GO:0008294 calcium- and calmodulin-responsive adenylate cyclase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0008294 describes a calcium- and calmodulin-responsive adenylate cyclase activity that catalyzes the conversion of ATP to 3',5'-cyclic AMP and diphosphate when stimulated by calcium-bound calmodulin.
• The defining genetic example is the Drosophila rutabaga gene, which encodes a Ca2+/calmodulin-responsive adenylyl cyclase required for learning and memory.
• Calcium/calmodulin-responsive adenylate cyclase activity links calcium signaling to cAMP second-messenger pathways, integrating two major intracellular signaling systems.
• This activity is distinct from other adenylate cyclases because its catalytic rate is directly stimulated by the calcium-calmodulin complex.
• Dysregulation of calcium- and calmodulin-responsive adenylate cyclase activity has been implicated in neurodevelopmental and memory-related processes.
• Experimental study of GO:0008294 benefits from CRISPR knockout, point-mutation, knock-in, and overexpression models to dissect gene function and signaling output.
Description
GO:0008294, calcium- and calmodulin-responsive adenylate cyclase activity, is a molecular function that couples calcium signaling to the production of the universal second messenger cyclic AMP (cAMP). The term is defined as catalysis of the reaction ATP = 3',5'-cyclic AMP + diphosphate, stimulated by calcium-bound calmodulin. This activity is central to signal transduction because it allows changes in intracellular calcium to be translated into changes in cAMP concentration, thereby influencing downstream effectors such as protein kinase A and cyclic nucleotide-gated channels. Researchers study this activity to understand how cells integrate calcium and cAMP signals in processes ranging from neuronal plasticity to hormone secretion. The Drosophila rutabaga gene provided the first molecular identification of a Ca2+/calmodulin-responsive adenylyl cyclase and demonstrated its requirement for associative learning and memory. Because the activity is defined by its regulation rather than by a single gene, it is important to distinguish it from other adenylate cyclases that are not calcium/calmodulin-responsive. The QuickGO definition and the literature indicate that this molecular function is a key node at the intersection of calcium and cAMP signaling pathways.
calcium- and calmodulin-responsive adenylate cyclase activity At A Glance
| GO ID | GO:0008294 |
|---|---|
| GO term | calcium- and calmodulin-responsive adenylate cyclase activity |
| Ontology | molecular_function |
| Synonym | calcium- and calmodulin-responsive adenylyl cyclase activity; calcium/calmodulin-responsive adenylate cyclase activity |
| Definition | Catalysis of the reaction: ATP = 3',5'-cyclic AMP + diphosphate, stimulated by calcium-bound calmodulin. |
| Major function | Production of cAMP in response to calcium-calmodulin signaling. |
| Reaction | ATP = 3',5'-cyclic AMP + diphosphate |
| Regulator | Calcium-bound calmodulin (stimulatory) |
| Example gene | rutabaga (Drosophila melanogaster) |
What Is GO:0008294?
In simple terms, GO:0008294 is the activity of an enzyme that makes cAMP from ATP, but only does so efficiently when calcium is bound to calmodulin. The official definition is: Catalysis of the reaction: ATP = 3',5'-cyclic AMP + diphosphate, stimulated by calcium-bound calmodulin. This means the enzyme has adenylate cyclase catalytic activity and is positively regulated by the calcium-calmodulin complex. The term is a molecular_function in the Gene Ontology and is synonymous with calcium- and calmodulin-responsive adenylyl cyclase activity and calcium/calmodulin-responsive adenylate cyclase activity.
Why Is calcium- and calmodulin-responsive adenylate cyclase activity Important in Cell Biology?
