA to a dihydrolipoyl-lysine residue on a protein, a key reaction in the pyruvate dehydrogenase complex. |
| Reaction | N(6)-[(R)-dihydrolipoyl]-L-lysyl-[protein] + acetyl-CoA = N(6)-[(R)-S(8)-acetyldihydrolipoyl]-L-lysyl-[protein] + CoA. |
| Cofactor | Lipoic acid (lipoamide) is covalently attached to the E2 subunit and cycles between oxidized and reduced forms. |
| Associated complex | Pyruvate dehydrogenase complex (PDC), comprising E1, E2, and E3 subunits. |
| Human gene | DLAT encodes the dihydrolipoyl acetyltransferase (E2) subunit. |
What Is GO:0004742?
In simple terms, GO:0004742 is the activity of an enzyme that moves an acetyl group from acetyl-CoA onto a specific lysine residue that carries a dihydrolipoamide group, forming an acetylated dihydrolipoyl-lysine and releasing CoA. This is a central step in the pyruvate dehydrogenase complex, where the E2 subunit accepts the acetyl group and later transfers it to coenzyme A to produce acetyl-CoA.
Why Is dihydrolipoyllysine-residue acetyltransferase activity Important in Cell Biology?
GO:0004742 is critical because it governs the terminal step of pyruvate oxidation, directly influencing cellular energy production and metabolic homeostasis. Its dysfunction is linked to severe mitochondrial disorders such as pyruvate dehydrogenase complex deficiency and Leigh syndrome, and it is the target of autoantibodies in primary biliary cholangitis. Moreover, this activity is emerging as a determinant of cancer cell metabolism and cuproptosis sensitivity, making it a compelling target for both mechanistic studies and therapeutic development.
• Essential for pyruvate dehydrogenase complex function and aerobic energy metabolism.
• Mutations in DLAT cause pyruvate dehydrogenase complex deficiency, a neurometabolic disorder.
• Autoantibodies against PDC-E2 are a hallmark of primary biliary cholangitis.
• DLAT-mediated mitochondrial function promotes hepatocellular carcinoma progression.
• DLAT is a cuproptosis-related gene, linking this activity to copper-induced cell death.
• The activity is a potential target for modulating obesity via Dlat-AMPK signaling.
• Mitochondrial copper overload inhibits pyruvate dehydrogenase activity, affecting this step.
• E4F1 coordinates pyruvate metabolism and Elongator complex activity, impacting PDC-related pathways.
• Structural studies of carnitine acyltransferases inform the catalytic mechanism of related acetyltransferases.
• CRISPR-based models enable precise interrogation of DLAT function in health and disease.
What Happens During dihydrolipoyllysine-residue acetyltransferase activity?
Substrate recognition and acetyl transfer
In simple terms: The enzyme grabs an acetyl group from acetyl-CoA and attaches it to a swinging arm on the protein.
The E2 subunit of the pyruvate dehydrogenase complex contains a lipoyl domain with a covalently attached lipoamide cofactor. In its reduced form, the dihydrolipoyl-lysine residue accepts an acetyl group from acetyl-CoA, forming S-acetyldihydrolipoyl-lysine and releasing CoA. This reaction is the defining catalytic event of GO:0004742.
Role within the pyruvate dehydrogenase complex
In simple terms: This step is the middle part of a three-enzyme assembly that converts pyruvate into acetyl-CoA.
The pyruvate dehydrogenase complex (PDC) comprises E1 (pyruvate dehydrogenase), E2 (dihydrolipoyl acetyltransferase), and E3 (dihydrolipoamide dehydrogenase). E1 decarboxylates pyruvate and transfers the acetyl group to the lipoyl domain of E2; E2 then catalyzes the acetyl transfer to CoA, producing acetyl-CoA, which feeds the TCA cycle. This integration is essential for energy production.
Cofactor cycling and redox regulation
In simple terms: The lipoamide arm switches between oxidized and reduced states to carry acetyl groups.
