GO:0038121 C-C motif chemokine 21 receptor activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0038121 (C-C motif chemokine 21 receptor activity) is the molecular function of binding CCL21 and transmitting a signal across the membrane to change cell activity.
• The principal receptor for CCL21 is CCR7, a G-protein-coupled receptor that also binds CCL19 and is expressed on dendritic cells, T cells, B cells, and macrophages.
• CCL21/CCR7 signaling activates multiple intracellular cascades, including ERK, PI3K/AKT, and calcium mobilization, which drive migration, survival, and invasion.
• This receptor activity is implicated in cancer progression, atherosclerosis, atherothrombosis, and inflammatory myopathies.
• CCR7 expression is regulated by transcription factors such as Ets-1 and correlates with enhanced migratory and survival responses in B-cell chronic lymphocytic leukemia.
• CRISPR-based knockout, knock-in, point-mutation, and overexpression models enable causal dissection of CCL21 receptor activity in health and disease.
Description
C-C motif chemokine 21 receptor activity (GO:0038121) is a molecular function defined by the specific binding of the chemokine CCL21 and the subsequent transmission of a signal from one side of the membrane to the other to initiate a change in cell activity. This activity is central to the directed migration of immune cells and is primarily mediated by the chemokine receptor CCR7, which is expressed on dendritic cells, T cells, B cells, and macrophages. The functional importance of this receptor-ligand pair extends beyond normal immune surveillance into pathological contexts such as cancer, cardiovascular disease, and chronic inflammation. Researchers study GO:0038121 to understand how chemokine gradients are interpreted by cells and how dysregulation of this activity contributes to disease. Because CCR7 is a G-protein-coupled receptor, its activation triggers multiple intracellular signaling cascades, including extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinase (PI3K) pathways, which can be interrogated using pharmacological and genetic tools. The availability of CRISPR-based cell models now allows precise manipulation of CCR7 and its downstream effectors, making GO:0038121 a tractable target for mechanistic and translational research.
C-C motif chemokine 21 receptor activity At A Glance
| GO ID | GO:0038121 |
|---|---|
| GO term | C-C motif chemokine 21 receptor activity |
| Ontology | molecular_function |
| Synonym | CCL21 receptor activity |
| Major function | Binding CCL21 and transmitting a signal across the membrane to initiate a change in cell activity |
| Primary receptor | CCR7 (C-C chemokine receptor type 7) |
| Primary ligand | CCL21 (C-C motif chemokine 21) |
| Signaling pathways | ERK, PI3K/AKT, calcium mobilization |
| Cellular context | Dendritic cells, T cells, B cells, macrophages, cancer cells |
What Is GO:0038121?
In simple terms, C-C motif chemokine 21 receptor activity is the function of a receptor protein that recognizes the chemokine CCL21 on the outside of a cell and relays that recognition into a signal inside the cell. According to the QuickGO definition, this activity involves combining with CCL21 and transmitting the signal from one side of the membrane to the other to initiate a change in cell activity. The receptor acts as a molecular antenna: when CCL21 binds, the receptor changes shape and activates intracellular signaling proteins, ultimately altering processes such as cell migration, survival, or gene expression. This activity is synonymous with CCL21 receptor activity and is a type of molecular function in the Gene Ontology.
Why Is C-C motif chemokine 21 receptor activity Important in Cell Biology?
C-C motif chemokine 21 receptor activity is important because it governs the positioning and behavior of immune cells and is hijacked in multiple diseases. In cancer, CCL21/CCR7 signaling promotes migration, invasion, and epithelial-mesenchymal transition, contributing to metastasis. In cardiovascular disease, CCL21 enhances platelet activation and atherothrombosis via CCR7, linking this receptor activity directly to thrombotic complications. In atherosclerosis, CCR7 ligands are elevated and differentially affect macrophages and smooth muscle cells, suggesting complex roles in plaque biology. In inflammatory myopathies such as inclusion body myositis, CCR7-positive immune cells invade muscle fibers, implicating this activity in tissue damage. Furthermore, CCR7 expression in B-cell chronic lymphocytic leukemia is associated with enhanced responses to migratory and survival signals, highlighting its prognostic and therapeutic relevance. Understanding GO:0038121 therefore provides a mechanistic handle on immune regulation, cancer progression, and vascular pathology.