Calcium- and calmodulin-responsive adenylate cyclase activity is important because it provides a direct biochemical link between two ubiquitous second-messenger systems, calcium and cAMP. By converting ATP to cAMP in a calcium-calmodulin-dependent manner, this activity allows cells to tune cAMP levels according to calcium signals, which is critical for processes such as synaptic plasticity, learning, and memory. In Drosophila, the rutabaga gene encoding this activity is essential for associative learning, and mutations cause memory defects. The activity is also relevant to alpha-adrenergic signaling, where calcium and cAMP interact to shape cellular responses. Because of its central role in signal integration, this molecular function is a target of interest for understanding neurodevelopmental disorders and for designing experiments that dissect calcium-cAMP crosstalk.
• Links calcium signaling to cAMP production, integrating two major second-messenger pathways.
• Required for associative learning and memory in Drosophila, as shown by rutabaga mutants.
• Provides a mechanism for calcium-dependent modulation of cAMP levels in neurons and other cells.
• Involved in alpha-adrenergic phenomena where calcium and cAMP signals interact.
• Serves as a model for studying calmodulin-dependent regulation of enzymes.
• Can be studied using CRISPR knockout, point mutation, knock-in, and overexpression models.
• Relevant to neurodevelopmental and cognitive disorders linked to cAMP signaling.
• Important for understanding how cells decode calcium oscillations into distinct cAMP responses.
• A key node for pharmacological targeting of calcium-cAMP crosstalk.
• Enables comparative analysis of adenylate cyclase isoforms with different regulatory properties.
What Happens During calcium- and calmodulin-responsive adenylate cyclase activity?
Calcium binding to calmodulin
In simple terms: Calcium ions bind to calmodulin, changing its shape so it can activate the enzyme.
The activity is stimulated by calcium-bound calmodulin, meaning that the first step is the binding of calcium to calmodulin. This binding induces a conformational change in calmodulin that allows it to interact with and activate the adenylate cyclase. The requirement for calcium-bound calmodulin distinguishes this activity from other adenylate cyclases that are not calcium-responsive.
Activation of the adenylate cyclase catalytic domain
In simple terms: The activated calmodulin turns on the enzyme's catalytic site.
Once calcium-calmodulin binds to the adenylate cyclase, the catalytic domain is stimulated to convert ATP to cAMP. The Drosophila rutabaga gene encodes a Ca2+/calmodulin-responsive adenylyl cyclase, and its activity is dependent on calcium-calmodulin. This activation step is the defining regulatory feature of GO:0008294.
Catalysis: ATP to cAMP and diphosphate
In simple terms: The enzyme cuts ATP into cAMP and diphosphate.
The catalytic reaction is ATP = 3',5'-cyclic AMP + diphosphate. This is the core biochemical output of the activity, producing cAMP as a second messenger. The reaction is stimulated by calcium-bound calmodulin, so the rate of cAMP production increases when calcium-calmodulin is present.
Downstream signaling by cAMP
In simple terms: The cAMP made by this enzyme goes on to activate other proteins.
The cAMP produced by this activity acts as a second messenger that can activate protein kinase A and other cAMP-responsive effectors. In Drosophila, this pathway is required for learning and memory, linking the biochemical activity to behavior. In alpha-adrenergic signaling, cAMP generated by such activities contributes to the integration of calcium and cAMP signals.
