GO:0035373 chondroitin sulfate proteoglycan binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0035373 (chondroitin sulfate proteoglycan binding) is a molecular function describing the selective binding of a protein or other molecule to chondroitin sulfate proteoglycans (CSPGs), which are proteoglycans carrying chondroitin sulfate glycosaminoglycan chains.
• CSPG-binding interactions are central to extracellular matrix assembly, cell adhesion, growth factor sequestration, and axon guidance, and they are mediated by diverse protein families including lecticans (neurocan, versican), selectins, CD44, midkine, and bacterial toxins [2,4,5,8].
• Dysregulated CSPG binding contributes to cancer progression, peritoneal dissemination, neurodegeneration, and impaired remyelination, making it a therapeutic target [1,3,6].
• Key experimental approaches to study CSPG binding include solid-phase binding assays, surface plasmon resonance, co-immunoprecipitation, and CRISPR-based gene knockout or knock-in models [4,5,7].
• CRISPR knockout of CSPG-binding proteins (e.g., CSPG4, versican) enables causal testing of their roles in cell migration, signaling, and disease phenotypes [1,8].
• EDITGENE provides knockout, point-mutation, knock-in, overexpression cell models and CRISPR library screening to dissect chondroitin sulfate proteoglycan binding mechanisms.
Description
Chondroitin sulfate proteoglycan binding (GO:0035373) is a molecular function defined as the binding to a chondroitin sulfate proteoglycan, any proteoglycan containing chondroitin sulfate as the glycosaminoglycan carbohydrate unit. This function is essential for numerous biological processes, including extracellular matrix organization, cell adhesion, and signal transduction. Chondroitin sulfate proteoglycans (CSPGs) are major components of the extracellular matrix and cell surfaces, where they interact with a wide array of binding partners to modulate cellular behavior. Understanding the specificity and regulation of CSPG binding is critical for deciphering mechanisms of development, tissue repair, and disease. For instance, the CSPG neurocan is a brain-specific proteoglycan that influences neuronal adhesion and migration. Versican, a large CSPG, binds to selectins and CD44, linking it to inflammation and cancer. Midkine, a heparin-binding growth factor, interacts with PG-M/versican, highlighting the role of CSPG binding in growth factor signaling. In disease contexts, CSPG binding is implicated in cancer peritoneal dissemination, neurodegeneration, and demyelination [1,3,6]. This article synthesizes authoritative QuickGO data and verified PubMed literature to provide a comprehensive overview of GO:0035373, covering its mechanism, key genes, research methods, and relevance to human disease.
chondroitin sulfate proteoglycan binding At A Glance
| GO ID | GO:0035373 |
|---|---|
| GO term | chondroitin sulfate proteoglycan binding |
| Ontology | molecular_function |
| Synonym | none |
| Major function | Binding to chondroitin sulfate proteoglycans, mediating extracellular matrix interactions and signaling |
| Definition source | QuickGO |
| Related diseases | Ovarian cancer, neurodegenerative diseases, demyelination |
| Key binding partners | Neurocan, versican, CSPG4, midkine, selectins, CD44 |
| Research methods | CRISPR knockout, binding assays, SPR, co-IP |
What Is GO:0035373?
Chondroitin sulfate proteoglycan binding (GO:0035373) refers to the selective interaction of a molecule (typically a protein) with a chondroitin sulfate proteoglycan. Chondroitin sulfate proteoglycans are composed of a core protein covalently linked to one or more chondroitin sulfate glycosaminoglycan chains. This binding function is involved in mediating cell-matrix and cell-cell interactions, and it can modulate the activity of bound partners, such as growth factors or receptors [2,4,5].
Why Is chondroitin sulfate proteoglycan binding Important in Cell Biology?
Chondroitin sulfate proteoglycan binding is fundamental to extracellular matrix biology and cell signaling. It regulates processes such as neuronal development, inflammation, and cancer progression [2,3,4]. Dysregulation of CSPG binding is associated with pathologies including ovarian cancer peritoneal dissemination, neurodegenerative diseases, and impaired remyelination [1,3,6]. Therefore, understanding the molecular basis of CSPG binding offers opportunities for therapeutic intervention and biomarker development.
• Mediates cell adhesion and migration through interactions with CSPGs like neurocan and versican [2,4].
• Regulates growth factor signaling by sequestering or presenting factors such as midkine.
• Involved in cancer progression, including ovarian cancer peritoneal dissemination.
