title: Tubulin isotype substitution revealed that isotype combination modulates microtubule dynamics inC. elegansembryos.
abstract: Microtubules (MTs) are polymers composed of α- and β-tubulin heterodimers that are generally encoded by genes at multiple loci. Despite implications of distinct properties depending on the isotype, how these heterodimers contribute to the diverse MT dynamicsin vivoremains unclear. Here, by using genome editing and depletion of tubulin isotypes following RNAi, we demonstrate that four tubulin isotypes (hereafter referred to as α1, α2, β1 and β2) cooperatively confer distinct MT properties inCaenorhabditis elegansearly embryos.GFP insertion into each isotype locus reveals their distinct expression levels and MT incorporation rates. Substitution of isotype coding regions demonstrates that, under the same isotype concentration, MTs composed of β1 have higher switching frequency between growth and shrinkage compared with MTs composed of β2. Lower concentration of β-tubulins results in slower growth rates, and the two α-tubulins distinctively affect growth rates of MTs composed of β1. Alteration of ratio and concentration of isotypes distinctively modulates both growth rate and switching frequency, and affects the amplitude of mitotic spindle oscillation. Collectively, our findings demonstrate that MT dynamics are modulated by the combination (ratio and concentration) of tubulin isotypes with distinct properties, which contributes to create diverse MT behaviorsin vivo.
authors.affiliation: Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Honda
authors.affiliation: Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Tsuchiya
authors.affiliation: Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Eisuke
authors.identifier: 0000-0001-7336-6095
authors.initials: E
authors.lastname: Sumiyoshi
authors.affiliation: Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Nami
authors.initials: N
authors.lastname: Haruta
authors.affiliation: Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan asugimoto@m.tohoku.ac.jp.
authors.forename: Asako
authors.identifier: 0000-0001-6001-4293
authors.initials: A
authors.lastname: Sugimoto
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology* / Q000378:metabolism*; D000072669:Gene Editing; D008870:Microtubules / Q000378:metabolism*; D008954:Models, Biological; D008941:Spindle Apparatus / Q000378:metabolism; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D014404:Tubulin
keywords: C. elegans; Microtubules; Tubulin isotypes