GO:0017118 lipoyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0017118 lipoyltransferase activity is a molecular_function that catalyzes the transfer of a lipoyl group from (R)-lipoyl-5'-AMP to a lysine residue on a lipoyl-carrier protein, releasing AMP and two protons.
• The reaction is essential for the post-translational lipoylation of mitochondrial enzyme complexes, including pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase.
• In humans, the principal enzyme carrying this activity is LIPT1 (lipoyltransferase 1), and mutations in LIPT1 cause a severe metabolic disorder with neurological and hepatic involvement.
• LIPT1 and lipoylation are mechanistically linked to cuproptosis, a copper-dependent cell death pathway, making them targets in cancer research [1,2,3,4].
• Dysregulation of lipoyltransferase activity has been implicated in bladder cancer, lung cancer, and oocyte meiotic arrest, highlighting its broad biological significance [1,2,8].
• Studying GO:0017118 requires combining genetic models (knockout, point mutation, knock-in) with biochemical assays and multi-omics to dissect its role in health and disease [5,7].
Description
Lipoyltransferase activity (GO:0017118) is a molecular function that attaches lipoic acid, a sulfur-containing cofactor, to specific lysine residues on target proteins. This modification, called lipoylation, is indispensable for the function of several mitochondrial multienzyme complexes that drive oxidative metabolism. The reaction is defined by the transfer of a lipoyl moiety from the activated intermediate (R)-lipoyl-5'-AMP to a lipoyl-carrier protein, producing a lipoyl-lysyl conjugate, AMP, and protons. In humans, the enzyme LIPT1 is the primary executor of this activity, and its dysfunction leads to severe metabolic disease. Beyond mitochondrial energetics, recent studies have connected lipoyltransferase activity to cuproptosis, a novel form of copper-induced cell death, thereby linking this basic biochemical function to cancer biology and potential therapeutic strategies [1,2,3,4]. Understanding GO:0017118 is therefore critical for researchers in metabolism, cancer, and rare genetic disorders.
lipoyltransferase activity At A Glance
| GO ID | GO:0017118 |
|---|---|
| GO term | lipoyltransferase activity |
| Ontology | molecular_function |
| Synonym | (none) |
| Major function | Catalyzes the transfer of a lipoyl group from (R)-lipoyl-5'-AMP to a lysine residue on a lipoyl-carrier protein, releasing AMP and protons. |
| Reaction | (R)-lipoyl-5'-AMP + L-lysyl-[lipoyl-carrier protein] = (R)-N6-lipoyl-L-lysyl-[lipoyl-carrier protein] + AMP + 2 H+. |
| Human gene | LIPT1 (lipoyltransferase 1). |
| Associated diseases | LIPT1 deficiency, metabolic disorders, cancer (e.g., bladder, lung) [1,2,5]. |
| Related process | Protein lipoylation, mitochondrial metabolism, cuproptosis [1,2,3,4]. |
What Is GO:0017118?
According to the Gene Ontology, GO:0017118 lipoyltransferase activity is defined as the catalysis of the reaction: (R)-lipoyl-5'-AMP + L-lysyl-[lipoyl-carrier protein] = (R)-N6-lipoyl-L-lysyl-[lipoyl-carrier protein] + AMP + 2 H+. In simpler terms, it is the enzyme activity that transfers a lipoyl group onto a lysine residue of a carrier protein, using lipoyl-AMP as the donor and releasing AMP. This activity is responsible for the covalent attachment of lipoic acid, a cofactor required for the function of several dehydrogenase complexes.
Why Is lipoyltransferase activity Important in Cell Biology?
Lipoyltransferase activity is essential for cellular energy metabolism because it enables the lipoylation of key mitochondrial enzyme complexes, such as pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase. Without this modification, these complexes cannot function, leading to impaired oxidative phosphorylation and metabolic collapse. In humans, mutations in LIPT1 cause a devastating disorder characterized by neurological and hepatic symptoms. Moreover, recent research has revealed that lipoylation is a critical component of the cuproptosis pathway, a copper-dependent cell death mechanism that can be exploited in cancer therapy [1,2,3,4]. Thus, understanding GO:0017118 offers insights into fundamental biochemistry, inherited metabolic diseases, and innovative cancer treatments.
