Recent controversy surrounding lipid rafts.

Lipid rafts (LRs)are highly enriched in glycosphingolipids, sphingomyelins, and cholesterol membrane microdomains, existing in a liquid-ordered phase of the plasma membrane. In the literature, LRs are also known as detergent-insoluble membranes, detergent-resistant membranes, glycosphingolipids-enriched membranes, detergent-insoluble glycolipid-rich membranes, and Triton-insoluble floating fractions. These properties enabled their separation from the rest of the phospholipid bilayer, providing new insight into the structure of the plasma membrane, which until then was believed to represent a two-dimensional liquid structure with proteins uniformly solubilized in the lipid solvent. Although there have been many articles concerning LRs, there is still controversy about their existence in the natural state, their size, definition, and function. Different techniques have been developed to visualize LRs in living cells, but the results are contradictory. In this minireview, some recent papers concerning LRs, their existence in vivo, their dynamics, size, methods of isolation, and their association with different proteins are discussed.