Adenomatous polyposis coli protein (APC)-independent regulation of beta-catenin/Tcf-4 mediated transcription in intestinal cells.
Alterations in the transcriptional activity of the beta-catenin-Tcf complex have been associated with the earlier stages of colonic transformation. We show here that the activation of protein kinase C by the phorbol ester PMA in several intestinal cell lines increases the levels of beta-catenin detected in the nucleus and augments the transcriptional activity mediated by beta-catenin. The response to PMA was not related to modifications in the cytosolic levels of beta-catenin and was observed not only in cells with wild-type adenomatous polyposis coli protein (APC) but also in APC-deficient cells. Binding assays in vitro revealed that PMA facilitates the interaction of the beta-catenin with the nuclear structure. Our results therefore show that beta-catenin-mediated transcription can be regulated independently of the presence of APC.
Baulida
J
J
Unitat de Biologia Cel.lular i Molecular, Institut Municipal d'Investigació Mèdica, Universitat Pompeu Fabra, Carrer Dr. Aiguader 80, Barcelona 08003, Spain.
Batlle
E
E
García De Herreros
A
A
D025601:Adenomatous Polyposis Coli Protein; D001692:Biological Transport; D002451:Cell Compartmentation; D002467:Cell Nucleus / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000166:cytology; D009685:Nuclear Envelope / Q000378:metabolism; D011485:Protein Binding; D011493:Protein Kinase C / Q000378:metabolism*; D015398:Signal Transduction; D051820:TCF Transcription Factors; D013755:Tetradecanoylphorbol Acetate; D015534:Trans-Activators; D058118:Transcription Factor 7-Like 2 Protein; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D051176:beta Catenin
D025601:Adenomatous Polyposis Coli Protein; D003598:Cytoskeletal Proteins; D051820:TCF Transcription Factors; D015534:Trans-Activators; D058118:Transcription Factor 7-Like 2 Protein; D014157:Transcription Factors; D051176:beta Catenin; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate