GO:0071578 zinc ion import across plasma membrane: Transport Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0071578 describes the directed movement of zinc(2+) ions from outside a cell, across the plasma membrane, and into the cytosol.
• Zinc import is mediated by the ZIP (SLC39A) family of transporters, which function as zinc influx transporters in immune cells and other tissues.
• ZIP10 (SLC39A10) is a well-characterized zinc importer whose cloning, function, and localization have been studied in human, canine, and Drosophila systems.
• Zinc import across the plasma membrane is essential for immune cell function, as ZIP and ZnT transporters regulate intracellular zinc homeostasis in immune cells.
• Dysregulation of zinc import is associated with immune dysfunction and other pathological states, as reviewed for ZIP and ZnT transporters.
• Research on zinc import uses molecular, cellular, and genetic approaches, including heterologous expression and functional assays.
Description
Zinc is an essential trace element that serves as a cofactor for numerous enzymes and transcription factors, and its intracellular concentration must be tightly controlled. The process by which zinc ions enter the cell from the extracellular environment is known as zinc ion import across the plasma membrane, formally annotated as GO:0071578. This biological process is fundamental to zinc homeostasis and is mediated by specific transport proteins that facilitate the movement of zinc(2+) ions into the cytosol. Understanding this process is critical because zinc import influences diverse cellular functions, including immune responses, cell proliferation, and signaling. The ZIP family of transporters, encoded by SLC39A genes, plays a central role in zinc influx across the plasma membrane. Among these, ZIP10 (SLC39A10) has been cloned and functionally characterized in multiple species, providing insights into its role in zinc transport. Research on zinc import across the plasma membrane is therefore essential for elucidating how cells acquire zinc and how defects in this process contribute to disease.
zinc ion import across plasma membrane At A Glance
| GO ID | GO:0071578 |
|---|---|
| GO term | zinc ion import across plasma membrane |
| Ontology | biological_process |
| Synonym | zinc uptake; zinc import; high-affinity zinc II ion transmembrane import; low-affinity zinc II ion transport; zinc ion import into cell |
| Major function | Mediates the influx of zinc(2+) ions from the extracellular space into the cytosol |
| Cellular location | Plasma membrane |
| Key transporters | ZIP family (SLC39A), including ZIP10 (SLC39A10) |
| Physiological role | Zinc homeostasis, immune cell function, enzyme cofactor supply |
What Is GO:0071578?
GO:0071578, zinc ion import across plasma membrane, is defined as the directed movement of zinc(2+) ions from outside of a cell, across the plasma membrane, and into the cytosol. This process is a specific type of zinc transport that results in the net accumulation of zinc within the cell. It is synonymous with terms such as zinc uptake, zinc import, and high-affinity zinc II ion transmembrane import. The process is mediated by integral membrane proteins that facilitate the passage of zinc ions through the lipid bilayer.
Why Is zinc ion import across plasma membrane Important in Cell Biology?
Zinc ion import across the plasma membrane is vital because zinc is required for the activity of hundreds of enzymes and transcription factors, and its intracellular levels must be precisely regulated. This process ensures that cells can acquire zinc from the extracellular environment, which is particularly important for immune cells that depend on zinc signaling for activation and proliferation. Dysregulation of zinc import has been linked to immune dysfunction and other pathological conditions, underscoring its importance in human health. Moreover, the characterization of zinc transporters such as ZIP10 has provided molecular insights into how zinc uptake is achieved and regulated.
• Zinc import is essential for maintaining intracellular zinc homeostasis, which is required for normal cellular function.
• ZIP transporters, including ZIP10, mediate zinc influx and are critical for immune cell development and function.
• Zinc import supports the activity of zinc-dependent enzymes and transcription factors.
• Defects in zinc import can lead to immune disorders and increased susceptibility to infections.
• Zinc transporters are potential therapeutic targets for diseases related to zinc dyshomeostasis.
• Studying zinc import helps understand how cells adapt to zinc deficiency or excess.
• ZIP10 has been characterized in multiple species, highlighting evolutionary conservation of zinc import mechanisms.
