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Frzb-1 is a secreted antagonist of Wnt signaling expressed in the Spemann organizer.

ABSTRACT: Frzb-1 is a secreted protein containing a domain similar to the putative Wnt-binding region of the frizzled family of transmembrane receptors. Frzb-1 is widely expressed in adult mammalian tissues. In the Xenopus gastrula, it is expressed and regulated as a typical Spemann organizer component. Injection of frzb-1 mRNA blocks expression of XMyoD mRNA and leads to embryos with enlarged heads and shortened trunks. Frzb-1 antagonizes the effects of Xwnt-8 ectopic expression in a non-cell-autonomous manner. Cultured cells transfected with a membrane-tethered form of Wnt-1 bind epitope-tagged Frzb-1 in the 10(-10) M range. The results strengthen the view that the Spemann organizer is a source of secreted inhibitory factors.

SUBMITTER: Leyns L

PROVIDER: S-EPMC3061830 | biostudies-literature | 1997 Mar

REPOSITORIES: biostudies-literature

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Frzb-1 is a secreted antagonist of Wnt signaling expressed in the Spemann organizer.

Leyns L L Bouwmeester T T Kim S H SH Piccolo S S De Robertis E M EM

Cell 19970301 6

Frzb-1 is a secreted protein containing a domain similar to the putative Wnt-binding region of the frizzled family of transmembrane receptors. Frzb-1 is widely expressed in adult mammalian tissues. In the Xenopus gastrula, it is expressed and regulated as a typical Spemann organizer component. Injection of frzb-1 mRNA blocks expression of XMyoD mRNA and leads to embryos with enlarged heads and shortened trunks. Frzb-1 antagonizes the effects of Xwnt-8 ectopic expression in a non-cell-autonomous ...[more]

PMID: 9118218

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Bighead is a Wnt antagonist secreted by the <i>Xenopus</i> Spemann organizer that promotes Lrp6 endocytosis.

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