GO:0044853 plasma membrane raft: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0044853 plasma membrane raft describes a membrane raft that is part of the plasma membrane, a sterol- and sphingolipid-enriched ordered domain that concentrates specific signaling and adhesion proteins.
• Rafts are dynamic, nanoscale assemblies rather than fixed platforms; single-molecule tracking shows transient confinement and dynamic assembly of raft-philic signaling molecules at the plasma membrane.
• Raft organization depends on cholesterol, sphingolipids, and lipid asymmetry; loss of plasma membrane lipid asymmetry can itself induce ordered domain (raft) formation, and non-vesicular sterol transport helps set the raft versus non-raft sterol distribution.
• Raft association is a determinant of plasma membrane localization for many proteins, making rafts a sorting and signaling hub.
• MPP1-based mechanisms contribute to resting-state raft organization, at least in erythroid cells, indicating cell-type-specific control of raft architecture.
• Raft composition and extent can be modeled biophysically, and raft cholesterol levels influence oncogenic signaling such as EGFR and HER3 activation in triple-negative breast cancer cells.
Description
GO:0044853 plasma membrane raft is a cellular component term describing a membrane raft that is part of the plasma membrane. Membrane rafts are small, dynamic, sterol- and sphingolipid-enriched ordered domains that compartmentalize the plasma membrane and concentrate specific proteins and lipids to support signaling, adhesion, and membrane trafficking. Because rafts are transient and nanoscale, they are defined operationally by their composition, order, and behavior rather than by a single static structure. Researchers study plasma membrane rafts to understand how cells organize signaling at the surface, how lipid environment shapes protein function, and how raft dysregulation contributes to disease. The term is therefore central to membrane biology, immunology, neuroscience, and cancer research, and it is increasingly targeted by CRISPR-based perturbation studies that test the causal role of raft-resident genes.
plasma membrane raft At A Glance
| GO ID | GO:0044853 |
|---|---|
| GO term | plasma membrane raft |
| Ontology | cellular_component |
| Synonym | none |
| Definition | A membrane raft that is part of the plasma membrane. |
| Parent term | membrane raft |
| Major function | Organization of sterol- and sphingolipid-enriched ordered domains that concentrate signaling and adhesion proteins at the cell surface |
| Key lipids | Cholesterol and sphingolipids; raft versus non-raft sterol distribution is maintained by non-vesicular transport |
| Regulatory example | MPP1-based mechanism of resting-state raft organization in erythroid cells |
| Disease relevance | Raft cholesterol levels modulate EGFR and HER3 signaling in triple-negative breast cancer |
What Is GO:0044853?
In your own words, GO:0044853 plasma membrane raft refers to a membrane raft that is physically part of the plasma membrane. A membrane raft is a small, dynamic, ordered domain enriched in cholesterol and sphingolipids that is distinct from the surrounding disordered membrane and that selectively associates with certain proteins and lipids. The plasma membrane raft is thus the plasma membrane-resident subset of raft domains, where signaling, adhesion, and sorting events are concentrated and regulated.
Why Is plasma membrane raft Important in Cell Biology?
Plasma membrane rafts are important because they provide a physical mechanism for compartmentalizing the cell surface, allowing cells to concentrate signaling molecules, receptors, and adhesion complexes into dynamic nanoscale domains. This organization influences how cells respond to extracellular cues, how proteins are sorted to the plasma membrane, and how lipid environment shapes protein activity. Because raft composition and dynamics are altered in cancer and other diseases, understanding GO:0044853 is essential for interpreting membrane signaling and for designing experiments that test causal roles of raft-associated genes.
• Rafts concentrate signaling molecules and receptors, enabling efficient signal transduction at the plasma membrane.
• Raft association determines plasma membrane localization for many proteins, linking lipid environment to protein sorting.
• Cholesterol and sphingolipid content define raft order and stability, and non-vesicular sterol transport regulates raft versus non-raft sterol distribution.
• Loss of plasma membrane lipid asymmetry can induce ordered domain (raft) formation, connecting lipid asymmetry to raft assembly.
• MPP1-based mechanisms contribute to resting-state raft organization, showing cell-type-specific regulation.
