The RNA-binding protein KSRP promotes decay of beta-catenin mRNA and is inactivated by PI3K-AKT signaling.

Roberto Gherzi, Michele Trabucchi, Marco Ponassi, Tina Ruggiero, Giorgio Corte, Christoph Moroni, Ching Yi Chen, Khalid S. Khabar, Jens S. Andersen, Paola Briata

Research output: Contribution to journalArticle

Abstract

Beta-catenin plays an essential role in several biological events including cell fate determination, cell proliferation, and transformation. Here we report that beta-catenin is encoded by a labile transcript whose half-life is prolonged by Wnt and phosphatidylinositol 3-kinase-AKT signaling. AKT phosphorylates the mRNA decay-promoting factor KSRP at a unique serine residue, induces its association with the multifunctional protein 14-3-3, and prevents KSRP interaction with the exoribonucleolytic complex exosome. This impairs KSRP's ability to promote rapid mRNA decay. Our results uncover an unanticipated level of control of beta-catenin expression pointing to KSRP as a required factor to ensure rapid degradation of beta-catenin in unstimulated cells. We propose KSRP phosphorylation as a link between phosphatidylinositol 3-kinase-AKT signaling and beta-catenin accumulation.

Original languageEnglish
JournalPLoS Biology
Volume5
Issue number1
DOIs
Publication statusPublished - Dec 2006

    Fingerprint

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)

Cite this