Proteolytic processing of the adherens junctions components beta-catenin and gamma-catenin/plakoglobin during apoptosis.
Apoptotic cells undergo specific morphological changes that include loss of cell-cell interactions. Cellular adhesiveness is dependent on members of the cadherin family of adhesion receptors and on the cytoplasmic adaptor proteins alpha-catenin, beta-catenin and gamma-catenin/plakoglobin. The caspase family of cystein proteases play a key role during the execution phase of the apoptotic program. These proteolytic enzymes, once activated, cleave cellular proteins which are important for the maintenance of cell integrity. Here we report that gamma-catenin is cleaved at different sites during apoptosis in various cell lines. The major apoptotic product of gamma-catenin still retains the ability to bind alpha-catenin but loses the carboxy-terminal region. We also show that gamma-catenin is cleaved by caspase-3 in vitro although with lower affinity when compared to PARP or beta-catenin. These findings indicate that multiple proteolytic events regulate the dismantling of the cell-cell junctional complexes during apoptosis.
Brancolini
C
C
Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie AREA, Trieste, Italy. brancoli@sci.area.trieste.it
Sgorbissa
A
A
Schneider
C
C
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D015820:Cadherins / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D051180:Desmoplakins; D004847:Epithelial Cells / Q000166:cytology* / Q000201:enzymology; D007365:Intercellular Junctions / Q000737:chemistry / Q000378:metabolism*; D007668:Kidney / Q000166:cytology; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D013379:Substrate Specificity; D015534:Trans-Activators; D051176:beta Catenin; D051185:gamma Catenin
D015820:Cadherins; D003598:Cytoskeletal Proteins; D051180:Desmoplakins; D015534:Trans-Activators; D051176:beta Catenin; D051185:gamma Catenin; D011064:Poly Adenosine Diphosphate Ribose; D011065:Poly(ADP-ribose) Polymerases; D053148:Caspase 3; D020169:Caspases