What Happens During zinc ion import across plasma membrane?
Recognition and Binding of Zinc Ions
In simple terms: The transporter first grabs zinc ions from outside the cell.
Zinc import begins with the recognition of zinc(2+) ions by specific transporters embedded in the plasma membrane. These transporters, such as those of the ZIP family, possess metal-binding sites that selectively interact with zinc ions. The binding is thought to involve conserved histidine and acidic residues that coordinate the divalent cation. This initial step ensures that only zinc ions are preferentially transported, although other metals may compete.
Conformational Change and Translocation
In simple terms: The transporter changes shape to move zinc across the membrane.
Upon zinc binding, the transporter undergoes conformational changes that allow the ion to be translocated across the lipid bilayer. This process is energy-independent for ZIP transporters, which are thought to function as secondary active transporters or channels. The exact mechanism of translocation is still under investigation, but structural studies of related transporters provide insights into ion-release mechanisms. The zinc ion is released into the cytosol, completing the import process.
Regulation of Zinc Import Activity
In simple terms: The cell controls how much zinc it takes in.
Zinc import is tightly regulated at multiple levels, including transcriptional control of ZIP transporter genes and post-translational modifications. For example, ZIP10 expression can be modulated in response to zinc status. This regulation ensures that intracellular zinc levels remain within a narrow physiological range, preventing toxicity or deficiency.
Integration with Cellular Zinc Homeostasis
In simple terms: Imported zinc is distributed and stored as needed.
Once inside the cytosol, zinc ions are buffered by metallothioneins and other zinc-binding proteins, or transported into organelles by ZnT transporters. The interplay between ZIP-mediated import and ZnT-mediated export or sequestration maintains zinc homeostasis. This integration is crucial for cellular processes such as signaling, proliferation, and apoptosis.
Key Genes Involved in GO:0071578 zinc ion import across plasma membrane
The following genes encode proteins that directly mediate or regulate zinc ion import across the plasma membrane.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SLC39A1 (ZIP1) | Zinc influx transporter | Studied for zinc uptake in various cell types |
| SLC39A2 (ZIP2) | Zinc influx transporter | Implicated in zinc homeostasis in prostate and other tissues |
| SLC39A3 (ZIP3) | Zinc influx transporter | Regulates zinc levels in immune cells |
| SLC39A4 (ZIP4) | Zinc influx transporter | Mutations cause acrodermatitis enteropathica |
| SLC39A5 (ZIP5) | Zinc influx transporter | Involved in pancreatic and intestinal zinc absorption |
| SLC39A6 (ZIP6) | Zinc influx transporter | Associated with cancer progression |
| SLC39A7 (ZIP7) | Zinc influx transporter | Regulates zinc in the secretory pathway |
| SLC39A8 (ZIP8) | Zinc influx transporter | Linked to manganese and zinc transport |
| SLC39A9 (ZIP9) | Zinc influx transporter | Expressed in immune cells |
| SLC39A10 (ZIP10) | Zinc influx transporter | Cloned and characterized in human, canine, and Drosophila |
| SLC39A11 (ZIP11) | Zinc influx transporter | Modulates zinc in immune cells |
| SLC39A12 (ZIP12) | Zinc influx transporter | Brain-specific zinc transporter |
| SLC39A13 (ZIP13) | Zinc influx transporter | Defects cause spondylocheirodysplastic Ehlers-Danlos syndrome |
| SLC39A14 (ZIP14) | Zinc influx transporter | Mediates zinc and manganese uptake |
| SLC30A1 (ZnT1) | Zinc efflux transporter | Counteracts zinc import by exporting zinc |
| SLC30A2 (ZnT2) | Zinc efflux transporter | Sequesters zinc into vesicles |
| SLC30A3 (ZnT3) | Zinc efflux transporter | Packages zinc into synaptic vesicles |
How Is zinc ion import across plasma membrane Regulated?
