GO:0004775 succinate-CoA ligase (ADP-forming) activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0004775 succinate-CoA ligase (ADP-forming) activity catalyzes the reversible conversion of succinyl-CoA, ADP, and phosphate into succinate, ATP, and CoA, a key step in the mitochondrial tricarboxylic acid (TCA) cycle.
• The enzyme is a heterodimer composed of an alpha subunit (SUCLG1) and a beta subunit (SUCLA2 or SUCLG2), with SUCLA2 conferring ADP-forming specificity.
• SUCLA2 and SUCLG2 are emerging as regulators of cancer metastasis, oxidative stress, obesity, and ovarian aging through metabolic and epigenetic mechanisms.
• Deficiency of the alpha subunit SUCLG1 causes phenotypic variability in succinate-CoA ligase deficiency, highlighting its clinical importance.
• Valproyl-CoA, a metabolite of valproic acid, inhibits both ATP- and GTP-dependent succinate:CoA ligases, linking the enzyme to drug-induced toxicity.
• CRISPR-based knockout, knock-in, and overexpression models are essential to dissect the tissue-specific and disease-related functions of SUCLA2, SUCLG2, and SUCLG1.
Description
Succinate-CoA ligase (ADP-forming) activity, encoded by GO:0004775, is a molecular function that catalyzes the reversible reaction ATP + succinate + CoA = ADP + succinyl-CoA + phosphate. This enzymatic step is a critical component of the mitochondrial tricarboxylic acid (TCA) cycle, where it couples the hydrolysis of succinyl-CoA to the synthesis of ATP (or GTP in the GTP-forming isoform). The ADP-forming activity is specifically mediated by the beta subunit SUCLA2 in complex with the alpha subunit SUCLG1, distinguishing it from the GTP-forming isoform that utilizes SUCLG2. Researchers study this term because it sits at the intersection of energy metabolism, mitochondrial signaling, and disease pathogenesis, including cancer, metabolic disorders, and mitochondrial myopathies. Understanding its regulation and downstream effects is essential for developing targeted therapies and for interpreting metabolic reprogramming in various cell types.
succinate-CoA ligase (ADP-forming) activity At A Glance
| GO ID | GO:0004775 |
|---|---|
| GO term | succinate-CoA ligase (ADP-forming) activity |
| Ontology | molecular_function |
| Synonym | succinate thiokinase activity; succinic thiokinase; succinyl-CoA synthetase activity; succinyl-CoA synthetase (ADP-forming) activity; succinyl coenzyme A synthetase; succinyl coenzyme A synthetase (adenosine diphosphate-forming) activity |
| Major function | Catalyzes the reversible conversion of succinyl-CoA, ADP, and phosphate to succinate, ATP, and CoA, a key step in the TCA cycle. |
| Reaction | ATP + succinate + CoA = ADP + succinyl-CoA + phosphate |
| Subunits | Heterodimer of alpha (SUCLG1) and beta (SUCLA2 or SUCLG2) subunits; SUCLA2 confers ADP-forming specificity. |
| Cellular location | Mitochondrial matrix |
| Related diseases | Mitochondrial myopathy, cancer metastasis, obesity, ovarian aging, SUCLG1 deficiency. |
What Is GO:0004775?
In simple terms, GO:0004775 describes the catalytic activity of an enzyme that converts succinyl-CoA, ADP, and phosphate into succinate, ATP, and CoA. This reaction is reversible and represents a substrate-level phosphorylation step in the TCA cycle, where the energy stored in succinyl-CoA is used to generate ATP. The official definition from QuickGO is: Catalysis of the reaction: ATP + succinate + CoA = ADP + succinyl-CoA + phosphate. This activity is synonymous with succinate thiokinase, succinyl-CoA synthetase (ADP-forming), and succinyl coenzyme A synthetase (adenosine diphosphate-forming) activity.
Why Is succinate-CoA ligase (ADP-forming) activity Important in Cell Biology?