• Raft cholesterol levels can modulate oncogenic signaling, as shown for EGFR and HER3 in triple-negative breast cancer cells.
• Single-molecule tracking reveals dynamic assembly and transient confinement of raft-philic molecules, informing models of raft function.
• Biophysical models quantify the extent of raft composition in model plasma membranes, aiding interpretation of experimental data.
• Rafts are implicated in membrane trafficking and adhesion, making them relevant to immunology and cell migration.
• CRISPR perturbation of raft-resident genes enables causal tests of raft function in disease models.
What Happens During plasma membrane raft?
Raft assembly and dynamic organization
In simple terms: Rafts form when certain lipids and proteins gather into small, ordered patches in the plasma membrane.
Plasma membrane rafts are dynamic, nanoscale assemblies enriched in cholesterol and sphingolipids that concentrate raft-philic signaling molecules. Single-molecule tracking shows that these molecules undergo transient confinement and dynamic assembly, indicating that rafts are not static platforms but continuously reorganizing domains. The extent of raft composition can be modeled biophysically, helping to explain how lipid mixtures produce ordered domains in a model plasma membrane.
Lipid asymmetry and raft induction
In simple terms: When the normal uneven distribution of lipids across the membrane is lost, ordered raft domains can form.
Loss of plasma membrane lipid asymmetry can induce ordered domain (raft) formation, linking changes in lipid distribution to raft assembly. Non-vesicular transport of sterols also contributes to the distribution of sterols between raft and non-raft phases, thereby influencing raft organization. These findings indicate that raft formation is sensitive to lipid asymmetry and sterol transport pathways.
Protein sorting and plasma membrane localization
In simple terms: Proteins that prefer raft environments are more likely to reach and stay at the cell surface.
Membrane raft association is a determinant of plasma membrane localization, meaning that raft affinity can control whether a protein is delivered to and retained at the plasma membrane. This sorting function connects raft composition to the surface expression of signaling and adhesion proteins. Consequently, perturbations that alter raft lipids or raft-resident proteins can change plasma membrane protein localization.
Resting-state raft organization
In simple terms: Even in resting cells, specific mechanisms keep rafts organized.
MPP1-based mechanisms contribute to resting-state raft organization, at least in erythroid cells, suggesting that specialized machinery can maintain raft architecture in the absence of activation. This raises the question of whether such mechanisms are general or cell-type-specific. Understanding resting-state organization is important because it sets the baseline for signaling and sorting events at the plasma membrane.
Key Genes Involved in GO:0044853 plasma membrane raft
The following genes and proteins are experimentally linked to plasma membrane raft composition, organization, or function, based on the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| MPP1 | Contributes to resting-state raft organization in erythroid cells | Model for cell-type-specific raft maintenance |
| PCSK9 | Reduces cholesterol levels at the plasma membrane, affecting raft-dependent EGFR and HER3 activation | Target in triple-negative breast cancer raft signaling |
| EGFR | Receptor tyrosine kinase whose activation is influenced by plasma membrane cholesterol and rafts | Readout for raft-dependent oncogenic signaling |
| HER3 | Receptor tyrosine kinase activated in concert with EGFR when raft cholesterol is reduced | Readout for raft-dependent oncogenic signaling |
| Cholesterol transporters (non-vesicular sterol transport machinery) | Regulate sterol distribution between raft and non-raft phases | Dissect how sterol transport shapes raft composition |
| Sphingolipid biosynthetic enzymes | Produce sphingolipids that are enriched in rafts | Test how sphingolipid changes alter raft order |
| Raft-philic signaling molecules (e.g., GPI-anchored proteins, Src-family kinases) | Dynamically assemble in rafts and participate in signaling | Single-molecule tracking of raft dynamics |
| Lipid asymmetry regulators (flippases, floppases, scramblases) | Control plasma membrane lipid asymmetry that can induce raft formation | Test causal links between asymmetry and raft assembly |
| Membrane raft-associated adhesion proteins | Use raft association for plasma membrane localization | Study sorting and surface retention |
| Model membrane lipid mixtures | Define the extent of raft composition in model plasma membranes | Biophysical modeling of raft domains |
| GPI-anchored proteins | Partition into ordered domains and report raft behavior | Imaging and tracking of raft-associated proteins |
| Src-family kinases | Raft-philic signaling molecules that assemble dynamically | Probe signaling at rafts |
| Caveolin | Raft-associated protein implicated in membrane organization | Study raft-associated membrane structures |
| Flotillin | Raft-associated protein used as a raft marker | Assess raft composition changes |
| Cholesterol-binding proteins | Sense and modify plasma membrane cholesterol | Link sterol transport to raft function |
| Sphingomyelin | Sphingolipid enriched in rafts | Lipidomic readout of raft composition |
| Gangliosides | Glycosphingolipids that partition into rafts | Markers of ordered domains |
| Membrane order sensors (e.g., Laurdan, di-4-ANEPPDHQ) | Report lipid order in membranes | Quantify raft-like order in cells and model membranes |
How Is plasma membrane raft Regulated?
