GO:0006633 fatty acid biosynthetic process: Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0006633 fatty acid biosynthetic process describes the chemical reactions and pathways that form fatty acids, predominantly straight-chain aliphatic monocarboxylic acids of 4 to 24 carbons that may be saturated or unsaturated.
• Fatty acid biosynthesis is a highly conserved anabolic process that converts acetyl-CoA and malonyl-CoA into fatty acyl chains, and it is central to membrane biogenesis, energy storage, and lipid signaling.
• The process is regulated transcriptionally and allosterically, and it is integrated with lipid transport, desaturation, and elongation pathways in animals, plants, and microorganisms.
• Dysregulation of fatty acid biosynthesis contributes to metabolic disease, cancer, and disorders of lipid metabolism, making its enzymes and regulators important experimental targets.
• Key genes include ACACA, FASN, SCD, ELOVL family members, and FADS family members, which catalyze committed steps in fatty acid formation and modification.
• CRISPR knockout, point-mutation, knock-in, and overexpression models enable causal testing of fatty acid biosynthetic genes in disease and metabolic research.
Description
GO:0006633 fatty acid biosynthetic process is the biological process by which cells synthesize fatty acids, defined as aliphatic monocarboxylic acids that can be liberated by hydrolysis from naturally occurring fats and oils. Fatty acids are predominantly straight-chain acids of 4 to 24 carbon atoms, and they may be saturated or unsaturated; branched and hydroxy fatty acids also occur, and very long chain acids of over 30 carbons are found in waxes. This process is fundamental to cellular life because fatty acids are essential building blocks of membranes, energy storage lipids, and signaling molecules. In animals, the liver is a major site of fatty acid biosynthesis and lipid metabolism, where acetyl-CoA is converted into fatty acids through the coordinated action of acetyl-CoA carboxylase and fatty acid synthase. In microorganisms and marine organisms, fatty acid biosynthetic pathways support membrane homeostasis and the production of omega-3 and other polyunsaturated fatty acids. Researchers study GO:0006633 to understand metabolic regulation, to identify therapeutic targets in cancer and metabolic disease, and to engineer lipid production in biotechnology. The process is not a single reaction but a network of enzymatic steps, including initiation, elongation, termination, desaturation, and elongation of very long chain fatty acids.
fatty acid biosynthetic process At A Glance
| GO ID | GO:0006633 |
|---|---|
| GO term | fatty acid biosynthetic process |
| Ontology | biological_process |
| Synonym | fatty acid anabolism; fatty acid biosynthesis; fatty acid formation; fatty acid synthesis |
| Major function | Formation of fatty acids from precursors such as acetyl-CoA and malonyl-CoA, including saturated and unsaturated fatty acid synthesis |
| Definition source | QuickGO definition: chemical reactions and pathways resulting in the formation of a fatty acid, any of the aliphatic monocarboxylic acids that can be liberated by hydrolysis from naturally occurring fats and oils |
| Typical carbon chain length | Predominantly straight-chain acids of 4 to 24 carbon atoms; very long chain acids of over 30 carbons are found in waxes |
| Representative enzymes | Acetyl-CoA carboxylase (ACACA), fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD), elongases (ELOVL), desaturases (FADS) |
| Related processes | Fatty acid elongation, fatty acid desaturation, lipid transport, and lipid metabolism |
What Is GO:0006633?
In our own words, GO:0006633 fatty acid biosynthetic process encompasses all chemical reactions and pathways that result in the formation of a fatty acid, which is any aliphatic monocarboxylic acid that can be liberated by hydrolysis from naturally occurring fats and oils. These fatty acids are predominantly straight-chain acids of 4 to 24 carbon atoms, and they may be saturated or unsaturated; branched fatty acids and hydroxy fatty acids also occur, and very long chain acids of over 30 carbons are found in waxes. The term includes the de novo synthesis of fatty acyl chains from precursors such as acetyl-CoA and malonyl-CoA, as well as subsequent modification steps such as desaturation and elongation that produce the diversity of fatty acid species. It is a biological process ontology term, meaning it describes a series of molecular events rather than a single molecular function or cellular component.
Why Is fatty acid biosynthetic process Important in Cell Biology?
