GO:0045990 carbon catabolite regulation of transcription: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0045990 describes how the presence of one carbon source modulates transcription of genes needed to use other carbon sources.
• In filamentous fungi, the zinc-finger transcription factor CreA is the central repressor, and its activity is controlled by phosphorylation and nuclear localization.
• In Streptomyces coelicolor, carbon catabolite regulation controls secondary metabolite formation and morphological differentiation.
• In Bacillus subtilis, catabolite regulation of the pta gene is part of the carbon flow pathway that determines acetate and overflow metabolism.
• In Vibrio parahaemolyticus, the catabolite activator protein (CAP) regulates the type III secretion system 2, linking carbon status to virulence.
• CRISPR knockout, point-mutation, knock-in, and overexpression models are essential to test causal roles of CreA, CAP, and other regulators in carbon catabolite regulation.
Description
Carbon catabolite regulation of transcription (GO:0045990) is the process by which the presence of one carbon source changes the transcription of genes required for the metabolism of other carbon sources. This regulatory logic allows microorganisms to prioritize preferred sugars such as glucose and to repress genes for less favorable carbon sources until they are needed. The term is a biological_process in the Gene Ontology and is often studied in fungi, bacteria, and other microbes where carbon source availability shapes growth, secondary metabolism, and virulence. Understanding GO:0045990 matters because it sits at the intersection of nutrient sensing, gene regulation, and metabolic engineering. In Aspergillus species, the CreA transcription factor is a master regulator of carbon catabolite repression, and its phosphorylation state determines whether target genes are repressed or derepressed. In Streptomyces coelicolor, carbon catabolite regulation coordinates secondary metabolite production with morphological differentiation, making it a target for natural product discovery. In Bacillus subtilis, catabolite regulation of the pta gene is embedded in the carbon flow pathways that balance acetate production and central metabolism. In Vibrio parahaemolyticus, the catabolite activator protein links carbon source availability to expression of the type III secretion system 2, a key virulence determinant. Together, these examples show that GO:0045990 is not a narrow fungal phenomenon but a broadly conserved strategy for matching gene expression to carbon economy.
carbon catabolite regulation of transcription At A Glance
| GO ID | GO:0045990 |
|---|---|
| GO term | carbon catabolite regulation of transcription |
| Ontology | biological_process |
| Synonym | regulation of transcription by carbon catabolites |
| Major function | Modulates transcription of genes for metabolism of alternative carbon sources in response to the presence of a preferred carbon source |
| Key regulators | CreA in filamentous fungi, CAP in Vibrio parahaemolyticus, and catabolite control proteins in Bacillus subtilis |
| Representative organisms | Aspergillus species, Streptomyces coelicolor, Bacillus subtilis, Vibrio parahaemolyticus |
| Related processes | Carbon catabolite repression, carbon flow pathways, secondary metabolite formation, type III secretion |
What Is GO:0045990?
GO:0045990, carbon catabolite regulation of transcription, is defined as a transcription regulation process in which the presence of one carbon source leads to the modulation of the frequency, rate, or extent of transcription of specific genes involved in the metabolism of other carbon sources. In practice, this means that when a preferred carbon source such as glucose is available, transcription of genes for alternative carbon source utilization is reduced, and when the preferred source is depleted, those genes become derepressed. The regulation can be negative (repression) or positive (activation), depending on the organism and the specific regulator.
Why Is carbon catabolite regulation of transcription Important in Cell Biology?
GO:0045990 is important because it determines how microorganisms allocate transcriptional resources when multiple carbon sources are available, which directly affects growth rate, metabolic yield, secondary metabolite production, and virulence. In industrial biotechnology, carbon catabolite repression can limit the efficient use of mixed sugars from lignocellulosic feedstocks, making it a central problem for Aspergillus-based cell factories and other production hosts. In medicine and microbial pathogenesis, the same regulatory logic can control virulence programs, as shown for the type III secretion system 2 in Vibrio parahaemolyticus. Therefore, researchers studying GO:0045990 need precise genetic tools to dissect which regulators are causal and which target genes are directly controlled.
• Controls preferential carbon source utilization and metabolic efficiency in fungi and bacteria.
• Regulates secondary metabolite formation and morphological differentiation in Streptomyces coelicolor.
• Shapes carbon flow pathways such as acetate metabolism in Bacillus subtilis.
