Negative regulation of Armadillo, a Wingless effector in Drosophila.

Journal Article (Journal Article)

Drosophila Armadillo and its vertebrate homolog beta-catenin play essential roles both in the transduction of Wingless/Wnt cell-cell signals and in the function of cell-cell adherens junctions. Wingless and Wnts direct numerous cell fate choices during development. We generated a mutant protein, Armadillo(S10), with a 54 amino acid deletion in its N-terminal domain. This mutant is constitutively active in Wingless signaling; its activity is independent of both Wingless signal and endogenous wild-type Armadillo. Armadillo's role in signal transduction is normally negatively regulated by Zeste-white 3 kinase, which modulates Armadillo protein stability. Armadillo(S10) is more stable than wild-type Armadillo, suggesting that it is less rapidly targeted for degradation. We show that Armadillo(S10) has escaped from negative regulation by Zeste white-3 kinase, and thus accumulates outside junctions even in the absence of Wingless signal. Finally, we present data implicating kinases in addition to Zeste white-3 in Armadillo phosphorylation. We discuss two models for the negative regulation of Armadillo in normal development and discuss how escape from this regulation contributes to tumorigenesis.

Duke Authors

Cited Authors

  • Pai, LM; Orsulic, S; Bejsovec, A; Peifer, M

Published Date

  • June 1997

Published In

Volume / Issue

  • 124 / 11

Start / End Page

  • 2255 - 2266

PubMed ID

  • 9187151

Electronic International Standard Serial Number (EISSN)

  • 1477-9129

International Standard Serial Number (ISSN)

  • 0950-1991


  • eng