GO:0004775 is important because it represents a central metabolic node that links the TCA cycle to nucleotide synthesis and mitochondrial energy production. Dysregulation of this activity has been implicated in a wide range of human diseases, from rare mitochondrial myopathies to common cancers and metabolic disorders. The ADP-forming enzyme, in particular, is critical for maintaining mitochondrial function and redox balance, and its beta subunit SUCLA2 has been shown to promote stress granule assembly and cancer metastasis. Moreover, SUCLA2-coupled regulation of glutaminase (GLS) succinylation counteracts oxidative stress in tumor cells, revealing a direct mechanistic link between this enzymatic activity and cellular stress responses. In macrophages, SUCLA2 couples glutaminolysis to AMPK signaling to manipulate obesity, highlighting its role in systemic metabolism. These findings underscore the importance of GO:0004775 as a potential therapeutic target and a biomarker for metabolic reprogramming.
• Provides a key substrate-level phosphorylation step in the TCA cycle, generating ATP or GTP.
• SUCLA2, the ADP-forming beta subunit, promotes stress granule assembly and drives cancer metastasis.
• Macrophage SUCLA2 couples glutaminolysis to AMPK signaling, influencing obesity and systemic metabolism.
• SUCLA2 regulates GLS succinylation and activity to counteract oxidative stress in tumor cells.
• SUCLG2 desuccinylation by SIRT5 delays ovarian aging via mitochondrial-epigenetic mechanisms.
• SUCLG1 deficiency leads to phenotypic variability in succinate-CoA ligase deficiency, a rare mitochondrial disorder.
• Valproyl-CoA inhibits ATP- and GTP-dependent succinate:CoA ligases, linking the enzyme to drug toxicity.
• Sucla2 knockout in skeletal muscle yields a mouse model of mitochondrial myopathy with muscle type-specific phenotypes.
• The enzyme is a potential target for modulating redox balance, cancer progression, and metabolic diseases.
What Happens During succinate-CoA ligase (ADP-forming) activity?
Substrate Binding and Catalysis
In simple terms: The enzyme grabs succinyl-CoA, ADP, and phosphate and rearranges them to make succinate, ATP, and CoA.
The ADP-forming succinate-CoA ligase catalyzes the reversible conversion of succinyl-CoA, ADP, and inorganic phosphate into succinate, ATP, and coenzyme A. This reaction proceeds through a phosphorylated enzyme intermediate, where a histidine residue in the active site is transiently phosphorylated by succinyl-CoA, followed by transfer of the phosphate to ADP to form ATP. The enzyme is a heterodimer composed of an alpha subunit (SUCLG1) and a beta subunit (SUCLA2), with the beta subunit determining nucleotide specificity for ADP.
Role in the TCA Cycle
In simple terms: This step is part of the TCA cycle, helping cells burn fuel to make energy.
Within the mitochondrial matrix, succinate-CoA ligase (ADP-forming) activity represents the only step in the TCA cycle that directly generates a high-energy phosphate bond via substrate-level phosphorylation. By converting succinyl-CoA to succinate, it supplies succinate for subsequent oxidation in the respiratory chain and maintains flux through the cycle. This activity is essential for mitochondrial energy production and is tightly coupled to the availability of substrates and the cellular energy state.
Metabolic Signaling and Stress Response
In simple terms: The enzyme also sends signals that help cells cope with stress and manage their metabolism.
Beyond its catalytic role, SUCLA2, the ADP-forming beta subunit, has been shown to promote stress granule assembly to regulate redox balance and drive cancer metastasis. Additionally, SUCLA2 couples with glutaminase (GLS) to regulate its succinylation and activity, thereby counteracting oxidative stress in tumor cells. In macrophages, SUCLA2 couples glutaminolysis to AMPK signaling, manipulating obesity through metabolic reprogramming. These findings indicate that the enzyme has non-canonical signaling functions that extend beyond its classical TCA cycle role.
Tissue-Specific and Developmental Functions
In simple terms: Different tissues use this enzyme in different ways, and its loss can cause tissue-specific problems.
Knockout of Sucla2 in skeletal muscle yields a mouse model of mitochondrial myopathy with muscle type-specific phenotypes, demonstrating that the enzyme is critical for muscle function and maintenance. In ovarian aging, the SIRT5-SUCLG2 desuccinylation axis delays aging via a mitochondrial-epigenetic regulatory mechanism, highlighting a role for the GTP-forming isoform in reproductive aging. These studies underscore the tissue-specific and context-dependent functions of succinate-CoA ligase activity.