GO:0006633 fatty acid biosynthetic process is important because fatty acids are indispensable for membrane structure, energy storage, and lipid signaling, and the pathway is a central node in cellular metabolism. In animals, the liver plays a major role in lipid metabolism, and dysregulation of fatty acid synthesis contributes to metabolic disorders such as fatty liver disease and obesity. In cancer, increased fatty acid biosynthesis supports rapid cell proliferation and membrane production, making enzymes such as FASN and ACACA attractive therapeutic targets. In marine and microbial organisms, fatty acid biosynthetic pathways determine the production of omega-3 and other nutritionally important fatty acids. Understanding this process also has biotechnological relevance for producing biofuels and nutraceuticals. Because the pathway is conserved but varies in regulation across species, comparative studies in organisms such as Thraustochytrium, chromerids, and Atlantic salmon provide insights into its diversity and evolution.
• Provides essential fatty acids for membrane phospholipid biosynthesis and cell proliferation.
• Supplies precursors for energy storage as triglycerides in adipose tissue and liver.
• Generates signaling lipids that regulate inflammation, insulin sensitivity, and gene expression.
• Is a metabolic hallmark of cancer, where increased fatty acid synthesis supports tumor growth.
• Contributes to the production of omega-3 and omega-6 polyunsaturated fatty acids with nutritional and pharmaceutical value.
• Is a target for metabolic disease research, including nonalcoholic fatty liver disease and dyslipidemia.
• Is studied in microorganisms for biotechnological production of lipids and biofuels.
• Is regulated by hormones, nutrients, and transcription factors, making it a model for metabolic regulation.
• Involves conserved enzymes that can be targeted by small molecules and genetic tools.
• Provides a framework for understanding lipid transport and fatty acid trafficking across membranes.
What Happens During fatty acid biosynthetic process?
Initiation and acetyl-CoA carboxylation
In simple terms: The cell first makes a small building block called malonyl-CoA from acetyl-CoA.
The committed step in fatty acid biosynthesis is the carboxylation of acetyl-CoA to malonyl-CoA, catalyzed by acetyl-CoA carboxylase (ACACA). This reaction consumes ATP and bicarbonate and is a key regulatory point in the pathway. In animals, ACACA is activated by citrate and inhibited by long-chain acyl-CoAs, linking fatty acid synthesis to energy status. In microorganisms and marine organisms, the same biochemical logic applies, although enzyme organization may differ.
Elongation cycle by fatty acid synthase
In simple terms: A large enzyme assembly adds two-carbon units repeatedly to build a growing fatty acid chain.
Fatty acid synthase (FASN) is a multifunctional enzyme that catalyzes the iterative condensation, reduction, dehydration, and reduction of acyl chains using malonyl-CoA as the two-carbon donor. In animals, FASN is a homodimeric megasynthase often described as a chemical nanofactory, and it produces primarily palmitate (16:0). The elongation cycle requires NADPH as a reducing agent and releases CO2. In bacteria and plants, the same reactions are carried out by discrete enzymes rather than a single multifunctional polypeptide.
Desaturation and formation of unsaturated fatty acids
In simple terms: After the chain is made, enzymes insert double bonds to create unsaturated fatty acids.
Stearoyl-CoA desaturase (SCD) introduces a double bond into saturated fatty acyl-CoAs to produce monounsaturated fatty acids, primarily oleate. In plants and some microorganisms, soluble desaturases act on acyl-ACP or acyl-lipid substrates. In animals, delta-5 and delta-6 desaturases (encoded by FADS1 and FADS2) further desaturate and elongate polyunsaturated fatty acids. These desaturation steps are essential for membrane fluidity and for the production of signaling lipids.
Elongation of long-chain and very long chain fatty acids
In simple terms: Enzymes called elongases extend fatty acids beyond the typical 16-carbon length.
The ELOVL family of enzymes catalyzes the elongation of long-chain and very long chain fatty acids by adding two-carbon units. In Atlantic salmon hepatocytes, the omega-3 fatty acid biosynthetic pathway is regulated by elongases and desaturases that convert precursors into EPA and DHA. Very long chain fatty acids of over 30 carbons are found in waxes and require specialized elongases. Elongation is tightly coordinated with desaturation to produce the full spectrum of cellular fatty acids.
