Transient structure associated with the spindle pole body directs meiotic microtubule reorganization in S. pombe.
Transient structure associated with the spindle pole body directs meiotic microtubule reorganization in S. pombe.
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DOI：
10.1016/j.cub.2012.02.042
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发表时间：
2012-04-10
期刊：
影响因子：
9.2
通讯作者：
Tanaka, Kayoko
中科院分区：
文献类型：
--
作者：
Funaya, Charlotta;Samarasinghe, Shivanthi;Pruggnaller, Sabine;Ohta, Midori;Connolly, Yvonne;Mueller, Jan;Murakami, Hiroshi;Grallert, Agnes;Yamamoto, Masayuki;Smith, Duncan;Antony, Claude;Tanaka, Kayoko
由细胞骨架组合驱动的活跃的染色体运动是性别分化的一种广泛保守的特征，以促进减数分裂重组。在分裂酵母中，这个过程包括从多个微管组织中心(MTOC)产生的细胞质微管阵列(MTS)戏剧性地转化为与纺锤体极体(SPB)相关的单个放射状MT(RMT)阵列，SPB是减数分裂前期的主要MTOC。然后RMT在减数分裂I开始时溶解，此时出现两极纺锤体来进行染色体分离。控制这些动态MT重排的结构特征和分子机制还知之甚少。SPBS的电子断层扫描表明，RMT来自一种新发现的非晶态结构，我们称之为rMTOC。位于SPB细胞质一侧的rMTOC高度富含γ-微管蛋白，这使人想起高等真核中心体的中心周围物质。RMTOC的形成依赖于Hrs1/Mcp6，这是一种位于rMTOC上的减数分裂特异性SPB组分。在减数分裂I开始时，Hrs1/Mcp6受到蛋白酶体依赖的降解和磷酸化的严格下调，导致rMTOC完全失活。这确保了RMT的溶解和两极纺锤体的形成。我们的研究揭示了一种新的MTOC瞬时产生的分子基础，它触发了减数分裂分化所需的MT重排程序。►是一种新型的专化型mTOC(RMTOC)，它可以组织减数分裂的径向微管(Rmt)阵列►rmtoC被瞬时产生，用于重组适合分化的mts，►hrs1/mcp6是一个潜在的裸体同源基因，它作为rmtoC►的支架，hrs1/mcp6的磷酸化和降解确保了rmtoC的失活
Vigorous chromosome movements driven by cytoskeletal assemblies are a widely conserved feature of sexual differentiation to facilitate meiotic recombination. In fission yeast, this process involves the dramatic conversion of arrays of cytoplasmic microtubules (MTs), generated from multiple MT organizing centers (MTOCs), into a single radial MT (rMT) array associated with the spindle pole body (SPB), the major MTOC during meiotic prophase. The rMT is then dissolved upon the onset of meiosis I when a bipolar spindle emerges to conduct chromosome segregation. Structural features and molecular mechanisms that govern these dynamic MT rearrangements are poorly understood. Electron tomography of the SPBs showed that the rMT emanates from a newly recognized amorphous structure, which we term the rMTOC. The rMTOC, which resides at the cytoplasmic side of the SPB, is highly enriched in γ-tubulin reminiscent of the pericentriolar material of higher eukaryotic centrosomes. Formation of the rMTOC depends on Hrs1/Mcp6, a meiosis-specific SPB component that is located at the rMTOC. At the onset of meiosis I, Hrs1/Mcp6 is subject to strict downregulation by both proteasome-dependent degradation and phosphorylation leading to complete inactivation of the rMTOC. This ensures rMT dissolution and bipolar spindle formation. Our study reveals the molecular basis for the transient generation of a novel MTOC, which triggers a program of MT rearrangement that is required for meiotic differentiation. ► A novel specialized MTOC (rMTOC) organizes a meiotic radial microtubule (rMT) array ► rMTOC is transiently generated to reorganize MTs appropriate for differentiation ► Hrs1/Mcp6, a potential NudE ortholog, scaffolds the rMTOC ► Both phosphorylation and degradation of Hrs1/Mcp6 ensure rMTOC inactivation
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影响因子：
2.1
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