GO:0005011 macrophage colony-stimulating factor receptor activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0005011 describes the molecular function of the macrophage colony-stimulating factor receptor (CSF-1R, also called Fms or CD115), a receptor tyrosine kinase that binds M-CSF/CSF-1 and transmits signals across the membrane by catalyzing ATP-dependent tyrosine phosphorylation of protein substrates.
• CSF-1R signaling is central to the survival, proliferation, differentiation, and function of myeloid cells, including monocytes, macrophages, and osteoclasts.
• Dysregulated CSF-1R activity contributes to tumor-associated macrophage biology, cancer progression, focal segmental glomerulosclerosis, lupus nephritis, and other inflammatory or malignant conditions.
• CSF-1R is a validated therapeutic target, with small-molecule inhibitors and anti-CSF-1R antibodies being developed for cancer immunotherapy and other diseases.
• Key genes and proteins in this pathway include CSF1R, CSF1, CSF2, PTPN11, GRB2, STAT3, and PI3K subunits, which together mediate ligand binding, kinase activation, and downstream signaling.
• CRISPR-based knockout, point-mutation, knock-in, and overexpression models enable precise dissection of CSF-1R function and its role in disease, supporting drug discovery and mechanistic studies.
Description
Macrophage colony-stimulating factor receptor activity (GO:0005011) is a molecular function that enables a cell to bind macrophage colony-stimulating factor (M-CSF, also known as CSF-1) and transmit a signal across the membrane by catalyzing the phosphorylation of protein tyrosine residues. This activity is intrinsic to the CSF-1 receptor (CSF-1R), a receptor tyrosine kinase encoded by the CSF1R gene (also known as Fms or CD115). The receptor is predominantly expressed on myeloid cells, where it controls survival, proliferation, and differentiation. Because CSF-1R signaling is a key driver of macrophage biology, its dysregulation is implicated in cancer, inflammatory diseases, and renal pathology. Researchers study GO:0005011 to understand how extracellular cues are converted into intracellular signals and to develop targeted therapies.
macrophage colony-stimulating factor receptor activity At A Glance
| GO ID | GO:0005011 |
|---|---|
| GO term | macrophage colony-stimulating factor receptor activity |
| Ontology | molecular_function |
| Synonym | CSF-1, Fms, macrophage colony stimulating factor receptor activity, M-CSF receptor activity |
| Major function | Binds M-CSF/CSF-1 and catalyzes ATP-dependent tyrosine phosphorylation of protein substrates to transmit signals across the membrane |
| Reaction | ATP + a protein-L-tyrosine = ADP + a protein-L-tyrosine phosphate |
| Primary ligand | Macrophage colony-stimulating factor (M-CSF/CSF-1) |
| Cellular context | Plasma membrane of myeloid cells, including monocytes, macrophages, and osteoclasts |
| Downstream pathways | PI3K-AKT, MAPK, and JAK-STAT signaling cascades |
What Is GO:0005011?
GO:0005011, macrophage colony-stimulating factor receptor activity, is defined as the molecular function of combining with the macrophage colony-stimulating factor (M-CSF) ligand and transmitting the signal from one side of the membrane to the other to initiate a change in cell activity by catalysis of the reaction: ATP + a protein-L-tyrosine = ADP + a protein-L-tyrosine phosphate. In simpler terms, it is the ability of the CSF-1 receptor to act as a tyrosine kinase that adds phosphate groups to proteins after binding M-CSF, thereby relaying a signal into the cell.
Why Is macrophage colony-stimulating factor receptor activity Important in Cell Biology?
GO:0005011 is important because it defines the first committed step in CSF-1R signaling, a pathway that governs the development and function of the mononuclear phagocyte system. This activity is essential for innate immunity, bone remodeling, and tissue homeostasis, and its aberrant activation drives tumor progression and chronic inflammation. Understanding the molecular details of this receptor kinase activity provides a foundation for therapeutic intervention in cancer, autoimmune diseases, and kidney disorders.
