Wang, S., Lu, Y., Yin, M.X., Wang, C., Wu, W., Li, J., Wu, W., Ge, L., Hu, L., Zhao, Y., Zhang, L. (2016). Importin α1 Mediates Yorkie Nuclear Import via an N-terminal Non-canonical Nuclear Localization Signal. J. Biol. Chem. 291(15): 7926--7937.
FlyBase ID
FBrf0233262
Publication Type
Research paper
Abstract
The Hippo signaling pathway controls organ size by orchestrating cell proliferation and apoptosis. When the Hippo pathway was inactivated, the transcriptional co-activator Yorkie translocates into the nucleus and forms a complex with transcription factor Scalloped to promote the expression of Hippo pathway target genes. Therefore, the nuclear translocation of Yorkie is a critical step in Hippo signaling. Here, we provide evidence that the N-terminal 1-55 amino acids of Yorkie, especially Arg-15, were essential for its nuclear localization. By mass spectrometry and biochemical analyses, we found that Importin α1 can directly interact with the Yorkie N terminus and drive Yorkie into the nucleus. Further experiments show that the upstream component Hippo can inhibit Importin α1-mediated Yorkie nuclear import. Taken together, we identified a potential nuclear localization signal at the N-terminal end of Yorkie as well as a critical role for Importin α1 in Yorkie nuclear import.
