Temperature-dependent regulation of rDNA condensation in Saccharomyces cerevisiae.
Temperature-dependent regulation of rDNA condensation in Saccharomyces cerevisiae.
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酿酒酵母中 rDNA 凝结的温度依赖性调节。
DOI：
10.1080/15384101.2017.1317409
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Skibbens,RobertV
中科院分区：
文献类型：
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作者：
Shen,Donglai;Skibbens,RobertV
有丝分裂期间的染色质凝聚产生在有丝分裂期间高保真姐妹染色单体分离所需的解缠结和离散的DNA实体，并在胞质分裂期间将DNA定位在远离卵裂沟的位置。G1期的区域浓缩也建立了一个核结构，通过该结构基因转录受到调节，但仍保持可塑性，以便细胞能够对营养水平、温度和信号分子的变化做出反应。然而，迄今为止，这种可塑性对有丝分裂染色体凝聚的潜在影响仍然未知。在这里，我们报告的结果，从一个新的缩合试验，野生型芽殖酵母细胞表现出显着的变化，响应温度的rDNA构象。与维持在23°C的细胞相比，维持在37°C的野生型细胞中rDNA超浓缩。这种超凝聚机制可以在后期前期被激活，但在暴露于较低温度时很容易失活。在23°C下延长的有丝分裂停滞不会导致过度浓缩，否定了基于动力学的论点，即当细胞置于37°C时，通常缓慢进行的浓缩被加速。无论是升高的重组，也没有减少转录出现促进这种超凝聚。这迄今未被发现的温度依赖性hypercondensation途径影响目前的染色质结构的基础上的条件突变基因分析的观点，显着扩展了我们的理解，在染色质结构的生理变化，以应对低温。
Chromatin condensation during mitosis produces detangled and discrete DNA entities required for high fidelity sister chromatid segregation during mitosis and positions DNA away from the cleavage furrow during cytokinesis. Regional condensation during G1 also establishes a nuclear architecture through which gene transcription is regulated but remains plastic so that cells can respond to changes in nutrient levels, temperature and signaling molecules. To date, however, the potential impact of this plasticity on mitotic chromosome condensation remains unknown. Here, we report results obtained from a new condensation assay that wildtype budding yeast cells exhibit dramatic changes in rDNA conformation in response to temperature. rDNA hypercondenses in wildtype cells maintained at 37°C, compared with cells maintained at 23°C. This hypercondensation machinery can be activated during preanaphase but readily inactivated upon exposure to lower temperatures. Extended mitotic arrest at 23°C does not result in hypercondensation, negating a kinetic-based argument in which condensation that typically proceeds slowly is accelerated when cells are placed at 37°C. Neither elevated recombination nor reduced transcription appear to promote this hypercondensation. This heretofore undetected temperature-dependent hypercondensation pathway impacts current views of chromatin structure based on conditional mutant gene analyses and significantly extends our understanding of physiologic changes in chromatin architecture in response to hypothermia.