• Required for the function of mitochondrial dehydrogenase complexes involved in energy production.
• Mutations in LIPT1 cause a rare but severe metabolic disorder with neurological and hepatic manifestations.
• Lipoylation is a key mediator of cuproptosis, a novel cell death pathway with therapeutic potential in cancer [1,2,3,4].
• LIPT1 expression is dysregulated in multiple cancers, including bladder and lung cancer [1,2,7].
• The activity is conserved across species, from plants to humans, underscoring its fundamental biological role.
• It represents a potential target for pharmacological correction in patients with LIPT1 mutations.
• Lipoyltransferase activity influences oocyte meiosis and fertility through mitochondrial function.
• Understanding its regulation may reveal new links between metabolism and cell death pathways [1,2,3,4].
What Happens During lipoyltransferase activity?
Activation of lipoic acid to lipoyl-AMP
In simple terms: First, lipoic acid is activated by attaching it to AMP, forming a reactive intermediate.
The reaction begins with the activation of (R)-lipoic acid by a lipoate-activating enzyme, which uses ATP to form (R)-lipoyl-5'-AMP. This activated intermediate is the direct donor of the lipoyl group in the transfer reaction catalyzed by lipoyltransferase. In humans, the activation step is thought to be carried out by a separate enzyme, although the exact mechanism remains an area of active research.
Transfer of the lipoyl group to the carrier protein
In simple terms: The activated lipoyl group is then transferred onto a specific lysine residue of a carrier protein.
Lipoyltransferase (LIPT1 in humans) catalyzes the transfer of the lipoyl moiety from (R)-lipoyl-5'-AMP to the epsilon-amino group of a conserved lysine residue on a lipoyl-carrier protein, such as the E2 subunit of pyruvate dehydrogenase. This forms an amide bond, releasing AMP and two protons. The reaction is highly specific for the carrier protein and the lysine residue, ensuring proper lipoylation.
Assembly and function of lipoylated complexes
In simple terms: Once lipoylated, the carrier protein becomes part of large enzyme complexes that produce energy.
After lipoylation, the modified carrier protein assembles into multienzyme complexes, including pyruvate dehydrogenase complex (PDC) and alpha-ketoglutarate dehydrogenase complex (KGDHC). These complexes are essential for the oxidative decarboxylation of pyruvate and alpha-ketoglutarate, linking glycolysis and the TCA cycle. Defects in lipoylation lead to reduced activity of these complexes and severe metabolic consequences.
Role in cuproptosis and cell death
In simple terms: Lipoylated proteins can bind copper, triggering a specific type of cell death called cuproptosis.
Recent studies have shown that lipoylated proteins are direct targets of copper, and their aggregation leads to cuproptosis, a copper-induced cell death pathway distinct from apoptosis [1,2,3,4]. Lipoyltransferase activity is therefore upstream of this process, as it provides the lipoyl modification required for copper binding. Modulating LIPT1 expression or activity can influence sensitivity to cuproptosis inducers, making it a potential therapeutic target in cancer [1,2,7].
Key Genes Involved in GO:0017118 lipoyltransferase activity
The following genes and proteins are directly or indirectly involved in lipoyltransferase activity and its downstream effects.
