Miju Kim1, Minchul Kim1, Mi-Sun Lee2, Cheol-Hee Kim2 & Dae-Sik Lim1
1 Department of Biological Sciences, National Creative Research Initiatives Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea. 2 Department of Biology, Chungnam National University, Daejeon 305-764, Korea.
Correspondence to: Dae-Sik Lim
Primary cilia are microtubule-based organelles that protrude from polarized epithelial cells. Although many structural and trafficking molecules that regulate ciliogenesis have been discovered, signalling proteins are not well defined. Here we show that the MST1/2-SAV1 complex, a core component of the Hippo pathway, promotes ciliogenesis. MST1 is activated during ciliogenesis and localizes to the basal body of cilia. Depletion of MST1/2 or SAV1 impairs ciliogenesis in cultured cells and induces ciliopathy phenotypes in zebrafish. MST1/2-SAV1 regulates ciliogenesis through two independent mechanisms: MST1/2 binds and phosphorylates Aurora kinase A (AURKA), leading to dissociation of the AURKA/HDAC6 cilia-disassembly complex; and MST1/2-SAV1 associates with the NPHP transition-zone complex, promoting ciliary localization of multiple ciliary cargoes. Our results suggest that components of the Hippo pathway contribute to establish a polarized cell structure in addition to regulating proliferation.