• Links carbon source availability to virulence gene expression in Vibrio parahaemolyticus.
• Affects lignocellulose degradation and bioconversion in microorganisms.
• Is a key target for metabolic engineering of Aspergillus-based cell factories.
• Involves phosphorylation-dependent control of transcription factor activity.
• Provides a model for studying nutrient sensing and gene regulation across microbes.
What Happens During carbon catabolite regulation of transcription?
Carbon source sensing and signal entry
In simple terms: The cell first senses which carbon source is available and sends a signal to the transcription machinery.
In filamentous fungi such as Aspergillus species, the presence of a preferred carbon source triggers signaling that ultimately controls the CreA transcription factor. In Vibrio parahaemolyticus, the catabolite activator protein (CAP) responds to carbon source status and regulates the type III secretion system 2. In Bacillus subtilis, catabolite regulation of the pta gene is part of the carbon flow pathways that respond to the available carbon source. These sensing events convert metabolic information into transcriptional outputs.
Regulator modification and nuclear localization
In simple terms: The key regulator protein is chemically modified and moves into the nucleus to act on target genes.
In Aspergillus species, CreA is regulated by phosphorylation, which affects its activity and its ability to repress target genes under carbon catabolite repressing conditions. Genome-wide characterization of CreA-mediated transcriptional regulation in Aspergillus oryzae under carbon catabolite derepression has identified many target genes whose expression changes when CreA is inactivated or modified. This step is critical because it determines whether the regulator is active or inactive in the nucleus.
Target gene repression or activation
In simple terms: Once active, the regulator turns down or turns up specific genes needed for other carbon sources.
CreA in Aspergillus species represses genes involved in the metabolism of alternative carbon sources when a preferred carbon source is present. In Streptomyces coelicolor, carbon catabolite regulation controls genes for secondary metabolite formation and morphological differentiation. In Bacillus subtilis, catabolite regulation of the pta gene modulates carbon flow through acetate pathways. In Vibrio parahaemolyticus, CAP regulates the type III secretion system 2, linking carbon status to virulence gene expression.
Derepression when preferred carbon source is depleted
In simple terms: When the preferred sugar runs out, the brake is released and alternative carbon source genes turn on.
Under carbon catabolite derepression, CreA-mediated repression is relieved, allowing transcription of genes for alternative carbon source utilization. Genome-wide studies in Aspergillus oryzae have characterized the transcriptional changes that occur under derepression, revealing the breadth of CreA target genes. This derepression step is essential for adapting to changing nutrient availability and for efficient substrate utilization.
Integration with secondary metabolism and virulence
In simple terms: The same regulatory process can also control specialized functions like antibiotic production or virulence.
In Streptomyces coelicolor, carbon catabolite regulation is integrated with secondary metabolite formation and morphological differentiation, so that antibiotic production is coordinated with carbon source availability. In Vibrio parahaemolyticus, catabolite activator protein regulation of the type III secretion system 2 connects carbon metabolism to virulence. These examples show that GO:0045990 is not limited to primary carbon metabolism but extends to ecologically and medically important traits.
