GO:0098703 calcium ion import across plasma membrane: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0098703 describes the directed movement of calcium ions from outside a cell, across the plasma membrane, and into the cytosol.
• This process is distinct from calcium release from intracellular stores such as the endoplasmic reticulum or lysosomes.
• Key protein families include voltage-gated calcium channels, store-operated Orai channels, and TRP channels.
• Calcium import across the plasma membrane is essential for excitation-contraction coupling, secretion, and gene expression.
• Dysregulation of this process is linked to cardiac arrhythmias, neurodegeneration, and cancer.
• CRISPR knockout, knock-in, and overexpression models enable causal dissection of calcium import genes.
Description
Calcium ion import across plasma membrane (GO:0098703) is a fundamental biological process that mediates the entry of extracellular calcium into the cytosol. This directed transport is critical for converting extracellular signals into intracellular responses, including muscle contraction, neurotransmitter release, and hormone secretion. Unlike calcium release from intracellular stores, plasma membrane import depends on the electrochemical gradient and specific channel or transporter proteins. Researchers study this process to understand how cells maintain calcium homeostasis and how its disruption contributes to disease. The QuickGO definition specifies the movement of calcium ions from outside of a cell, across the plasma membrane, and into the cytosol. This article synthesizes authoritative GO annotations and published literature to provide a research-grade overview of the mechanisms, genes, and experimental models associated with GO:0098703.
calcium ion import across plasma membrane At A Glance
| GO ID | GO:0098703 |
|---|---|
| GO term | calcium ion import across plasma membrane |
| Ontology | biological_process |
| Synonym | calcium ion import into cell; calcium ion uptake into cell |
| Major function | Mediates entry of extracellular Ca2+ into the cytosol |
| Directionality | From outside of cell to cytosol |
| Cellular location | Plasma membrane |
| Related processes | Calcium ion transport, store-operated calcium entry, excitation-contraction coupling |
What Is GO:0098703?
GO:0098703, calcium ion import across plasma membrane, is defined as the directed movement of calcium ions from outside of a cell, across the plasma membrane, and into the cytosol. This process is also known as calcium ion import into cell or calcium ion uptake into cell. It encompasses the transport step itself, including channel-mediated and transporter-mediated flux, but excludes downstream signaling events or intracellular store release.
Why Is calcium ion import across plasma membrane Important in Cell Biology?
Calcium ion import across the plasma membrane is essential for diverse physiological processes, including cardiac and skeletal muscle contraction, neuronal excitability, immune cell activation, and hormone secretion. Because calcium serves as a universal second messenger, the rate and timing of its entry must be tightly controlled. Defects in this process can lead to pathological calcium overload or insufficient signaling, contributing to arrhythmias, neurodegeneration, and cancer progression. Understanding GO:0098703 therefore provides mechanistic insight into both normal physiology and disease.
• Required for excitation-contraction coupling in cardiac and skeletal muscle.
• Controls neurotransmitter release and neuronal excitability.
• Regulates gene expression through calcium-dependent signaling pathways.
• Essential for immune cell activation and cytokine production.
• Contributes to cell proliferation and migration in cancer.
• Dysregulation leads to cardiac arrhythmias and heart failure.
• Implicated in neurodegeneration and excitotoxicity.
• Target for pharmacological modulators such as calcium channel blockers.
• Key process for understanding calcium homeostasis and signaling.
• Enables CRISPR-based functional studies of calcium channels and transporters.
What Happens During calcium ion import across plasma membrane?
Sensing extracellular calcium and membrane potential
In simple terms: The cell detects when calcium is available outside and when it needs to let it in.
Calcium import begins with the detection of extracellular calcium or changes in membrane potential that activate calcium-permeable channels. Voltage-gated calcium channels respond to depolarization, while store-operated channels respond to depletion of intracellular calcium stores. This sensing step ensures that calcium entry is coupled to physiological demand.
Channel opening and calcium permeation
In simple terms: Once activated, channels open a pore that lets calcium flow into the cell.
Activated channels undergo conformational changes that open a selective pore, allowing calcium ions to move down their electrochemical gradient into the cytosol. Selectivity is achieved by pore-lining residues that coordinate calcium ions. The rate of permeation depends on the open probability and the number of channels at the plasma membrane.
Calcium buffering and signal termination
In simple terms: After calcium enters, the cell quickly buffers or removes it to end the signal.
Once inside, calcium is rapidly bound by buffers such as calmodulin and transported into organelles or back across the plasma membrane. Termination of import involves channel inactivation, closure, or removal from the membrane. These feedback mechanisms prevent toxic calcium overload.
Integration with intracellular signaling
In simple terms: The entering calcium triggers downstream responses like contraction or gene expression.
Imported calcium activates effectors including calmodulin-dependent kinases and calcineurin, which regulate contraction, secretion, and transcription. Spatial and temporal patterns of calcium entry determine the specificity of downstream responses. This integration links plasma membrane import to long-term cellular adaptations.