• Drives directed migration of dendritic cells, T cells, and B cells to lymphoid organs.
• Promotes cancer cell migration and invasion via epithelial-mesenchymal transition and ERK signaling.
• Enhances platelet activation and atherothrombosis through CCR7.
• Is associated with elevated CCR7 ligand levels in carotid atherosclerosis.
• Contributes to immune cell invasion in inclusion body myositis.
• Supports survival and migratory signals in B-cell chronic lymphocytic leukemia.
• Is regulated by transcription factors such as Ets-1, linking gene expression to migratory capacity.
• Serves as a target for pharmacological and genetic interrogation of chemokine signaling.
• Provides a basis for precision treatment strategies in hepatocellular carcinoma.
• Enables CRISPR-based dissection of receptor function in immune and cancer models.
What Happens During C-C motif chemokine 21 receptor activity?
Ligand binding and receptor activation
In simple terms: CCL21 docks onto the CCR7 receptor, flipping a molecular switch inside the cell.
The activity begins when the chemokine CCL21 binds to its receptor CCR7 on the cell surface. Pharmacological and signaling analysis of human CCR7 stably expressed in HEK-293 cells demonstrated high-affinity binding of recombinant ligands, including MIP-3beta and SLC (CCL21), which stimulates multiple signaling cascades. This binding event is the defining step of GO:0038121, as it transmits the signal from one side of the membrane to the other to initiate a change in cell activity.
Intracellular signaling cascades
In simple terms: Once activated, the receptor triggers a relay of signals inside the cell.
Following CCL21 binding, CCR7 activates multiple intracellular pathways. In HEK-293 cells, stimulation with recombinant ligands led to activation of multiple signaling cascades. In lung cancer cells, CCL21/CCR7 triggers migration and invasion through the extracellular signal-regulated kinase (ERK) signaling pathway. In B-cell chronic lymphocytic leukemia, ZAP-70 expression is associated with enhanced ability to respond to migratory and survival signals, suggesting that downstream signaling strength modulates the functional outcome of receptor activity.
Cytoskeletal rearrangement and migration
In simple terms: The cell changes its shape and moves toward the CCL21 signal.
A major physiological consequence of CCL21 receptor activity is directed cell migration. CCR7-positive myeloid dendritic cells, T cells, and macrophages invade CCL19-positive nonnecrotic muscle fibers in inclusion body myositis, demonstrating that this receptor activity drives cell movement into tissues. In lung cancer, CCL21/CCR7 promotes migration and invasion via epithelial-mesenchymal transition, a process that involves cytoskeletal and adhesion changes.
Survival and activation responses
In simple terms: The signal can also keep cells alive or make them more active.
Beyond migration, CCL21 receptor activity can promote survival and activation. In B-cell chronic lymphocytic leukemia, ZAP-70 expression is associated with enhanced ability to respond to migratory and survival signals, indicating that CCR7 signaling can support cell survival. In platelets, CCL21 enhances platelet activation and atherothrombosis via CCR7 activation, showing that this receptor activity can trigger rapid functional changes in non-immune cells.
