Isolation of desmosomes from the epidermis of Xenopus laevis and immunochemical characterization of the Xenopus desmosomal cadherins.
Here we report a new method of isolating epidermal desmosomes from Xenopus laevis, and a major constituent of desmosomes designated as Xenopus desmogleins (XDsg). Isolation of desmosomes from Xenopus laevis epidermis was carried out by a two step-incubation with different concentrations of NP-40. After discontinuous sucrose gradient centrifugation at 30,000 g for 60 min, a pure desmosomal fraction was obtained at 30%/40% interface. In the SDS-PAGE of isolated desmosomes, at least 12 bands (XDB1 to XDB12) were observed over a 75 kD region. Among them, three bands (XDB3, XDB7, XDB8; estimated MW 175, 124, and 112 kD respectively) were recognized as glycoproteins based on ConA binding. Monospecific polyclonal antibody against XDB3 cross-reacted with bovine Dsgs and vis-a-vis anti-bovine Dsgs with XDB3. By contrast, monospecific antibody against bovine Dsc a/b did not cross-react with either XDB7 or XDB8. Heterogeneous molecular constituents of desmosomal adhesion molecule, which have been observed among different bovine tissues, were confirmed in a phylogenetically different animal, Xenopus laevis. Combined results with other evidence could suggest an alternative system for desmosome-mediated cell adhesion.
Ohga
Rie
R
Laboratory of Molecular Cell Biology, Faculty of Medicine, Yamanashi University, Tamaho, Japan.
Shida
Mariko
M
Shida
Hisato
H
D000818:Animals; D015820:Cadherins / Q000032:analysis*; D002417:Cattle; D003896:Desmosomes / Q000737:chemistry* / Q000648:ultrastructure; D004591:Electrophoresis, Polyacrylamide Gel; D004817:Epidermis / Q000737:chemistry*; D006023:Glycoproteins / Q000032:analysis; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D014982:Xenopus laevis
D015820:Cadherins; D006023:Glycoproteins