Key Genes Involved in GO:0045990 carbon catabolite regulation of transcription
The following genes and proteins are central to carbon catabolite regulation of transcription (GO:0045990) based on the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CreA | Zinc-finger transcription factor that represses genes for alternative carbon source utilization in Aspergillus species | Central regulator for studying carbon catabolite repression and derepression in filamentous fungi |
| creA (Aspergillus oryzae) | Mediates genome-wide transcriptional regulation under carbon catabolite derepression | Target for genome-wide characterization of CreA-dependent genes |
| CAP (catabolite activator protein) | Regulates type III secretion system 2 in Vibrio parahaemolyticus in response to carbon source | Links carbon catabolite regulation to virulence gene expression |
| pta | Catabolite-regulated gene involved in carbon flow pathways in Bacillus subtilis | Model for studying catabolite regulation of central metabolic genes |
| CreA phosphorylation sites | Phosphorylation controls CreA activity in filamentous fungi | Target for point-mutation studies to test phosphorylation-dependent regulation |
| Carbon catabolite repression regulators in Streptomyces coelicolor | Control secondary metabolite formation and morphological differentiation | Model system for carbon catabolite regulation of specialized metabolism |
| Lignocellulose degradation regulators | Regulate genes for lignocellulose degradation in microorganisms | Relevant for biofuel and bioproduct production from plant biomass |
| Aspergillus cell factory regulators | Modulate carbon catabolite repression in industrial Aspergillus strains | Targets for metabolic engineering to improve mixed-sugar utilization |
| Catabolite control proteins in Bacillus subtilis | Participate in catabolite regulation of pta and carbon flow | Model for Gram-positive carbon catabolite regulation |
| Type III secretion system 2 regulators | Controlled by CAP in Vibrio parahaemolyticus | Relevant for understanding virulence regulation by carbon source |
| CreA target genes in Aspergillus oryzae | Genes whose transcription changes under carbon catabolite derepression | Provide a genome-wide view of CreA regulon |
| Secondary metabolite gene clusters in Streptomyces coelicolor | Regulated by carbon catabolite regulation | Important for natural product discovery |
| Carbon flow pathway genes in Bacillus subtilis | Include pta and related genes regulated by catabolite availability | Model for central carbon metabolism regulation |
| CreA homologs in filamentous fungi | Conserved regulators of carbon catabolite repression | Comparative studies across fungal species |
| Catabolite-responsive elements | DNA sequences through which regulators act | Targets for promoter and enhancer studies |
How Is carbon catabolite regulation of transcription Regulated?
Carbon catabolite regulation of transcription is itself regulated by carbon source availability and by post-translational modification of the key transcription factors. In Aspergillus species, phosphorylation of CreA controls its activity and its ability to repress target genes. Under carbon catabolite derepression, CreA-mediated repression is relieved, leading to genome-wide changes in transcription. In Vibrio parahaemolyticus, the catabolite activator protein responds to carbon source status to regulate the type III secretion system 2. In Bacillus subtilis, catabolite regulation of the pta gene is integrated with carbon flow pathways. These layers of regulation ensure that gene expression matches the available carbon source.
carbon catabolite regulation of transcription and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CreA | Fungal growth and virulence in Aspergillus species | Aspergillus knockout and point-mutation strains |
| CAP | Virulence regulation in Vibrio parahaemolyticus | Vibrio parahaemolyticus CAP knockout and overexpression strains |
| pta | Carbon flow and acetate metabolism in Bacillus subtilis | Bacillus subtilis pta knockout and promoter reporter strains |
| Secondary metabolite regulators in Streptomyces coelicolor | Antibiotic production and morphological differentiation | Streptomyces coelicolor regulatory mutants |
| Lignocellulose degradation regulators | Biomass conversion and biofuel production | Microbial knockout and overexpression strains for lignocellulolytic enzymes |
Carbon catabolite regulation and fungal virulence
In Aspergillus species, CreA-mediated carbon catabolite repression controls genes required for growth on alternative carbon sources, which can influence the ability of the fungus to colonize host tissues where glucose availability varies. Understanding GO:0045990 may therefore inform studies of Aspergillus pathogenesis and antifungal strategies.
Carbon catabolite regulation and bacterial virulence
In Vibrio parahaemolyticus, the catabolite activator protein regulates the type III secretion system 2, a major virulence determinant. This links carbon source availability directly to expression of virulence genes, suggesting that GO:0045990-related regulators could be explored as targets for anti-virulence interventions.
Carbon catabolite regulation and secondary metabolite production
In Streptomyces coelicolor, carbon catabolite regulation controls secondary metabolite formation and morphological differentiation. Because many secondary metabolites are antibiotics or bioactive compounds, dysregulation of this process can affect the production of clinically important molecules.
Carbon catabolite regulation in industrial biotechnology
In Aspergillus-based cell factories, carbon catabolite repression can limit the efficient use of mixed sugars from plant biomass, which is a major bottleneck for sustainable bioproduction. Modulating GO:0045990-related regulators is therefore a strategy to improve lignocellulose conversion and product yields.