The lipoamide cofactor on E2 cycles between oxidized (lipoamide) and reduced (dihydrolipoamide) forms. After acetyl transfer, the dihydrolipoyl group is reoxidized by E3, which uses NAD+ as an electron acceptor. This redox cycling is tightly coupled to the overall PDC activity and is sensitive to the cellular NAD+/NADH ratio.
Structural organization of the E2 core
In simple terms: Many E2 subunits assemble into a cube-like core that holds the complex together.
The E2 subunit forms the structural core of PDC, typically a 24- or 60-mer assembly. Each E2 monomer includes lipoyl domains, a peripheral subunit-binding domain, and a catalytic domain. The catalytic domain harbors the active site for GO:0004742 and is responsible for acetyl transfer from acetyl-CoA to the dihydrolipoyl-lysine. This architecture allows efficient substrate channeling between E1 and E3.
Regulation by phosphorylation and metabolic signals
In simple terms: The complex can be turned on or off by chemical modifications and energy signals.
PDC activity is regulated by phosphorylation of E1 by pyruvate dehydrogenase kinases (PDKs) and dephosphorylation by pyruvate dehydrogenase phosphatases (PDPs). Although GO:0004742 itself is not directly phosphorylated, its flux depends on the overall complex activity. Additionally, Dlat-AMPK signaling has been shown to modulate thermogenesis in adipose tissue, linking this activity to energy sensing.
Key Genes Involved in GO:0004742 dihydrolipoyllysine-residue acetyltransferase activity
The following genes and proteins are directly or functionally associated with dihydrolipoyllysine-residue acetyltransferase activity (GO:0004742) and its broader metabolic context.
| Gene | Major Role | Research Relevance |
|---|---|---|
| DLAT | Encodes the E2 subunit of PDC; carries the catalytic activity of GO:0004742 | Mutations cause PDC deficiency; autoantigen in primary biliary cholangitis; linked to cancer and cuproptosis |
| PDHA1 | Encodes the E1 alpha subunit of PDC; decarboxylates pyruvate | Defects cause PDC deficiency and Leigh syndrome |
| PDHB | Encodes the E1 beta subunit of PDC | Mutations lead to PDC deficiency |
| DLD | Encodes the E3 subunit (dihydrolipoamide dehydrogenase); reoxidizes lipoamide | Defects cause E3 deficiency with neurological and hepatic symptoms |
| PDK1 | Phosphorylates and inhibits E1 | Regulates PDC flux; target for metabolic modulation |
| PDP1 | Dephosphorylates and activates E1 | Controls PDC activity in response to energy demand |
| SLC25A19 | Mitochondrial thiamine pyrophosphate carrier | Thiamine metabolism affects PDC function |
| LIAS | Lipoyl synthase; synthesizes lipoic acid cofactor | Required for lipoylation of E2; defects cause lipoic acid biosynthesis disorders |
| LIPT1 | Lipoyltransferase 1; attaches lipoate to E2 | Mutations impair PDC and other complexes |
| LIPT2 | Lipoyltransferase 2; involved in lipoate synthesis | Defects cause neonatal encephalopathy |
| E4F1 | Coordinates pyruvate metabolism and Elongator complex | Regulates translation fidelity during brain development |
| SLC31A1 | Copper transporter; affects cuproptosis | Copper overload inhibits PDC activity |
| FDX1 | Ferredoxin 1; involved in cuproptosis | Links copper homeostasis to DLAT lipoylation |
| AMPK | Energy sensor kinase | Dlat-AMPK signaling axis modulates thermogenesis |
| PDHX | E3-binding protein of PDC | Structural component; mutations cause PDC deficiency |
| PDHA2 | Testis-specific E1 alpha subunit | Potential role in spermatogenesis |
| DLST | Dihydrolipoamide succinyltransferase; analogous E2 in alpha-ketoglutarate dehydrogenase complex | Related acetyltransferase activity |
| ACAT1 | Acetyl-CoA acetyltransferase; related acyltransferase | Structural and mechanistic comparisons |
How Is dihydrolipoyllysine-residue acetyltransferase activity Regulated?
