Author/Editor     Resnik, Nataša; Sepčić, Kristina; Plemenitaš, Ana; Windoffer, Reinhard; Leube, Rudolf; Veranič, Peter
Title     Desmosome assembly and cell-cell adhesion are membrane raft-dependent processes
Type     članek
Source     J Biol Chem
Vol. and No.     Letnik 286, št. 2
Publication year     2011
Volume     str. 1499-507
Language     eng
Abstract     The aim of our study was to investigate the association of desmosomal proteins with 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 the remainder 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 data indicate 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.
Descriptors     DESMOSOMES
CELL COMMUNICATION
CELL ADHESION MOLECULES
CHOLESTEROL
CADHERINS
INTRACELLULAR MEMBRANES
MICROSCOPY, FLUORESCENCE
CELLS, CULTURED
BLOTTING, WESTERN