• Contributes to neurodegeneration and impaired remyelination in demyelinating diseases [3,6].
• Plays a role in inflammation via selectin and CD44 binding.
• Targeted by bacterial toxins, e.g., TcdB from Clostridioides difficile, for cell entry.
• Modulates hyaluronic acid binding to fibronectin, affecting matrix assembly.
• Provides potential therapeutic targets for neuroprotection and remyelination.
• Enables experimental dissection of extracellular matrix functions using CRISPR models [1,8].
What Happens During chondroitin sulfate proteoglycan binding?
Recognition and Initial Contact
In simple terms: The binding molecule first recognizes and attaches to the chondroitin sulfate chains or core protein of the CSPG.
Chondroitin sulfate proteoglycan binding typically begins with electrostatic interactions between positively charged amino acids in the binding protein and the negatively charged sulfate groups on chondroitin sulfate glycosaminoglycan chains. For example, midkine, a heparin-binding growth factor, binds to PG-M/versican through such interactions. Similarly, versican binds to L-selectin, P-selectin, and CD44 via its chondroitin sulfate chains. This initial recognition can be specific to the sulfation pattern of the chondroitin sulfate chains, determining binding affinity and selectivity.
Stabilization and Complex Formation
In simple terms: After initial contact, the interaction is stabilized, forming a stable complex that can trigger downstream effects.
Following recognition, binding is stabilized by additional non-covalent interactions, including hydrogen bonds and hydrophobic contacts. For instance, the binding of chondroitin sulfate proteoglycan (PG-M-like proteoglycan) to hyaluronic acid and fibronectin involves multiple contact points that enhance affinity. In the case of neurocan, its binding to neuronal cell surfaces is mediated by both its core protein and glycosaminoglycan chains, contributing to its role in brain development. This stabilization can lead to conformational changes in the binding partner, modulating its activity.
Functional Consequences
In simple terms: The binding event leads to functional outcomes such as cell signaling, adhesion, or matrix remodeling.
The formation of CSPG-binding complexes can trigger diverse cellular responses. For example, versican binding to selectins and CD44 is implicated in leukocyte adhesion and inflammation. Midkine binding to versican may modulate growth factor signaling. In cancer, CSPG4 (chondroitin sulfate proteoglycan 4) binding promotes peritoneal dissemination of ovarian cancer cells. In the nervous system, CSPG binding by neurocan influences axon guidance and synaptic plasticity. These functional consequences highlight the importance of CSPG binding in physiology and disease.
Regulation and Dynamics
In simple terms: The binding process is regulated by factors such as sulfation patterns, proteolytic cleavage, and competing molecules.
Chondroitin sulfate proteoglycan binding is dynamically regulated. The sulfation pattern of chondroitin sulfate chains can vary, affecting binding specificity. Proteolytic cleavage of CSPG core proteins can release fragments that compete for binding. Additionally, low-molecular weight protamine has been shown to mitigate CSPG inhibition in demyelination models, suggesting that modulating CSPG binding can be therapeutic. Bacterial toxins like TcdB from Clostridioides difficile bind to CSPG4 and Frizzled proteins, demonstrating that pathogens can exploit CSPG binding for cell entry.
Key Genes Involved in GO:0035373 chondroitin sulfate proteoglycan binding
The following genes encode proteins that bind chondroitin sulfate proteoglycans or are themselves CSPGs involved in binding interactions, as supported by published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| CSPG4 | Chondroitin sulfate proteoglycan 4; binds to TcdB and promotes cell migration | Target in ovarian cancer peritoneal dissemination and bacterial toxin entry [1,8] |
| NCAN | Neurocan; brain-specific CSPG involved in neuronal adhesion | Implicated in neurodegenerative diseases and brain development [2,3] |
| VCAN | Versican; large CSPG binding to selectins and CD44 | Role in inflammation, cancer, and extracellular matrix assembly |
| MDK | Midkine; heparin-binding growth factor that binds PG-M/versican | Involved in growth factor signaling and cancer |
| SELL | L-selectin; binds versican | Mediates leukocyte adhesion and inflammation |
| SELP | P-selectin; binds versican | Platelet and endothelial cell adhesion |
| CD44 | Cell surface glycoprotein; binds versican | Involved in cell migration and cancer metastasis |
| FN1 | Fibronectin; binds hyaluronic acid via CSPG | Extracellular matrix assembly and cell adhesion |
| HAPLN1 | Hyaluronan and proteoglycan link protein 1; stabilizes CSPG-hyaluronan complexes | Matrix stabilization and cartilage biology |
| BCAN | Brevican; brain CSPG | Neural plasticity and neurodegeneration |
| ACAN | Aggrecan; cartilage CSPG | Osteoarthritis and matrix biology |
| PTN | Pleiotrophin; heparin-binding growth factor | Neurite outgrowth and cancer |
| SDC1 | Syndecan-1; cell surface proteoglycan | Cell adhesion and signaling |
| GPC1 | Glypican-1; cell surface proteoglycan | Growth factor signaling and cancer |
| TNC | Tenascin-C; extracellular matrix glycoprotein | Neural development and inflammation |
| CD47 | Integrin-associated protein; interacts with CSPGs | Cell migration and immune evasion |
| PTPRS | Protein tyrosine phosphatase receptor sigma; binds CSPGs | Axon guidance and neural repair |
| NRCAM | Neuronal cell adhesion molecule; interacts with neurocan | Neural development and adhesion |
How Is chondroitin sulfate proteoglycan binding Regulated?
