Phosphorylation by the β-catenin/MAPK complex promotes 14-3-3-mediated nuclear export of TCF/POP-1 in signal-responsive cells in C. elegans

Miao Chia Lo, Frédérique Gay, Raanan Odom, Yang Shi, Rueyling Lin

Research output: Contribution to journalArticle

109 Scopus citations

Abstract

In C. elegans embryos, a Wnt/MAPK signaling pathway downregulates the TCF/LEF transcription factor POP-1, resulting in a lower nuclear level in signal-responsive cells compared to their sisters. Although the β-catenin WRM-1 is required for POP-1 downregulation, a direct interaction between these two proteins does not seem to be required, as the β-catenin-interacting domain of POP-1 is dispensable for both POP-1 downregulation and function in early embryos. We show here that WRM-1 downregulates POP-1 by promoting its phosphorylation by the MAP kinase LIT-1 and subsequent nuclear export via a 14-3-3 protein, PAR-5. In signal-responsive cells, we also detect a concurrent upregulation of nuclear LIT-1 that is dependent on Wnt/MAPK signaling. Our results suggest a model whereby Wnt/MAPK signaling downregulates POP-1 levels in responsive cells, in part by increasing nuclear LIT-1 levels, thereby increasing POP-1 phosphorylation and PAR-5-mediated nuclear export.

Original languageEnglish (US)
Pages (from-to)95-106
Number of pages12
JournalCell
Volume117
Issue number1
DOIs
StatePublished - Apr 2 2004

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ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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