Contributions of cytoplasmic domains of desmosomal cadherins to desmosome assembly and intermediate filament anchorage.
To examine the potential of cytoplasmic portions ("tails") of desmosomal cadherins for assembly of desmosome plaque structures and anchorage of intermediate filaments (IFs), we transfected cultured human A-431 carcinoma cells, abundant in desmosomes and cytokeratin IFs, with constructs encoding chimeric proteins in which the transmembranous region of connexin 32 had been fused with tails of desmocollin (Dsc) or desmoglein (Dsg). The results show that the tail of the long splice form a of Dsc, but not its shorter splice form b, contains sufficient information to recruit desmoplakin and plakoglobin to connexon membrane paracrystals (gap junctions) and to form a novel kind of plaque at which cytokeratin IFs attach. By contrast, chimeras containing a Dsg tail, which accumulated in the plasma membrane, showed a dominant-negative effect: they not only were unable to form gap junction structures and plaques but also led to the disappearance of all endogenous desmosomes and the detachment of IFs from the plasma membrane.
Troyanovsky
S M
SM
Division for Cell Biology, German Cancer Research Center, Heidelberg.
Eshkind
L G
LG
Troyanovsky
R B
RB
Leube
R E
RE
Franke
W W
WW
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015820:Cadherins / Q000502:physiology*; D002448:Cell Adhesion; D017630:Connexins; D003593:Cytoplasm / Q000648:ultrastructure; D003598:Cytoskeletal Proteins / Q000378:metabolism* / Q000648:ultrastructure; D051187:Desmocollins; D051182:Desmogleins; D051180:Desmoplakins; D003896:Desmosomes / Q000648:ultrastructure*; D005455:Fluorescent Antibody Technique; D006801:Humans; D066298:In Vitro Techniques; D007382:Intermediate Filaments / Q000648:ultrastructure*; D007633:Keratins / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011485:Protein Binding; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured; D051185:gamma Catenin
D015820:Cadherins; D017630:Connexins; D003598:Cytoskeletal Proteins; C495294:DSP protein, human; D051187:Desmocollins; D051182:Desmogleins; D051180:Desmoplakins; D008565:Membrane Proteins; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; D051185:gamma Catenin; D007633:Keratins