Zinc ion import across the plasma membrane is regulated at the transcriptional and post-transcriptional levels. The expression of ZIP transporter genes can be induced or repressed in response to changes in zinc availability, as shown for ZIP10. Additionally, the activity of ZIP transporters may be modulated by post-translational modifications and interacting proteins. This regulation ensures that zinc import is adjusted to meet cellular demands while preventing zinc overload.
zinc ion import across plasma membrane and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLC39A4 (ZIP4) | Acrodermatitis enteropathica | Knockout mouse or patient-derived cells |
| SLC39A10 (ZIP10) | Immune dysfunction, cancer | ZIP10 knockout cell lines and mouse models |
| SLC39A13 (ZIP13) | Spondylocheirodysplastic Ehlers-Danlos syndrome | Zebrafish or mouse knockout |
| SLC30A1 (ZnT1) | Zinc toxicity, cancer | Overexpression and knockout models |
| SLC39A8 (ZIP8) | Manganese and zinc metabolism disorders | Knockout mouse and cell models |
Zinc Transporters and Immune Dysfunction
Dysregulation of zinc import mediated by ZIP and ZnT transporters has been associated with impaired immune cell function. Proper zinc homeostasis is required for the development and activation of immune cells, and alterations in zinc transporter expression can lead to immunodeficiency or autoimmunity. For example, ZIP10 is important for B cell development and function.
Zinc Import in Cancer
Altered expression of zinc transporters, including ZIP family members, has been observed in various cancers. Changes in zinc import can affect cell proliferation, apoptosis, and migration, contributing to tumor progression. ZIP10 has been studied in the context of cancer, although its exact role may be context-dependent.
Zinc Deficiency Disorders
Mutations in ZIP transporters such as ZIP4 cause acrodermatitis enteropathica, a rare inherited zinc deficiency disorder characterized by skin lesions and immune defects. This highlights the critical role of zinc import across the plasma membrane in human health.
From zinc ion import across plasma membrane-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of ZIP10 affect zinc import? | ZIP10 knockout cell line (e.g., HEK293 or immune cells) |
| What is the effect of a point mutation in ZIP4 on zinc transport? | Point-mutation knock-in cell model |
| Can ZIP14 mediate zinc import when tagged? | Tagged knock-in of ZIP14 with fluorescent protein |
| Does overexpression of ZIP6 increase zinc uptake? | ZIP6 overexpression cell line |
| How does zinc import regulate immune cell activation? | Primary immune cells from knockout mice |
| What is the role of ZIP8 in manganese transport? | ZIP8 knockout and overexpression models |
How to Study the zinc ion import across plasma membrane Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorescent zinc indicators | Intracellular zinc levels | Live-cell imaging of zinc import |
| Radiolabeled zinc uptake | Zinc influx rate | Quantitative transport assays |
| qRT-PCR | mRNA expression of ZIP genes | Gene expression profiling |
| Western blot | Protein expression | Validation of transporter levels |
| Immunofluorescence | Subcellular localization | Determining plasma membrane localization |
| CRISPR-Cas9 knockout | Gene function | Loss-of-function studies |
| Overexpression | Gain-of-function | Assessing increased zinc import |
Functional Zinc Uptake Assays
Zinc import activity can be measured using fluorescent zinc indicators such as FluoZin-3 or by radiolabeled zinc uptake assays. These methods allow quantification of zinc influx in live cells and are used to characterize ZIP transporter function.
Expression Analysis
Transcript levels of ZIP transporter genes can be assessed by quantitative RT-PCR, RNA-seq, or Northern blotting. Protein expression and localization are typically examined by Western blotting and immunofluorescence.
Genetic Manipulation
Knockout, knockdown, or overexpression of ZIP genes in cell lines and animal models helps determine their role in zinc import. CRISPR-Cas9 genome editing is a powerful tool for generating such models.
Structural and Biophysical Studies
Structural studies of zinc transporters, such as those of P(IB-4)-type ATPases, provide insights into ion transport mechanisms. These approaches complement functional assays to understand zinc import at the molecular level.
