GO:0043682 P-type divalent copper transporter activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0043682 describes a P-type ATPase molecular function that uses ATP hydrolysis to move divalent copper (Cu2+) across a membrane against its concentration gradient.
• The reaction is ATP + H2O + Cu2+(in) = ADP + phosphate + Cu2+(out), a phosphorylative transport cycle typical of P-type ATPases.
• Soluble copper chaperones can directly deliver Cu+ to transmembrane transport sites of Cu+-transporting ATPases, linking cytoplasmic copper handling to transport.
• The same protein fold can accept multiple soft metal substrates, as shown for CtpG (Cd2+ preference) and CadA (Cd2+ binding domain), which informs specificity studies.
• N-terminal cysteine-rich domains are common in these transporters but are not always essential for function, as demonstrated for ZntA.
• Studying GO:0043682 requires combining transport assays, metal-binding biochemistry, and CRISPR-based cell models to separate transport from chaperone and homeostasis effects.
Description
GO:0043682, P-type divalent copper transporter activity, is a molecular function ontology term for membrane proteins that couple ATP hydrolysis to the transfer of divalent copper ions across a lipid bilayer. The activity belongs to the P-type ATPase superfamily, whose members form a phosphorylated intermediate during the catalytic cycle and move substrates in a direction defined by the reaction ATP + H2O + Cu2+(in) = ADP + phosphate + Cu2+(out). This function is central to copper homeostasis because cells must both acquire copper for cuproenzymes and prevent toxic accumulation of free copper ions. Researchers encounter GO:0043682 when annotating metal-transport functions, when interpreting microbial metal resistance, and when modeling human copper-transport disorders. Biochemical work on Escherichia coli CopA established that this enzyme is a Cu(I)-translocating P-type ATPase with a phosphorylative mechanism, while work on Archaeoglobus fulgidus CopA showed that the same catalytic scaffold can display additional phosphomonoesterase activity. Structural and mechanistic studies of related P1-type ATPases such as CadA have clarified how metal-binding specificity is achieved in the N-terminal domain. Because copper transport is embedded in a network of chaperones, sensors, and homeostatic regulators, GO:0043682 is best studied as one node in a larger system. For example, the yeast transcriptional activator Imp2p maintains ion homeostasis and affects copper-related phenotypes, and dietary copper deficiency alters iron metabolism in vivo. These findings show that perturbing a single copper-transporting ATPase can have systemic consequences, making controlled genetic models essential for rigorous functional annotation.
P-type divalent copper transporter activity At A Glance
| GO ID | GO:0043682 |
|---|---|
| GO term | P-type divalent copper transporter activity |
| Ontology | molecular_function |
| Synonym | copper-exporting ATPase activity; copper-translocating P-type ATPase activity; Cu2+-exporting ATPase activity |
| Major function | ATP-driven transfer of divalent copper across a membrane |
| Reaction | ATP + H2O + Cu2+(in) = ADP + phosphate + Cu2+(out) |
| Mechanism class | P-type ATPase with a phosphorylated intermediate |
| Substrate | Divalent copper (Cu2+); related P1-type ATPases can also handle Cu+, Cd2+, Zn2+, or Pb2+ |
| Directionality | Export from the cytoplasmic side to the opposite side of the membrane |
What Is GO:0043682?
In plain terms, GO:0043682 is the activity of a membrane pump that uses ATP energy to push divalent copper ions out of a compartment or cell. The official definition states that it enables transfer of a solute or solutes from one side of a membrane to the other according to the reaction ATP + H2O + Cu2+(in) = ADP + phosphate + Cu2+(out). This is a primary active transport activity, and it is classified as a P-type ATPase because the catalytic cycle involves a phosphorylated enzyme intermediate. The term is a molecular_function in the Gene Ontology and is synonymous with copper-exporting ATPase activity, copper-translocating P-type ATPase activity, and Cu2+-exporting ATPase activity.
Why Is P-type divalent copper transporter activity Important in Cell Biology?
GO:0043682 matters because copper is both essential and toxic, and cells must maintain a narrow window of intracellular copper availability. P-type divalent copper transporters provide one of the main ATP-dependent routes for removing excess copper and for delivering copper to cuproproteins in specific compartments. Defects or imbalances in this activity are linked to metal homeostasis phenotypes, altered iron metabolism, and microbial metal resistance. For researchers, the term is a precise annotation target that connects biochemical transport assays to genetic and cell-biological models, enabling mechanistic studies of metal selectivity, chaperone coupling, and homeostatic regulation.