From carbon catabolite regulation of transcription-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is CreA required for carbon catabolite repression of a target gene? | CreA knockout in Aspergillus species |
| Does phosphorylation of CreA control its repressor activity? | Point-mutation knock-in of phospho-null or phospho-mimetic CreA alleles |
| What genes are directly regulated by CreA under derepression? | CreA knockout combined with RNA-seq in Aspergillus oryzae |
| Does CAP regulate type III secretion system 2 in response to carbon source? | CAP knockout and overexpression in Vibrio parahaemolyticus |
| How does catabolite regulation affect carbon flow through pta? | pta promoter reporter and knockout in Bacillus subtilis |
| Can carbon catabolite regulation be engineered to improve mixed-sugar utilization? | Overexpression or knockout of regulators in Aspergillus cell factories |
How to Study the carbon catabolite regulation of transcription Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Genome-wide transcript levels | Identify CreA-regulated genes under derepression |
| Phosphoproteomics | Protein phosphorylation sites | Map CreA phosphorylation in filamentous fungi |
| Knockout and complementation | Causal role of a regulator | Test CreA or CAP function in carbon catabolite regulation |
| Promoter-reporter assay | Transcriptional activity of a promoter | Study pta regulation in Bacillus subtilis |
| Chromatin immunoprecipitation | DNA binding by transcription factors | Identify CreA binding sites genome-wide |
| Transcriptomic analysis of regulatory mutants | Changes in gene expression due to regulator loss | Characterize carbon catabolite regulation in Streptomyces coelicolor |
| Metabolic profiling | Carbon flow and metabolite levels | Link catabolite regulation to carbon metabolism |
| Virulence gene expression assays | Expression of virulence genes | Study CAP regulation of type III secretion system 2 |
Transcriptomics and RNA-seq
RNA-seq is used to measure genome-wide transcriptional changes under carbon catabolite repressing and derepressing conditions. In Aspergillus oryzae, genome-wide characterization of CreA-mediated transcriptional regulation under carbon catabolite derepression identified target genes and regulatory networks. In Streptomyces coelicolor, transcriptomic analysis of a classical model of carbon catabolite regulation revealed coordinated changes in secondary metabolism and differentiation genes.
Phosphoproteomics and protein modification analysis
Phosphoproteomics can identify phosphorylation sites on regulators such as CreA. In filamentous fungi, phosphorylation of CreA is a key regulatory event in carbon catabolite repression. Point-mutation studies can then test whether specific phosphorylation sites are required for repressor activity.
Genetic knockout and complementation
Knockout of candidate regulators followed by complementation is a standard approach to test causality. CreA knockout in Aspergillus species has been used to define its role in carbon catabolite repression. CAP knockout in Vibrio parahaemolyticus has been used to test its role in regulating the type III secretion system 2.
Reporter assays and promoter analysis
Promoter-reporter fusions can measure the activity of carbon catabolite-regulated promoters. In Bacillus subtilis, catabolite regulation of the pta gene has been studied using promoter and gene expression assays. In Aspergillus species, CreA target promoters can be tested for repression and derepression.
How CRISPR Can Be Used to Study GO:0045990 carbon catabolite regulation of transcription
Knockout
CRISPR knockout of CreA in Aspergillus species can be used to test whether CreA is required for carbon catabolite repression of specific target genes. Similarly, knockout of CAP in Vibrio parahaemolyticus can test its role in regulating the type III secretion system 2. Knockout of pta in Bacillus subtilis can reveal its role in carbon flow pathways.
Point Mutation
CRISPR point mutation can be used to introduce phospho-null or phospho-mimetic mutations in CreA to test whether specific phosphorylation sites control its repressor activity. This approach allows precise dissection of post-translational regulation without deleting the entire protein.
Knock-in
CRISPR knock-in of tagged CreA or CAP alleles can enable chromatin immunoprecipitation and imaging studies to determine where and when these regulators bind target genes. Tagged knock-in lines are also useful for tracking protein localization under different carbon source conditions.
Overexpression
CRISPR overexpression of CreA or CAP can test whether increased regulator levels enhance repression or activation of target genes. Overexpression of carbon catabolite regulators in Aspergillus cell factories may also be used to engineer improved mixed-sugar utilization.
How EDITGENE Supports carbon catabolite regulation of transcription Research
Researchers studying carbon catabolite regulation of transcription-related genes often need to determine whether a candidate gene is causally involved in the process or is merely correlated with transcriptional changes. This requires precise genetic models that can knockout, mutate, tag, or overexpress the regulator and its targets in the relevant organism. EDITGENE provides CRISPR-based services tailored to these needs, from single-gene knockout to genome-wide library screening and bioinformatics analysis.