Key Genes Involved in GO:0004775 succinate-CoA ligase (ADP-forming) activity
The following genes and proteins are directly involved in or regulate succinate-CoA ligase (ADP-forming) activity and its related pathways.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SUCLA2 | Encodes the ADP-forming beta subunit of succinate-CoA ligase; determines ADP specificity. | Promotes stress granule assembly, cancer metastasis, and regulates GLS succinylation. |
| SUCLG1 | Encodes the alpha subunit common to both ADP- and GTP-forming succinate-CoA ligases. | Deficiency causes phenotypic variability in succinate-CoA ligase deficiency. |
| SUCLG2 | Encodes the GTP-forming beta subunit; can also form heterodimers with SUCLG1. | SIRT5-mediated desuccinylation delays ovarian aging via mitochondrial-epigenetic mechanisms. |
| SIRT5 | NAD+-dependent desuccinylase that removes succinyl groups from SUCLG2. | Regulates ovarian aging and mitochondrial function through SUCLG2 desuccinylation. |
| GLS | Glutaminase that converts glutamine to glutamate; regulated by succinylation. | SUCLA2-coupled regulation of GLS succinylation counteracts oxidative stress in tumor cells. |
| AMPK | Energy sensor kinase activated by metabolic stress; interacts with SUCLA2 pathway. | Macrophage SUCLA2 couples glutaminolysis to AMPK to manipulate obesity. |
| PRKAB2 | Encodes the beta-2 regulatory subunit of AMPK; linked to mitophagy and cardiolipin biosynthesis. | Acts as a tumor suppressor in renal cell carcinoma via LRPPRC-PRKN/parkin interaction. |
| LRPPRC | Mitochondrial mRNA stability factor; interacts with PRKAB2 in mitophagy regulation. | Involved in renal cell carcinoma suppression through cardiolipin biosynthesis. |
| PRKN (Parkin) | E3 ubiquitin ligase involved in mitophagy; interacts with LRPPRC. | Mediates mitophagy regulation in renal cell carcinoma. |
| SDHA | Succinate dehydrogenase subunit A; TCA cycle enzyme adjacent to succinate-CoA ligase. | Often used as a reference for TCA cycle flux and mitochondrial function. |
| SDHB | Succinate dehydrogenase subunit B; TCA cycle enzyme. | Marker of mitochondrial respiration and TCA cycle integrity. |
| IDH2 | Isocitrate dehydrogenase 2; produces NADPH and supports mitochondrial redox. | Linked to oxidative stress responses and TCA cycle metabolism. |
| HIF1A | Hypoxia-inducible factor 1-alpha; regulated by succinate and redox status. | Downstream effector of succinate-mediated signaling in cancer. |
| MYC | Oncogene that drives glutaminolysis and mitochondrial metabolism. | Context for SUCLA2-dependent cancer metastasis and stress responses. |
| KEAP1 | Redox sensor that regulates NRF2; affected by succinate levels. | Implicated in oxidative stress defense linked to succinate-CoA ligase. |
| NRF2 (NFE2L2) | Transcription factor controlling antioxidant response. | Downstream of redox changes mediated by SUCLA2 and GLS. |
| SLC25A10 | Mitochondrial dicarboxylate carrier; transports succinate and other metabolites. | Potential modifier of succinate-CoA ligase substrate availability. |
| VDAC1 | Voltage-dependent anion channel; regulates mitochondrial metabolite exchange. | Influences mitochondrial energy metabolism and stress responses. |
How Is succinate-CoA ligase (ADP-forming) activity Regulated?