| Gene | Major Role | Research Relevance |
|---|---|---|
| LIPT1 | Human lipoyltransferase that transfers lipoyl groups to carrier proteins | Mutations cause LIPT1 deficiency; target for cancer and metabolic studies [5,7]. |
| LIPT2 | Lipoyltransferase involved in mitochondrial lipoylation | Potential redundancy or specificity in lipoylation pathways. |
| LIAS | Lipoyl synthase, generates lipoic acid for transfer | Upstream of LIPT1; mutations cause hyperglycinemia. |
| DLD | Dihydrolipoamide dehydrogenase, component of dehydrogenase complexes | Lipoylation-dependent; mutations cause E3 deficiency. |
| PDHA1 | Pyruvate dehydrogenase E1 alpha subunit | Requires lipoylation for function; linked to PDH deficiency. |
| PDHB | Pyruvate dehydrogenase E1 beta subunit | Part of PDC; lipoylation essential. |
| DLAT | Dihydrolipoamide acetyltransferase, carries lipoyl group | Direct substrate of LIPT1; central to PDC. |
| DLST | Dihydrolipoamide succinyltransferase, carries lipoyl group | Substrate of LIPT1 in KGDHC. |
| GCSH | Glycine cleavage system H protein, lipoyl carrier | Lipoylation required for glycine decarboxylation. |
| SLC25A19 | Mitochondrial thiamine pyrophosphate carrier | Indirectly supports dehydrogenase complexes. |
| FDX1 | Ferredoxin 1, involved in lipoylation and cuproptosis | Regulates lipoylation and copper-induced cell death [1,2,3]. |
| LIAS | Lipoyl synthase, generates lipoate | Essential for lipoylation; linked to cuproptosis [1,2]. |
| MTF1 | Metal-responsive transcription factor 1 | Regulates genes involved in copper homeostasis and lipoylation. |
| SLC31A1 | Copper transporter 1 | Influences intracellular copper levels and cuproptosis sensitivity [1,2]. |
| ATP7A | Copper-transporting ATPase | Copper efflux; affects cuproptosis. |
| ATP7B | Copper-transporting ATPase | Copper homeostasis; linked to Wilson disease and cuproptosis. |
| PDHX | Pyruvate dehydrogenase complex component X | Lipoylation-dependent structural component. |
| MPC1 | Mitochondrial pyruvate carrier 1 | Supplies pyruvate to PDC; indirect role. |
How Is lipoyltransferase activity Regulated?
Lipoyltransferase activity is regulated at multiple levels. Transcriptionally, LIPT1 expression can be influenced by metabolic status and oncogenic signals, as suggested by pan-cancer analyses. Post-transcriptionally, m6A modification of LIPT1 mRNA has been shown to inhibit bladder cancer progression by modulating cuproptosis, indicating epitranscriptomic control. Additionally, o8G modification of circular RNA circKIAA1797 affects lung cancer development by inhibiting cuproptosis, potentially through regulation of lipoylation-related genes. At the protein level, the activity of LIPT1 may be modulated by substrate availability, such as lipoyl-AMP and carrier proteins, and by interactions with other components of the lipoylation machinery. Copper homeostasis also indirectly regulates the downstream effects of lipoylation by determining cuproptosis sensitivity [3,4].
lipoyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| LIPT1 | LIPT1 deficiency (neurological, hepatic) | Patient-derived fibroblasts, CRISPR KO/point mutation in cell lines. |
| LIPT1 | Bladder cancer progression | Bladder cancer cell lines with LIPT1 KO or overexpression. |
| LIPT1 | Lung cancer development | Lung cancer cell lines with circKIAA1797 modulation. |
| FDX1 | Cuproptosis sensitivity in cancers | Cancer cell lines with FDX1 KO [1,2,3]. |
| LIAS | Cuproptosis and metabolic disorders | Cell models with LIAS mutations. |
LIPT1 deficiency and metabolic disorders
Biallelic mutations in LIPT1 cause a rare autosomal recessive disorder characterized by neurological impairment, lactic acidosis, and hepatic dysfunction. Patient-derived cellular models have shown defective lipoylation of dehydrogenase complexes, leading to reduced mitochondrial energy production. Pharmacological correction of the mutation has been explored as a therapeutic strategy.
Cancer and cuproptosis
Lipoyltransferase activity is intimately linked to cuproptosis, a copper-dependent cell death pathway. In bladder cancer, m6A modification of LIPT1 inhibits progression by activating cuproptosis. In lung cancer, o8G-modified circKIAA1797 promotes development by inhibiting cuproptosis, implicating lipoylation in tumor suppression. Pan-cancer analyses have revealed that LIPT1 expression correlates with prognosis and immune infiltration in multiple cancer types. These findings suggest that targeting lipoyltransferase activity could enhance cuproptosis-based cancer therapies [3,4].
Reproductive biology and oocyte meiosis
Cuproptosis, driven by lipoylated proteins, causes meiotic metaphase I arrest in oocytes by disrupting mitochondrial functions. This highlights a role for lipoyltransferase activity in fertility and reproductive health, as proper lipoylation is required for oocyte maturation.
From lipoyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the effect of LIPT1 loss on mitochondrial metabolism? | LIPT1 knockout cell lines (e.g., HEK293, HeLa). |
| How do patient mutations affect lipoyltransferase activity? | Point-mutation knock-in of LIPT1 variants in patient-derived cells. |
| Can wild-type LIPT1 rescue lipoylation defects? | Knock-in of tagged LIPT1 for rescue experiments. |
| Does LIPT1 overexpression alter cuproptosis sensitivity? | LIPT1 overexpression in cancer cell lines [1,2]. |
| What is the role of LIPT1 in tumor growth? | Xenograft models with LIPT1 KO or overexpression [1,7]. |
| How does LIPT1 regulate oocyte meiosis? | Oocyte-specific LIPT1 knockout mouse models. |
How to Study the lipoyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| In vitro lipoyltransferase assay | Enzymatic transfer of lipoyl group | Kinetic analysis of LIPT1 mutants. |
| Western blot with anti-lipoic acid antibody | Global lipoylation levels | Assessing LIPT1 function in cells. |
| Mass spectrometry | Identification of lipoylated proteins | Mapping the lipoylome. |
| RNA-seq | Gene expression changes | Pan-cancer analysis of LIPT1. |
| MeRIP-seq | m6A modification sites | Regulation of LIPT1 mRNA. |
| Seahorse assay | Mitochondrial respiration | Functional impact of LIPT1 KO. |
| CRISPR knockout | Gene function loss | Studying LIPT1 in cancer and metabolism [1,5]. |
| CRISPR knock-in | Introduction of specific mutations | Modeling patient variants. |
Biochemical assays for lipoyltransferase activity
Direct measurement of lipoyltransferase activity can be performed using recombinant LIPT1 and radiolabeled or fluorescently labeled lipoyl-AMP, followed by detection of the lipoylated carrier protein by gel electrophoresis or mass spectrometry. These assays are crucial for validating enzyme kinetics and the impact of mutations.
Genomic and transcriptomic profiling
RNA-seq and pan-cancer analyses can reveal expression patterns of LIPT1 and related genes across tissues and tumor types. Epitranscriptomic modifications, such as m6A and o8G, can be mapped using MeRIP-seq or specific antibodies to understand post-transcriptional regulation [1,2].
Proteomic analysis of lipoylation
Mass spectrometry-based proteomics can identify lipoylated proteins and quantify changes in lipoylation status upon LIPT1 manipulation. This approach provides a global view of the lipoylome and its dynamics.
Functional studies in cell and animal models
CRISPR-Cas9 knockout, point mutation knock-in, and overexpression models are used to dissect the role of LIPT1 in cellular metabolism, cuproptosis, and tumor growth [1,2,5,8]. These models can be combined with metabolic assays, such as Seahorse analysis, to measure mitochondrial function.
How CRISPR Can Be Used to Study GO:0017118 lipoyltransferase activity
Knockout
CRISPR-Cas9 knockout of LIPT1 is used to abolish lipoyltransferase activity, leading to defective lipoylation of dehydrogenase complexes and impaired mitochondrial metabolism. This model is valuable for studying the consequences of LIPT1 loss in cancer cells, where it can sensitize cells to cuproptosis inducers [1,2].
Point Mutation
Point mutation knock-in models, such as the LIPT1 mutations found in patients, allow researchers to study the specific effects of these variants on enzyme activity and cellular function. These models are essential for understanding genotype-phenotype correlations and for testing pharmacological correctors.
Knock-in
Knock-in of tagged LIPT1 (e.g., FLAG or GFP) enables visualization and immunoprecipitation of the enzyme, facilitating studies of its localization, interactions, and dynamics. This approach can also be used to express wild-type LIPT1 in patient-derived cells for rescue experiments.
Overexpression
Overexpression of LIPT1 in cancer cell lines can enhance lipoylation and modulate sensitivity to cuproptosis, providing insights into its role in tumor progression [1,2]. Overexpression models are also useful for biochemical purification of the enzyme and for studying its regulation.
How EDITGENE Supports lipoyltransferase activity Research
Researchers studying lipoyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in metabolic regulation, cuproptosis, or cancer progression. Generating precise genetic models is a critical step in this process, and EDITGENE provides a comprehensive suite of CRISPR services to accelerate discovery.
Contact EDITGENE today to design your custom CRISPR model for lipoyltransferase activity research.
Frequently Asked Questions About lipoyltransferase activity
What is lipoyltransferase activity?