• Provides a defined molecular function for annotating ATP-driven copper export in genomes and metagenomes.
• Links copper transport to cellular metal homeostasis and to the activity of copper-dependent enzymes.
• Explains how cells avoid copper toxicity while maintaining copper supply for essential processes.
• Supports mechanistic studies of P-type ATPase catalysis, including the phosphorylated intermediate and phosphomonoesterase side reactions.
• Helps interpret metal selectivity, because related P1-type ATPases can transport Cd2+, Zn2+, or Pb2+ in addition to copper.
• Connects copper transport to systemic physiology, as shown by dietary copper deficiency effects on iron metabolism.
• Guides microbial metal-resistance research, including Mycobacterium tuberculosis CtpG and its Cd2+ preference.
• Enables comparative studies of N-terminal metal-binding domains and their contribution to function.
• Informs the design of CRISPR knockout, point-mutation, and knock-in models to test causality of candidate transporters.
• Supports drug and inhibitor discovery efforts targeting metal-transport ATPases in pathogens and in human cells.
What Happens During P-type divalent copper transporter activity?
Substrate recognition and metal delivery
In simple terms: The pump first has to get the right metal ion handed to it.
For Cu+-transporting ATPases, soluble copper chaperones can directly transfer Cu+ to the transmembrane transport sites, coupling cytoplasmic copper handling to the pump. In related P1-type ATPases, the N-terminal domain can bind soft metals such as Cd2+, and structural work on CadA has defined the basis for metal-binding specificity. However, the cysteine-rich N-terminal domain of ZntA is not essential for function, indicating that substrate recognition can also occur at other sites. These observations show that GO:0043682 activity depends on both the membrane transport sites and accessory metal-binding modules.
Phosphorylation and catalytic cycle
In simple terms: The pump uses ATP to add a phosphate to itself, changing shape to move the metal.
P-type ATPases form a phosphorylated intermediate during turnover, and this phosphorylative mechanism is part of the definition of GO:0043682. Biochemical characterization of E. coli CopA established that it is a Cu(I)-translocating P-type ATPase that hydrolyzes ATP in a metal-dependent manner. A. fulgidus CopA also displays a promiscuous phosphomonoesterase activity, showing that the catalytic site can hydrolyze phosphate esters in addition to running the full transport cycle. These features make the enzyme sensitive to assays that measure ATP hydrolysis, phosphate release, and phosphoenzyme formation.
Translocation and export
In simple terms: After activation, the pump pushes the metal across the membrane to the other side.
The transport event moves the metal from the cytoplasmic side to the opposite side of the membrane, consistent with the reaction ATP + H2O + Cu2+(in) = ADP + phosphate + Cu2+(out). In M. tuberculosis, the P-type ATPase CtpG preferentially transports Cd2+ across the plasma membrane, illustrating that related pumps can export different soft metals while sharing the same overall architecture. This step is the defining output of GO:0043682 and is typically measured by vesicle transport assays or by metal-sensitive reporters.
Coupling to cellular copper homeostasis
In simple terms: The pump does not work alone; it is part of a system that keeps copper levels balanced.
Copper export activity is embedded in homeostatic networks. In Saccharomyces cerevisiae, the transcriptional activator Imp2p maintains ion homeostasis and influences copper-related phenotypes, showing that transcriptional regulation can feed back on transport capacity. In vivo, dietary copper deficiency alters iron metabolism in the pregnant rat, demonstrating that systemic copper status affects other metal pathways. Together, these findings indicate that GO:0043682 activity must be interpreted within a broader homeostatic context rather than as an isolated reaction.
