Lipid rafts are subdomains of the plasma membrane rich in cholesterol and glycosphingolipids, forming liquid-ordered regions resistant to nonionic detergents. They are thought to play a role in signal transduction by organizing signaling components. While rafts vary in protein and lipid composition, they are involved in regulating cell signaling through mechanisms such as pathway activation, sequestration of signaling components, or suppression of protein activity. Studies show that lipid rafts are involved in receptor tyrosine kinase and G protein-coupled receptor signaling. Rafts may facilitate signaling by bringing together signaling components, or by limiting signaling through physical separation or suppression of protein activity. The size of lipid rafts is estimated to be between 100-200 nm, and they constitute a significant fraction of the plasma membrane. Rafts are enriched in cholesterol, sphingomyelin, and gangliosides, while being relatively poor in glycerophospholipids. The composition of rafts varies between different cell types and raft subtypes. The protein composition of rafts includes caveolins, flotillins, GPI-linked proteins, and various signaling proteins. The localization of proteins to rafts is influenced by lipid modifications, transmembrane domains, and extracellular motifs. Not all rafts are identical, and distinct rafts may contain different subsets of proteins. Rafts may play a role in signal termination by internalizing signaling components. In receptor tyrosine kinase signaling, rafts are involved in the activation of signaling pathways such as MAPK. Cholesterol depletion impairs receptor tyrosine kinase signaling, suggesting that rafts are important for signaling. In G protein-coupled receptor signaling, rafts are involved in the localization of receptors and G proteins, and may facilitate signaling by bringing together signaling components. Cholesterol depletion impairs G protein-coupled receptor signaling, indicating that rafts are important for signaling. Overall, lipid rafts are important for organizing signaling components and regulating cell signaling.Lipid rafts are subdomains of the plasma membrane rich in cholesterol and glycosphingolipids, forming liquid-ordered regions resistant to nonionic detergents. They are thought to play a role in signal transduction by organizing signaling components. While rafts vary in protein and lipid composition, they are involved in regulating cell signaling through mechanisms such as pathway activation, sequestration of signaling components, or suppression of protein activity. Studies show that lipid rafts are involved in receptor tyrosine kinase and G protein-coupled receptor signaling. Rafts may facilitate signaling by bringing together signaling components, or by limiting signaling through physical separation or suppression of protein activity. The size of lipid rafts is estimated to be between 100-200 nm, and they constitute a significant fraction of the plasma membrane. Rafts are enriched in cholesterol, sphingomyelin, and gangliosides, while being relatively poor in glycerophospholipids. The composition of rafts varies between different cell types and raft subtypes. The protein composition of rafts includes caveolins, flotillins, GPI-linked proteins, and various signaling proteins. The localization of proteins to rafts is influenced by lipid modifications, transmembrane domains, and extracellular motifs. Not all rafts are identical, and distinct rafts may contain different subsets of proteins. Rafts may play a role in signal termination by internalizing signaling components. In receptor tyrosine kinase signaling, rafts are involved in the activation of signaling pathways such as MAPK. Cholesterol depletion impairs receptor tyrosine kinase signaling, suggesting that rafts are important for signaling. In G protein-coupled receptor signaling, rafts are involved in the localization of receptors and G proteins, and may facilitate signaling by bringing together signaling components. Cholesterol depletion impairs G protein-coupled receptor signaling, indicating that rafts are important for signaling. Overall, lipid rafts are important for organizing signaling components and regulating cell signaling.