The activity of GO:0004742 is primarily regulated at the level of the pyruvate dehydrogenase complex. Phosphorylation of E1 by pyruvate dehydrogenase kinases (PDKs) inhibits the complex, while dephosphorylation by pyruvate dehydrogenase phosphatases (PDPs) activates it. This reversible phosphorylation responds to metabolic signals such as NADH/NAD+ ratio, acetyl-CoA/CoA ratio, and ATP/ADP ratio. Additionally, Dlat-AMPK signaling has been shown to modulate thermogenesis in adipose tissue, indicating that AMPK can influence this activity indirectly. Mitochondrial copper overload has been reported to inhibit pyruvate dehydrogenase activity, affecting the overall flux through GO:0004742. Furthermore, E4F1 coordinates pyruvate metabolism and Elongator complex activity, which may impact translation fidelity and PDC-related pathways during brain development.
dihydrolipoyllysine-residue acetyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| DLAT | PDC deficiency, Leigh syndrome, primary biliary cholangitis, cancer | CRISPR knockout or point-mutation in cell lines; patient-derived fibroblasts |
| PDHA1 | PDC deficiency, Leigh syndrome | Knockout in neuroblastoma or iPSC-derived neurons |
| DLD | E3 deficiency with neurological and hepatic symptoms | Liver-specific knockout mouse or hepatocyte cell model |
| LIAS | Lipoic acid biosynthesis disorder | Knockout in HEK293T or patient fibroblasts |
| SLC31A1 | Copper overload and renal fibrosis | Knockout in renal tubular cells or mouse models |
Pyruvate dehydrogenase complex deficiency and Leigh syndrome
Mutations in DLAT and other PDC genes cause pyruvate dehydrogenase complex deficiency, a severe neurometabolic disorder characterized by lactic acidosis and neurological impairment. This condition often presents as Leigh syndrome, with bilateral lesions in the basal ganglia and brainstem. The loss of GO:0004742 activity directly impairs acetyl-CoA production, leading to energy failure in high-demand tissues such as the brain.
Primary biliary cholangitis
Primary biliary cholangitis (PBC) is an autoimmune liver disease in which the E2 subunit of PDC (PDC-E2) is the dominant autoantigen. Autoantibodies against PDC-E2 are detected in the majority of PBC patients, and the lipoyl domain is a key epitope. Recent studies have identified a novel PDC-E2 epitope and explored engineered Treg therapy, highlighting the clinical relevance of this activity.
Cancer and cuproptosis
DLAT, which carries GO:0004742, is a cuproptosis-related gene. In hepatocellular carcinoma, MELK promotes carcinogenesis by modulating DLAT-mediated mitochondrial function. Copper overload can inhibit pyruvate dehydrogenase activity, linking this metabolic step to copper-induced cell death and renal fibrosis. These findings suggest that targeting GO:0004742 may have therapeutic potential in oncology.
Metabolic and thermogenic regulation
The phytochemical hyperforin triggers thermogenesis in adipose tissue via a Dlat-AMPK signaling axis, indicating that this activity can be modulated to curb obesity. This positions GO:0004742 as a potential target for metabolic disorders beyond classical PDC deficiency.
