GO:0070653 high-density lipoprotein particle receptor binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0070653 describes the molecular function of binding to a high-density lipoprotein (HDL) receptor, a critical interaction for HDL metabolism and reverse cholesterol transport.
• Key receptors include SR-BI (SCARB1), cubilin (CUBN), and other HDL-binding proteins that mediate cellular uptake and signaling.
• The binding is often negatively cooperative, allowing dynamic regulation of HDL docking and lipid transfer.
• HDL particle surfaceome interactions are complex and involve multiple proteins and lipids, influencing functional heterogeneity.
• Dysregulation of HDL receptor binding is linked to atherosclerotic cardiovascular disease, making it a therapeutic target.
• CRISPR-based models (KO, point mutation, knock-in, overexpression) enable precise dissection of receptor-ligand interactions and their physiological consequences.
Description
High-density lipoprotein (HDL) particles are central to reverse cholesterol transport, and their interaction with specific cell-surface receptors is a key regulatory step in lipid homeostasis. The Gene Ontology (GO) term GO:0070653, high-density lipoprotein particle receptor binding, defines the molecular function of binding to an HDL receptor, encompassing the physical interaction between HDL particles and receptor proteins. This function is essential for HDL docking, lipid exchange, and downstream signaling, and its perturbation is implicated in cardiovascular and metabolic diseases. Researchers study this term to understand how HDL particles are recognized by cells, how receptor specificity is achieved, and how these interactions can be targeted therapeutically. The binding event is not merely a passive tethering but involves dynamic conformational changes and cooperative effects that modulate affinity and downstream responses. This article synthesizes authoritative GO annotations and published literature to provide a comprehensive overview of the mechanism, key genes, and experimental approaches for investigating GO:0070653.
high-density lipoprotein particle receptor binding At A Glance
| GO ID | GO:0070653 |
|---|---|
| GO term | high-density lipoprotein particle receptor binding |
| Ontology | molecular_function |
| Synonym | HDL receptor binding, high-density lipoprotein receptor binding |
| Major function | Binding to a high-density lipoprotein receptor, mediating HDL recognition and downstream cellular responses |
| Related receptors | SR-BI (SCARB1), cubilin (CUBN), and other HDL-binding proteins |
| Biological context | Reverse cholesterol transport, lipid metabolism, atherosclerosis |
| Research relevance | Target for cardiovascular disease, drug delivery, and nanobiologics |
What Is GO:0070653?
GO:0070653 is a molecular function term defined as binding to a high-density lipoprotein receptor. It encompasses the selective interaction between an HDL particle (or its components) and a receptor protein on the cell surface, initiating processes such as lipid transfer, endocytosis, or signal transduction. This function is distinct from binding to other lipoprotein classes and is mediated by specific structural motifs on both the HDL particle and the receptor.
Why Is high-density lipoprotein particle receptor binding Important in Cell Biology?
Understanding GO:0070653 is crucial because HDL receptor binding is the first committed step in reverse cholesterol transport, a process that protects against atherosclerosis by removing excess cholesterol from peripheral tissues. Dysfunctional HDL receptor binding contributes to cardiovascular disease risk, and modulating this interaction holds therapeutic potential. Moreover, HDL particles can be engineered as nanocarriers for precision medicine, where receptor binding dictates targeting specificity. Thus, this molecular function sits at the intersection of basic lipid biology, disease mechanisms, and translational applications.
• Mediates the initial recognition of HDL particles by cells, enabling cholesterol efflux and reverse transport.
• Determines tissue specificity of HDL uptake, influencing lipid distribution and homeostasis.
• Negatively cooperative binding allows fine-tuned regulation of HDL docking and release.
• Alterations in HDL receptor binding are associated with atherosclerotic cardiovascular disease.
• HDL surfaceome interactions modulate binding affinity and functional heterogeneity.
• Enables targeted delivery of drugs or imaging agents via HDL nanobiologics.
• Provides a molecular target for CRISPR-based screens to identify novel regulators.
• Relevant to transendothelial transport of lipoproteins, linking binding to tissue delivery.
• Cubilin acts as an HDL receptor in kidney and other tissues, expanding the functional repertoire.
• Dynamic HDL synapse formation highlights the spatiotemporal regulation of receptor binding.
Molecular Mechanism of high-density lipoprotein particle receptor binding
Recognition and Docking of HDL Particles
In simple terms: HDL particles first stick to receptors on the cell surface.
The binding event begins with the recognition of HDL particles by specific receptors such as SR-BI (SCARB1) and cubilin (CUBN). This interaction is mediated by apolipoproteins (e.g., apoA-I) on the HDL surface and extracellular domains of the receptors. The binding is often reversible and can exhibit negative cooperativity, meaning that the binding of one HDL particle reduces the affinity for subsequent particles, allowing dynamic exchange.