• Controls survival, proliferation, and differentiation of monocytes, macrophages, and osteoclasts.
• Drives tumor-associated macrophage recruitment and polarization, supporting cancer progression.
• Promotes prostate cancer cell growth and aggressiveness in vitro and in vivo.
• Contributes to focal segmental glomerulosclerosis by activating glomerular parietal epithelial cells.
• Is associated with expanded non-classical monocytes in systemic lupus erythematosus and lupus nephritis.
• Serves as a target for anti-CSF-1R antibodies and small-molecule inhibitors in cancer immunotherapy.
• Enables CAR T-cell targeting of CSF-1R for potential therapeutic applications.
• Provides a model for studying receptor tyrosine kinase signal transduction mechanisms.
• Links extracellular growth factor cues to transcriptional programs via STAT, PI3K, and MAPK pathways.
• Offers opportunities for CRISPR-based functional genomics to identify modulators of kinase activity.
What Happens During macrophage colony-stimulating factor receptor activity?
Ligand binding and receptor dimerization
In simple terms: M-CSF grabs two receptor molecules and pulls them together.
The process begins when macrophage colony-stimulating factor (M-CSF/CSF-1) binds to the extracellular domain of CSF-1R, inducing receptor dimerization. This dimerization is a prerequisite for activation of the intracellular kinase domains.
Kinase activation and autophosphorylation
In simple terms: The receptors phosphorylate each other to switch on.
Upon dimerization, the intracellular tyrosine kinase domains of CSF-1R trans-autophosphorylate specific tyrosine residues, which serves to enhance catalytic activity and create docking sites for downstream signaling proteins.
Substrate phosphorylation and signal propagation
In simple terms: The active receptor adds phosphate tags to other proteins, passing the message along.
Activated CSF-1R catalyzes the transfer of phosphate from ATP to tyrosine residues on substrate proteins, as described by the GO:0005011 reaction. This phosphorylation triggers the assembly of signaling complexes that activate PI3K-AKT, MAPK, and JAK-STAT pathways.
Downstream cellular responses
In simple terms: The signal leads to changes in gene expression and cell behavior.
The propagated signals lead to changes in gene expression, cytoskeletal reorganization, and metabolic reprogramming that promote cell survival, proliferation, and differentiation. In myeloid cells, this results in functional activation and cytokine production.
Signal attenuation and receptor downregulation
In simple terms: The signal is eventually turned off to prevent overactivity.
CSF-1R signaling is attenuated by internalization, degradation, and dephosphorylation mediated by phosphatases and ubiquitin ligases. This negative feedback is crucial for preventing excessive myeloid cell activation.
Key Genes Involved in GO:0005011 macrophage colony-stimulating factor receptor activity
The following genes and proteins are central to macrophage colony-stimulating factor receptor activity and its downstream signaling.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CSF1R | Encodes the receptor tyrosine kinase that binds M-CSF and catalyzes tyrosine phosphorylation | Primary target for knockout, point-mutation, and knock-in studies of kinase activity |
| CSF1 | Encodes macrophage colony-stimulating factor, the ligand that activates CSF-1R | Used in overexpression and ligand-binding assays to stimulate receptor activity |
| CSF2 | Encodes GM-CSF, a related cytokine that can modulate myeloid cell responses | Studied for cross-talk with CSF-1R signaling in macrophage differentiation |
| PTPN11 | Encodes SHP-2 phosphatase, which regulates CSF-1R signaling | Investigated for its role in attenuating or modulating kinase activity |
| GRB2 | Adaptor protein that binds phosphorylated CSF-1R and activates RAS-MAPK | Target for knock-in of binding-site mutations to dissect downstream pathways |
| STAT3 | Transcription factor activated downstream of CSF-1R | Used as a readout of CSF-1R activity in reporter assays |
