Investigating the Hippo Signaling Pathway using High-throughput Protein-protein Interaction LUMIER Screens

• Main Author: Shiban, Ahmed
• Other Authors: Attisano, Liliana
• Language: en_ca
• Published: 2013
• Subjects: Biochemistry; Molecular Biology; 0487
• Online Access: http://hdl.handle.net/1807/35681

The Hippo pathway plays a key role in controlling organ growth and size. In mammals, core pathway components include the Lats1/2 and Mst1/2 kinases, which phosphorylate the transcriptional regulators, Taz and Yap. To identify novel upstream pathway regulators high throughput protein-protein interaction screens, called LUMIER (LUminescence-based Mammalian IntERactome) were performed together with a functional screen using a luciferase reporter that examines Hippo pathway responses. The screens revealed 1103 protein-protein interactions and 227 transcriptional regulators, which were particularly enriched in cytoskeletal regulators. A subset of these hits including BTK, Dvl1, Dvl2, Dvl3, Ing2, Magi2, Mark4 and Trip6 were validated by manual LUMIER assays and co-immunoprecipitation (Co-IP). Of particular interest was the microtubule dynamics regulatory protein MARK4. Loss of Mark4 prevents Taz activity demonstrating its role as a potential negative regulator of the Hippo pathway. Further studies could help decipher mechanisms of how Mark4 and the other cytoskeletal hits act to modulate the Hippo pathway.