GO:0036116 long-chain fatty-acyl-CoA catabolic process: Mitochondrial Beta-Oxidation, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0036116 describes the breakdown of long-chain fatty-acyl-CoA esters (13-22 carbon chains) into acetyl-CoA and reducing equivalents.
• The process is central to mitochondrial beta-oxidation and requires carnitine-dependent transport for long-chain substrates.
• ACSL family enzymes activate long-chain fatty acids to their CoA esters, feeding directly into this catabolic pathway.
• Malonyl-CoA and long-chain fatty acyl-CoAs act as metabolic signals that regulate insulin sensitivity and AMPK activity.
• Dysregulation of long-chain fatty-acyl-CoA catabolism is linked to fatty liver disease, insulin resistance, and macrophage polarization.
• CRISPR knockout, knock-in, and overexpression models enable causal dissection of this pathway in metabolic and inflammatory diseases.
Description
Long-chain fatty-acyl-CoA catabolic process (GO:0036116) is the set of chemical reactions and pathways that break down long-chain fatty-acyl-CoA esters, which are coenzyme A derivatives carrying fatty acids with aliphatic tails of 13 to 22 carbons. This process is a core component of mitochondrial beta-oxidation and is essential for energy production, especially in tissues such as skeletal muscle, liver, and heart. The pathway begins with the activation of long-chain fatty acids to their CoA esters by acyl-CoA synthetase enzymes, followed by carnitine-dependent transport into mitochondria and sequential cycles of oxidation that generate acetyl-CoA, NADH, and FADH2. Researchers study GO:0036116 because it sits at the intersection of energy homeostasis, lipid signaling, and disease. Long-chain fatty acyl-CoAs are not only substrates for oxidation but also signaling molecules that influence AMPK activity, insulin sensitivity, and gene expression. For example, malonyl-CoA and long-chain fatty acyl-CoAs have been implicated in skeletal muscle insulin resistance, and AMPK senses long-chain fatty acyl-CoA esters to adjust metabolic flux. In addition, pharmacological inhibition of fatty acid oxidation, such as with etomoxir, disrupts CoA homeostasis and macrophage polarization, highlighting the broader immunological relevance of this pathway. Understanding GO:0036116 therefore requires integrating enzymology, transport, and regulation. The pathway is dynamically controlled by substrate availability, hormonal signals, and feedback inhibition, and its dysfunction contributes to fatty liver disease, metabolic syndrome, and inflammatory conditions. This article provides a research-grade overview of the genes, mechanisms, and experimental models used to study long-chain fatty-acyl-CoA catabolic process, with a focus on CRISPR-based approaches for causal validation.
long-chain fatty-acyl-CoA catabolic process At A Glance
| GO ID | GO:0036116 |
|---|---|
| GO term | long-chain fatty-acyl-CoA catabolic process |
| Ontology | biological_process |
| Synonym | long-chain fatty-acyl-CoA breakdown; long-chain fatty-acyl-CoA catabolism; long-chain fatty-acyl-CoA degradation |
| Major function | Breakdown of long-chain fatty-acyl-CoA esters (13-22 carbons) to generate acetyl-CoA and reducing equivalents |
| Substrates | Long-chain fatty-acyl-CoA esters |
| Key organelles | Mitochondria, peroxisomes |
| Related pathways | Beta-oxidation, fatty acid activation, carnitine shuttle |
| Regulatory signals | Malonyl-CoA, AMPK, insulin, substrate availability |
What Is GO:0036116?
GO:0036116, long-chain fatty-acyl-CoA catabolic process, is defined as the chemical reactions and pathways resulting in the breakdown of long-chain fatty-acyl-CoAs. These are derivatives of coenzyme A in which the sulfhydryl group is in a thioester linkage with a long-chain fatty-acyl group, where a long-chain fatty acid has an aliphatic tail containing 13 to 22 carbons. In practice, this term encompasses the enzymatic steps that convert long-chain fatty-acyl-CoA esters into smaller products, primarily through beta-oxidation, and includes the associated transport and regulatory events that enable this catabolism.
Why Is long-chain fatty-acyl-CoA catabolic process Important in Cell Biology?