Plasma membrane raft organization is regulated by lipid composition, lipid asymmetry, sterol transport, and specific proteins such as MPP1. Non-vesicular sterol transport controls the distribution of sterols between raft and non-raft phases, thereby tuning raft stability and composition. Loss of lipid asymmetry can induce ordered domain formation, indicating that asymmetry-maintaining enzymes regulate raft assembly. MPP1-based mechanisms contribute to resting-state raft organization in erythroid cells, suggesting cell-type-specific regulation. In cancer cells, PCSK9 can reduce plasma membrane cholesterol and thereby alter raft-dependent EGFR and HER3 signaling, showing that disease-associated regulators can remodel rafts.
plasma membrane raft and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PCSK9 | Triple-negative breast cancer; reduces plasma membrane cholesterol and activates EGFR/HER3 | PCSK9 knockout and overexpression in TNBC cell lines with EGFR/HER3 readouts |
| MPP1 | Erythroid raft organization; resting-state raft maintenance | MPP1 knockout in erythroid cell models with raft marker imaging |
| EGFR | Oncogenic signaling influenced by raft cholesterol | EGFR point-mutation and knock-in reporters in raft-perturbed cells |
| HER3 | Oncogenic signaling influenced by raft cholesterol | HER3 knockout and rescue in TNBC cells |
| Lipid asymmetry regulators | Disorders of lipid asymmetry that induce raft formation | Knockout of flippase/scramblase genes with ordered domain probes |
Cancer: raft cholesterol and oncogenic signaling
In triple-negative breast cancer cells, PCSK9 promotes malignancy by reducing cholesterol levels at the plasma membrane, which activates EGFR and HER3. This links plasma membrane raft cholesterol content to oncogenic receptor signaling and suggests that raft composition is a modifiable determinant of cancer cell behavior. Because raft association determines plasma membrane localization of proteins, changes in raft lipids may broadly affect surface signaling networks in cancer.
Erythroid biology and MPP1-dependent raft organization
MPP1-based mechanisms contribute to resting-state raft organization in erythroid cells, raising the question of whether this is a general or specialized mechanism. This has implications for red blood cell membrane stability and for understanding how raft architecture is maintained in specific cell types. The finding also motivates comparative studies of raft organization across tissues.
Lipid asymmetry disorders and raft formation
Loss of plasma membrane lipid asymmetry can induce ordered domain (raft) formation, connecting defects in lipid asymmetry to altered raft assembly. This is relevant to diseases where lipid asymmetry is perturbed, because ectopic raft formation could change signaling and protein sorting. Non-vesicular sterol transport further modulates raft versus non-raft sterol distribution, providing another layer of disease-relevant regulation.