Key Genes Involved in GO:0008294 calcium- and calmodulin-responsive adenylate cyclase activity
The following genes and proteins are directly or functionally associated with calcium- and calmodulin-responsive adenylate cyclase activity, based on the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| rutabaga (Drosophila melanogaster) | Encodes a Ca2+/calmodulin-responsive adenylyl cyclase | Required for learning and memory; model for GO:0008294 |
| Calmodulin (Drosophila melanogaster) | Calcium-binding regulator that stimulates the adenylate cyclase | Essential for calcium-dependent activation of the enzyme |
| Calmodulin (mammalian) | Calcium sensor that activates calmodulin-responsive enzymes | Mediates calcium stimulation of adenylate cyclase activity |
| Adenylate cyclase (mammalian) | Catalyzes ATP to cAMP; some isoforms are calmodulin-responsive | Studied for calcium-cAMP crosstalk |
| Protein kinase A (mammalian) | Downstream effector of cAMP | Mediates cAMP signaling following adenylate cyclase activation |
| Alpha-adrenergic receptors (mammalian) | Receptors that can modulate calcium and cAMP pathways | Linked to alpha-adrenergic phenomena involving calcium and cAMP |
| Calcium channels (mammalian) | Provide calcium for calmodulin activation | Upstream of calcium-calmodulin-dependent adenylate cyclase |
| Calmodulin-dependent protein kinases (mammalian) | Calcium-calmodulin effectors | Share regulatory logic with calmodulin-responsive adenylate cyclase |
| G proteins (mammalian) | Regulate some adenylate cyclases | Context for adenylate cyclase regulation |
| Phosphodiesterases (mammalian) | Degrade cAMP | Determine cAMP levels produced by adenylate cyclase |
| Calcineurin (mammalian) | Calcium-calmodulin-dependent phosphatase | Illustrates calmodulin-dependent signaling |
| Ca2+/Mg2+-ATPase (bone cells) | Calmodulin-responsive calcium pump | Shows calmodulin-responsive activities in other systems |
| Adenylyl cyclase type 1 (mammalian) | Calcium-calmodulin-stimulated isoform | Model for GO:0008294 |
| Adenylyl cyclase type 8 (mammalian) | Calcium-calmodulin-stimulated isoform | Model for GO:0008294 |
| cAMP response element-binding protein (CREB) | Transcription factor activated by cAMP | Downstream of cAMP produced by this activity |
| Ras (Drosophila melanogaster) | Signaling protein affecting learning | Interacts with rutabaga pathway |
| Dunce (Drosophila melanogaster) | cAMP phosphodiesterase | Regulates cAMP levels opposite to rutabaga |
| Amnesiac (Drosophila melanogaster) | Neuropeptide affecting memory | Functionally linked to rutabaga in memory |
How Is calcium- and calmodulin-responsive adenylate cyclase activity Regulated?
The activity of calcium- and calmodulin-responsive adenylate cyclase is regulated primarily by the concentration of free calcium and the availability of calmodulin. When calcium binds to calmodulin, the complex stimulates the enzyme, increasing cAMP production. This regulation is distinct from G-protein-mediated regulation of other adenylate cyclases, although some adenylate cyclases can integrate both inputs. In Drosophila, the rutabaga-encoded enzyme is a key regulated node in memory formation, and its activity is modulated by calcium signals. Additionally, calmodulin-responsive activities such as the Ca2+/Mg2+-ATPase in bone cells demonstrate that calmodulin-dependent regulation is a general theme in calcium signaling.
calcium- and calmodulin-responsive adenylate cyclase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| rutabaga (Drosophila) | Learning and memory defects | Knockout or point-mutation Drosophila lines |
| Calmodulin (mammalian) | Calcium signaling disorders | CRISPR knock-in of calmodulin mutations |
| Adenylyl cyclase type 1 (mammalian) | Neurodevelopmental and memory disorders | Knockout mouse or overexpression models |
| Adenylyl cyclase type 8 (mammalian) | Cardiac and neuronal signaling | Knock-in and overexpression models |
| Ca2+/Mg2+-ATPase (bone cells) | Bone calcium homeostasis | Bone cell knockout models |
Learning and memory disorders
Mutations in the Drosophila rutabaga gene, which encodes a Ca2+/calmodulin-responsive adenylyl cyclase, cause defects in associative learning and memory. This establishes a direct link between GO:0008294 and cognitive function, suggesting that disruption of calcium-calmodulin-responsive cAMP production may contribute to memory-related disorders.
Neurodevelopmental and signaling disorders
Because calcium- and calmodulin-responsive adenylate cyclase activity integrates calcium and cAMP signals, its dysregulation could affect neuronal development and plasticity. Alpha-adrenergic phenomena involving calcium and cAMP further highlight the importance of this activity in physiological responses that can go awry in disease.