Conformational Changes and Lipid Transfer
In simple terms: After binding, the receptor changes shape to allow cholesterol to move.
Upon binding, receptors like SR-BI undergo conformational changes that facilitate the transfer of cholesterol esters and other lipids from the HDL particle into the cell. This process does not necessarily require internalization of the entire HDL particle; instead, selective lipid uptake occurs. The binding affinity and lipid transfer efficiency are influenced by the composition of the HDL particle and the receptor's oligomeric state.
Cooperative Binding and Regulation
In simple terms: The binding can be tuned by how many receptors are present and their arrangement.
Negatively cooperative binding of HDL to SR-BI ensures that cells can sense and respond to HDL concentrations over a wide range. This cooperativity is thought to arise from allosteric interactions between receptor subunits. Additionally, the formation of an HDL synapse, a dynamic clustering of receptors and signaling molecules, regulates the duration and strength of binding.
Downstream Signaling and Functional Consequences
In simple terms: Binding triggers signals inside the cell that affect cholesterol handling.
HDL receptor binding can activate intracellular signaling pathways, including those involving kinases and small GTPases, which modulate cholesterol efflux, inflammatory responses, and endothelial function. For example, SR-BI binding activates eNOS and influences nitric oxide production. These signaling events link HDL binding to broader cardiovascular protective effects.
Receptor Diversity and Tissue Specificity
In simple terms: Different tissues use different receptors to grab HDL.
Beyond SR-BI, cubilin (CUBN) acts as an HDL receptor in kidney proximal tubules and other epithelia, mediating endocytosis of HDL. Other HDL-binding proteins, such as those identified in surfaceome studies, contribute to tissue-specific uptake and signaling. This diversity allows for specialized functions of HDL in different physiological contexts, including transendothelial transport.
Key Genes Involved in GO:0070653 high-density lipoprotein particle receptor binding
The following genes encode proteins that directly bind HDL particles or regulate this interaction, as supported by published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SCARB1 | Encodes SR-BI, the primary HDL receptor mediating selective cholesterol uptake | Central to reverse cholesterol transport; target for atherosclerosis research |
| CUBN | Encodes cubilin, an HDL receptor in kidney and intestine | Mediates HDL endocytosis; linked to proteinuria and kidney disease |
| APOA1 | Major apolipoprotein on HDL, ligand for SR-BI and cubilin | Determines HDL structure and binding affinity |
| APOA2 | Second most abundant HDL apolipoprotein, modulates HDL function | Influences HDL binding and metabolism |
| LCAT | Enzyme that esterifies cholesterol on HDL, affecting particle maturation | Impacts HDL composition and receptor binding |
| CETP | Transfers cholesteryl esters between lipoproteins, altering HDL pool | Modulates HDL levels and receptor interactions |
| ABCA1 | Cholesterol efflux pump that lipidates apoA-I to form HDL | Essential for HDL biogenesis; affects available HDL for binding |
| ABCG1 | Cholesterol efflux pump to mature HDL | Contributes to cellular cholesterol removal |
| PDZK1 | Scaffold protein that stabilizes SR-BI at the cell surface | Regulates SR-BI expression and HDL binding |
| DAB2 | Adaptor protein involved in SR-BI endocytosis | Modulates SR-BI trafficking and HDL uptake |
| MAPK1 | Kinase activated downstream of HDL binding | Mediates HDL-induced signaling |
| AKT1 | Kinase involved in HDL-induced survival signaling | Links HDL binding to cell survival |
| NOS3 | Endothelial nitric oxide synthase activated by HDL binding | Mediates vasoprotective effects of HDL |
| GUCY1A1 | Guanylate cyclase subunit involved in HDL signaling | Contributes to nitric oxide signaling |
| RhoA | Small GTPase regulated by HDL binding | Affects cytoskeletal dynamics and receptor clustering |
| ARF6 | GTPase involved in endosomal trafficking of SR-BI | Regulates HDL uptake and recycling |
| VAMP3 | SNARE protein involved in vesicle fusion | Facilitates SR-BI trafficking |
| CLTC | Clathrin heavy chain, mediates endocytosis of HDL receptors | Required for cubilin-mediated HDL uptake |
How Is high-density lipoprotein particle receptor binding Regulated?
