Essential role of the Dishevelled DEP domain in a Wnt-dependent human-cell-based complementation assay
In: Journal of cell science, Jg. 129 (2016-07-22), Heft 20
Online
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Zugriff:
Dishevelled (DVL) assembles Wnt signalosomes through dynamic head-to-tail polymerisation by means of its DIX domain. It thus transduces Wnt signals to cytoplasmic effectors including β-catenin, to control cell fates during normal development, tissue homeostasis and also in cancer. To date, most functional studies of Dishevelled relied on its Wnt-independent signalling activity resulting from overexpression, which is sufficient to trigger polymerisation, bypassing the requirement for Wnt signals. Here, we generate a human cell line devoid of endogenous Dishevelled (DVL1– DVL3), which lacks Wnt signal transduction to β-catenin. However, Wnt responses can be restored by DVL2 stably re-expressed at near-endogenous levels. Using this assay to test mutant DVL2, we show that its DEP domain is essential, whereas its PDZ domain is dispensable, for signalling to β-catenin. Our results imply two mutually exclusive functions of the DEP domain in Wnt signal transduction – binding to Frizzled to recruit Dishevelled to the receptor complex, and dimerising to cross-link DIX domain polymers for signalosome assembly. Our assay avoids the caveats associated with overexpressing Dishevelled, and provides a powerful tool for rigorous functional tests of this pivotal human signalling protein.
Summary: A physiological complementation assay in Dishevelled null-mutant human cells establishes an essential function of the DEP domain of Dishevelled in its binding to Frizzled for signal transduction to β-catenin.
Titel: |
Essential role of the Dishevelled DEP domain in a Wnt-dependent human-cell-based complementation assay
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Autor/in / Beteiligte Person: | Gammons, Melissa V. ; Bienz, Mariann ; Steinhart, Zachary ; Angers, Stephane ; Rutherford, Trevor J. |
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Zeitschrift: | Journal of cell science, Jg. 129 (2016-07-22), Heft 20 |
Veröffentlichung: | 2016 |
Medientyp: | unknown |
ISSN: | 1477-9137 (print) |
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