Desmosome assembly and cell-cell adhesion are membrane raft-dependent processesResnik, Nataša (Avtor) Sepčić, Kristina (Avtor) Plemenitaš, Ana (Avtor) Windoffer, Reinhard (Avtor) Leube, Rudolf (Avtor) Veranič, Peter (Avtor) The aim of our study was to investigate the association of desmosomal proteinswith cholesterol-enriched membrane domains, commonly called membrane rafts, and the influence of cholesterol on desmosome assembly in epithelial MDCK cells (clone MDc-2). Biochemical analysis proved an association of desmosomal cadherin desmocollin 2 (Dsc2) in cholesterol-enriched fractions that contain membrane raft markers caveolin-1 and flotillin-1 and the novel raft marker ostreolysin. Cold detergent extraction of biotinylated plasma membranes revealed that ~ 60% of Dsc2 associates with membrane rafts while theremainder is present in non-raft and cholesterol-poor membranes. The results of immunofluorescence microscopy confirmed colocalization of Dsc2 and ostreolysin. Partial depletion of cholesterol with methyl-beta-cyclodextrin disturbs desmosome assembly, as revealed by sequential recordings of live cells. Moreover, cholesterol depletion significantly reduces the strength of cell-cell junctions and partially releases Dsc2 from membrane rafts. Our dataindicate that a pool of Dsc2 is associated with membrane rafts; particularly with the ostreolysin type of membrane raft and that intact membrane rafts are necessary for desmosome assembly. Taken together, these data suggest cholesterol as a potential regulator that promotes desmosome assembly.20112026-06-15 10:44:03Članek v reviji183562sl