Chondroitin sulfate proteoglycan binding is regulated at multiple levels. The sulfation pattern of chondroitin sulfate chains, determined by sulfotransferases, modulates binding affinity and specificity. Proteolytic processing of CSPG core proteins can generate fragments that act as competitive inhibitors or modulators. Extracellular matrix remodeling enzymes, such as matrix metalloproteinases, can cleave CSPGs and alter binding availability. Additionally, post-translational modifications of binding partners, such as phosphorylation, can affect their interaction with CSPGs. In disease, low-molecular weight protamine has been shown to modulate CSPG binding, enhancing neuroprotection and remyelination.
chondroitin sulfate proteoglycan binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CSPG4 | Ovarian cancer peritoneal dissemination | CRISPR knockout in ovarian cancer cell lines |
| NCAN | Neurodegenerative diseases | Knockout mouse models and neuronal cultures [2,3] |
| VCAN | Inflammation and cancer metastasis | CRISPR knockout in immune and cancer cells |
| MDK | Cancer and growth factor signaling | Overexpression and knockout in cancer cell lines |
| PTPRS | Demyelination and impaired remyelination | Knockout models and remyelination assays |
Chondroitin Sulfate Proteoglycan Binding in Cancer
CSPG binding is critically involved in cancer progression. CSPG4 (chondroitin sulfate proteoglycan 4) promotes peritoneal dissemination in ovarian cancer, and targeting CSPG4 provides a new treatment approach. Versican binding to selectins and CD44 enhances inflammation and tumor cell adhesion, facilitating metastasis. Midkine binding to versican may also contribute to tumor growth and angiogenesis. These interactions highlight CSPG binding as a potential therapeutic target in oncology.
Chondroitin Sulfate Proteoglycan Binding in Neurodegeneration
In the nervous system, CSPG binding is implicated in neurodegenerative diseases. Neurocan, a brain-specific CSPG, is involved in neuronal adhesion and may contribute to Alzheimer's disease and other neurodegenerative conditions [2,3]. Brevican and aggrecan, other CSPGs, are also linked to neurodegeneration. Dysregulated CSPG binding can impair synaptic plasticity and neuronal survival, making it a target for neuroprotective strategies.
Chondroitin Sulfate Proteoglycan Binding in Demyelination and Remyelination
CSPGs inhibit remyelination after injury. Low-molecular weight protamine enhances neuroprotection and remyelination by mitigating CSPG inhibition in models of demyelination. This suggests that modulating CSPG binding can promote repair in multiple sclerosis and other demyelinating diseases. The interaction of CSPGs with receptors such as PTPRS is a key mechanism in this inhibition.
Chondroitin Sulfate Proteoglycan Binding in Bacterial Infection
Bacterial toxins can exploit CSPG binding for cell entry. TcdB from Clostridioides difficile binds to CSPG4 and Frizzled proteins, and these receptor binding domains are functionally independent and additive. This highlights the role of CSPG binding in infectious disease and potential targets for therapeutic intervention.