Key Genes Involved in GO:0098703 calcium ion import across plasma membrane
The following genes encode channels, transporters, and regulatory proteins that directly mediate or modulate calcium ion import across the plasma membrane (GO:0098703).
| Gene | Major Role | Research Relevance |
|---|---|---|
| CACNA1C | Voltage-gated L-type calcium channel alpha-1C subunit | Cardiac and neuronal calcium import; target for calcium channel blockers |
| CACNA1D | Voltage-gated L-type calcium channel alpha-1D subunit | Hormone secretion and neuronal excitability |
| CACNA1S | Voltage-gated L-type calcium channel alpha-1S subunit | Skeletal muscle excitation-contraction coupling |
| ORAI1 | Store-operated calcium channel subunit | Immune cell activation and calcium release-activated calcium current |
| ORAI2 | Store-operated calcium channel subunit | Modulates store-operated calcium entry |
| ORAI3 | Store-operated calcium channel subunit | Store-operated calcium entry in various cell types |
| STIM1 | ER calcium sensor that activates ORAI channels | Store-operated calcium entry; calcium homeostasis |
| STIM2 | ER calcium sensor that activates ORAI channels | Modulates store-operated calcium entry |
| TRPC1 | Transient receptor potential canonical channel | Receptor-operated calcium entry |
| TRPC3 | Transient receptor potential canonical channel | Neuronal and cardiac calcium signaling |
| TRPC6 | Transient receptor potential canonical channel | Podocyte function and vascular tone |
| TRPV4 | Transient receptor potential vanilloid channel | Osmoregulation and mechanotransduction |
| TRPM7 | Transient receptor potential melastatin channel | Magnesium and calcium homeostasis |
| ATP2B1 | Plasma membrane calcium ATPase 1 | Calcium efflux; maintains low resting calcium |
| SLC8A1 | Sodium/calcium exchanger 1 | Calcium extrusion and cardiac relaxation |
| TMEM165 | Lysosomal calcium importer and ion homeostasis | Lysosomal calcium import and survival |
| VDAC2 | Voltage-dependent anion channel 2 | Mitochondrial calcium transport and apoptosis |
How Is calcium ion import across plasma membrane Regulated?
Calcium ion import across the plasma membrane is regulated at multiple levels, including channel gating by voltage, ligand binding, and phosphorylation. Store-operated calcium entry is controlled by the ER calcium sensor STIM1, which translocates to ER-plasma membrane junctions to activate ORAI channels upon store depletion. Calcium-dependent feedback, such as calmodulin binding to channels, promotes inactivation and prevents overload. Additionally, transcriptional and post-translational mechanisms adjust channel abundance and activity in response to chronic changes in calcium demand.
calcium ion import across plasma membrane and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CACNA1C | Timothy syndrome, Brugada syndrome, arrhythmias | Knock-in of patient mutations in cardiomyocytes |
| ORAI1 | Immunodeficiency, autoimmunity | Knockout in T cells or Jurkat cells |
| STIM1 | Immunodeficiency, myopathy | Knockout in fibroblasts or immune cells |
| TRPC6 | Focal segmental glomerulosclerosis | Overexpression in podocytes |
| TMEM165 | Congenital disorder of glycosylation | Knockout in HeLa or HEK293 cells |
Cardiac arrhythmias and heart failure
Altered calcium import through voltage-gated calcium channels and store-operated pathways contributes to arrhythmogenesis and contractile dysfunction. Mutations in CACNA1C are associated with Timothy syndrome, which includes cardiac arrhythmias. Targeting calcium import is a therapeutic strategy for heart failure.
Neurodegeneration and excitotoxicity
Excessive calcium entry through plasma membrane channels can trigger neuronal death in conditions such as ischemia and Alzheimer's disease. Dysregulation of TRP channels and voltage-gated calcium channels has been implicated in neurodegeneration. Modulating calcium import may offer neuroprotective benefits.
Cancer progression
Calcium import supports proliferation, migration, and survival of cancer cells. Remodeling of calcium channels and transporters is observed in multiple cancers. Inhibiting specific calcium import pathways is being explored as an anticancer strategy.
Immune disorders
Defects in store-operated calcium entry due to ORAI1 or STIM1 mutations cause immunodeficiency. Calcium import is essential for T cell activation and cytokine production. Understanding these pathways informs immunomodulatory therapies.