Key Genes Involved in GO:0038121 C-C motif chemokine 21 receptor activity
The following genes and proteins are central to C-C motif chemokine 21 receptor activity, either as the receptor, ligand, or downstream regulators.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CCR7 | Primary receptor for CCL21; mediates signal transduction | Knockout and knock-in models to dissect migration and survival |
| CCL21 | Ligand that binds and activates CCR7 | Overexpression or knockout to study gradient formation |
| CCL19 | Alternative ligand for CCR7 | Comparative studies of ligand-specific responses |
| ETS1 | Transcription factor regulating CCR7 expression | Knockdown to assess CCR7-dependent migration |
| ZAP70 | Signaling molecule associated with enhanced migratory and survival responses | Expression studies in leukemia |
| ERK1/2 | Downstream kinases activated by CCL21/CCR7 | Pharmacological inhibition and CRISPR knockout |
| PI3K | Downstream signaling pathway | Inhibitor studies and genetic models |
| AKT | Survival kinase downstream of PI3K | Phosphorylation assays |
| MAPK1 | ERK pathway component | Knockout to block CCL21-induced migration |
| MAPK3 | ERK pathway component | Knockout to block CCL21-induced migration |
| GNAI1 | G-protein subunit coupled to CCR7 | Knockout to disrupt chemokine signaling |
| GNAI2 | G-protein subunit coupled to CCR7 | Knockout to disrupt chemokine signaling |
| GNAI3 | G-protein subunit coupled to CCR7 | Knockout to disrupt chemokine signaling |
| ARRB1 | Beta-arrestin involved in receptor desensitization | Knockout to study receptor internalization |
| ARRB2 | Beta-arrestin involved in receptor desensitization | Knockout to study receptor internalization |
| GRK2 | G-protein-coupled receptor kinase | Overexpression to promote desensitization |
| GRK5 | G-protein-coupled receptor kinase | Overexpression to promote desensitization |
| GRK6 | G-protein-coupled receptor kinase | Overexpression to promote desensitization |
How Is C-C motif chemokine 21 receptor activity Regulated?
C-C motif chemokine 21 receptor activity is regulated at multiple levels. Receptor expression is controlled by transcription factors such as Ets-1, which enhances tumor migration through regulation of CCR7 expression. Ligand availability is influenced by the presence of CCL21 and CCL19 in the microenvironment, and elevated levels of CCR7 ligands have been observed in carotid atherosclerosis. At the receptor level, signaling is subject to desensitization and internalization via G-protein-coupled receptor kinases and beta-arrestins, as demonstrated in HEK-293 cells stably expressing CCR7. Downstream, the strength and duration of signaling can be modulated by kinases such as ERK, which is required for CCL21/CCR7-induced migration and invasion in lung cancer cells. In B-cell chronic lymphocytic leukemia, ZAP-70 expression is associated with enhanced ability to respond to migratory and survival signals, suggesting that intracellular signaling components can tune the output of receptor activity.
C-C motif chemokine 21 receptor activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CCR7 | Lung cancer metastasis | CCR7 knockout lung cancer cell line |
| CCR7 | Atherothrombosis | Platelet-specific CCR7 knockout mouse |
| CCR7 | Inclusion body myositis | CCR7 knock-in reporter in immune cells |
| CCR7 | Hepatocellular carcinoma | Patient-derived organoids with CCR7 knockout |
| CCR7 | B-cell chronic lymphocytic leukemia | ZAP-70 overexpression in B-cell lines |
Cancer progression and metastasis
CCL21/CCR7 signaling promotes migration and invasion of human lung cancer cells by epithelial-mesenchymal transition via the ERK signaling pathway. In hepatocellular carcinoma, differential expression of CCR7 guides precision treatment strategies, indicating that receptor activity levels can inform therapeutic decisions. Ets-1 enhances tumor migration through regulation of CCR7 expression, linking transcriptional control of the receptor to metastatic behavior.
Cardiovascular disease and thrombosis
CCL21 enhances platelet activation and atherothrombosis via CCR7 activation, directly implicating this receptor activity in thrombotic complications. Increased levels of CCR7 ligands have been found in carotid atherosclerosis, with different effects in macrophages and smooth muscle cells, suggesting a complex role in plaque progression.
Inflammatory myopathies
In inclusion body myositis, CCR7-positive myeloid dendritic cells together with CCR7-positive T cells and macrophages invade CCL19-positive nonnecrotic muscle fibers, demonstrating that CCL21 receptor activity contributes to immune cell infiltration and tissue damage.
Leukemia and hematological malignancies
In B-cell chronic lymphocytic leukemia, ZAP-70 expression is associated with enhanced ability to respond to migratory and survival signals, suggesting that CCL21 receptor activity supports leukemic cell survival and migration.