Long-chain fatty-acyl-CoA catabolic process is essential for energy production and metabolic homeostasis, particularly in high-energy-demand tissues such as skeletal muscle, heart, and liver. Beyond ATP generation, the pathway generates signaling metabolites that regulate insulin sensitivity, AMPK activity, and inflammatory responses. Its dysregulation is associated with insulin resistance, nonalcoholic fatty liver disease, and altered macrophage function, making it a key area for therapeutic targeting and biomarker discovery.
• Provides a major source of ATP through mitochondrial beta-oxidation of long-chain fatty acids.
• Generates acetyl-CoA for the TCA cycle and ketogenesis during fasting.
• Long-chain fatty acyl-CoAs act as signaling molecules that modulate AMPK activity.
• Malonyl-CoA and long-chain fatty acyl-CoAs contribute to skeletal muscle insulin resistance.
• Dysregulation is linked to nonalcoholic fatty liver disease and hepatic steatosis.
• Inhibition of fatty acid oxidation alters macrophage polarization and CoA homeostasis.
• Enzymes such as ACSL5 are regulated by acetylation, connecting the pathway to epigenetic control.
• The pathway is a target for metabolic drugs and for understanding drug-induced toxicity.
• CRISPR models enable causal testing of genes in this pathway for metabolic and inflammatory diseases.
• Understanding substrate channeling and transport is critical for interpreting metabolic flux data.
What Happens During long-chain fatty-acyl-CoA catabolic process?
Activation of long-chain fatty acids to acyl-CoA esters
In simple terms: Before a long-chain fatty acid can be broken down, it must be attached to a carrier molecule called coenzyme A.
The first step in long-chain fatty-acyl-CoA catabolic process is the activation of long-chain fatty acids to their corresponding acyl-CoA esters. This reaction is catalyzed by long-chain fatty acyl-CoA synthetases (ACSL family), which ligate coenzyme A to the fatty acid in an ATP-dependent manner. The resulting long-chain fatty acyl-CoA is the substrate for subsequent catabolic steps. Measurement of ACSL activity is a standard approach to assess the entry of fatty acids into this pathway.
Carnitine-dependent transport into mitochondria
In simple terms: Long-chain acyl-CoAs cannot cross the mitochondrial membrane directly, so they are shuttled in using carnitine.
Long-chain fatty-acyl-CoA esters require the carnitine shuttle to enter the mitochondrial matrix, where beta-oxidation occurs. This transport involves carnitine palmitoyltransferase 1 (CPT1) on the outer mitochondrial membrane, the carnitine-acylcarnitine translocase, and CPT2 on the inner membrane. This step is a key regulatory node, as malonyl-CoA inhibits CPT1 to prevent excessive fatty acid oxidation when fatty acid synthesis is active.
Beta-oxidation cycles and generation of acetyl-CoA
In simple terms: Inside the mitochondria, the long-chain acyl-CoA is chopped into two-carbon units that feed into energy production.
Once inside the mitochondrial matrix, long-chain fatty-acyl-CoA undergoes repeated cycles of beta-oxidation, each cycle removing a two-carbon unit as acetyl-CoA. The four reactions of each cycle are catalyzed by acyl-CoA dehydrogenase, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and 3-ketoacyl-CoA thiolase. The acetyl-CoA produced enters the TCA cycle or is used for ketogenesis, while NADH and FADH2 are used for oxidative phosphorylation.
Peroxisomal oxidation of very long-chain fatty acids
In simple terms: Some very long fatty acids are first shortened in peroxisomes before mitochondrial breakdown.
Peroxisomes contribute to the catabolism of long-chain and very long-chain fatty-acyl-CoAs by performing initial rounds of beta-oxidation, particularly for substrates that are poor mitochondrial substrates. Peroxisomal beta-oxidation shortens these fatty acids, which are then transferred to mitochondria for complete oxidation. This division of labor ensures efficient breakdown of a wide range of long-chain fatty-acyl-CoAs.
Regulation by malonyl-CoA and AMPK signaling
In simple terms: The pathway is turned up or down depending on energy status and signals like AMPK.