From plasma membrane raft-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does a candidate gene control plasma membrane raft composition? | Knockout cell model with lipidomics and raft marker imaging |
| Does a specific residue regulate raft association? | Point-mutation knock-in of the target gene |
| Can a raft-resident protein be tracked at the plasma membrane? | Tagged knock-in with fluorescent tag for single-molecule imaging |
| Does overexpression of a raft regulator alter signaling? | Overexpression cell model with receptor activation readouts |
| Which genes are required for raft-dependent signaling? | CRISPR library screening with raft-dependent phenotypic readout |
| How does sterol transport affect raft versus non-raft distribution? | Knockout of sterol transport genes with sterol distribution assays |
How to Study the plasma membrane raft Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Single-molecule tracking | Diffusion and confinement of raft-associated molecules | Dynamic assembly of raft-philic signaling molecules |
| Lipidomics | Cholesterol, sphingolipid, and ganglioside composition | Raft versus non-raft lipid distribution |
| Membrane order probes (e.g., Laurdan) | Lipid order in membranes | Quantify raft-like order in cells and model membranes |
| Biophysical modeling | Extent of raft composition in model membranes | Interpret experimental raft data |
| Fluorescence imaging of raft markers | Localization of raft-associated proteins | Assess raft composition changes |
| CRISPR knockout | Loss-of-function effects on raft phenotype | Test causal role of candidate genes |
| CRISPR knock-in tagging | Endogenous protein localization and dynamics | Single-molecule imaging of raft proteins |
| Signaling assays (e.g., EGFR/HER3 activation) | Receptor activation status | Link raft cholesterol to oncogenic signaling |
Single-molecule tracking and imaging
Single-molecule tracking of membrane molecules reveals plasma membrane compartmentalization and dynamic assembly of raft-philic signaling molecules. This method can quantify transient confinement and diffusion of raft-associated proteins, providing direct evidence for dynamic raft behavior. It is typically combined with fluorescent tagging of endogenous proteins via knock-in.
Lipidomics and raft composition analysis
Lipidomic profiling of cholesterol, sphingolipids, and gangliosides can assess raft composition and how it changes upon perturbation. Non-vesicular sterol transport assays help determine the distribution of sterols between raft and non-raft phases. These methods are essential for linking genotype to raft lipid phenotype.
Biophysical modeling and order probes
Biophysical models quantify the extent of raft composition in model plasma membranes, providing a framework to interpret experimental data. Membrane order probes such as Laurdan can report lipid order in cells and model membranes. Combining modeling with order measurements helps test hypotheses about raft size and stability.
CRISPR perturbation and signaling readouts
CRISPR knockout, point mutation, knock-in, and overexpression can test causal roles of raft-associated genes in signaling. For example, PCSK9 perturbation alters plasma membrane cholesterol and EGFR/HER3 activation in triple-negative breast cancer cells. Raft association can also be tested by measuring plasma membrane localization of candidate proteins.
How CRISPR Can Be Used to Study GO:0044853 plasma membrane raft
Knockout
CRISPR knockout of candidate genes such as PCSK9 can test whether loss of function alters plasma membrane cholesterol and raft-dependent signaling. Knockout of lipid asymmetry regulators can reveal whether raft formation depends on lipid asymmetry. Knockout models are typically validated by lipidomics and imaging of raft markers.
Point Mutation
Point-mutation knock-in can test whether specific residues control raft association and plasma membrane localization. This approach is useful when a protein domain is hypothesized to mediate raft partitioning. Point mutants can be compared with wild-type in single-molecule tracking assays.
Knock-in
Tagged knock-in of raft-associated proteins enables single-molecule tracking and imaging of endogenous molecules. Knock-in of reporters can also be used to monitor raft-dependent signaling in live cells. This preserves endogenous regulation better than overexpression.
Overexpression
Overexpression of raft regulators such as PCSK9 can drive changes in plasma membrane cholesterol and activate EGFR/HER3. Overexpression models are useful for gain-of-function studies of raft-associated proteins. They should be interpreted alongside knockout data to establish causality.
How EDITGENE Supports plasma membrane raft Research
Researchers studying plasma membrane raft-related genes often need to determine whether a candidate gene is causally involved in raft composition, dynamics, or raft-dependent signaling. EDITGENE provides CRISPR-based cell model services that enable knockout, point-mutation, knock-in, and overexpression studies, as well as library screening and bioinformatics support, to test such hypotheses in relevant cell backgrounds.
Contact EDITGENE today to design your custom CRISPR model for plasma membrane raft research.
Frequently Asked Questions About plasma membrane raft
What is GO:0044853 plasma membrane raft?