Key Genes Involved in GO:0043682 P-type divalent copper transporter activity
The following genes and proteins are experimentally linked to P-type divalent copper transporter activity or to closely related P1-type ATPase functions, based on the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| copA (E. coli) | Cu(I)-translocating P-type ATPase | Biochemical model for ATP-dependent copper transport and phosphorylative mechanism |
| CopA (A. fulgidus) | Thermophilic Cu+ transport ATPase | Shows phosphomonoesterase side activity and catalytic flexibility |
| ctpG (M. tuberculosis) | P-type ATPase that preferentially transports Cd2+ | Model for metal selectivity and plasma membrane export |
| cadA | P1-type ATPase with N-terminal Cd2+ binding domain | Structural basis for metal binding specificity |
| zntA (E. coli) | Pb(II)/Zn(II)/Cd(II)-translocating ATPase | Demonstrates that the cysteine-rich N-terminal domain is not essential |
| IMP2 (S. cerevisiae) | Transcriptional activator maintaining ion homeostasis | Links transcriptional control to copper-related phenotypes |
| Copper chaperones (general) | Deliver Cu+ to transmembrane transport sites | Mechanistic coupling of chaperones to Cu+-transporting ATPases |
| Dietary copper status (rat model) | Systemic copper availability | Copper deficiency alters iron metabolism in vivo |
| P-type ATPase family (general) | ATP-driven metal transport | Shared phosphorylative mechanism across family members |
| P1-type ATPase family (general) | Soft metal transport | Metal promiscuity and specificity determinants |
| Cu2+-exporting ATPase (annotation) | GO:0043682 molecular function | Primary annotation target for genome and metagenome analysis |
| Cu+-transporting ATPase (annotation) | Related copper transport activity | Mechanistic comparison with divalent copper transport |
| Metal-binding domain proteins | N-terminal metal-sensing modules | Contribution to specificity and regulation |
| Copper homeostasis regulators | Maintain intracellular copper balance | Feedback on transport capacity |
| Iron metabolism genes | Cross-talk with copper status | Systemic effects of copper deficiency |
| Membrane transport reporters | Readouts of transport activity | Assay development for GO:0043682 |
How Is P-type divalent copper transporter activity Regulated?
Regulation of GO:0043682 occurs at multiple levels. Transcriptionally, the yeast activator Imp2p maintains ion homeostasis and affects copper-related phenotypes, indicating that copper transport capacity can be adjusted by gene expression. At the protein level, soluble copper chaperones directly transfer Cu+ to transmembrane transport sites, providing a post-translational route for controlling metal delivery to the pump. Systemically, dietary copper status influences iron metabolism, showing that whole-organism metal balance can modulate copper-dependent processes. Finally, the catalytic cycle itself is regulated by ATP availability and by the phosphorylative mechanism, which can be probed with phosphomonoesterase and phosphoenzyme assays.
P-type divalent copper transporter activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ctpG (M. tuberculosis) | Metal resistance and host survival | Knockout and point-mutation strains in mycobacteria |
| copA (E. coli) | Copper resistance | Knockout and overexpression in E. coli |
| IMP2 (S. cerevisiae) | Ion homeostasis and copper-related phenotypes | Knockout and overexpression in yeast |
| cadA | Cd2+ binding specificity | Point mutations in the N-terminal metal-binding domain |
| zntA (E. coli) | Pb(II)/Zn(II)/Cd(II) transport | Domain-deletion and point-mutation constructs |
Copper imbalance and metal homeostasis disorders
Because GO:0043682 activity controls copper export, changes in its efficiency can contribute to cellular copper imbalance. Studies in model systems show that copper status affects other metal pathways: dietary copper deficiency alters iron metabolism in the pregnant rat, and the yeast regulator Imp2p maintains ion homeostasis with effects on copper-related phenotypes. These findings support the view that copper-transporting ATPases are part of a homeostatic network whose perturbation can produce systemic metal-related phenotypes.
Microbial metal resistance and infection biology
In Mycobacterium tuberculosis, the P-type ATPase CtpG preferentially transports Cd2+ across the plasma membrane, indicating a role in metal handling that may affect survival in the host. In Escherichia coli, CopA is a Cu(I)-translocating P-type ATPase that contributes to copper resistance. These microbial systems provide tractable models for understanding how GO:0043682-related activity supports adaptation to metal stress and how it might be targeted in pathogens.
Metal selectivity and toxicity in human-relevant pathways
Related P1-type ATPases can transport Cd2+, Zn2+, or Pb2+, and structural work on CadA has defined the basis for Cd2+ binding specificity. The ZntA study further shows that the cysteine-rich N-terminal domain is not essential for function, which complicates simple models of metal recognition. These results are relevant to understanding how cells handle toxic metals and how mutations in metal-binding domains might alter transport specificity.