The binding of HDL to its receptors is regulated at multiple levels. Receptor expression is controlled by transcription factors such as SREBP and LXRs in response to cellular cholesterol levels. Post-translational modifications, including phosphorylation and ubiquitination, modulate receptor stability and trafficking. The formation of the HDL synapse, a dynamic clustering of receptors and signaling proteins, provides spatiotemporal regulation. Additionally, the lipid composition of HDL particles, influenced by enzymes like LCAT and CETP, affects binding affinity. Cooperative interactions between receptor subunits further fine-tune the binding response to HDL concentration.
high-density lipoprotein particle receptor binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SCARB1 | Atherosclerosis, cardiovascular disease | Scarb1 knockout mouse, hepatic overexpression |
| CUBN | Imerslund-Gräsbeck syndrome, proteinuria | Cubn knockout mouse, kidney-specific KO |
| APOA1 | Familial amyloidosis, cardiovascular risk | Apoa1 transgenic and knockout mice |
| LCAT | Fish-eye disease, corneal opacities | Lcat knockout mouse |
| CETP | Dyslipidemia, cardiovascular risk | CETP transgenic mice, human CETP expression |
Atherosclerotic Cardiovascular Disease
Impaired HDL receptor binding leads to reduced reverse cholesterol transport, promoting cholesterol accumulation in macrophages and atherosclerotic plaque formation. Genetic variants in SCARB1 and CUBN have been associated with altered HDL levels and cardiovascular risk. Therapies aimed at enhancing SR-BI function or HDL binding are under investigation.
Kidney Disease
Cubilin (CUBN) mediates HDL uptake in the kidney, and mutations in CUBN cause Imerslund-Gräsbeck syndrome and proteinuria. Defective cubilin-HDL binding contributes to renal lipid accumulation and kidney injury.
Metabolic Syndrome and Diabetes
Insulin resistance and type 2 diabetes are associated with dysfunctional HDL particles that exhibit reduced receptor binding and cholesterol efflux capacity. This contributes to accelerated atherosclerosis in diabetic patients.
Neurodegeneration
HDL-like particles in the brain, such as apoE-containing lipoproteins, interact with receptors like LRP1 and SR-BI. Altered binding may affect amyloid-beta clearance and neurodegeneration, though direct evidence for GO:0070653 in this context is emerging.
From high-density lipoprotein particle receptor binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of SR-BI affect HDL binding and cholesterol efflux? | SCARB1 knockout cell line (e.g., HepG2, CHO) |
| What is the effect of a point mutation in the SR-BI ligand-binding domain? | Point-mutation knock-in via CRISPR in cell lines |
| Can a tagged SR-BI be used to track HDL binding dynamics? | Knock-in of fluorescent tag (e.g., GFP) at SCARB1 locus |
| Does overexpression of cubilin enhance HDL uptake? | Cubilin overexpression in HEK293 or polarized epithelial cells |
| Which genes regulate HDL receptor binding? | Genome-wide CRISPR knockout library screening |
| How does HDL particle composition affect binding? | Isolation of HDL from different donors, surfaceome analysis |
How to Study the high-density lipoprotein particle receptor binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Radioligand binding assay | Binding affinity and cooperativity | Characterize SR-BI-HDL interaction |
| Surface plasmon resonance | Kinetic constants (kon, koff) | Real-time binding analysis |
| CRISPR knockout screen | Genes required for HDL binding | Identify novel regulators |
| Proteomics | Protein composition of HDL-receptor complexes | Discover new binding partners |
| Live-cell imaging | Dynamics of binding and internalization | Visualize HDL synapse formation |
| Flow cytometry | Cell surface binding of fluorescent HDL | Quantify binding in mutant cell lines |
| Immunoprecipitation | Physical interaction between receptor and HDL proteins | Confirm binding partners |
| Lipid efflux assay | Functional consequence of binding | Measure cholesterol removal |
Binding Assays
Direct binding assays using radiolabeled or fluorescently labeled HDL particles are used to measure affinity and cooperativity. Surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) provide kinetic and thermodynamic parameters.
CRISPR Screening
Genome-wide CRISPR knockout or activation screens can identify genes that regulate HDL receptor binding and downstream lipid uptake. These screens typically use fluorescent HDL particles and FACS sorting to isolate cells with altered binding.
Proteomics and Surfaceome Analysis
Mass spectrometry-based proteomics of HDL particles and receptor complexes reveals interacting partners and post-translational modifications. Surfaceome profiling of HDL particles identifies proteins that mediate binding.
Imaging and Trafficking Studies
Live-cell imaging with fluorescent HDL and tagged receptors allows visualization of binding, internalization, and recycling. Total internal reflection fluorescence (TIRF) microscopy can resolve single binding events.
How CRISPR Can Be Used to Study GO:0070653 high-density lipoprotein particle receptor binding
Knockout
CRISPR knockout of SCARB1 or CUBN abolishes HDL receptor binding, providing a clean background to study downstream effects. Knockout cell lines are used to measure cholesterol efflux and signaling.
