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2025-02-18T11:30:04Z

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← Older revision		Revision as of 11:30, 18 February 2025
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	[[Category:Membrane biology]]		[[Category:Membrane biology]]
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			<gallery>
			File:Lipid_raft_organisation_scheme.svg\|Lipid raft organization scheme
			File:Space-Filling_Model_Sphingomyelin_and_Cholesterol.jpg\|Space-filling model of sphingomyelin and cholesterol
			File:Components_for_IgE_signalling.jpeg\|Components for IgE signalling
			File:IgE_signalling_process.jpeg\|IgE signalling process
			File:Components_for_T-cell_antigen_receptor_signalling.jpeg\|Components for T-cell antigen receptor signalling
			File:T-cell_antigen_receptor_signalling_process.jpeg\|T-cell antigen receptor signalling process
			</gallery>

Prab: CSV import

2024-03-19T06:35:29Z

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'''Lipid rafts''' are specialized, dynamic microdomains in the plasma membrane of cells, characterized by their unique composition and functions. Unlike the rest of the cell membrane, lipid rafts are rich in [[cholesterol]], [[sphingolipids]], and certain types of [[proteins]], which confer them with a distinct order and functionality. These microdomains are involved in a variety of cellular processes, including signal transduction, membrane trafficking, and the entry of pathogens.

==Composition and Structure==
Lipid rafts are more ordered and tightly packed than the surrounding membrane, primarily due to the high concentration of cholesterol and sphingolipids. Cholesterol interacts with the saturated fatty acid chains of sphingolipids, stabilizing the raft structure and making it less fluid than the surrounding membrane. The specific lipid composition also influences the types of proteins that associate with these domains. Proteins found in lipid rafts often have post-translational modifications, such as [[Glycosylphosphatidylinositol (GPI) anchors]] or palmitoylation, that facilitate their association with the raft.

==Functions==
Lipid rafts play critical roles in various cellular functions:
* '''Signal Transduction''': They serve as platforms for the assembly of signaling molecules, facilitating efficient signal transduction. For example, they are involved in the signaling pathways of [[G protein-coupled receptors (GPCRs)]] and [[Receptor Tyrosine Kinases (RTKs)]].
* '''Membrane Trafficking''': Lipid rafts are implicated in the sorting and transport of proteins and lipids within the cell. They participate in the formation of vesicles for [[endocytosis]] and [[exocytosis]].
* '''Pathogen Entry''': Certain viruses and bacteria exploit lipid rafts to enter and infect host cells. The human immunodeficiency virus (HIV), for instance, targets lipid rafts for entry into T-cells.

==Detection and Analysis==
Studying lipid rafts has been challenging due to their small size and dynamic nature. Techniques such as [[fluorescence resonance energy transfer (FRET)]], [[fluorescence recovery after photobleaching (FRAP)]], and [[mass spectrometry]] have been employed to analyze their composition and dynamics. Additionally, the isolation of lipid rafts through detergent-resistant membrane (DRM) fractionation has been a common method, though it has limitations and has led to some controversy regarding the existence and nature of lipid rafts.

==Clinical Significance==
Alterations in lipid raft composition and function have been linked to various diseases, including Alzheimer's disease, cardiovascular diseases, and cancer. For instance, the disruption of lipid rafts affects the processing of the amyloid precursor protein (APP) and is associated with the pathogenesis of Alzheimer's disease. Understanding the role of lipid rafts in disease mechanisms is crucial for developing therapeutic strategies targeting these microdomains.

==See Also==
* [[Cell membrane]]
* [[Cholesterol]]
* [[Sphingolipid]]
* [[Signal transduction]]

[[Category:Cell biology]]
[[Category:Membrane biology]]
{{medicine-stub}}

Lipid raft - Revision history

Prab: CSV import

Prab: CSV import