Long-chain fatty-acyl-CoA catabolic process is tightly regulated by malonyl-CoA, which inhibits CPT1 and thereby limits mitochondrial fatty acid uptake. AMPK senses long-chain fatty acyl-CoA esters and adjusts metabolic flux to maintain energy balance. In skeletal muscle, elevated long-chain fatty acyl-CoA levels are associated with insulin resistance, linking this pathway to systemic metabolic regulation. Additionally, protein acyltransferases such as zDHHC enzymes can utilize long-chain fatty acyl-CoAs for protein palmitoylation, competing with catabolism and influencing signaling.
Key Genes Involved in GO:0036116 long-chain fatty-acyl-CoA catabolic process
The following genes and proteins are central to long-chain fatty-acyl-CoA catabolic process, spanning activation, transport, oxidation, and regulation.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ACSL1 | Activates long-chain fatty acids to acyl-CoA esters | Key entry enzyme for beta-oxidation; target for metabolic studies |
| ACSL5 | Long-chain acyl-CoA synthetase; regulated by SIRT6 deacetylation | Implicated in hepatic fatty acid oxidation and NAFLD |
| CPT1A | Carnitine palmitoyltransferase 1; rate-limiting for mitochondrial import | Regulated by malonyl-CoA; target for insulin resistance research |
| CPT2 | Inner membrane carnitine palmitoyltransferase | Defects cause fatty acid oxidation disorders |
| ACADVL | Very long-chain acyl-CoA dehydrogenase | First step of beta-oxidation for long-chain substrates |
| ACADM | Medium-chain acyl-CoA dehydrogenase | Beta-oxidation enzyme; model for metabolic disease |
| HADHA | Trifunctional protein subunit; 3-hydroxyacyl-CoA dehydrogenase | Catalyzes multiple beta-oxidation steps |
| HADHB | Trifunctional protein subunit; thiolase | Catalyzes thiolytic cleavage in beta-oxidation |
| ACAA2 | 3-ketoacyl-CoA thiolase | Final step of beta-oxidation cycle |
| SIRT6 | Deacetylates ACSL5 to promote fatty acid oxidation | Links epigenetic regulation to this pathway |
| PRKAA1 | AMPK catalytic subunit; senses long-chain fatty acyl-CoAs | Regulates energy homeostasis |
| PRKAA2 | AMPK catalytic subunit | Mediates metabolic sensing |
| ZDHHC proteins | Protein acyltransferases using long-chain fatty acyl-CoA | Competes with catabolism for substrate |
| ETFA | Electron transfer flavoprotein subunit | Supports acyl-CoA dehydrogenases |
| ETFB | Electron transfer flavoprotein subunit | Electron transfer in beta-oxidation |
| CPT1B | Muscle isoform of CPT1 | Regulates fatty acid oxidation in muscle |
| ACOX1 | Peroxisomal acyl-CoA oxidase | Initiates peroxisomal beta-oxidation |
How Is long-chain fatty-acyl-CoA catabolic process Regulated?
Long-chain fatty-acyl-CoA catabolic process is regulated at multiple levels. Malonyl-CoA inhibits CPT1, reducing mitochondrial import of long-chain fatty acyl-CoAs and preventing futile oxidation when fatty acid synthesis is active. AMPK senses long-chain fatty acyl-CoA esters and phosphorylates downstream targets to enhance catabolic flux during energy stress. Hormonal signals such as insulin suppress fatty acid oxidation in fed states, while glucagon and fasting promote it. Additionally, acetylation of ACSL5 by SIRT6 modulates hepatic fatty acid oxidation, linking nutrient status to epigenetic regulation. Substrate availability and competition with protein acyltransferases also influence flux through this pathway.
long-chain fatty-acyl-CoA catabolic process and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ACSL5 | Nonalcoholic fatty liver disease | Liver-specific knockout or SIRT6 deacetylation mutant knock-in |
| CPT1A | Insulin resistance, metabolic syndrome | Point mutation to alter malonyl-CoA sensitivity |
| ACADVL | Very long-chain acyl-CoA dehydrogenase deficiency | Knockout or patient-derived point mutation knock-in |
| HADHA | Mitochondrial trifunctional protein deficiency | Knockout in hepatocytes or cardiomyocytes |
| PRKAA1 | Energy homeostasis, diabetes | Kinase-dead knock-in or knockout |
Metabolic syndrome and insulin resistance
Elevated long-chain fatty acyl-CoA levels in skeletal muscle are associated with insulin resistance, and malonyl-CoA dysregulation contributes to impaired fatty acid oxidation. This pathway is therefore a target for understanding and treating type 2 diabetes and metabolic syndrome.