GO:0044853 plasma membrane raft is a cellular component term for a membrane raft that is part of the plasma membrane, a sterol- and sphingolipid-enriched ordered domain that concentrates specific proteins and lipids.
What genes are involved in plasma membrane raft organization?
Genes and proteins linked to raft organization include MPP1, PCSK9, EGFR, HER3, cholesterol transporters, sphingolipid biosynthetic enzymes, and lipid asymmetry regulators.
How are plasma membrane rafts defined experimentally?
Rafts are defined by their enrichment in cholesterol and sphingolipids, ordered lipid state, and dynamic assembly of raft-philic molecules, often measured by single-molecule tracking and lipidomics.
Are plasma membrane rafts static structures?
No, rafts are dynamic nanoscale assemblies; single-molecule tracking shows transient confinement and dynamic assembly of raft-philic signaling molecules.
How does cholesterol affect plasma membrane rafts?
Cholesterol is a key raft lipid; non-vesicular sterol transport regulates sterol distribution between raft and non-raft phases, and reducing plasma membrane cholesterol can alter raft-dependent signaling.
What is the role of lipid asymmetry in raft formation?
Loss of plasma membrane lipid asymmetry can induce ordered domain (raft) formation, linking asymmetry-maintaining enzymes to raft assembly.
How does raft association affect protein localization?
Membrane raft association is a determinant of plasma membrane localization, so raft affinity can control surface delivery and retention of proteins.
Which diseases are linked to plasma membrane rafts?
Raft cholesterol levels influence EGFR and HER3 signaling in triple-negative breast cancer, and MPP1-dependent raft organization is studied in erythroid cells.
What methods are used to study plasma membrane rafts?
Common methods include single-molecule tracking, lipidomics, membrane order probes, biophysical modeling, and CRISPR perturbation with signaling readouts.
How can CRISPR help study plasma membrane raft genes?
CRISPR knockout, point mutation, knock-in, and overexpression can test causal roles of raft-associated genes in raft composition and signaling.
Conclusion
GO:0044853 plasma membrane raft defines a dynamic, sterol- and sphingolipid-enriched ordered domain of the plasma membrane that concentrates signaling and adhesion proteins and influences protein sorting. Its organization is regulated by lipid composition, lipid asymmetry, sterol transport, and proteins such as MPP1, and it is linked to disease through raft-dependent oncogenic signaling. CRISPR-based models provide a rigorous way to test causal roles of raft-associated genes, and EDITGENE offers knockout, point-mutation, knock-in, overexpression, library screening, and bioinformatics services to support such studies.
References
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- 2. Sokolov SS et al.. 2025. Interrelationship between the Non-Vesicular Transport of Sterols and Their Distribution between the Rafts and the Non-Raft Phase of the Plasma Membrane.. Biochemistry (Mosc) 90(3):321-333 PMID: 40367076
- 3. Trybus M et al.. 2019. MPP1-based mechanism of resting state raft organization in the plasma membrane. Is it a general or specialized mechanism in erythroid cells?. Folia Histochem Cytobiol 57(2):43-55 PMID: 31099889
- 4. Kakuda S et al.. 2022. Loss of plasma membrane lipid asymmetry can induce ordered domain (raft) formation.. J Lipid Res 63(1):100155 PMID: 34843684
- 5. Allender DW et al.. 2023. Extent of raft composition in a model plasma membrane.. Biophys J 122(11):1956-1961 PMID: 36050886
- 6. Li T et al.. 2025. PCSK9 Promotes the Malignancy of Triple-negative Breast Cancer Cells by Reducing Cholesterol Levels at the Plasma Membrane to Activate EGFR and HER3.. Adv Sci (Weinh) 12(20):e2408514 PMID: 40192514
- 7. Kusumi A et al.. 2005. Single-molecule tracking of membrane molecules: plasma membrane compartmentalization and dynamic assembly of raft-philic signaling molecules.. Semin Immunol 17(1):3-21 PMID: 15582485
- 8. Diaz-Rohrer BB et al.. 2014. Membrane raft association is a determinant of plasma membrane localization.. Proc Natl Acad Sci U S A 111(23):8500-5 PMID: 24912166