Contact EDITGENE today to design your custom CRISPR model for carbon catabolite regulation of transcription research.
Frequently Asked Questions About carbon catabolite regulation of transcription
What is carbon catabolite regulation of transcription?
It is the process by which the presence of one carbon source modulates transcription of genes involved in the metabolism of other carbon sources, defined as GO:0045990.
What genes are involved in carbon catabolite regulation of transcription?
Key genes include CreA in Aspergillus species, CAP in Vibrio parahaemolyticus, and pta in Bacillus subtilis, among others.
Which organisms use carbon catabolite regulation of transcription?
It is well studied in filamentous fungi such as Aspergillus, in Streptomyces coelicolor, Bacillus subtilis, and Vibrio parahaemolyticus.
How is CreA regulated in carbon catabolite repression?
CreA activity is controlled by phosphorylation, which affects its ability to repress target genes under carbon catabolite repressing conditions.
What happens during carbon catabolite derepression?
When the preferred carbon source is depleted, CreA-mediated repression is relieved, leading to transcription of genes for alternative carbon source utilization.
Why is carbon catabolite regulation important for biotechnology?
It affects the efficient use of mixed sugars from plant biomass in Aspergillus-based cell factories and other industrial hosts.
Does carbon catabolite regulation affect virulence?
Yes, in Vibrio parahaemolyticus the catabolite activator protein regulates the type III secretion system 2, linking carbon status to virulence.
How can CRISPR be used to study carbon catabolite regulation?
CRISPR knockout, point mutation, knock-in, and overexpression can test the causal roles of regulators such as CreA and CAP.
What methods are used to study carbon catabolite regulation of transcription?
RNA-seq, phosphoproteomics, knockout and complementation, promoter-reporter assays, and ChIP are commonly used.
What is the GO ID for carbon catabolite regulation of transcription?
The GO ID is GO:0045990, a biological_process term in the Gene Ontology.
Conclusion
GO:0045990, carbon catabolite regulation of transcription, is a conserved regulatory process that allows microorganisms to prioritize carbon sources and coordinate gene expression with metabolic needs. Its key regulators, including CreA in fungi and CAP in Vibrio parahaemolyticus, are controlled by phosphorylation and other post-translational mechanisms, and they influence secondary metabolism, carbon flow, and virulence. Studying this process requires precise genetic models, and CRISPR-based knockout, point-mutation, knock-in, and overexpression approaches are powerful tools for dissecting causal relationships. As research continues, genome-wide and bioinformatics methods will further clarify the regulatory networks underlying GO:0045990 and their applications in biotechnology and medicine.
References
- 1. de Assis LJ et al.. 2021. Carbon Catabolite Repression in Filamentous Fungi Is Regulated by Phosphorylation of the Transcription Factor CreA.. mBio 12(1) PMID: 33402538
- 2. Ogasawara N et al.. 2025. Genome-wide characterization of CreA-mediated transcriptional regulation in Aspergillus oryzae under carbon catabolite derepression.. Biosci Biotechnol Biochem 90(1):99-108 PMID: 41118253
- 3. Wang ZD et al.. 2024. Implications of carbon catabolite repression for Aspergillus-based cell factories: A review.. Biotechnol J 19(2):e2300551 PMID: 38403447
- 4. Romero-Rodríguez A et al.. 2016. Carbon Catabolite Regulation of Secondary Metabolite Formation and Morphological Differentiation in Streptomyces coelicolor.. Appl Biochem Biotechnol 180(6):1152-1166 PMID: 27372741
- 5. Romero-Rodríguez A et al.. 2016. Transcriptomic analysis of a classical model of carbon catabolite regulation in Streptomyces coelicolor.. BMC Microbiol 16:77 PMID: 27121083
- 6. Gurovic MSV et al.. 2023. Regulation of lignocellulose degradation in microorganisms.. J Appl Microbiol 134(1) PMID: 36626734
- 7. Presecan-Siedel E et al.. 1999. Catabolite regulation of the pta gene as part of carbon flow pathways in Bacillus subtilis.. J Bacteriol 181(22):6889-97 PMID: 10559153
- 8. Tanabe T et al.. 2024. Expression regulation of type III secretion system 2 in Vibrio parahaemolyticus by catabolite activator protein.. FEMS Microbiol Lett 371 PMID: 39054297
