Myosin Light Chain Phosphatase regulates the transcription of Wingless target genes in Drosophila

Canonical Wnt, or Wingless (Wg) in Drosophila, is an evolutionarily well-conserved signalling pathway that is important for a wide range of processes, including cell fate determination, axis formation and stem cell renewal. Wg signalling primarily functions to regulate the cytosolic stability of the key effector β-catenin (Armadillo, Arm, in Drosophila). Arm promotes the transcription of Wg target genes but also is required for the formation of stable adherens junctions. Previously, the Verheyen lab identified the non-muscle myosin II regulator Myosin Light Chain Phosphatase (MLCP) as a putative regulator of Wg signalling. Here we find that reducing the expression MLCP components leads to the attenuation of Wg target gene expression. I present our evidence that MLCP knock down directly regulates Wg signal transduction and that this regulation is through Arm localization. Thus, our work supports mounting evidence of a regulatory relationship between the adherens junctions and the Wg signalling pathway.