| PIK3CA | Catalytic subunit of PI3K, activated by CSF-1R | Studied for its role in CSF-1R-driven survival signaling |
| PIK3R1 | Regulatory subunit of PI3K, binds phosphorylated CSF-1R | Target for knockout to assess PI3K dependence |
| AKT1 | Serine/threonine kinase downstream of PI3K | Used as a phosphorylation readout of CSF-1R pathway activation |
| MAPK1 | ERK2, a kinase in the MAPK cascade activated by CSF-1R | Monitored to assess MAPK pathway engagement |
| MAPK3 | ERK1, a kinase in the MAPK cascade activated by CSF-1R | Monitored to assess MAPK pathway engagement |
| JAK2 | Janus kinase that can associate with CSF-1R and activate STATs | Investigated for its role in cytokine signaling cross-talk |
| CBL | E3 ubiquitin ligase that targets activated CSF-1R for degradation | Studied for negative regulation of receptor activity |
| SOS1 | Guanine nucleotide exchange factor linking GRB2 to RAS activation | Target for knockout to block RAS-MAPK signaling |
| PTPN6 | SHP-1 phosphatase that negatively regulates CSF-1R | Investigated for its role in signal termination |
| SOCS1 | Suppressor of cytokine signaling, feedback inhibitor of CSF-1R signaling | Studied for negative feedback control |
| CD115 | Alternative name for CSF-1R protein (encoded by CSF1R) | Used as a surface marker for monocyte/macrophage identification |
| FMS | Alternative gene name for CSF1R | Historical name used in early literature |
How Is macrophage colony-stimulating factor receptor activity Regulated?
CSF-1R activity is tightly regulated at multiple levels. Ligand-induced dimerization and autophosphorylation are the primary activation steps. Negative regulation is mediated by phosphatases such as SHP-1 (PTPN6) and SHP-2 (PTPN11), which dephosphorylate the receptor and its substrates. Ubiquitination by CBL leads to receptor internalization and degradation. Additionally, feedback inhibitors like SOCS1 attenuate downstream STAT signaling. These regulatory mechanisms ensure that CSF-1R activity is transient and appropriate to the cellular context.
macrophage colony-stimulating factor receptor activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CSF1R | Cancer (tumor-associated macrophages) | CSF1R knockout in macrophage cell lines or conditional knockout mice |
| CSF1R | Focal segmental glomerulosclerosis | CSF1R point-mutation knock-in in podocytes or parietal epithelial cells |
| CSF1R | Systemic lupus erythematosus / lupus nephritis | CSF1R overexpression in monocytes or CRISPR knock-in of risk variants |
| CSF1 | Prostate cancer growth and aggressiveness | CSF1 overexpression in prostate cancer cell lines |
| CSF1R | CAR T-cell therapy target | CSF1R knock-in into CAR T cells for targeting |
CSF-1R in cancer and tumor-associated macrophages
CSF-1R signaling promotes the recruitment and polarization of tumor-associated macrophages, which support tumor growth, angiogenesis, and immunosuppression. Targeting CSF-1R with antibodies or small-molecule inhibitors has emerged as a promising immunotherapeutic strategy for cancer treatment. In prostate cancer, CSF-1R enhances cancer cell growth and aggressiveness in vitro and in vivo, and increases osteopontin expression.
CSF-1R in kidney disease
CSF-1R drives glomerular parietal epithelial cell activation in focal segmental glomerulosclerosis, contributing to disease pathogenesis. In systemic lupus erythematosus, expanded non-classical monocytes expressing CD115 (CSF-1R) are associated with lupus nephritis. These findings suggest that CSF-1R activity is a potential therapeutic target in renal disorders.
CSF-1R in immune regulation and inflammation
CSF-1R signaling is essential for the development and function of monocytes and macrophages, key players in innate immunity and inflammation. Dysregulated CSF-1R activity can lead to chronic inflammatory conditions and autoimmune diseases. Understanding its role in immune regulation is critical for developing therapies that modulate macrophage function.