From P-type divalent copper transporter activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is the candidate gene required for ATP-dependent copper export? | CRISPR knockout cell line or microbial knockout |
| Does a specific residue control metal selectivity? | CRISPR point mutation at the metal-binding site |
| Can a tagged transporter be tracked in live cells? | Knock-in of an epitope or fluorescent tag |
| Does overexpression change copper tolerance? | Overexpression cell line or microbial strain |
| Which chaperones deliver metal to the pump? | Knockout of chaperone genes combined with transport assays |
| Does copper status affect other metal pathways? | Dietary or chelator-based copper manipulation in animal models |
How to Study the P-type divalent copper transporter activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| ATP hydrolysis assay | ATPase activity of the transporter | Confirming P-type ATPase function |
| Phosphomonoesterase assay | Catalytic site activity | Detecting side reactions of Cu+ transport ATPases |
| Vesicle metal transport assay | Transmembrane metal movement | Measuring export activity |
| Metal-binding spectroscopy | Metal coordination and affinity | Characterizing N-terminal metal-binding domains |
| Domain deletion and mutagenesis | Requirement of specific domains | Testing essentiality of cysteine-rich regions |
| Chaperone perturbation | Metal delivery to transport sites | Mapping chaperone-transporter coupling |
| Ion homeostasis reporters | Intracellular metal balance | Linking transport to cellular homeostasis |
| Systemic metal measurements | Whole-organism metal status | Studying dietary copper effects on iron metabolism |
Transport and ATPase activity assays
Direct measurement of GO:0043682 activity uses ATP hydrolysis and metal transport assays. Biochemical characterization of E. coli CopA established conditions for detecting Cu(I)-translocating P-type ATPase activity, and A. fulgidus CopA was used to define phosphomonoesterase activity as a readout of the catalytic site. These assays are essential for confirming that a candidate protein has the annotated function.
Metal-binding and structural analysis
Metal-binding domains can be studied by structural methods and mutagenesis. The N-terminal cadmium-binding domain of CadA provided a structural basis for metal binding specificity, while deletion analysis of ZntA showed that the cysteine-rich N-terminal domain is not essential for function. Combining these approaches clarifies which domains are required for transport and which modulate specificity.
Chaperone coupling and cellular transport
Soluble copper chaperones can directly transfer Cu+ to transmembrane transport sites, so transport assays should be paired with chaperone perturbation experiments. In microbial systems, plasma membrane transport can be monitored in cells expressing the transporter of interest, as shown for CtpG in M. tuberculosis. These cellular assays connect biochemical activity to physiological metal handling.
Homeostasis and systemic readouts
Because copper transport affects broader metal balance, researchers use homeostasis readouts such as ion-sensitive reporters and systemic metal measurements. The Imp2p study linked transcriptional regulation to ion homeostasis in yeast, and dietary copper deficiency was shown to alter iron metabolism in the pregnant rat. Such readouts help place GO:0043682 activity in a physiological context.
How CRISPR Can Be Used to Study GO:0043682 P-type divalent copper transporter activity
Knockout
CRISPR knockout of a candidate copper-transporting ATPase gene removes the protein and allows direct testing of whether the observed metal phenotype depends on GO:0043682 activity. This approach is analogous to microbial knockout studies of copA and ctpG, where loss of the transporter alters metal handling. Knockout cell lines are also useful for separating transporter function from chaperone and homeostatic compensation.
Point Mutation
CRISPR point mutation can be used to alter specific residues in the catalytic or metal-binding domains. Structural and mutagenesis work on CadA and ZntA identified residues and domains that affect metal binding and function, providing a template for designing point mutants that test the phosphorylative mechanism and metal selectivity of GO:0043682.
Knock-in
Knock-in of a tag or reporter into the endogenous locus enables tracking of the transporter in its native regulatory context. This is valuable because copper chaperones deliver metal directly to transmembrane transport sites, and tagged transporters can be used to monitor localization and turnover in cells.
Overexpression
Overexpression of a copper-transporting ATPase can increase export capacity and reveal gain-of-function phenotypes. Overexpression studies in microbial systems, such as E. coli CopA and yeast Imp2p-related homeostasis, show that altering transporter levels changes metal tolerance and ion balance. Overexpression models are therefore useful for testing whether increased GO:0043682 activity is sufficient to change cellular metal status.
How EDITGENE Supports P-type divalent copper transporter activity Research
Researchers studying P-type divalent copper transporter activity-related genes often need to determine whether a candidate gene is causally involved in metal transport, metal selectivity, or homeostatic regulation. EDITGENE provides CRISPR-based cell models and screening services that allow precise perturbation of these genes, from complete knockout to single-residue point mutations, so that transport phenotypes can be attributed to defined molecular changes.
Contact EDITGENE today to design your custom CRISPR model for P-type divalent copper transporter activity research.
Frequently Asked Questions About P-type divalent copper transporter activity
What is GO:0043682?
GO:0043682 is the Gene Ontology molecular function term for P-type divalent copper transporter activity, an ATP-driven membrane transport activity that moves divalent copper according to the reaction ATP + H2O + Cu2+(in) = ADP + phosphate + Cu2+(out).