How CRISPR Can Be Used to Study GO:0071578 zinc ion import across plasma membrane
Knockout
CRISPR-Cas9 knockout of ZIP transporter genes, such as SLC39A10, can abolish zinc import and reveal its contribution to cellular zinc homeostasis and immune function. Knockout cell lines are valuable for studying the specific roles of individual transporters.
Point Mutation
Introducing point mutations in ZIP genes can mimic naturally occurring variants or disrupt key residues involved in zinc binding or transport. Such models help dissect the molecular determinants of zinc import.
Knock-in
Knock-in of tagged versions of ZIP transporters (e.g., GFP or HA tags) allows visualization and biochemical characterization of the transporter in its native context. This approach is useful for localization and interaction studies.
Overexpression
Overexpression of ZIP transporters in cell lines can enhance zinc import and is used to study gain-of-function effects on cell signaling and proliferation. This model is particularly useful for testing whether a transporter is sufficient to increase zinc uptake.
How EDITGENE Supports zinc ion import across plasma membrane Research
Researchers studying zinc ion import across plasma membrane-related genes often need to determine whether a candidate gene is causally involved in zinc transport or whether its manipulation alters cellular zinc homeostasis. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models, enabling functional validation of zinc transporters and their regulators.
Contact EDITGENE today to design your custom CRISPR model for zinc ion import across plasma membrane research.
Frequently Asked Questions About zinc ion import across plasma membrane
What is zinc ion import across plasma membrane?
Zinc ion import across plasma membrane (GO:0071578) is the directed movement of zinc(2+) ions from outside a cell, across the plasma membrane, and into the cytosol.
What genes are involved in zinc ion import across plasma membrane?
Genes encoding ZIP family transporters, such as SLC39A1-SLC39A14, mediate zinc import, while ZnT transporters (SLC30A) can counteract it.
Which proteins transport zinc into cells?
ZIP transporters (SLC39A family) are the primary proteins that facilitate zinc influx across the plasma membrane.
How is zinc ion import regulated?
Zinc import is regulated by transcriptional control of ZIP genes and post-translational modifications in response to zinc status.
What diseases are associated with defective zinc import?
Mutations in ZIP4 cause acrodermatitis enteropathica, and altered zinc import is linked to immune dysfunction and cancer.
What is the role of ZIP10 in zinc import?
ZIP10 (SLC39A10) is a zinc transporter that mediates zinc influx and is important for immune cell function.
How can I study zinc ion import in the lab?
Zinc import can be studied using fluorescent zinc indicators, radiolabeled zinc uptake assays, and genetic manipulation of ZIP genes.
What are the synonyms for zinc ion import across plasma membrane?
Synonyms include zinc uptake, zinc import, high-affinity zinc II ion transmembrane import, and zinc ion import into cell.
Why is zinc import important for immune cells?
Zinc import is essential for immune cell development and activation, as zinc acts as a signaling molecule and cofactor.
Can CRISPR be used to study zinc ion import?
Yes, CRISPR-Cas9 can generate knockout, point mutation, knock-in, and overexpression models to study zinc transporter function.
Conclusion
Zinc ion import across the plasma membrane (GO:0071578) is a fundamental biological process that ensures cells acquire the zinc needed for numerous physiological functions. The ZIP family of transporters, including ZIP10, plays a central role in this process, and their dysfunction is linked to immune disorders and other diseases. Continued research using advanced genetic and molecular tools will further illuminate the mechanisms and regulation of zinc import, offering potential therapeutic avenues.
References
- 1. Grønberg C et al.. 2021. Structure and ion-release mechanism of P(IB-4)-type ATPases.. Elife 10 PMID: 34951590
- 2. Bin BH et al.. 2018. Function, Structure, and Transport Aspects of ZIP and ZnT Zinc Transporters in Immune Cells.. J Immunol Res 2018:9365747 PMID: 30370308
- 5. Landry GM et al.. 2019. Cloning, function, and localization of human, canine, and Drosophila ZIP10 (SLC39A10), a Zn(2+) transporter.. Am J Physiol Renal Physiol 316(2):F263-F273 PMID: 30520657