From C-C motif chemokine 21 receptor activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does CCR7 mediate CCL21-induced migration? | CCR7 knockout cell line |
| Which residues are required for CCL21 binding? | Point-mutation knock-in of CCR7 |
| How does CCR7 signaling affect tumor growth in vivo? | CCR7 knockout mouse xenograft |
| Can we track CCR7 expression in real time? | Tagged knock-in of CCR7 with fluorescent protein |
| Does overexpression of CCR7 enhance metastasis? | CCR7 overexpression in cancer cell lines |
| What is the role of ZAP-70 in CCL21 responses? | ZAP-70 knockout in leukemia cells |
How to Study the C-C motif chemokine 21 receptor activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Radioligand binding | Affinity of CCL21 for CCR7 | Receptor pharmacology |
| Calcium flux assay | G-protein activation | Functional receptor activity |
| Transwell migration | Cell migration toward CCL21 | Chemotaxis studies |
| Matrigel invasion | Cell invasion through matrix | Metastasis research |
| Western blot | Phosphorylation of ERK/AKT | Signaling pathway activation |
| qRT-PCR | CCR7 mRNA levels | Expression regulation |
| Immunohistochemistry | CCR7 protein localization | Tissue analysis |
| Flow cytometry | Surface CCR7 expression | Immune cell phenotyping |
Binding and signaling assays
Pharmacological and signaling analysis of CCR7 stably expressed in HEK-293 cells can measure high-affinity binding of recombinant CCL21 and activation of multiple signaling cascades. These assays typically use radiolabeled ligands, calcium flux, and phosphorylation-specific antibodies to quantify receptor activity.
Migration and invasion assays
Transwell migration and Matrigel invasion assays are used to measure the functional output of CCL21 receptor activity. In lung cancer cells, CCL21/CCR7 triggers migration and invasion via ERK signaling, which can be blocked with ERK inhibitors or genetic knockdown.
Expression and regulation studies
Quantitative PCR, western blotting, and reporter assays can assess CCR7 expression levels and transcriptional regulation. Ets-1 enhances tumor migration through regulation of CCR7 expression, and such studies can be performed in cancer cell lines with Ets-1 knockdown or overexpression.
In vivo disease models
Animal models of atherothrombosis, cancer metastasis, and inflammatory myopathy can be used to study CCL21 receptor activity in a physiological context. For example, CCL21 enhances platelet activation and atherothrombosis via CCR7 activation, which can be tested in platelet-specific knockout mice.
How CRISPR Can Be Used to Study GO:0038121 C-C motif chemokine 21 receptor activity
Knockout
CRISPR knockout of CCR7 in cell lines or primary cells can abolish CCL21 receptor activity, providing a clean background to test downstream signaling and functional responses. For example, CCR7 knockout in lung cancer cells would block CCL21-induced migration and invasion. Knockout of downstream effectors such as ERK1/2 can also be used to dissect pathway requirements.
Point Mutation
Point mutations in CCR7 can be introduced to map residues required for CCL21 binding or G-protein coupling. Such models are valuable for understanding the structural basis of receptor activation and for testing whether specific mutations alter signaling, as demonstrated by pharmacological analysis of CCR7 in HEK-293 cells.
Knock-in
Knock-in of tagged CCR7 (e.g., fluorescent protein or epitope tag) allows real-time tracking of receptor localization and trafficking. This approach can be used to study receptor internalization and desensitization in response to CCL21, as suggested by studies of CCR7 signaling in HEK-293 cells.
Overexpression
Overexpression of CCR7 or its ligands can enhance CCL21 receptor activity and drive phenotypic changes such as increased migration and invasion. In lung cancer cells, CCL21/CCR7 signaling promotes epithelial-mesenchymal transition, and overexpression models can amplify this effect for study. Overexpression of ZAP-70 in leukemia cells can also enhance responses to migratory and survival signals.
How EDITGENE Supports C-C motif chemokine 21 receptor activity Research
Researchers studying C-C motif chemokine 21 receptor activity-related genes often need to determine whether a candidate gene is causally involved in receptor signaling, migration, or disease progression. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models, enabling rigorous functional validation of genes such as CCR7, CCL21, and their downstream effectors.
Contact EDITGENE today to design your custom CRISPR model for C-C motif chemokine 21 receptor activity research.
Frequently Asked Questions About C-C motif chemokine 21 receptor activity
What is C-C motif chemokine 21 receptor activity?
