Plasma membrane cholesterol-rich microdomain (Lipid raft) (LR)

Plasma membrane cholesterol-rich microdomains, frequently termed lipid rafts, are small, heterogeneous, and highly dynamic domains enriched in sterols and sphingolipids that compartmentalize cellular processes (Lingwood & Simons, 2010). These structures function as specialized platforms for the assembly of signaling complexes, influencing pathways such as those mediated by G protein-coupled receptors and receptor tyrosine kinases (Simons & Gerl, 2010). In oncology, lipid rafts are known to facilitate the clustering of survival and proliferative proteins, making them attractive targets for anti-tumor therapies like edelfosine (Mollinedo et al., 2011). Furthermore, many pathogens, including viruses like HIV-1 and SARS-CoV-2, utilize these cholesterol-rich regions for host cell entry and viral budding (Sviridov et al., 2020). Pharmacological intervention typically involves cholesterol depletion using agents like methyl-beta-cyclodextrin or the sequestration of lipids to disrupt the spatial organization of these domains, thereby inhibiting pathological signaling or infection (Varshney et al., 2016). However, the lack of specificity and potential for disrupting normal membrane physiology remain significant therapeutic challenges.

Other names

Lipid raftsDetergent-resistant membranes (DRMs)Cholesterol-rich microdomainsMembrane raftsCaveolae

The primary mechanism involves the depletion, sequestration, or redistribution of membrane cholesterol, which is essential for the structural integrity of lipid rafts. This disruption leads to the dissociation of raft-resident proteins, thereby inhibiting signal transduction pathways, preventing viral entry/egress, or inducing apoptosis in malignant cells (Mollinedo & Sahini, 2023; Sviridov et al., 2020).