Point Mutation
Introducing point mutations in the ligand-binding domain of SR-BI or cubilin allows structure-function analysis. For example, mutations in the SR-BI extracellular loop can disrupt HDL binding without affecting surface expression.
Knock-in
Knock-in of epitope tags (e.g., FLAG, GFP) at endogenous loci enables tracking of receptor trafficking and interaction with HDL in real time. This approach preserves physiological expression levels.
Overexpression
Overexpression of wild-type or mutant receptors in cell lines enhances HDL binding and uptake, facilitating biochemical studies. It is also used to test gain-of-function variants.
How EDITGENE Supports high-density lipoprotein particle receptor binding Research
Researchers studying high-density lipoprotein particle receptor binding-related genes often need to determine whether a candidate gene is causally involved in HDL recognition, lipid transfer, or downstream signaling. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models, enabling rigorous functional validation.
Contact EDITGENE today to design your custom CRISPR model for high-density lipoprotein particle receptor binding research.
Frequently Asked Questions About high-density lipoprotein particle receptor binding
What is GO:0070653?
GO:0070653 is a Gene Ontology molecular function term defined as binding to a high-density lipoprotein receptor, encompassing the interaction between HDL particles and specific cell-surface receptors.
What genes are involved in high-density lipoprotein particle receptor binding?
Key genes include SCARB1 (SR-BI), CUBN (cubilin), APOA1, and other apolipoproteins and receptors that mediate HDL recognition.
What is the function of SR-BI in HDL binding?
SR-BI (encoded by SCARB1) is the primary HDL receptor that mediates selective cholesterol uptake and exhibits negatively cooperative binding.
How is HDL receptor binding regulated?
It is regulated by receptor expression, post-translational modifications, cooperative interactions, and the lipid composition of HDL particles.
What diseases are associated with defective HDL receptor binding?
Atherosclerotic cardiovascular disease, kidney disease (cubilin mutations), and metabolic syndrome are linked to impaired HDL receptor binding.
What methods are used to study HDL receptor binding?
Common methods include radioligand binding assays, surface plasmon resonance, CRISPR screens, proteomics, and live-cell imaging.
Can CRISPR be used to study HDL receptor binding?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models enable precise dissection of receptor function and binding mechanisms.
What is the role of cubilin in HDL metabolism?
Cubilin acts as an HDL receptor in kidney and intestine, mediating endocytosis and contributing to HDL clearance.
How does HDL particle composition affect receptor binding?
The surfaceome of HDL particles, including apolipoproteins and enzymes, influences binding affinity and specificity.
What is the HDL synapse?
The HDL synapse is a dynamic clustering of receptors and signaling molecules that forms upon HDL binding, regulating the duration and strength of the interaction.
Conclusion
GO:0070653, high-density lipoprotein particle receptor binding, is a fundamental molecular function that governs HDL recognition and downstream lipid metabolism. Its dysregulation is implicated in cardiovascular and kidney diseases, making it a prime target for therapeutic intervention. Advances in CRISPR-based models and screening technologies are accelerating the discovery of novel regulators and the development of HDL-based nanobiologics. EDITGENE offers comprehensive services to support these research efforts, from knockout to overexpression and library screening.
References
- 1. Frey K et al.. 2023. Mapping the dynamic high-density lipoprotein synapse.. Atherosclerosis 380:117200 PMID: 37619408
- 2. Mulder WJM et al.. 2018. High-Density Lipoprotein Nanobiologics for Precision Medicine.. Acc Chem Res 51(1):127-137 PMID: 29281244
- 3. Moestrup SK et al.. 2000. Cubilin, a high-density lipoprotein receptor.. Curr Opin Lipidol 11(2):133-40 PMID: 10787174
- 4. Nieland TJ et al.. 2011. Negatively cooperative binding of high-density lipoprotein to the HDL receptor SR-BI.. Biochemistry 50(11):1818-30 PMID: 21254782
- 5. Frey K et al.. 2022. Decoding Functional High-Density Lipoprotein Particle Surfaceome Interactions.. Int J Mol Sci 23(16) PMID: 36012766
- 6. Schaefer EJ et al.. 2025. High Density Lipoprotein Particle Composition, Functionality, Deficiency, and Atherosclerotic Cardiovascular Disease Risk: A Review.. Curr Atheroscler Rep 27(1):62 PMID: 40489011
- 7. Fidge NH. 1999. High density lipoprotein receptors, binding proteins, and ligands.. J Lipid Res 40(2):187-201 PMID: 9925647
- 8. Jang E et al.. 2020. Transendothelial transport of lipoproteins.. Atherosclerosis 315:111-125 PMID: 33032832
