RT Journal Article SR Electronic T1 The Protein Phosphatase 4 complex promotes the Notch pathway and wingless transcription JF bioRxiv FD Cold Spring Harbor Laboratory SP 113852 DO 10.1101/113852 A1 Eric T. Hall A1 Tirthadipa Pradhan-Sundd A1 Faaria Samnani A1 Esther M. Verheyen YR 2017 UL http://biorxiv.org/content/early/2017/03/04/113852.abstract AB The Wnt/Wingless (Wg) pathway controls cell fate specification, tissue differentiation and organ development across organisms. Using an in vivo RNAi screen to identify novel kinase and phosphatase regulators of the Wg pathway, we identified subunits of the serine threonine phosphatase Protein phosphatase 4 (PP4). Knockdown of the catalytic and the regulatory subunits of PP4 cause reductions in the Wg pathway targets Senseless and Distal-less. We find that PP4 regulates the Wg pathway by controlling Notch-driven wg transcription. Genetic interaction experiments identified that PP4 likely promotes Notch signaling within the nucleus of the Notch-receiving cell. Although the PP4 complex is implicated in various cellular processes, its role in the regulation of Wg and Notch pathways was previously uncharacterized. Our study identifies a novel role of PP4 in regulating Notch pathway, resulting in aberrations in Notch-mediated transcriptional regulation of the Wingless ligand. Furthermore, we show that PP4 regulates proliferation independent of its interaction with Notch.Summary statement The protein phosphatase 4 complex promotes Notch signaling and target gene expression during Drosophila wing development.