From calcium ion import across plasma membrane-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a calcium channel affect calcium import? | CRISPR knockout in HEK293 or HeLa cells |
| Does a specific point mutation alter channel gating? | Point mutation knock-in in cardiomyocytes |
| Can a tagged channel be used to track localization? | Tagged knock-in of CACNA1C |
| Does overexpression of ORAI1 enhance store-operated calcium entry? | Overexpression in Jurkat T cells |
| What is the role of TMEM165 in lysosomal calcium import? | Knockout in HeLa cells |
| How does VDAC2 regulate mitochondrial calcium? | Knockout in mouse embryonic fibroblasts |
How to Study the calcium ion import across plasma membrane Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorescent calcium imaging | Cytosolic calcium concentration over time | Measuring store-operated calcium entry |
| Patch-clamp electrophysiology | Ion currents through single channels | Characterizing voltage-gated calcium channels |
| Genetically encoded calcium indicators | Calcium dynamics in specific cells | In vivo neuronal activity imaging |
| CRISPR knockout screens | Gene requirement for calcium import | Identifying novel regulators |
| RNA-seq | Transcriptional changes after calcium import modulation | Pathway analysis |
| Proteomics | Protein interactions and modifications | Identifying channel complexes |
| Live-cell imaging | Channel localization and trafficking | Studying ORAI1-STIM1 puncta |
Calcium imaging with fluorescent indicators
Fluorescent calcium indicators such as Fura-2 or Fluo-4 are used to measure real-time changes in cytosolic calcium concentration upon plasma membrane import. This method allows kinetic analysis of channel activity and store-operated calcium entry.
Patch-clamp electrophysiology
Patch-clamp recordings directly measure calcium currents through single channels or whole cells, providing information on conductance, gating, and pharmacology. It is the gold standard for studying voltage-gated calcium channels.
Genetically encoded calcium indicators (GECIs)
GECIs such as GCaMP enable targeted calcium measurements in specific cell types and subcellular compartments. They are useful for in vivo imaging and long-term monitoring.
CRISPR-based genetic screens
Pooled CRISPR knockout or activation screens can identify genes that regulate calcium import across the plasma membrane. These screens link candidate genes to calcium-dependent phenotypes.
How CRISPR Can Be Used to Study GO:0098703 calcium ion import across plasma membrane
Knockout
CRISPR knockout of genes such as ORAI1 or CACNA1C eliminates specific calcium import pathways, allowing researchers to test their contribution to calcium signaling and downstream phenotypes. Knockout models are essential for validating gene function in GO:0098703.
Point Mutation
Point mutations can be introduced to mimic disease-associated variants or to dissect channel gating residues. For example, knock-in of Timothy syndrome mutations in CACNA1C reveals gain-of-function effects on calcium import.
Knock-in
Knock-in of tagged channels (e.g., GFP-ORAI1) enables real-time tracking of channel localization and dynamics at the plasma membrane. This approach helps visualize store-operated calcium entry machinery.
Overexpression
Overexpression of calcium channels or transporters can enhance calcium import and amplify signaling responses. It is used to study gain-of-function effects and to screen for modulators.
How EDITGENE Supports calcium ion import across plasma membrane Research
Researchers studying calcium ion import across plasma membrane-related genes often need to determine whether a candidate gene is causally involved in calcium entry, and to dissect its mechanism using precise genetic models. EDITGENE provides end-to-end CRISPR services to generate such models efficiently.
Contact EDITGENE today to design your custom CRISPR model for calcium ion import across plasma membrane research.
Frequently Asked Questions About calcium ion import across plasma membrane
What is GO:0098703?
GO:0098703 is the Gene Ontology term for calcium ion import across plasma membrane, defined as the directed movement of calcium ions from outside of a cell, across the plasma membrane, and into the cytosol.
What genes are involved in calcium ion import across plasma membrane?
Key genes include CACNA1C, ORAI1, STIM1, TRPC1, and ATP2B1, among others.
What is the difference between calcium import and calcium release?
Calcium import refers to entry from outside the cell across the plasma membrane, while calcium release refers to efflux from intracellular stores such as the endoplasmic reticulum.
How is calcium ion import across plasma membrane regulated?
It is regulated by voltage, ligand binding, store depletion via STIM1-ORAI1 coupling, and feedback phosphorylation.
Which diseases are associated with defects in calcium ion import?
Cardiac arrhythmias, neurodegeneration, immunodeficiency, and cancer have been linked to altered calcium import.
What methods are used to study calcium ion import?
Fluorescent calcium imaging, patch-clamp electrophysiology, genetically encoded indicators, and CRISPR screens are commonly used.
Can CRISPR be used to study calcium ion import?
Yes, CRISPR knockout, knock-in, point mutation, and overexpression models are widely used to dissect calcium import genes.
What is the role of ORAI1 in calcium import?
ORAI1 forms store-operated calcium channels that mediate calcium entry upon ER calcium depletion.
How does TMEM165 contribute to calcium import?
TMEM165 mediates lysosomal calcium import and ion homeostasis, influencing cell survival.
What is the clinical relevance of calcium ion import?
It is a target for calcium channel blockers and is implicated in cardiovascular, neurological, and immune disorders.
Conclusion
Calcium ion import across plasma membrane (GO:0098703) is a central process in cellular physiology, enabling rapid and precise calcium signaling. Its dysregulation underlies numerous diseases, making it a prime target for therapeutic intervention. Advances in CRISPR-based models and imaging technologies continue to unravel the molecular details of this process. Researchers can leverage these tools to identify novel regulators and develop targeted therapies.
References
- 1. Chen R et al.. 2025. Lysosomal TMEM165 controls cellular ion homeostasis and survival by mediating lysosomal Ca(2+) import and H(+) efflux.. Nat Commun 16(1):5209 PMID: 40473625
