Expression of full-length desmosomol glycoproteins (desmocollins) is not sufficient to confer strong adhesion on transfected L929 cells.
Desmocollins are cadherin-like glycoproteins that are localized in desmosomes. They are thought to play a role in cell adhesion but direct evidence for this is currently unavailable. For this reason we have expressed cDNAs encoding full-length bovine desomocollin type 1a and type 1b in mouse fibroblast (L929) cells. This system has previously been used to demonstrate the adhesive properties of E-cadherin. E-cadherin-mediated cell-cell adhesion is thought to require interaction of the cytoplasmic domain with the catenins that are expressed in L-cells. Because L929 cells do not express cytoplasmic desmosomal components that may be required for desmocollin-mediated adhesion, we constructed a chimeric cDNA encoding the bovine type 1 extracellular domain linked to the mouse E-cadherin transmembrane and cytoplasmic domains. cDNAs were transfected into cells and clones that expressed heterologous protein at the cell surface were isolated. The full-length desmocollins apparently did not interact with any other molecules, but the chimeric protein did bind to endogenous mouse alpha- and beta-catenin. Surprisingly none of the desmocollin-transfected cell lines showed significant adhesive properties under conditions where cells transfected with E-cadherin exhibited strong adhesiveness. We conclude that desmcollin expression alone is not sufficient to confer adhesion on transfected cells and more than one desmosomal component may be required.
Chidgey
M A
MA
School of Biological Sciences, University of Manchester, UK.
Clarke
J P
JP
Garrod
D R
DR
D000818:Animals; D001483:Base Sequence; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000032:analysis*; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000032:analysis* / Q000502:physiology; D051187:Desmocollins; D051180:Desmoplakins; D003896:Desmosomes / Q000737:chemistry*; D005347:Fibroblasts; D051379:Mice; D008969:Molecular Sequence Data; D014162:Transfection
D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D051187:Desmocollins; D051180:Desmoplakins