From macrophage colony-stimulating factor receptor activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the effect of CSF1R loss on macrophage survival? | CSF1R knockout in primary macrophages or cell lines |
| How does a specific kinase-domain mutation affect CSF-1R activity? | Point mutation (e.g., kinase-dead) knock-in via CRISPR |
| What are the downstream targets of CSF-1R phosphorylation? | Knock-in of tagged CSF-1R for phosphoproteomics |
| Can CSF-1R be targeted by CAR T cells? | CSF1R overexpression in target cells for CAR T-cell assays |
| Does CSF-1R drive prostate cancer aggressiveness? | CSF1R overexpression in prostate cancer cell lines and xenografts |
| What is the role of CSF-1R in glomerular disease? | CSF1R knockout or point-mutation in kidney organoids or mouse models |
How to Study the macrophage colony-stimulating factor receptor activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| In vitro kinase assay | Catalytic activity of CSF-1R | Screening inhibitors and testing mutants |
| Phosphoproteomics | Tyrosine phosphorylation of substrates | Mapping signaling networks |
| CRISPR knockout screen | Genes required for CSF-1R signaling | Identifying modulators |
| Flow cytometry | Surface CSF-1R expression | Characterizing monocyte/macrophage populations |
| Immunoblotting | Phosphorylation of CSF-1R and downstream proteins | Validating pathway activation |
| qPCR | mRNA levels of CSF1R and target genes | Assessing transcriptional responses |
| Proximity ligation assay | Protein-protein interactions | Detecting receptor complexes |
| Xenograft models | Tumor growth and macrophage infiltration | Testing CSF-1R inhibitors |
Kinase activity assays
In vitro kinase assays using recombinant CSF-1R and substrate peptides measure the catalytic activity defined by GO:0005011. These assays are used to screen inhibitors and assess the impact of mutations on kinase function.
Phosphoproteomics
Mass spectrometry-based phosphoproteomics identifies tyrosine-phosphorylated substrates of CSF-1R following ligand stimulation, providing a global view of signaling networks. This method is valuable for discovering novel downstream effectors.
CRISPR screening
Genome-wide CRISPR knockout or activation screens can identify genes that modulate CSF-1R activity or downstream signaling. These screens are powerful for uncovering regulators and therapeutic targets.
Flow cytometry and imaging
Flow cytometry using anti-CSF-1R antibodies (CD115) quantifies receptor surface expression, while imaging techniques visualize receptor localization and internalization. These methods are used to study receptor dynamics and cell populations.
How CRISPR Can Be Used to Study GO:0005011 macrophage colony-stimulating factor receptor activity
Knockout
CRISPR knockout of CSF1R or downstream signaling genes in myeloid cell lines or primary macrophages ablates receptor activity, enabling studies of its role in survival, proliferation, and differentiation. Knockout models are also used to validate drug targets.
Point Mutation
Point mutations introduced into the CSF1R kinase domain (e.g., kinase-dead or constitutively active) allow precise dissection of catalytic mechanisms and downstream pathways. These models are valuable for understanding how specific residues contribute to GO:0005011 activity.
Knock-in
Knock-in of epitope tags or fluorescent proteins into the endogenous CSF1R locus enables real-time tracking of receptor expression, localization, and interactions. Knock-in of disease-associated variants can model human pathologies.
Overexpression
Overexpression of CSF1R or its ligand CSF1 in cell lines or xenografts drives constitutive pathway activation, modeling cancer and inflammatory diseases. Overexpression models are used to test targeted therapies.
How EDITGENE Supports macrophage colony-stimulating factor receptor activity Research
Researchers studying macrophage colony-stimulating factor receptor activity-related genes often need to determine whether a candidate gene is causally involved in receptor signaling, disease progression, or therapeutic response. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models, enabling functional validation and drug discovery.
Contact EDITGENE today to design your custom CRISPR model for macrophage colony-stimulating factor receptor activity research.
