TY - JOUR
T1 - Tubulin isotype substitution revealed that isotype combination modulates microtubule dynamics in C. elegans embryos
AU - Honda, Yu
AU - Tsuchiya, Kenta
AU - Sumiyoshi, Eisuke
AU - Haruta, Nami
AU - Sugimoto, Asako
N1 - Publisher Copyright:
© 2017. Published by The Company of Biologists Ltd.
PY - 2017/5/1
Y1 - 2017/5/1
N2 - 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 dynamics in vivo remains 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 in Caenorhabditis elegans early 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 behaviors in vivo.
AB - 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 dynamics in vivo remains 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 in Caenorhabditis elegans early 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 behaviors in vivo.
KW - C. elegans
KW - Microtubules
KW - Tubulin isotypes
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U2 - 10.1242/jcs.200923
DO - 10.1242/jcs.200923
M3 - Article
C2 - 28302908
AN - SCOPUS:85018272212
VL - 130
SP - 1652
EP - 1661
JO - The Quarterly journal of microscopical science
JF - The Quarterly journal of microscopical science
SN - 0021-9533
IS - 9
ER -