It is the molecular function of binding the chemokine CCL21 and transmitting a signal across the membrane to initiate a change in cell activity, as defined by GO:0038121.
What genes are involved in C-C motif chemokine 21 receptor activity?
The primary genes are CCR7 (the receptor) and CCL21 (the ligand), along with downstream signaling genes such as ERK1/2, PI3K, and AKT.
Which receptor binds CCL21?
CCR7 is the principal receptor that binds CCL21 and mediates its signaling effects.
What diseases are associated with CCL21 receptor activity?
It is implicated in cancer metastasis, atherosclerosis, atherothrombosis, inclusion body myositis, and B-cell chronic lymphocytic leukemia.
How is CCL21 receptor activity regulated?
It is regulated by transcription factors like Ets-1, receptor desensitization via GRKs and beta-arrestins, and downstream kinase activity.
What signaling pathways are activated by CCL21/CCR7?
CCL21/CCR7 activates ERK, PI3K/AKT, and calcium mobilization, among other cascades.
Can CRISPR be used to study CCL21 receptor activity?
Yes, CRISPR knockout, knock-in, point mutation, and overexpression models allow precise dissection of CCR7 and its signaling partners.
What is the role of CCR7 in cancer?
CCR7 promotes migration, invasion, and epithelial-mesenchymal transition in cancer cells, contributing to metastasis.
Is CCL21 receptor activity involved in cardiovascular disease?
Yes, CCL21 enhances platelet activation and atherothrombosis via CCR7, and CCR7 ligands are elevated in carotid atherosclerosis.
What experimental models are used to study CCL21 receptor activity?
Common models include CCR7 knockout cell lines, tagged knock-in reporters, overexpression systems, and animal models of cancer and thrombosis.
Conclusion
C-C motif chemokine 21 receptor activity (GO:0038121) is a fundamental molecular function that governs immune cell migration and survival, with broad implications for cancer, cardiovascular disease, and inflammatory disorders. The receptor CCR7 and its ligand CCL21 are the central players, and their signaling is modulated by transcription factors, kinases, and desensitization machinery. CRISPR-based cell models provide powerful tools to dissect the causal roles of CCR7 and its downstream effectors, enabling the development of targeted therapeutic strategies.
References
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- 2. Qin J et al.. 2025. Differential expression pattern of CC chemokine receptor 7 guides precision treatment of hepatocellular carcinoma.. Signal Transduct Target Ther 10(1):229 PMID: 40685403
- 3. Fang LW et al.. 2019. Ets-1 enhances tumor migration through regulation of CCR7 expression.. BMB Rep 52(9):548-553 PMID: 31072446
- 4. Tateyama M et al.. 2009. CCR7+ myeloid dendritic cells together with CCR7+ T cells and CCR7+ macrophages invade CCL19+ nonnecrotic muscle fibers in inclusion body myositis.. J Neurol Sci 279(1-2):47-52 PMID: 19171354
- 5. Zhong G et al.. 2017. Chemokine (C‑C motif) ligand 21/C‑C chemokine receptor type 7 triggers migration and invasion of human lung cancer cells by epithelial‑mesenchymal transition via the extracellular signal‑regulated kinase signaling pathway.. Mol Med Rep 15(6):4100-4108 PMID: 28487957
- 6. Halvorsen B et al.. 2014. Increased levels of CCR7 ligands in carotid atherosclerosis: different effects in macrophages and smooth muscle cells.. Cardiovasc Res 102(1):148-56 PMID: 24518141
- 7. Sullivan SK et al.. 1999. Pharmacological and signaling analysis of human chemokine receptor CCR-7 stably expressed in HEK-293 cells: high-affinity binding of recombinant ligands MIP-3beta and SLC stimulates multiple signaling cascades.. Biochem Biophys Res Commun 263(3):685-90 PMID: 10512740
- 8. Richardson SJ et al.. 2006. ZAP-70 expression is associated with enhanced ability to respond to migratory and survival signals in B-cell chronic lymphocytic leukemia (B-CLL).. Blood 107(9):3584-92 PMID: 16332969
