When Wnts antagonize Wnts.
Secreted Wnt ligands appear to activate a variety of signaling pathways. Two papers in this issue now present genetic evidence that "noncanonical" Wnt signaling inhibits the "canonical" Wnt/beta-catenin pathway. Westfall et al. (2003a) show that zebrafish embryos lacking maternal Wnt-5 function are dorsalized due to ectopic activation of beta-catenin, whereas Topol et al. (2003) report that chondrogenesis in the distal mouse limb bud depends on inhibition of Wnt/beta-catenin signaling by a paralogue of Wnt-5. These studies present the first genetic confirmation of the previous hypothesis that vertebrate Wnt signaling pathways can act in an antagonistic manner.
Weidinger
Gilbert
G
Howard Hughes Medical Institute and Department of Pharmacology, University of Washington, Box 357370, Seattle, WA 98195, USA.
Moon
Randall T
RT
D000818:Animals; D003598:Cytoskeletal Proteins / Q000378:metabolism; D051379:Mice; D009024:Morphogenesis / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D015534:Trans-Activators / Q000378:metabolism; D051153:Wnt Proteins; D015027:Zebrafish / Q000196:embryology; D029961:Zebrafish Proteins; D051176:beta Catenin
C495267:CTNNB1 protein, mouse; D003598:Cytoskeletal Proteins; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D051153:Wnt Proteins; D029961:Zebrafish Proteins; D051176:beta Catenin; C495269:ctnnb1 protein, zebrafish; C094522:wnt8b protein, zebrafish