Lipoyltransferase activity (GO:0017118) is the enzyme function that transfers a lipoyl group from (R)-lipoyl-5'-AMP to a lysine residue on a carrier protein, releasing AMP and protons.
What genes are involved in lipoyltransferase activity?
The primary human gene is LIPT1, which encodes lipoyltransferase 1. Other related genes include LIAS, DLD, and components of dehydrogenase complexes.
What diseases are associated with lipoyltransferase activity?
Mutations in LIPT1 cause a rare metabolic disorder with neurological and hepatic symptoms. Dysregulation of lipoylation is also linked to cancer and cuproptosis [1,2,5].
How is lipoyltransferase activity measured?
It can be measured using in vitro assays with recombinant enzyme and labeled substrates, or by detecting lipoylated proteins via Western blot or mass spectrometry.
What is the role of LIPT1 in cancer?
LIPT1-mediated lipoylation is required for cuproptosis, a copper-induced cell death. Modulating LIPT1 can affect cancer cell sensitivity to cuproptosis inducers [1,2,7].
What is cuproptosis?
Cuproptosis is a form of regulated cell death triggered by copper binding to lipoylated proteins, leading to their aggregation and mitochondrial dysfunction [1,2,3,4].
Can lipoyltransferase activity be targeted therapeutically?
Yes, pharmacological correction of LIPT1 mutations has been explored in patient cells, and targeting lipoylation may enhance cuproptosis-based cancer therapies [5,3].
What model systems are used to study lipoyltransferase activity?
Common models include CRISPR knockout/knock-in cell lines, patient-derived fibroblasts, and animal models such as oocyte-specific knockouts [5,8].
How does lipoyltransferase activity affect metabolism?
It is essential for the function of pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase complexes, which are key for mitochondrial energy production.
What is the relationship between lipoyltransferase activity and oocyte meiosis?
Cuproptosis, driven by lipoylated proteins, causes meiotic metaphase I arrest in oocytes by disrupting mitochondrial functions.
Conclusion
Lipoyltransferase activity (GO:0017118) is a fundamental molecular function that governs protein lipoylation, a modification critical for mitochondrial metabolism and emerging as a key player in cuproptosis and cancer. The human enzyme LIPT1 is central to this activity, and its dysfunction leads to severe metabolic disorders. Ongoing research continues to uncover the regulatory mechanisms and therapeutic potential of targeting this pathway. By leveraging advanced CRISPR models and multi-omics approaches, researchers can further elucidate the roles of lipoyltransferase activity in health and disease.
References
- 1. Du K et al.. 2024. m(6)A modification of lipoyltransferase 1 inhibits bladder cancer progression by activating cuproptosis.. Oncogene 43(40):2971-2985 PMID: 39198615
- 2. Xu H et al.. 2025. o8G-modified circKIAA1797 promotes lung cancer development by inhibiting cuproptosis.. J Exp Clin Cancer Res 44(1):110 PMID: 40176113
- 3. Zhao R et al.. 2024. Cuproptosis, the novel type of oxidation-induced cell death in thoracic cancers: can it enhance the success of immunotherapy?. Cell Commun Signal 22(1):379 PMID: 39068453
- 4. Liu YH et al.. 2025. Machine learning-based model identifies a novel cuproptosis-related mitochondrial gene signature with a key role in the prognosis and treatment of lung adenocarcinoma.. Oncol Lett 30(5):494 PMID: 40904599
- 5. Gómez-Fernández D et al.. 2024. A Multi-Target Pharmacological Correction of a Lipoyltransferase LIPT1 Gene Mutation in Patient-Derived Cellular Models.. Antioxidants (Basel) 13(8) PMID: 39199267
- 6. Wada M et al.. 2001. Lipoic acid metabolism in Arabidopsis thaliana: cloning and characterization of a cDNA encoding lipoyltransferase.. Plant Cell Physiol 42(6):650-6 PMID: 11427685
- 7. Liu Y et al.. 2022. A pan-cancer analysis of copper homeostasis-related gene lipoyltransferase 1: Its potential biological functions and prognosis values.. Front Genet 13:1038174 PMID: 36330439
- 8. Lu YH et al.. 2026. Cuproptosis causes meiotic metaphase I arrest by disrupting mitochondrial functions in oocytes.. Cell Death Discov 12(1) PMID: 42177195