Fatty acid transport and trafficking
In simple terms: Fatty acids must be moved around the cell and body by transport proteins.
Fatty acid transport proteins facilitate the uptake and distribution of fatty acids across membranes. Albumin acts as a fatty acid transporter in the bloodstream, carrying hydrophobic fatty acids to tissues. In the liver, fatty acid transport and metabolism are integrated with lipoprotein assembly and secretion. These transport mechanisms ensure that newly synthesized fatty acids reach their destinations for membrane synthesis, storage, or oxidation.
Key Genes Involved in GO:0006633 fatty acid biosynthetic process
The following genes and proteins are central to GO:0006633 fatty acid biosynthetic process, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ACACA | Catalyzes carboxylation of acetyl-CoA to malonyl-CoA, the committed step in fatty acid synthesis | Target for metabolic disease and cancer; knockout models show reduced fatty acid synthesis |
| FASN | Multifunctional enzyme that catalyzes the elongation cycle to produce palmitate | Highly expressed in many cancers; target for inhibitors and genetic knockout |
| SCD | Desaturates saturated fatty acyl-CoAs to monounsaturated fatty acids | Regulates membrane fluidity and lipid signaling; linked to metabolic disease |
| ELOVL1 | Elongates very long chain fatty acids | Important for skin barrier and lipid homeostasis |
| ELOVL2 | Elongates polyunsaturated fatty acids | Involved in omega-3 and omega-6 fatty acid synthesis |
| ELOVL5 | Elongates long-chain polyunsaturated fatty acids | Key for arachidonic and eicosapentaenoic acid production |
| FADS1 | Delta-5 desaturase for polyunsaturated fatty acid synthesis | Genetic variants associated with lipid levels and metabolic traits |
| FADS2 | Delta-6 desaturase for polyunsaturated fatty acid synthesis | Regulates omega-3 and omega-6 pathway flux |
| ACSL1 | Activates long-chain fatty acids to acyl-CoA for metabolism | Links fatty acid synthesis to oxidation and storage |
| ACSL3 | Activates fatty acids for lipid synthesis | Involved in lipid droplet formation |
| ACSL4 | Activates arachidonic acid and other PUFAs | Implicated in ferroptosis and lipid signaling |
| GPAT1 | Catalyzes the first step in glycerolipid synthesis using acyl-CoA | Connects fatty acid synthesis to triglyceride production |
| DGAT1 | Catalyzes the final step in triglyceride synthesis | Target for obesity and lipid disorders |
| DGAT2 | Catalyzes triglyceride synthesis in liver and adipose tissue | Important for very low density lipoprotein secretion |
| CD36 | Fatty acid transport protein | Mediates fatty acid uptake and signaling |
| FABP1 | Liver fatty acid binding protein | Intracellular fatty acid trafficking |
| SREBF1 | Transcription factor regulating lipogenic genes | Master regulator of fatty acid biosynthesis |
How Is fatty acid biosynthetic process Regulated?
Fatty acid biosynthetic process is regulated at multiple levels. In animals, the transcription factor SREBP-1c (encoded by SREBF1) controls the expression of lipogenic genes such as ACACA, FASN, and SCD in response to insulin and nutrient status. Acetyl-CoA carboxylase is allosterically activated by citrate and inhibited by long-chain acyl-CoAs, providing immediate feedback control. In Atlantic salmon hepatocytes, the omega-3 fatty acid biosynthetic pathway is regulated by nutritional and hormonal signals that affect desaturase and elongase expression. In microorganisms such as Thraustochytrium, fatty acid biosynthesis is regulated in response to growth conditions and may involve distinct transcriptional networks. Additionally, fatty acid transport proteins and albumin influence the availability of substrates and products, indirectly shaping pathway flux.