From dihydrolipoyllysine-residue acetyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the catalytic mechanism of GO:0004742? | Recombinant DLAT catalytic domain with site-directed mutagenesis |
| How does loss of DLAT affect mitochondrial metabolism? | CRISPR knockout of DLAT in cancer cell lines followed by Seahorse and metabolomics |
| Can point mutations in DLAT cause PDC deficiency? | Knock-in of patient-specific mutations in iPSCs or cell lines |
| How is DLAT regulated by AMPK signaling? | Tagged knock-in of DLAT with AMPK phosphorylation sites mutated |
| What is the role of DLAT in cuproptosis? | Overexpression or knockout of DLAT in cells treated with copper ionophores |
| Does DLAT lipoylation affect autoantibody recognition? | Knock-in of lipoylation-deficient DLAT in B cells or hepatocytes |
How to Study the dihydrolipoyllysine-residue acetyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| PDC activity assay | NADH production from pyruvate oxidation | Quantifying GO:0004742 flux in cell lysates |
| Seahorse XF | Oxygen consumption rate and extracellular acidification | Assessing mitochondrial function after DLAT knockout |
| LC-MS/MS proteomics | Protein lipoylation and acetylation | Identifying E2 modifications in disease models |
| CRISPR knockout screening | Gene essentiality and drug sensitivity | Discovering modulators of cuproptosis |
| Western blot | Protein expression and phosphorylation | Validating DLAT and PDC subunit levels |
| Immunohistochemistry | Tissue distribution of PDC-E2 | Diagnosing primary biliary cholangitis |
| Site-directed mutagenesis | Catalytic residues and substrate binding | Mapping the active site of GO:0004742 |
| Metabolomics | Acetyl-CoA and TCA cycle intermediates | Linking DLAT activity to metabolic rewiring |
Enzymatic activity assays
Direct measurement of GO:0004742 activity can be performed using spectrophotometric assays that monitor the reduction of NAD+ to NADH at 340 nm in the presence of pyruvate, CoA, and PDC components. This provides a quantitative readout of complex activity.
Metabolic flux analysis
Seahorse extracellular flux analysis and 13C-labeled substrate tracing can measure the impact of DLAT perturbations on oxidative phosphorylation and TCA cycle flux. These methods are particularly useful in cancer and metabolic disease models.
Proteomics and lipoylation profiling
Mass spectrometry-based proteomics can identify lipoylated proteins and quantify the acetylation state of the E2 lipoyl domain. This helps assess the functional status of GO:0004742 in cells and tissues.
CRISPR screening and functional genomics
Genome-wide CRISPR knockout screens can identify genes that modulate sensitivity to PDC inhibition or copper-induced cell death. Such screens have implicated DLAT and other cuproptosis-related genes.
How CRISPR Can Be Used to Study GO:0004742 dihydrolipoyllysine-residue acetyltransferase activity
Knockout
CRISPR-Cas9 knockout of DLAT or other PDC genes can abolish GO:0004742 activity, leading to impaired mitochondrial respiration and increased reliance on glycolysis. Such models are valuable for studying PDC deficiency, cancer metabolism, and cuproptosis sensitivity.
Point Mutation
Introducing patient-specific point mutations into DLAT via CRISPR base editing or homology-directed repair allows researchers to dissect the impact of missense variants on catalytic activity and complex assembly. This is particularly relevant for PDC deficiency and Leigh syndrome.
Knock-in
Knock-in of tagged DLAT (e.g., FLAG or HA) enables affinity purification and interaction studies. Additionally, knock-in of lipoylation-deficient DLAT can clarify the role of the lipoyl domain in autoantibody recognition and enzymatic function.
Overexpression
CRISPR activation (CRISPRa) or lentiviral overexpression of DLAT can increase GO:0004742 activity, which may promote tumor growth or alter metabolic flux. Overexpression models are useful for studying gain-of-function effects in cancer and metabolic disorders.
How EDITGENE Supports dihydrolipoyllysine-residue acetyltransferase activity Research
Researchers studying dihydrolipoyllysine-residue acetyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in metabolic regulation, disease progression, or drug response. EDITGENE provides a comprehensive suite of CRISPR-based services to enable precise functional interrogation of GO:0004742 and its associated pathways.
Contact EDITGENE today to design your custom CRISPR model for dihydrolipoyllysine-residue acetyltransferase activity research.
Frequently Asked Questions About dihydrolipoyllysine-residue acetyltransferase activity
What is dihydrolipoyllysine-residue acetyltransferase activity?
