Luc Leyns, Tewis Bouwmeester, Sung-Hyun Kim, Stefano Piccolo and Eddy M. De Robertis.
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 10-10M range.
The results strengthen the view that the Spemann
organizer is a source of secreted inhibitory factors.
Last updated: March 2019