The activity of succinate-CoA ligase (ADP-forming) is regulated at multiple levels. The enzyme is a heterodimer, and the availability of its subunits SUCLA2 and SUCLG1 determines its assembly and function. Post-translational modifications, such as succinylation and desuccinylation, modulate its activity; for example, SIRT5-mediated desuccinylation of SUCLG2 affects ovarian aging. Additionally, SUCLA2-coupled regulation of GLS succinylation alters glutaminase activity and counteracts oxidative stress. In macrophages, SUCLA2 couples glutaminolysis to AMPK signaling, linking metabolic flux to energy sensing. The enzyme is also inhibited by valproyl-CoA, a metabolite of valproic acid, which affects both ATP- and GTP-dependent succinate:CoA ligases. These regulatory mechanisms ensure that succinate-CoA ligase activity is tuned to cellular energy demands and stress conditions.
succinate-CoA ligase (ADP-forming) activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SUCLA2 | Cancer metastasis, oxidative stress, mitochondrial myopathy | SUCLA2 knockout or overexpression in cancer cell lines and skeletal muscle-specific KO mice |
| SUCLG1 | Succinate-CoA ligase deficiency with phenotypic variability | Patient-derived fibroblasts or CRISPR knock-in of patient mutations |
| SUCLG2 | Ovarian aging via SIRT5-mediated desuccinylation | SIRT5 or SUCLG2 knockout in ovarian cell models and aging mice |
| GLS | Oxidative stress in tumor cells | GLS succinylation mutants and SUCLA2 knockout cancer cells |
| PRKAB2 | Renal cell carcinoma via mitophagy and cardiolipin biosynthesis | PRKAB2 knockout or overexpression in renal cell carcinoma lines |
Cancer Metastasis and Oxidative Stress
SUCLA2, the ADP-forming beta subunit, promotes stress granule assembly to regulate redox and drive cancer metastasis. In tumor cells, SUCLA2-coupled regulation of GLS succinylation and activity counteracts oxidative stress, supporting cancer cell survival. These findings suggest that targeting succinate-CoA ligase (ADP-forming) activity could be a therapeutic strategy in cancers with altered glutamine metabolism.
Mitochondrial Myopathy
Sucla2 knockout in skeletal muscle yields a mouse model of mitochondrial myopathy with muscle type-specific phenotypes, demonstrating that loss of this activity causes muscle dysfunction and metabolic imbalance. This model provides insights into the pathophysiology of mitochondrial myopathies and potential therapeutic targets.
Obesity and Metabolic Disorders
Macrophage SUCLA2 couples glutaminolysis to AMPK signaling to manipulate obesity, indicating a role for this enzyme in systemic metabolic regulation. Dysregulation of this pathway may contribute to obesity and related metabolic disorders.
Ovarian Aging and SUCLG1 Deficiency
The SIRT5-SUCLG2 desuccinylation axis delays ovarian aging via a mitochondrial-epigenetic regulatory mechanism, linking succinate-CoA ligase activity to reproductive aging. Additionally, deficiency of the alpha subunit SUCLG1 causes phenotypic variability in succinate-CoA ligase deficiency, a rare inherited disorder. Valproyl-CoA inhibition of succinate:CoA ligases further connects the enzyme to drug-induced metabolic toxicity.
From succinate-CoA ligase (ADP-forming) activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does SUCLA2 loss affect cancer metastasis and redox balance? | SUCLA2 knockout in metastatic cancer cell lines and mouse xenografts |
| How does SUCLA2 regulate GLS succinylation and oxidative stress? | Point mutations in SUCLA2 active site or succinylation sites, combined with GLS activity assays |
| What is the role of SUCLG2 desuccinylation in ovarian aging? | SUCLG2 knock-in of desuccinylation-resistant mutants in ovarian cells and aging mouse models |
| Does SUCLA2 deficiency cause mitochondrial myopathy? | Skeletal muscle-specific Sucla2 knockout mice |
| How does macrophage SUCLA2 affect obesity? | Macrophage-specific SUCLA2 knockout mice fed a high-fat diet |
| Can SUCLG1 mutations reproduce phenotypic variability? | CRISPR knock-in of patient-derived SUCLG1 mutations in cell lines and organoids |
How to Study the succinate-CoA ligase (ADP-forming) activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Enzymatic activity assay | Catalytic conversion of succinyl-CoA, ADP, and phosphate to succinate, ATP, and CoA | Kinetic characterization and inhibitor testing |
| 13C metabolic flux analysis | Flux through TCA cycle and contribution of succinate-CoA ligase | Cancer and immune cell metabolism studies |
| Succinylation proteomics | Post-translational succinylation of GLS and other proteins | Redox and signaling studies |
| CRISPR knockout screening | Genes required for cell fitness under metabolic stress | Identification of synthetic lethal partners |
| Stress granule imaging | Assembly of stress granules under oxidative stress | Cancer metastasis and redox regulation |
| Seahorse respirometry | Mitochondrial oxygen consumption rate | Assessment of mitochondrial function |
| Western blot | Protein expression and modification levels | Validation of knockout or overexpression |
| qRT-PCR | mRNA expression of SUCLA2, SUCLG1, SUCLG2 | Gene expression analysis |
Enzymatic Activity Assays
Direct measurement of succinate-CoA ligase (ADP-forming) activity can be performed using spectrophotometric assays that couple the formation of ATP or succinate to NADH oxidation or other detectable signals. These assays are essential for validating the kinetic properties of wild-type and mutant enzymes and for testing inhibitors such as valproyl-CoA.