Nonalcoholic fatty liver disease (NAFLD)
Hepatic fatty acid oxidation is critical for preventing lipid accumulation. SIRT6-mediated deacetylation of ACSL5 promotes fatty acid oxidation and impedes NAFLD progression, highlighting the role of this catabolic process in liver disease.
Inflammation and macrophage function
Etomoxir, an inhibitor of fatty acid oxidation, disrupts CoA homeostasis and inhibits macrophage polarization, demonstrating that long-chain fatty-acyl-CoA catabolism is required for inflammatory responses. This links the pathway to immunometabolism and diseases involving macrophage dysfunction.
Inherited fatty acid oxidation disorders
Defects in enzymes of mitochondrial beta-oxidation, such as ACADVL and HADHA, cause inherited disorders presenting with hypoketotic hypoglycemia and cardiomyopathy. These conditions underscore the essential role of this pathway in human health.
From long-chain fatty-acyl-CoA catabolic process-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of ACSL5 impair hepatic fatty acid oxidation? | ACSL5 knockout hepatocytes or mouse liver |
| Does a point mutation in CPT1A alter malonyl-CoA sensitivity? | CPT1A point-mutation knock-in cell line |
| Can SIRT6-mediated deacetylation of ACSL5 be mimicked? | ACSL5 acetylation-site mutant knock-in |
| Is AMPK required for sensing long-chain fatty acyl-CoAs? | PRKAA1/2 double knockout cells |
| Does overexpression of ACSL1 increase beta-oxidation flux? | ACSL1 overexpression cell model |
| Can tagged ACSL5 be used to track localization? | Endogenous ACSL5 tagged knock-in |
How to Study the long-chain fatty-acyl-CoA catabolic process Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Acyl-CoA synthetase assay | Enzyme activity converting fatty acids to acyl-CoA | Assessing ACSL family function |
| Beta-oxidation flux assay | Rate of acetyl-CoA production or labeled water release | Measuring pathway activity in cells |
| LC-MS acyl-CoA profiling | Levels of individual long-chain fatty acyl-CoA species | Metabolic phenotyping |
| Seahorse oxygen consumption | Mitochondrial respiration linked to fatty acid oxidation | Live-cell metabolic analysis |
| Western blot for beta-oxidation enzymes | Protein expression of ACADVL, HADHA, etc. | Validating knockout or overexpression |
| CRISPR knockout screening | Gene essentiality for pathway function | Identifying novel regulators |
| AMPK activity assay | Phosphorylation of AMPK substrates | Testing long-chain fatty acyl-CoA sensing |
Measuring acyl-CoA synthetase activity
Long-chain fatty acyl-CoA synthetase activity can be measured using radiolabeled or fluorescent fatty acid substrates and HPLC-based detection of acyl-CoA products. This method quantifies the entry step of GO:0036116 and is useful for assessing enzyme kinetics and inhibitor effects.
Assessing beta-oxidation flux
Beta-oxidation flux can be measured by tracking the release of tritiated water from labeled fatty acids or by monitoring oxygen consumption and acetyl-CoA production. These assays provide functional readouts of long-chain fatty-acyl-CoA catabolic process in cells and isolated mitochondria.
Detecting long-chain fatty acyl-CoA levels
Long-chain fatty acyl-CoA species can be quantified by liquid chromatography-mass spectrometry (LC-MS), allowing profiling of individual acyl-CoA chain lengths and saturation states. This is critical for linking substrate availability to pathway activity and signaling.
Genetic and pharmacological perturbation
CRISPR knockout, knock-in, and overexpression models combined with pharmacological inhibitors such as etomoxir enable causal testing of genes in this pathway. Etomoxir treatment disrupts CoA homeostasis and can reveal dependencies on fatty acid oxidation in immune cells.
