title: The Vip1 inositol polyphosphate kinase family regulates polarized growth and modulates the microtubule cytoskeleton in fungi.
abstract: Microtubules (MTs) are pivotal for numerous eukaryotic processes ranging from cellular morphogenesis, chromosome segregation to intracellular transport. Execution of these tasks requires intricate regulation of MT dynamics. Here, we identify a new regulator of the Schizosaccharomyces pombe MT cytoskeleton: Asp1, a member of the highly conserved Vip1 inositol polyphosphate kinase family. Inositol pyrophosphates generated by Asp1 modulate MT dynamic parameters independent of the central +TIP EB1 and in a dose-dependent and cellular-context-dependent manner. Importantly, our analysis of the in vitro kinase activities of various S. pombe Asp1 variants demonstrated that the C-terminal phosphatase-like domain of the dual domain Vip1 protein negatively affects the inositol pyrophosphate output of the N-terminal kinase domain. These data suggest that the former domain has phosphatase activity. Remarkably, Vip1 regulation of the MT cytoskeleton is a conserved feature, as Vip1-like proteins of the filamentous ascomycete Aspergillus nidulans and the distantly related pathogenic basidiomycete Ustilago maydis also affect the MT cytoskeleton in these organisms. Consistent with the role of interphase MTs in growth zone selection/maintenance, all 3 fungal systems show aspects of aberrant cell morphogenesis. Thus, for the first time we have identified a conserved biological process for inositol pyrophosphates.
authors.affiliation: Lehrstuhl für funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Pöhlmann
authors.affiliation: Lehrstuhl für funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
authors.forename: Carmen
authors.initials: C
authors.lastname: Risse
authors.affiliation: Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Dept. of Microbiology, Karlsruhe, Germany.
authors.forename: Constanze
authors.initials: C
authors.lastname: Seidel
authors.affiliation: Institut für Mikrobiologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Pohlmann
authors.affiliation: Lehrstuhl für funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
authors.forename: Visnja
authors.initials: V
authors.lastname: Jakopec
authors.affiliation: Lehrstuhl für funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Walla
authors.affiliation: Lehrstuhl für funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
authors.forename: Pascal
authors.initials: P
authors.lastname: Ramrath
authors.affiliation: Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Dept. of Microbiology, Karlsruhe, Germany; University of Tsukuba, Faculty of Life and Environmental Sciences, Ibaraki, Tsukuba, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Takeshita
authors.affiliation: Institut für Mikrobiologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Baumann
authors.affiliation: Institut für Mikrobiologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Feldbrügge
authors.affiliation: Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Dept. of Microbiology, Karlsruhe, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Fischer
authors.affiliation: Lehrstuhl für funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Fleig
mesh_terms: D049109:Cell Proliferation; D005656:Fungal Proteins / Q000378:metabolism; D005658:Fungi / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D007295:Inositol Phosphates / Q000378:metabolism; D007399:Interphase; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D007295:Inositol Phosphates; D008869:Microtubule-Associated Proteins; D017856:Phosphotransferases (Phosphate Group Acceptor); C099438:inositol hexakisphosphate kinase