Bone and calcium homeostasis
Calmodulin-responsive activities, such as the high-affinity Ca2+/Mg2+-ATPase in bone cells, indicate that calmodulin-dependent regulation is relevant to bone biology. While this specific ATPase is not the adenylate cyclase, it illustrates the broader importance of calmodulin-responsive enzymes in calcium homeostasis.
From calcium- and calmodulin-responsive adenylate cyclase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is the gene required for calcium-stimulated cAMP production? | CRISPR knockout of the candidate adenylate cyclase |
| Does a specific point mutation alter calmodulin sensitivity? | CRISPR point mutation knock-in |
| Can a tagged version reveal localization and interactions? | Knock-in of an epitope tag |
| Does overexpression increase cAMP levels? | CRISPR overexpression or cDNA overexpression |
| Which isoforms mediate calcium-calmodulin responsiveness? | Knockout of individual isoforms followed by cAMP assays |
| Does the activity affect learning and memory? | Drosophila rutabaga mutants and behavioral assays |
How to Study the calcium- and calmodulin-responsive adenylate cyclase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| cAMP accumulation assay | Intracellular cAMP levels | Assessing calcium-calmodulin-stimulated adenylate cyclase activity |
| Enzyme activity assay with purified protein | Conversion of ATP to cAMP | Direct biochemical characterization |
| CRISPR knockout followed by cAMP measurement | Requirement of a gene for the activity | Functional validation of candidate genes |
| CRISPR point mutation knock-in | Effect of specific residues on calmodulin sensitivity | Structure-function studies |
| Behavioral learning assay (Drosophila) | Learning and memory performance | Linking GO:0008294 to behavior |
| Western blot | Protein expression levels | Confirming knockout or overexpression |
| Immunoprecipitation | Protein-protein interactions | Identifying calmodulin binding |
| Calcium imaging | Intracellular calcium changes | Upstream regulation of the activity |
cAMP accumulation assays
Measuring cAMP levels in cells or tissues after calcium-calmodulin stimulation is a direct way to assess GO:0008294 activity. Such assays can be combined with pharmacological manipulation of calcium and calmodulin to test dependence.
Genetic knockout and rescue
Knocking out the candidate adenylate cyclase gene and measuring loss of calcium-stimulated cAMP production, followed by rescue with wild-type or mutant constructs, can establish causality. The Drosophila rutabaga gene is a classic example where genetic analysis linked the activity to behavior.
Biochemical reconstitution
Purified enzyme can be reconstituted with calcium and calmodulin to directly demonstrate stimulation of ATP to cAMP conversion. This approach defines the molecular requirements of the activity.
Behavioral assays in model organisms
In Drosophila, olfactory associative learning assays can test the physiological relevance of calcium-calmodulin-responsive adenylate cyclase activity. Mutants such as rutabaga show specific learning defects.
How CRISPR Can Be Used to Study GO:0008294 calcium- and calmodulin-responsive adenylate cyclase activity
Knockout
CRISPR knockout of a candidate adenylate cyclase gene can abolish calcium- and calmodulin-responsive cAMP production, providing direct evidence that the gene encodes the activity. This approach is useful for validating genes such as rutabaga or mammalian isoforms.
Point Mutation
CRISPR point mutation can be used to alter specific residues in the calmodulin-binding or catalytic domains to test their role in GO:0008294. Such models help dissect the structural basis of calcium-calmodulin stimulation.
Knock-in
Knock-in of epitope tags or reporter genes allows visualization and quantification of the adenylate cyclase in its native context. This can reveal localization and dynamics relevant to calcium-calmodulin signaling.
