title: Rafting through traffic: Membrane domains in cellular logistics.
abstract: The intricate and tightly regulated organization of eukaryotic cells into spatially and functionally distinct membrane-bound compartments is a defining feature of complex organisms. These compartments are defined by their lipid and protein compositions, with their limiting membrane as the functional interface to the rest of the cell. Thus, proper segregation of membrane proteins and lipids is necessary for the maintenance of organelle identity, and this segregation must be maintained despite extensive, rapid membrane exchange between compartments. Sorting processes of high efficiency and fidelity are required to avoid potentially deleterious mis-targeting and maintain cellular function. Although much molecular machinery associated with membrane traffic (i.e. membrane budding/fusion/fission) has been characterized both structurally and biochemically, the mechanistic details underlying the tightly regulated distribution of membranes between subcellular locations remain to be elucidated. This review presents evidence for the role of ordered lateral membrane domains known as lipid rafts in both biosynthetic sorting in the late secretory pathway, as well as endocytosis and recycling to/from the plasma membrane. Although such evidence is extensive and the involvement of membrane domains in sorting is definitive, specific mechanistic details for raft-dependent sorting processes remain elusive.
authors.affiliation: University of Texas Health Science Center at Houston, 6431 Fannin St, Houston, TX 77030, USA.
authors.forename: Blanca
authors.initials: B
authors.lastname: Diaz-Rohrer
authors.affiliation: University of Texas Health Science Center at Houston, 6431 Fannin St, Houston, TX 77030, USA.
authors.forename: Kandice R
authors.initials: KR
authors.lastname: Levental
authors.affiliation: University of Texas Health Science Center at Houston, 6431 Fannin St, Houston, TX 77030, USA; Cancer Prevention and Research Institute of Texas, USA. Electronic address: ilya.levental@uth.tmc.edu.
authors.forename: Ilya
authors.initials: I
authors.lastname: Levental
keywords: Endocytosis; Lipid raft; Membrane domain; Sorting; Subcellular traffic