What does P-type divalent copper transporter activity do?
It uses ATP hydrolysis to export divalent copper across a membrane, and it belongs to the P-type ATPase family that forms a phosphorylated intermediate during catalysis.
What genes are involved in P-type divalent copper transporter activity?
Experimentally studied examples include E. coli copA, A. fulgidus CopA, M. tuberculosis ctpG, cadA, and E. coli zntA, along with chaperones that deliver copper to transport sites.
How is P-type divalent copper transporter activity regulated?
It is regulated by transcription factors such as yeast Imp2p, by copper chaperones that deliver metal to the pump, and by systemic copper status that affects other metal pathways.
Why is copper export important for cells?
Copper is essential but toxic in excess, so ATP-driven export helps maintain a safe intracellular copper balance while supporting copper-dependent enzymes.
Can P-type ATPases transport metals other than copper?
Yes, related P1-type ATPases can transport Cd2+, Zn2+, or Pb2+, and M. tuberculosis CtpG preferentially transports Cd2+ across the plasma membrane.
What methods are used to study GO:0043682?
Common methods include ATP hydrolysis assays, phosphomonoesterase assays, vesicle metal transport assays, metal-binding spectroscopy, and mutagenesis of metal-binding domains.
Is the N-terminal metal-binding domain required for function?
Not always; the cysteine-rich N-terminal domain of E. coli ZntA is not essential for its function, although such domains can contribute to metal specificity in other transporters.
How do copper chaperones relate to this activity?
Soluble copper chaperones can directly transfer Cu+ to transmembrane transport sites of Cu+-transporting ATPases, linking cytoplasmic copper handling to the transport reaction.
How can CRISPR help study P-type divalent copper transporter activity?
CRISPR knockout, point mutation, knock-in, and overexpression models allow researchers to test whether a specific gene or residue is required for ATP-dependent copper transport and for cellular metal homeostasis.
Conclusion
GO:0043682, P-type divalent copper transporter activity, defines an ATP-driven molecular function that moves divalent copper across membranes through a phosphorylative mechanism. Work on bacterial and archaeal P-type ATPases has revealed key features of substrate handling, including chaperone-mediated metal delivery and metal promiscuity among related P1-type ATPases. These findings provide a foundation for interpreting copper homeostasis phenotypes and for designing precise genetic models. For researchers, the most rigorous path forward is to combine biochemical transport assays with CRISPR-based perturbation of candidate genes and their regulatory partners. This integrated approach clarifies which proteins truly carry GO:0043682 activity and how that activity fits into cellular and systemic metal balance.
References
- 1. López M et al.. 2018. The P-type ATPase CtpG preferentially transports Cd(2+) across the Mycobacterium tuberculosis plasma membrane.. Arch Microbiol 200(3):483-492 PMID: 29197950
- 2. Bredeston LM et al.. 2016. The promiscuous phosphomonoestearase activity of Archaeoglobus fulgidus CopA, a thermophilic Cu+ transport ATPase.. Biochim Biophys Acta 1858(7 Pt A):1471-8 PMID: 27086711
- 3. Fan B et al.. 2002. Biochemical characterization of CopA, the Escherichia coli Cu(I)-translocating P-type ATPase.. J Biol Chem 277(49):46987-92 PMID: 12351646
- 4. Andersen HS et al.. 2007. Effect of dietary copper deficiency on iron metabolism in the pregnant rat.. Br J Nutr 97(2):239-46 PMID: 17298691
- 5. González-Guerrero M et al.. 2008. Mechanism of Cu+-transporting ATPases: soluble Cu+ chaperones directly transfer Cu+ to transmembrane transport sites.. Proc Natl Acad Sci U S A 105(16):5992-7 PMID: 18417453
- 6. Masson JY et al.. 1998. The transcriptional activator Imp2p maintains ion homeostasis in Saccharomyces cerevisiae.. Genetics 149(2):893-901 PMID: 9611200
- 7. Banci L et al.. 2006. Structural basis for metal binding specificity: the N-terminal cadmium binding domain of the P1-type ATPase CadA.. J Mol Biol 356(3):638-50 PMID: 16388822
- 8. Mitra B et al.. 2001. The cysteine-rich amino-terminal domain of ZntA, a Pb(II)/Zn(II)/Cd(II)-translocating ATPase from Escherichia coli, is not essential for its function.. Biochemistry 40(25):7694-9 PMID: 11412123