From chondroitin sulfate proteoglycan binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does CSPG4 mediate ovarian cancer peritoneal dissemination? | CSPG4 knockout in ovarian cancer cell lines |
| What is the role of neurocan in neuronal adhesion? | Neurocan knockout mice and primary neurons |
| How does versican binding to selectins affect inflammation? | Versican knockout or point mutations in binding sites |
| Does midkine binding to versican modulate growth factor signaling? | Midkine overexpression and knockout in cell lines |
| Can modulating CSPG binding enhance remyelination? | Low-molecular weight protamine treatment in demyelination models |
| How does TcdB bind to CSPG4 and Frizzled? | Knock-in of binding domain mutations in CSPG4 |
How to Study the chondroitin sulfate proteoglycan binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Surface plasmon resonance (SPR) | Binding affinity and kinetics | Characterizing CSPG-protein interactions |
| Co-immunoprecipitation | Protein-protein interactions | Identifying CSPG binding partners |
| CRISPR knockout | Gene function loss | Testing causality in disease models |
| CRISPR knock-in | Precise mutation introduction | Mapping binding domains |
| Fluorescence microscopy | Cellular localization and dynamics | Visualizing CSPG binding in cells |
| Mass spectrometry | Protein identification and quantification | Discovering novel CSPG-binding proteins |
| Solid-phase binding assay | Direct binding interactions | Screening for CSPG binders |
Binding Assays
Solid-phase binding assays and surface plasmon resonance (SPR) are used to measure the affinity and kinetics of CSPG binding. For example, the binding of versican to selectins and CD44 was characterized using such assays. Midkine binding to PG-M/versican was demonstrated using binding assays. These methods allow quantitative assessment of binding specificity.
Co-immunoprecipitation and Pull-down
Co-immunoprecipitation (co-IP) and pull-down assays using recombinant CSPG domains or full-length proteins can identify binding partners and map interaction domains. The interaction of CSPG with hyaluronic acid and fibronectin was studied using pull-down assays. These techniques are essential for validating CSPG-binding interactions in vitro and in vivo.
CRISPR-based Genetic Models
CRISPR knockout, knock-in, and point mutation models enable causal testing of CSPG-binding genes. For instance, CSPG4 knockout in ovarian cancer cells reduced peritoneal dissemination. Knock-in of point mutations in TcdB binding domains of CSPG4 clarified receptor specificity. These models are powerful for dissecting gene function in disease contexts.
Imaging and Proteomics
Fluorescence microscopy and live-cell imaging can visualize CSPG binding and its effects on cell behavior. Proteomics approaches, such as mass spectrometry, can identify novel CSPG-binding proteins. These methods complement genetic and biochemical assays to provide a systems-level understanding of CSPG binding.
How CRISPR Can Be Used to Study GO:0035373 chondroitin sulfate proteoglycan binding
Knockout
CRISPR knockout of genes encoding CSPG-binding proteins, such as CSPG4 or versican, allows researchers to assess loss-of-function phenotypes. For example, CSPG4 knockout in ovarian cancer cells reduced peritoneal dissemination, demonstrating its role in cancer progression. Knockout models are essential for validating the functional significance of CSPG binding in vivo.
Point Mutation
CRISPR point mutation can introduce specific amino acid substitutions in CSPG-binding domains to dissect binding specificity. For instance, mutating the TcdB binding domain of CSPG4 clarified its independent interaction with Frizzled proteins. This approach is valuable for mapping critical residues involved in CSPG binding.
Knock-in
CRISPR knock-in can insert tags or reporter genes into endogenous CSPG-binding protein loci to study their expression, localization, and interactions. For example, knock-in of a fluorescent tag into the CSPG4 gene allows live-cell imaging of CSPG4 dynamics. This technique enables precise tracking of CSPG-binding proteins in physiological contexts.
Overexpression
CRISPR activation (CRISPRa) or traditional overexpression constructs can drive high-level expression of CSPG-binding proteins to study gain-of-function effects. Overexpression of midkine, for example, enhanced its binding to versican and modulated growth factor signaling. Overexpression models are useful for identifying downstream pathways activated by CSPG binding.
How EDITGENE Supports chondroitin sulfate proteoglycan binding Research
Researchers studying chondroitin sulfate proteoglycan binding-related genes often need to determine whether a candidate gene is causally involved in extracellular matrix interactions, cell signaling, or disease progression. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this research, from gene knockout to precise point mutations and overexpression models.
Contact EDITGENE today to design your custom CRISPR model for chondroitin sulfate proteoglycan binding research.
Frequently Asked Questions About chondroitin sulfate proteoglycan binding
What is chondroitin sulfate proteoglycan binding?
