Continual assembly of desmosomes within stable intercellular contacts of epithelial A-431 cells.
Subclones of human carcinoma-derived A-431 cell line stably producing fusion proteins consisting of the enhanced green fluorescent protein and either human desmoglein 2 (Dsg-GFP) or human plakoglobin (GFP-Pg) were used to examine the behavior of desmosomes in living cells. Immunofluorescence microscopy of the fixed cells showed that both fusion proteins, which were expressed in significantly lower levels relative to their endogenous counterparts, were efficiently recruited into desmosomes. Time-lapse confocal imaging of these cells reveals that such GFP-labeled desmosomes (GFP desmosomes) are stable structures which exhibit various dynamic and motile activities. The most notable are independent lateral mobility and fusion. Furthermore, the continual assembly of new nascent desmosomes is observed within stable contacts located at the middle of the epithelial sheet. A new GFP desmosome appears as a closely apposed group of fine patches which after a few minutes aggregate into a single structure. These three dynamic processes resulted in constant changes of desmosome distribution, numbers, and sizes. In addition, fluorescence recovery after photobleaching experiments showed that fine patches of desmosomal proteins may participate in desmosome maintenance. Such a diverse range of dynamic activities of desmosomes apparently produces flexible but tight cell-cell adhesion required for different morphogenetic events in epithelial structures.
Gloushankova
Natalia A
NA
Cancer Research Center of the Russian Federation, Moscow, Russia.
Wakatsuki
Tetsuro
T
Troyanovsky
Regina B
RB
Elson
Elliot
E
Troyanovsky
Sergey M
SM
D002448:Cell Adhesion / Q000502:physiology*; D002450:Cell Communication / Q000502:physiology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000378:metabolism; D051301:Desmoglein 2; D051182:Desmogleins; D051180:Desmoplakins; D003896:Desmosomes / Q000378:metabolism* / Q000648:ultrastructure; D004847:Epithelial Cells / Q000378:metabolism* / Q000648:ultrastructure; D036681:Fluorescence Recovery After Photobleaching; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins; D018613:Microscopy, Confocal; D021381:Protein Transport / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D051185:gamma Catenin
D003598:Cytoskeletal Proteins; C495314:DSG2 protein, human; D051301:Desmoglein 2; D051182:Desmogleins; D051180:Desmoplakins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D051185:gamma Catenin; D049452:Green Fluorescent Proteins