Characterization of Mouse Dishevelled (Dvl) Proteins in Wnt/Wingless Signaling Pathway*
- From the Department of Viral Oncology, Institute for Virus Research, Kyoto University, Sakyo-Ku, Kyoto 606-8507, Japan
Abstract
The dishevelled (dsh) gene family encodes cytoplasmic proteins that have been implicated in Wnt/Wingless (Wg) signaling. To demonstrate functional conservation of Dsh family proteins, two mouse homologs of Drosophila Dsh, Dvl-1 and Dvl-2, were biochemically characterized in mouse andDrosophila cell culture systems. We found that treatment with a soluble Wnt-3A leads to hyperphosphorylation of Dvl proteins and a concomitant elevation of the cytoplasmic β-catenin levels in mouse NIH3T3, L, and C57MG cells. This coincides well with our finding in aDrosophila wing disc cell line, clone-8, that Wg treatment induced hyperphosphorylation of Dsh (Yanagawa, S., van Leeuwen, F., Wodarz, A., Klingensmith, J., and Nusse, R. (1995) Genes Dev. 9, 1087–1097). Furthermore, we showed that mouse Dvl proteins affect downstream components of Drosophila Wg signaling as Dsh does; overexpression of Dvl proteins in clone-8 cells results in elevation of Armadillo (Drosophila homolog of β-catenin) and Drosophila E-cadherin levels, hyperphosphorylation of Dvl proteins themselves, and inhibition of Zeste-White3 kinase-mediated phosphorylation of a microtubule-binding protein, Tau. In addition, casein kinase II was shown to coimmunoprecipitate with Dvl proteins, and Dvl proteins were phosphorylated in these immune complexes. These results are direct evidence that Dsh family proteins mediate a set of conserved biochemical processes in the Wnt/Wg signaling pathway.
Footnotes
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↵* This work was supported by a grant-in-aid from the Ministry of Education, Science, Sports, and Culture of Japan (to S. Y.).The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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↵‡ To whom correspondence should be addressed. Tel.: 81-75-751-3996; Fax: 81-75-751-3995; E-mail: syanagaw@virus1.virus.kyotou.ac.jp.
- Abbreviations:
- GSK-3β
-
glycogen synthase kinase-3β
- PAGE
-
polyacrylamide gel electrophoresis
- kb
-
kilobase pair(s)
- PCR
-
polymerase chain reaction
- CM
-
conditioned medium
- UAS
-
upstream activated sequence
- CKII
-
casein kinase II
- PDZ
-
PSD-95, Discs-large, and ZO-1
- DEP
-
Dsh/egl-10/pleckstrin
- DIX
-
domain of similarity between the N terminus of Dsh family proteins and the C terminus of the Axin protein,
-
- Received March 30, 1999.
- Revision received May 4, 1999.
- The American Society for Biochemistry and Molecular Biology, Inc.