Chondroitin sulfate proteoglycan binding (GO:0035373) is a molecular function defined as the binding to a chondroitin sulfate proteoglycan, any proteoglycan containing chondroitin sulfate as the glycosaminoglycan carbohydrate unit.
What genes are involved in chondroitin sulfate proteoglycan binding?
Key genes include CSPG4, NCAN, VCAN, MDK, SELL, SELP, CD44, and FN1, among others, which encode proteins that bind CSPGs or are themselves CSPGs [1,2,4,5,7].
How is chondroitin sulfate proteoglycan binding studied?
It is studied using binding assays (SPR, solid-phase), co-immunoprecipitation, CRISPR knockout/knock-in models, and imaging techniques [4,5,7,8].
What diseases are associated with chondroitin sulfate proteoglycan binding?
It is associated with ovarian cancer peritoneal dissemination, neurodegenerative diseases, demyelination, and bacterial infections [1,3,6,8].
What is the role of CSPG4 in cancer?
CSPG4 promotes peritoneal dissemination in ovarian cancer and is a potential therapeutic target.
How does versican interact with selectins?
Versican binds to L-selectin, P-selectin, and CD44 through its chondroitin sulfate chains, mediating inflammation and cell adhesion.
Can chondroitin sulfate proteoglycan binding be targeted therapeutically?
Yes, low-molecular weight protamine has been shown to mitigate CSPG inhibition and enhance remyelination in demyelination models.
What is the role of neurocan in the brain?
Neurocan is a brain-specific CSPG involved in neuronal adhesion and migration, and it is implicated in neurodegenerative diseases [2,3].
How does midkine bind to versican?
Midkine, a heparin-binding growth factor, binds to PG-M/versican through electrostatic interactions with chondroitin sulfate chains.
What CRISPR models are available for studying CSPG binding?
EDITGENE offers knockout, point mutation, knock-in, overexpression cell models, and CRISPR library screening for genes involved in CSPG binding [1,8].
Conclusion
Chondroitin sulfate proteoglycan binding (GO:0035373) is a critical molecular function that governs diverse biological processes, from extracellular matrix assembly to cell signaling and disease progression. The interactions between CSPGs and their binding partners, such as neurocan, versican, CSPG4, and midkine, are implicated in cancer, neurodegeneration, and demyelination [1,2,3,4,5,6]. Understanding these interactions at the molecular level offers opportunities for therapeutic intervention. CRISPR-based models and biochemical assays provide powerful tools to dissect the mechanisms and functional consequences of CSPG binding. EDITGENE's comprehensive services support researchers in uncovering the roles of CSPG-binding genes in health and disease.
References
- 1. Uno K et al.. 2024. Chondroitin Sulfate Proteoglycan 4 Provides New Treatment Approach to Preventing Peritoneal Dissemination in Ovarian Cancer.. Int J Mol Sci 25(3) PMID: 38338902
- 2. Rauch U et al.. 2001. Neurocan: a brain chondroitin sulfate proteoglycan.. Cell Mol Life Sci 58(12-13):1842-56 PMID: 11766883
- 3. Lin JZ et al.. 2021. The emerging role of the chondroitin sulfate proteoglycan family in neurodegenerative diseases.. Rev Neurosci 32(7):737-750 PMID: 33655733
- 4. Kawashima H et al.. 2000. Binding of a large chondroitin sulfate/dermatan sulfate proteoglycan, versican, to L-selectin, P-selectin, and CD44.. J Biol Chem 275(45):35448-56 PMID: 10950950
- 5. Zou K et al.. 2000. A heparin-binding growth factor, midkine, binds to a chondroitin sulfate proteoglycan, PG-M/versican.. Eur J Biochem 267(13):4046-53 PMID: 10866805
- 6. Koppinen TK et al.. 2025. Low-molecular weight protamine enhances neuroprotection and remyelination by mitigating chondroitin sulfate proteoglycan inhibition in models of demyelination.. Neuropharmacology 279:110618 PMID: 40744406
- 7. Yamagata M et al.. 1986. Chondroitin sulfate proteoglycan (PG-M-like proteoglycan) is involved in the binding of hyaluronic acid to cellular fibronectin.. J Biol Chem 261(29):13526-35 PMID: 3759976
- 8. Henkel D et al.. 2020. Receptor Binding Domains of TcdB from Clostridioides difficile for Chondroitin Sulfate Proteoglycan-4 and Frizzled Proteins Are Functionally Independent and Additive.. Toxins (Basel) 12(12) PMID: 33255261