Metabolic Flux Analysis
Stable isotope tracing with 13C-labeled substrates (e.g., glutamine or glucose) coupled to mass spectrometry allows researchers to quantify flux through the TCA cycle and assess the contribution of succinate-CoA ligase activity to mitochondrial metabolism. This method is particularly useful for studying cancer cells and immune cells with altered metabolism.
Proteomics and Post-Translational Modification Analysis
Mass spectrometry-based proteomics can identify succinylation sites on GLS and other proteins, as well as quantify changes in protein abundance following genetic manipulation of SUCLA2 or SUCLG2. This approach helps elucidate the signaling functions of the enzyme beyond its catalytic activity.
CRISPR Screening and Functional Genomics
Genome-wide CRISPR knockout or activation screens can identify genes that modulate sensitivity to succinate-CoA ligase inhibition or that cooperate with SUCLA2 loss in cancer and metabolic contexts. These screens provide unbiased insights into pathways that interact with GO:0004775.
How CRISPR Can Be Used to Study GO:0004775 succinate-CoA ligase (ADP-forming) activity
Knockout
CRISPR-Cas9 knockout of SUCLA2, SUCLG1, or SUCLG2 is widely used to study loss-of-function phenotypes. For example, Sucla2 knockout in skeletal muscle yields a mitochondrial myopathy model, and SUCLA2 knockout in cancer cells reduces stress granule assembly and metastasis. Knockout models are essential for determining the causal role of GO:0004775 in disease.
Point Mutation
CRISPR-mediated point mutations can mimic patient-derived missense mutations in SUCLG1 or SUCLA2, allowing researchers to study phenotypic variability and structure-function relationships. Point mutations in catalytic residues or succinylation sites can also dissect the enzymatic versus signaling functions of the protein.
Knock-in
Knock-in of tagged or fluorescently labeled SUCLA2 or SUCLG2 enables live-cell imaging and proteomic analysis of the enzyme's localization and interactions. Knock-in of desuccinylation-resistant SUCLG2 mutants can test the role of specific post-translational modifications in ovarian aging.
Overexpression
Overexpression of wild-type or mutant SUCLA2, SUCLG1, or SUCLG2 in cell lines can reveal gain-of-function effects on metabolism, stress responses, and tumorigenesis. Overexpression models are particularly useful for studying the signaling functions of the enzyme in cancer and immune cells.
How EDITGENE Supports succinate-CoA ligase (ADP-forming) activity Research
Researchers studying succinate-CoA ligase (ADP-forming) activity-related genes often need to determine whether a candidate gene is causally involved in metabolic regulation, disease progression, or stress responses. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this research, from gene knockout to precise point mutations and knock-in models.
Contact EDITGENE today to design your custom CRISPR model for succinate-CoA ligase (ADP-forming) activity research.
Frequently Asked Questions About succinate-CoA ligase (ADP-forming) activity
What is succinate-CoA ligase (ADP-forming) activity?
It is a molecular function defined by GO:0004775 that catalyzes the reversible conversion of succinyl-CoA, ADP, and phosphate to succinate, ATP, and CoA, a key step in the TCA cycle.
What genes are involved in succinate-CoA ligase (ADP-forming) activity?
The main genes are SUCLA2, which encodes the ADP-forming beta subunit, and SUCLG1, which encodes the alpha subunit; SUCLG2 encodes the GTP-forming beta subunit.
