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-Structure paper
タイトル | Tubulin isoform composition tunes microtubule dynamics. |
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ジャーナル・号・ページ | Mol Biol Cell, Vol. 28, Issue 25, Page 3564-3572, Year 2017 |
掲載日 | 2017年12月1日 |
著者 | Annapurna Vemu / Joseph Atherton / Jeffrey O Spector / Carolyn A Moores / Antonina Roll-Mecak / |
PubMed 要旨 | Microtubules polymerize and depolymerize stochastically, a behavior essential for cell division, motility, and differentiation. While many studies advanced our understanding of how microtubule- ...Microtubules polymerize and depolymerize stochastically, a behavior essential for cell division, motility, and differentiation. While many studies advanced our understanding of how microtubule-associated proteins tune microtubule dynamics in trans, we have yet to understand how tubulin genetic diversity regulates microtubule functions. The majority of in vitro dynamics studies are performed with tubulin purified from brain tissue. This preparation is not representative of tubulin found in many cell types. Here we report the 4.2-Å cryo-electron microscopy (cryo-EM) structure and in vitro dynamics parameters of α1B/βI+βIVb microtubules assembled from tubulin purified from a human embryonic kidney cell line with isoform composition characteristic of fibroblasts and many immortalized cell lines. We find that these microtubules grow faster and transition to depolymerization less frequently compared with brain microtubules. Cryo-EM reveals that the dynamic ends of α1B/βI+βIVb microtubules are less tapered and that these tubulin heterodimers display lower curvatures. Interestingly, analysis of EB1 distributions at dynamic ends suggests no differences in GTP cap sizes. Last, we show that the addition of recombinant α1A/βIII tubulin, a neuronal isotype overexpressed in many tumors, proportionally tunes the dynamics of α1B/βI+βIVb microtubules. Our study is an important step toward understanding how tubulin isoform composition tunes microtubule dynamics. |
リンク | Mol Biol Cell / PubMed:29021343 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 4.2 Å |
構造データ | |
化合物 | ChemComp-G2P: ChemComp-MG: ChemComp-GTP: |
由来 |
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キーワード | STRUCTURAL PROTEIN / Microtubules Dynamics Tubulin Isoform |