Frequently Asked Questions About macrophage colony-stimulating factor receptor activity
What is macrophage colony-stimulating factor receptor activity?
It is the molecular function defined by GO:0005011, where the CSF-1 receptor binds M-CSF and catalyzes tyrosine phosphorylation of proteins to transmit signals across the membrane.
What genes are involved in macrophage colony-stimulating factor receptor activity?
Key genes include CSF1R (encoding the receptor), CSF1 (the ligand), and downstream effectors such as PTPN11, GRB2, STAT3, and PI3K subunits.
What diseases are associated with CSF-1R activity?
CSF-1R activity is implicated in cancer, focal segmental glomerulosclerosis, lupus nephritis, and inflammatory diseases.
How is CSF-1R activity regulated?
It is regulated by ligand-induced dimerization, autophosphorylation, phosphatases (SHP-1, SHP-2), ubiquitination by CBL, and feedback inhibitors like SOCS1.
What is the reaction catalyzed by CSF-1R?
CSF-1R catalyzes ATP + a protein-L-tyrosine = ADP + a protein-L-tyrosine phosphate, as defined in GO:0005011.
What cell types express CSF-1R?
CSF-1R is predominantly expressed on myeloid cells, including monocytes, macrophages, and osteoclasts.
Can CSF-1R be targeted for cancer therapy?
Yes, anti-CSF-1R antibodies and small-molecule inhibitors are being developed as immunotherapeutic drugs for cancer treatment.
What is the role of CSF-1R in prostate cancer?
CSF-1R enhances prostate cancer cell growth and aggressiveness in vitro and in vivo, and increases osteopontin expression.
How can CRISPR be used to study CSF-1R?
CRISPR knockout, point mutation, knock-in, and overexpression models allow precise dissection of CSF-1R function and its role in disease.
What is the synonym for GO:0005011?
Synonyms include CSF-1, Fms, macrophage colony stimulating factor receptor activity, and M-CSF receptor activity.
Conclusion
Macrophage colony-stimulating factor receptor activity (GO:0005011) is a fundamental molecular function that drives myeloid cell biology and contributes to cancer, kidney disease, and autoimmunity. Understanding its mechanism, regulation, and downstream effects is essential for developing targeted therapies. CRISPR-based models and functional genomics provide powerful tools to dissect this pathway and accelerate translational research.
References
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- 2. Wen J et al.. 2023. CSF1R inhibitors are emerging immunotherapeutic drugs for cancer treatment.. Eur J Med Chem 245(Pt 1):114884 PMID: 36335744
- 3. Cruzado JM et al.. 2024. Colony stimulating factor-1 receptor drives glomerular parietal epithelial cell activation in focal segmental glomerulosclerosis.. Kidney Int 106(1):67-84 PMID: 38428734
- 4. Roussel MF. 1994. Signal transduction by the macrophage-colony-stimulating factor receptor (CSF-1R).. J Cell Sci Suppl 18:105-8 PMID: 7883784
- 5. Achkova DY et al.. 2022. CAR T-Cell Targeting of Macrophage Colony-Stimulating Factor Receptor.. Cells 11(14) PMID: 35883636
- 6. Mougel A et al.. 2022. Macrophage-Colony-Stimulating Factor Receptor Enhances Prostate Cancer Cell Growth and Aggressiveness In Vitro and In Vivo and Increases Osteopontin Expression.. Int J Mol Sci 23(24) PMID: 36555673
- 7. Zeisbrich M et al.. 2025. Macrophage colony-stimulating factor receptor/CD115(+) non-classical monocytes are expanded in systemic lupus erythematosus and associated with lupus nephritis.. Scand J Rheumatol 54(2):125-134 PMID: 39171822
- 8. Ries CH et al.. 2014. Targeting tumor-associated macrophages with anti-CSF-1R antibody reveals a strategy for cancer therapy.. Cancer Cell 25(6):846-59 PMID: 24898549