How CRISPR Can Be Used to Study GO:0036116 long-chain fatty-acyl-CoA catabolic process
Knockout
CRISPR knockout of genes such as ACSL5, CPT1A, or ACADVL can abolish or reduce long-chain fatty-acyl-CoA catabolic process, enabling causal tests of their requirement for fatty acid oxidation and downstream phenotypes. Knockout models are particularly useful for validating metabolic dependencies in liver and immune cells.
Point Mutation
Point mutations can be introduced to mimic disease-associated variants or to alter regulatory sites, such as the malonyl-CoA sensitivity of CPT1A or acetylation sites on ACSL5. These models help dissect specific residues required for pathway regulation without confounding effects of complete protein loss.
Knock-in
Knock-in of tagged or reporter alleles, such as endogenous ACSL5 with an epitope tag, allows tracking of protein localization and interactions under physiological expression levels. Knock-in of disease mutations can also model inherited fatty acid oxidation disorders.
Overexpression
Overexpression of ACSL1 or other pathway enzymes can increase flux through long-chain fatty-acyl-CoA catabolic process, providing gain-of-function models to study metabolic remodeling and signaling. These models are useful for testing whether increased catabolism protects against lipid accumulation or alters inflammatory responses.
How EDITGENE Supports long-chain fatty-acyl-CoA catabolic process Research
Researchers studying long-chain fatty-acyl-CoA catabolic process-related genes often need to determine whether a candidate gene is causally involved in pathway regulation, substrate flux, or disease phenotypes. EDITGENE provides CRISPR-based cell model services that enable precise genetic perturbations to answer these questions.
Contact EDITGENE today to design your custom CRISPR model for long-chain fatty-acyl-CoA catabolic process research.
Frequently Asked Questions About long-chain fatty-acyl-CoA catabolic process
What is long-chain fatty-acyl-CoA catabolic process?
It is the breakdown of long-chain fatty-acyl-CoA esters, primarily through mitochondrial beta-oxidation, to generate acetyl-CoA and energy.
What genes are involved in long-chain fatty-acyl-CoA catabolic process?
Key genes include ACSL1, ACSL5, CPT1A, CPT2, ACADVL, HADHA, HADHB, and ACAA2, among others.
What is the GO ID for long-chain fatty-acyl-CoA catabolic process?
The GO ID is GO:0036116.
How is long-chain fatty-acyl-CoA catabolic process regulated?
It is regulated by malonyl-CoA inhibition of CPT1, AMPK sensing of long-chain fatty acyl-CoAs, and hormonal signals such as insulin.
What diseases are linked to long-chain fatty-acyl-CoA catabolic process?
Dysregulation is linked to insulin resistance, nonalcoholic fatty liver disease, inherited fatty acid oxidation disorders, and altered macrophage function.
What is the role of ACSL5 in this pathway?
ACSL5 activates long-chain fatty acids to acyl-CoA esters, and its deacetylation by SIRT6 promotes hepatic fatty acid oxidation and impedes NAFLD.
How can I study long-chain fatty-acyl-CoA catabolic process in the lab?
Common methods include acyl-CoA synthetase assays, beta-oxidation flux measurements, LC-MS acyl-CoA profiling, and CRISPR-based genetic perturbation.
What is the difference between long-chain and short-chain fatty acid oxidation?
Long-chain fatty acids (13-22 carbons) require carnitine-dependent transport into mitochondria, whereas short- and medium-chain fatty acids can enter mitochondria more freely.
Does etomoxir affect long-chain fatty-acyl-CoA catabolic process?
Etomoxir inhibits fatty acid oxidation and disrupts CoA homeostasis, affecting macrophage polarization and inflammatory responses.
What CRISPR models are available for this pathway?
Knockout, point mutation, knock-in, tagged knock-in, and overexpression models can be generated for genes such as ACSL5, CPT1A, and ACADVL.
Conclusion
Long-chain fatty-acyl-CoA catabolic process (GO:0036116) is a fundamental metabolic pathway that converts long-chain fatty-acyl-CoA esters into acetyl-CoA and reducing equivalents, with critical roles in energy homeostasis, signaling, and disease. Its dysregulation contributes to insulin resistance, fatty liver disease, and inflammatory disorders, making it a compelling target for therapeutic development. CRISPR-based cell models provide powerful tools to dissect the causal roles of individual genes in this pathway and to accelerate translational research.
References
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