It is the enzymatic activity (GO:0004742) that transfers an acetyl group from acetyl-CoA to a dihydrolipoyl-lysine residue on a protein, a key step in the pyruvate dehydrogenase complex.
What genes are involved in dihydrolipoyllysine-residue acetyltransferase activity?
The primary gene is DLAT, which encodes the E2 subunit. Other PDC genes such as PDHA1, PDHB, DLD, and PDHX are also involved.
What is the role of DLAT in metabolism?
DLAT encodes the E2 subunit that carries GO:0004742 activity, essential for converting pyruvate to acetyl-CoA and feeding the TCA cycle.
How is dihydrolipoyllysine-residue acetyltransferase activity regulated?
It is regulated by phosphorylation of the pyruvate dehydrogenase complex, as well as by metabolic signals such as NADH/NAD+ ratio and AMPK signaling.
What diseases are associated with GO:0004742 dysfunction?
Mutations cause pyruvate dehydrogenase complex deficiency and Leigh syndrome; autoantibodies against PDC-E2 are found in primary biliary cholangitis; DLAT is linked to cancer and cuproptosis.
How can I study dihydrolipoyllysine-residue acetyltransferase activity in the lab?
Common methods include enzymatic activity assays, Seahorse flux analysis, proteomics, and CRISPR knockout models.
What is the pyruvate dehydrogenase complex?
It is a multienzyme complex comprising E1, E2, and E3 subunits that converts pyruvate to acetyl-CoA. GO:0004742 is the E2-catalyzed step.
Is DLAT a cuproptosis-related gene?
Yes, DLAT is a cuproptosis-related gene, and its lipoylation is important for copper-induced cell death.
Can CRISPR be used to study GO:0004742?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are powerful tools to dissect the function of DLAT and related genes.
What is the clinical significance of PDC-E2 autoantibodies?
PDC-E2 autoantibodies are a diagnostic hallmark of primary biliary cholangitis and target the lipoyl domain of the E2 subunit.
Conclusion
Dihydrolipoyllysine-residue acetyltransferase activity (GO:0004742) is a fundamental molecular function in mitochondrial energy metabolism, catalyzing a key step in the pyruvate dehydrogenase complex. Its dysregulation is implicated in severe neurometabolic disorders, autoimmune liver disease, and cancer, making it a compelling target for basic and translational research. Advances in CRISPR-based genome editing and metabolic profiling now enable precise interrogation of this activity in physiologically relevant models. EDITGENE offers comprehensive services to support these efforts, from custom knockout and knock-in cell lines to high-throughput screening and bioinformatics.
References
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- 2. Chen S et al.. 2021. The phytochemical hyperforin triggers thermogenesis in adipose tissue via a Dlat-AMPK signaling axis to curb obesity.. Cell Metab 33(3):565-580.e7 PMID: 33657393
- 3. Li Z et al.. 2023. MELK promotes HCC carcinogenesis through modulating cuproptosis-related gene DLAT-mediated mitochondrial function.. Cell Death Dis 14(11):733 PMID: 37949877
- 4. Gulamhusein AF et al.. 2020. Primary biliary cholangitis: pathogenesis and therapeutic opportunities.. Nat Rev Gastroenterol Hepatol 17(2):93-110 PMID: 31819247
- 5. Tewari R et al.. 2024. Identification of a novel PDC-E2 epitope in primary biliary cholangitis: Application for engineered Treg therapy.. J Autoimmun 149:103327 PMID: 39476446
- 6. Zhu S et al.. 2024. Mitochondrial copper overload promotes renal fibrosis via inhibiting pyruvate dehydrogenase activity.. Cell Mol Life Sci 81(1):340 PMID: 39120696
- 7. Di Michele M et al.. 2025. E4F1 coordinates pyruvate metabolism and the activity of the elongator complex to ensure translation fidelity during brain development.. Nat Commun 16(1):67 PMID: 39747033
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