title: Phosphorylation-dependent Akt-Inversin interaction at the basal body of primary cilia.
abstract: A primary cilium is a microtubule-based sensory organelle that plays an important role in human development and disease. However, regulation of Akt in cilia and its role in ciliary development has not been demonstrated. Using yeast two-hybrid screening, we demonstrate that Inversin (INVS) interacts with Akt. Mutation in the INVS gene causes nephronophthisis type II (NPHP2), an autosomal recessive chronic tubulointerstitial nephropathy. Co-immunoprecipitation assays show that Akt interacts with INVS via the C-terminus. In vitro kinase assays demonstrate that Akt phosphorylates INVS at amino acids 864-866 that are required not only for Akt interaction, but also for INVS dimerization. Co-localization of INVS and phosphorylated form of Akt at the basal body is augmented by PDGF-AA Akt-null MEF cells as well as siRNA-mediated inhibition of Akt attenuated ciliary growth, which was reversed by Akt reintroduction. Mutant phosphodead- or NPHP2-related truncated INVS, which lack Akt phosphorylation sites, suppress cell growth and exhibit distorted lumen formation and misalignment of spindle axis during cell division. Further studies will be required for elucidating functional interactions of Akt-INVS at the primary cilia for identifying the molecular mechanisms underlying NPHP2.
authors.affiliation: Division of Cancer Biology, Institute for Genetic Medicine Hokkaido University, Sapporo, Japan.
authors.forename: Futoshi
authors.initials: F
authors.lastname: Suizu
authors.affiliation: Division of Cancer Biology, Institute for Genetic Medicine Hokkaido University, Sapporo, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Hirata
authors.affiliation: Division of Cancer Biology, Institute for Genetic Medicine Hokkaido University, Sapporo, Japan.
authors.forename: Kohki
authors.initials: K
authors.lastname: Kimura
authors.affiliation: Division of Cancer Biology, Institute for Genetic Medicine Hokkaido University, Sapporo, Japan.
authors.forename: Tatsuma
authors.initials: T
authors.lastname: Edamura
authors.affiliation: Division of Cancer Biology, Institute for Genetic Medicine Hokkaido University, Sapporo, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Division of Cancer Biology, Institute for Genetic Medicine Hokkaido University, Sapporo, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Ishigaki
authors.affiliation: Chemistry Department, Faculty of Science, Tanta University, Tanta, Egypt.
authors.forename: Thoria
authors.initials: T
authors.lastname: Donia
authors.affiliation: Department of Pathology, Teine Keijinkai Hospital, Sapporo, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Noguchi
authors.affiliation: Laboratory of Histology and Cytology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Iwanaga
authors.affiliation: Division of Cancer Biology, Institute for Genetic Medicine Hokkaido University, Sapporo, Japan m_noguch@igm.hokudai.ac.jp.
authors.forename: Masayuki
authors.identifier: 0000-0002-1787-2724
authors.initials: M
authors.lastname: Noguchi
mesh_terms: D000818:Animals; D064652:Basal Bodies / Q000378:metabolism*; D002460:Cell Line; D002923:Cilia / Q000378:metabolism*; D004252:DNA Mutational Analysis; D006801:Humans; D051379:Mice; D010766:Phosphorylation; D025941:Protein Interaction Mapping; D011499:Protein Processing, Post-Translational; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: C114503:INVS protein, human; D014157:Transcription Factors; D051057:Proto-Oncogene Proteins c-akt
keywords: Akt; Inversin; primary cilia; signal transduction