Eaf1 and Eaf2 negatively regulate canonical Wnt/β-catenin signaling.

Area of Science:

• Developmental Biology
• Molecular Biology
• Cancer Research

Background:

• Eaf factors are critical for tumor suppression and embryogenesis.
• The precise molecular mechanisms underlying Eaf factor functions remain largely unexplored.

Purpose of the Study:

• To elucidate the mechanism by which Eaf1 and Eaf2 regulate biological processes.
• To investigate the interaction of Eaf factors with the Wnt/β-catenin signaling pathway.

Main Methods:

• Loss- and gain-of-function assays in zebrafish using morpholino and mRNA injections.
• Reporter assays in embryos and cultured cells.
• Immunoprecipitation to identify protein interactions.
• Analysis of Eaf1 and Eaf2 functional domains.

Main Results:

• Eaf1 and Eaf2 were found to inhibit Wnt/β-catenin signaling, affecting mesodermal and neural patterning.
• Ectopic expression of Eaf1 and Eaf2 blocked β-catenin reporter activity.
• Eaf1 and Eaf2 directly bind to β-catenin and associated transcription complex proteins (c-Jun, Tcf, Axin).
• Both N- and C-termini of Eaf1 and Eaf2 are essential for their suppressive activity.

Conclusions:

• Eaf1 and Eaf2 novelly inhibit canonical Wnt/β-catenin signaling.
• This inhibition mechanism may underlie the tumor suppressor roles of Eaf1 and Eaf2.
• Eaf family proteins exhibit conserved biological activities across species.