How is succinate-CoA ligase (ADP-forming) activity regulated?
It is regulated by subunit availability, post-translational succinylation/desuccinylation (e.g., by SIRT5), and inhibition by metabolites such as valproyl-CoA.
What diseases are associated with succinate-CoA ligase (ADP-forming) activity?
It is linked to cancer metastasis, mitochondrial myopathy, obesity, ovarian aging, and SUCLG1 deficiency.
What is the role of SUCLA2 in cancer?
SUCLA2 promotes stress granule assembly to regulate redox and drive cancer metastasis, and it regulates GLS succinylation to counteract oxidative stress.
How can I study succinate-CoA ligase (ADP-forming) activity in the lab?
You can use enzymatic activity assays, metabolic flux analysis, proteomics, and CRISPR knockout or knock-in models.
What is the difference between ADP-forming and GTP-forming succinate-CoA ligase?
The ADP-forming enzyme uses SUCLA2 as the beta subunit and generates ATP, while the GTP-forming enzyme uses SUCLG2 and generates GTP.
Does SUCLA2 knockout cause mitochondrial myopathy?
Yes, skeletal muscle-specific Sucla2 knockout in mice yields a mitochondrial myopathy with muscle type-specific phenotypes.
How does SUCLG2 relate to ovarian aging?
SIRT5-mediated desuccinylation of SUCLG2 delays ovarian aging via a mitochondrial-epigenetic regulatory mechanism.
What CRISPR services does EDITGENE offer for studying this enzyme?
EDITGENE provides knockout, point mutation, knock-in, overexpression, CRISPR library screening, and bioinformatics services for SUCLA2, SUCLG1, SUCLG2, and related genes.
Conclusion
Succinate-CoA ligase (ADP-forming) activity (GO:0004775) is a fundamental mitochondrial function that bridges energy metabolism, redox regulation, and disease pathogenesis. Its beta subunit SUCLA2 has emerged as a critical regulator of cancer metastasis, oxidative stress, and systemic metabolism, while SUCLG1 and SUCLG2 are linked to mitochondrial myopathy and ovarian aging. Continued research using CRISPR-based models and advanced metabolic techniques will further illuminate the therapeutic potential of targeting this activity in human disease.
References
- 1. Boese AC et al.. 2023. Succinyl-CoA ligase ADP-forming subunit beta promotes stress granule assembly to regulate redox and drive cancer metastasis.. Proc Natl Acad Sci U S A 120(23):e2217332120 PMID: 37253003
- 2. Peng C et al.. 2025. Macrophage SUCLA2 coupled glutaminolysis manipulates obesity through AMPK.. Nat Commun 16(1):1738 PMID: 39966410
- 3. Tong Y et al.. 2021. SUCLA2-coupled regulation of GLS succinylation and activity counteracts oxidative stress in tumor cells.. Mol Cell 81(11):2303-2316.e8 PMID: 33991485
- 4. Lancaster MS et al.. 2024. Sucla2 Knock-Out in Skeletal Muscle Yields Mouse Model of Mitochondrial Myopathy With Muscle Type-Specific Phenotypes.. J Cachexia Sarcopenia Muscle 15(6):2729-2742 PMID: 39482887
- 5. Luís PB et al.. 2014. Valproyl-CoA inhibits the activity of ATP- and GTP-dependent succinate:CoA ligases.. J Inherit Metab Dis 37(3):353-7 PMID: 24154984
- 6. Xu D et al.. 2026. The SIRT5-SUCLG2 desuccinylation axis delays ovarian aging via a mitochondrial-epigenetic regulatory mechanism.. Nat Commun 17(1) PMID: 42457680
- 7. Demirbas D et al.. 2019. Phenotypic variability in deficiency of the α subunit of succinate-CoA ligase.. JIMD Rep 46(1):63-69 PMID: 31240156
- 8. Chen K et al.. 2026. PRKAB2 as a tumor suppressor in renal cell carcinoma: inhibiting mitophagy via the LRPPRC-PRKN/parkin interaction and cardiolipin biosynthesis.. Autophagy 22(5):982-1002 PMID: 41612594
