title: Drosophila gene tao-1 encodes proteins with and without a Ste20 kinase domain that affect cytoskeletal architecture and cell migration differently.
abstract: Tao-1, the single representative of the Sterile 20 kinase subfamily in Drosophila, is best known for destabilizing microtubules at the actin-rich cortex, regulating the cytoskeletal architecture of cells. More recently, Tao-1 was shown to act in the Salvador-Warts-Hippo pathway by phosphorylating Hippo, regulating cell growth as well as cell polarity. Here, we show that tao-1 encodes two proteins, one with the Sterile 20 kinase domain (Tao-L) and one without it (Tao-S), and that they act in an antagonistic manner. Tao-L expression causes lamellipodia-like cell protrusions, whereas Tao-S expression results in filopodia-like structures that make cells stick to the surface they attach to. Ectopic Tao-1 expression in the anterior region of Drosophila embryos results in pole cell formation as normally observed at the posterior end. Tao-S expression causes primordial germ cells (PGCs) to adhere to the inner wall of the gut primordia and prevents proper transepithelial migration to the gonads. Conversely, RNAi knockdowns of Tao-1 cause disordered migration of PGCs out of the gut epithelium, their dispersal within the embryo and cell death. The results reveal a novel function of Tao-1 in cell migration, which is based on antagonistic activities of two proteins encoded by a single gene.
authors.affiliation: Abteilung Molekulare Entwicklungsbiologie, Max Planck Institut für Biophysikalische Chemie, Göttingen, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Pflanz
authors.affiliation: Abteilung Molekulare Entwicklungsbiologie, Max Planck Institut für Biophysikalische Chemie, Göttingen, Germany Department of Neurology, University Medical Centre Aachen, Aachen, Germany.
authors.forename: Aaron
authors.initials: A
authors.lastname: Voigt
authors.affiliation: Abteilung Molekulare Entwicklungsbiologie, Max Planck Institut für Biophysikalische Chemie, Göttingen, Germany Renal Division, University Hospital Freiburg, Freiburg, Germany.
authors.forename: Toma
authors.initials: T
authors.lastname: Yakulov
authors.affiliation: Abteilung Molekulare Entwicklungsbiologie, Max Planck Institut für Biophysikalische Chemie, Göttingen, Germany hjaeckl@gwdg.de.
authors.forename: Herbert
authors.initials: H
authors.lastname: Jäckle
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000818:Animals; D002465:Cell Movement; D022081:Cell Surface Extensions / Q000378:metabolism; D004330:Drosophila / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D005854:Germ Cells / Q000378:metabolism / Q000502:physiology; D020930:MAP Kinase Kinase Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases; D017434:Protein Structure, Tertiary
chemical_list: D017346:Protein Serine-Threonine Kinases; C115483:TAO1 protein kinase; D020930:MAP Kinase Kinase Kinases
keywords: Ste20 kinase; cytoskeletal architecture; ectopic pole cell induction; germline cell migration