fatty acid biosynthetic process and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| FASN | Cancer; increased lipogenesis supports tumor growth | Knockout or point-mutation in cancer cell lines; xenograft models |
| ACACA | Metabolic disease; dysregulated fatty acid synthesis in liver | Liver-specific knockout or overexpression in mice |
| SCD | Metabolic syndrome; altered monounsaturated fatty acid levels | Knockout mice and cell models |
| FADS1/FADS2 | Altered polyunsaturated fatty acid levels; metabolic traits | Knock-in of human variants in cell lines |
| ELOVL5 | Impaired omega-3 and omega-6 fatty acid synthesis | Knockout in hepatocytes or zebrafish |
Cancer and fatty acid biosynthesis
Many cancer cells exhibit increased de novo fatty acid biosynthesis to support rapid proliferation and membrane production. Overexpression of FASN and ACACA is observed in several tumor types, and inhibition of these enzymes can reduce tumor growth in preclinical models. This makes fatty acid biosynthetic enzymes potential targets for anticancer therapy.
Metabolic disorders and liver disease
Dysregulation of hepatic fatty acid synthesis contributes to nonalcoholic fatty liver disease, insulin resistance, and dyslipidemia. The liver is a major site of lipid metabolism, and altered expression of SREBP-1c, ACACA, and FASN is associated with excessive lipid accumulation. Understanding these pathways is essential for developing therapies for metabolic syndrome.
Disorders of fatty acid desaturation and elongation
Genetic variants in FADS1 and FADS2 have been associated with altered levels of polyunsaturated fatty acids and metabolic traits. Impaired elongation or desaturation can affect membrane composition and signaling, contributing to disease risk. Inborn errors of fatty acid metabolism can also result from defects in these pathways.
From fatty acid biosynthetic process-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of FASN reduce cancer cell proliferation? | CRISPR knockout of FASN in cancer cell lines |
| Does a specific point mutation in ACACA alter enzyme activity? | CRISPR point mutation knock-in in hepatocytes |
| Does overexpression of SREBF1 increase fatty acid synthesis? | CRISPR-mediated overexpression or cDNA overexpression |
| How does a disease-associated FADS1 variant affect desaturase activity? | Knock-in of the variant in a cell line |
| What is the role of ELOVL5 in omega-3 fatty acid production? | Knockout in Atlantic salmon hepatocytes or cell models |
| Can tagged FASN be used to track its localization? | Tagged knock-in of endogenous FASN |
How to Study the fatty acid biosynthetic process Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Expression levels of fatty acid biosynthetic genes | Transcriptional regulation studies |
| Lipidomics (LC-MS) | Fatty acid species abundance and composition | Metabolic profiling of cells or tissues |
| Enzyme activity assay | Catalytic activity of ACACA, FASN, SCD, ELOVL | Functional validation of mutations |
| CRISPR knockout screen | Genes required for fatty acid synthesis and growth | Identification of metabolic dependencies |
| Western blot | Protein expression of lipogenic enzymes | Validation of knockout or overexpression |
| Immunofluorescence | Subcellular localization of enzymes | Studying enzyme organization |
| Metabolic flux analysis | Rate of fatty acid synthesis from labeled precursors | Quantifying pathway activity |
Transcriptomics and RNA-seq
RNA sequencing can quantify the expression of fatty acid biosynthetic genes such as ACACA, FASN, SCD, and ELOVL family members under different conditions. In Atlantic salmon hepatocytes, RNA-seq has been used to study the regulation of the omega-3 fatty acid biosynthetic pathway. This method provides a global view of transcriptional changes in response to nutrients or hormones.
Lipidomics and mass spectrometry
Mass spectrometry-based lipidomics measures the abundance and composition of fatty acid species, including saturated, monounsaturated, and polyunsaturated fatty acids. This approach is essential for determining how genetic or pharmacological perturbations alter flux through GO:0006633. In Thraustochytrium, lipid profiling has been used to analyze fatty acid biosynthetic products.
Enzymatic activity assays
In vitro assays using radiolabeled or fluorescent substrates can measure the activity of acetyl-CoA carboxylase, fatty acid synthase, desaturases, and elongases. These assays are useful for validating the functional impact of point mutations identified in disease or experimental studies. They can be performed with purified enzymes or cell lysates.
CRISPR-based genetic screens
Pooled CRISPR knockout screens can identify genes required for fatty acid biosynthesis and cell growth under lipid-limited conditions. Such screens have been used to uncover metabolic vulnerabilities in cancer cells. Combining screens with lipidomics can reveal gene-lipid relationships.
