Open AccessMechanical strain regulates the Hippo pathway in Drosophila
Author(s) -
Georgina Fletcher,
María-del-Carmen Díaz-de-la-Loza,
Nerea Borreguero-Muñoz,
Maxine Holder,
Mario Aguilar-Aragon,
B. J. Thompson
Publication year - 2018
Publication title -
development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.15
H-Index - 36
eISSN - 1477-9129
pISSN - 0950-1991
DOI - 10.1242/dev.159467
Subject(s) - hippo signaling pathway , microbiology and biotechnology , biology , imaginal disc , drosophila melanogaster , epithelium , kinase , nuclear export signal , focal adhesion , schneider 2 cells , mechanotransduction , cytoplasm , signal transduction , cell nucleus , genetics , gene , rna interference , rna
Animal cells are thought to sense mechanical forces via the transcriptional co-activators YAP (or YAP1) and TAZ (or WWTR1), the sole Drosophila homolog of which is named Yorkie (Yki). In mammalian cells in culture, artificial mechanical forces induce nuclear translocation of YAP and TAZ. Here, we show that physiological mechanical strain can also drive nuclear localisation of Yki and activation of Yki target genes in the Drosophila follicular epithelium. Mechanical strain activates Yki by stretching the apical domain, reducing the concentration of apical Crumbs, Expanded, Kibra and Merlin, and reducing apical Hippo kinase dimerisation. Overexpressing Hippo kinase to induce ectopic activation in the cytoplasm is sufficient to prevent Yki nuclear localisation even in flattened follicle cells. Conversely, blocking Hippo signalling in warts clones causes Yki nuclear localisation even in columnar follicle cells. We find no evidence for involvement of other pathways, such as Src42A kinase, in regulation of Yki. Finally, our results in follicle cells appear generally applicable to other tissues, as nuclear translocation of Yki is also readily detectable in other flattened epithelial cells such as the peripodial epithelium of the wing imaginal disc, where it promotes cell flattening.