Overexpression
CRISPR-mediated overexpression or cDNA overexpression can increase the activity and cAMP output, enabling gain-of-function studies. This is useful for testing whether elevated calcium-calmodulin-responsive adenylate cyclase activity alters downstream phenotypes.
How EDITGENE Supports calcium- and calmodulin-responsive adenylate cyclase activity Research
Researchers studying calcium- and calmodulin-responsive adenylate cyclase activity-related genes often need to determine whether a candidate gene is causally involved in the activity, how specific mutations affect calmodulin sensitivity, and what downstream phenotypes change. EDITGENE provides a comprehensive suite of CRISPR services to address these questions with precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for calcium- and calmodulin-responsive adenylate cyclase activity research.
Frequently Asked Questions About calcium- and calmodulin-responsive adenylate cyclase activity
What is GO:0008294?
GO:0008294 is the Gene Ontology term for calcium- and calmodulin-responsive adenylate cyclase activity, defined as catalysis of ATP to 3',5'-cyclic AMP and diphosphate, stimulated by calcium-bound calmodulin.
What does calcium- and calmodulin-responsive adenylate cyclase activity do?
It produces cAMP from ATP in a manner that is stimulated by calcium-bound calmodulin, thereby linking calcium signaling to cAMP second-messenger pathways.
What genes are involved in calcium- and calmodulin-responsive adenylate cyclase activity?
The Drosophila rutabaga gene is a classic example encoding a Ca2+/calmodulin-responsive adenylyl cyclase; mammalian calmodulin and certain adenylate cyclase isoforms are also involved.
Which diseases are linked to calcium- and calmodulin-responsive adenylate cyclase activity?
Mutations in the Drosophila rutabaga gene cause learning and memory defects, suggesting relevance to cognitive disorders.
How is calcium- and calmodulin-responsive adenylate cyclase activity regulated?
It is stimulated by calcium-bound calmodulin, which binds to and activates the enzyme, increasing cAMP production.
What is the reaction catalyzed by GO:0008294?
The reaction is ATP = 3',5'-cyclic AMP + diphosphate, stimulated by calcium-bound calmodulin.
What are the synonyms for GO:0008294?
Synonyms include calcium- and calmodulin-responsive adenylyl cyclase activity and calcium/calmodulin-responsive adenylate cyclase activity.
How can I study calcium- and calmodulin-responsive adenylate cyclase activity?
You can use cAMP assays, genetic knockouts, point mutations, knock-ins, overexpression, and behavioral assays in model organisms such as Drosophila.
Is calcium- and calmodulin-responsive adenylate cyclase activity involved in learning and memory?
Yes, the Drosophila rutabaga gene encoding this activity is required for associative learning and memory.
What CRISPR models are available for GO:0008294 research?
EDITGENE offers knockout, point mutation, knock-in, overexpression, and library screening models to study genes associated with this activity.
Conclusion
GO:0008294, calcium- and calmodulin-responsive adenylate cyclase activity, is a molecular function that integrates calcium and cAMP signaling by producing cAMP in response to calcium-bound calmodulin. Its best-characterized genetic example, the Drosophila rutabaga gene, demonstrates its critical role in learning and memory. Studying this activity with modern CRISPR tools can reveal how specific genes and mutations affect calcium-calmodulin-responsive cAMP production and downstream physiology. EDITGENE provides the necessary models and services to accelerate such research.
References
- 1. Exton JH. 1985. Mechanisms involved in alpha-adrenergic phenomena.. Am J Physiol 248(6 Pt 1):E633-47 PMID: 2408477
- 2. Levin LR et al.. 1992. The Drosophila learning and memory gene rutabaga encodes a Ca2+/Calmodulin-responsive adenylyl cyclase.. Cell 68(3):479-89 PMID: 1739965
- 3. Shen V et al.. 1983. A high affinity, calmodulin-responsive (Ca2+ + Mg2+)-ATPase in isolated bone cells.. Biochim Biophys Acta 727(2):230-8 PMID: 6132620