How CRISPR Can Be Used to Study GO:0006633 fatty acid biosynthetic process
Knockout
CRISPR knockout of genes such as FASN, ACACA, or SCD can abolish or reduce fatty acid biosynthetic flux, enabling researchers to test their requirement for cell proliferation, lipid storage, and signaling. Knockout cell lines are valuable for metabolic studies and drug target validation.
Point Mutation
CRISPR point mutation knock-in can introduce specific amino acid substitutions identified in human disease or functional studies, allowing precise testing of enzyme activity and regulation. For example, mutations in ACACA or FASN can be modeled to understand their impact on catalysis.
Knock-in
Knock-in of reporter tags or disease-associated variants (e.g., in FADS1) enables tracking of endogenous protein localization and function. Tagged knock-in of FASN can be used to study its cellular distribution and interactions.
Overexpression
CRISPR-mediated overexpression or cDNA overexpression of lipogenic transcription factors such as SREBF1 or enzymes like FASN can drive increased fatty acid synthesis, modeling conditions of lipid accumulation. Overexpression models are useful for studying pathway flux and identifying downstream effects.
How EDITGENE Supports fatty acid biosynthetic process Research
Researchers studying fatty acid biosynthetic process-related genes often need to determine whether a candidate gene is causally involved in lipid metabolism, disease progression, or cellular stress responses. EDITGENE provides CRISPR-based cell model services to enable precise genetic perturbations of genes in GO:0006633, from knockout to point mutation and overexpression.
Contact EDITGENE today to design your custom CRISPR model for fatty acid biosynthetic process research.
Frequently Asked Questions About fatty acid biosynthetic process
What is GO:0006633 fatty acid biosynthetic process?
GO:0006633 is a Gene Ontology biological process term describing the chemical reactions and pathways that result in the formation of a fatty acid, defined as an aliphatic monocarboxylic acid that can be liberated by hydrolysis from naturally occurring fats and oils.
What genes are involved in fatty acid biosynthetic process?
Key genes include ACACA, FASN, SCD, ELOVL family members, FADS1, FADS2, and transcription factors such as SREBF1, which regulate the pathway.
Why is fatty acid biosynthesis important in cancer?
Many cancer cells increase de novo fatty acid synthesis to support rapid proliferation, and enzymes like FASN and ACACA are considered potential therapeutic targets.
How is fatty acid biosynthetic process regulated?
It is regulated by transcription factors such as SREBP-1c, allosteric regulation of acetyl-CoA carboxylase, and nutritional and hormonal signals.
What are the main steps of fatty acid biosynthesis?
The main steps include acetyl-CoA carboxylation to malonyl-CoA, elongation by fatty acid synthase, desaturation, and further elongation by ELOVL enzymes.
Which enzymes catalyze fatty acid desaturation?
Stearoyl-CoA desaturase (SCD) and delta-5/delta-6 desaturases (FADS1/FADS2) introduce double bonds into fatty acyl chains.
How can CRISPR be used to study fatty acid biosynthesis?
CRISPR knockout, point mutation, knock-in, and overexpression can be used to test the causal role of specific genes in fatty acid synthesis and metabolism.
What diseases are linked to fatty acid biosynthetic process?
Dysregulation is linked to cancer, nonalcoholic fatty liver disease, insulin resistance, and disorders of polyunsaturated fatty acid metabolism.
What model organisms are used to study fatty acid biosynthesis?
Common models include mammalian cell lines, mouse liver models, Atlantic salmon hepatocytes, and microorganisms such as Thraustochytrium.
What methods measure fatty acid synthesis?
Methods include RNA-seq, lipidomics, enzyme activity assays, metabolic flux analysis, and CRISPR screens.
Conclusion
GO:0006633 fatty acid biosynthetic process is a fundamental metabolic pathway that produces fatty acids essential for membrane structure, energy storage, and signaling. Its dysregulation is implicated in cancer, metabolic disease, and disorders of lipid metabolism, making it a rich area for research. Advances in CRISPR-based models and lipidomics continue to uncover the genetic and biochemical mechanisms controlling this pathway. Understanding fatty acid biosynthesis at a systems level will support the development of new therapeutic and biotechnological applications.
References
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