Dynamics of septin ring and collar formation in Saccharomyces cerevisiae
Dynamics of septin ring and collar formation in Saccharomyces cerevisiae
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DOI：
10.1515/bc.2011.075
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发表时间：
2011-08-01
影响因子：
3.7
通讯作者：
Lew, Daniel J.
中科院分区：
文献类型：
--
作者：
Chen, Hsin;Howell, Audrey S.;Lew, Daniel J.
尽管出芽酵母中的隔素环和环在20多年前就被描述了，但关于隔素丝在这些结构中的组织，以及环最初形成的方式以及它如何在母芽颈部转化为环仍然存在争议。在这里，我们通过细胞周期对荧光标记的septin在环和环上的招募进行了定量分析。隔素环组装在极性建立后几分钟开始，子细胞的间隔时间比母细胞长，表明隔素调节因子的不对称遗传。septin最初形成了一个微弱而不规则的环，随着septin以恒定的速率被吸收，这个环变得更加规则。这种稳定的septin招募率在芽出时环转化为项圈后持续了几分钟。在环到环过渡期间，我们没有检测到septin荧光的逐步变化。在花圈形成后，芽颈处的间隔素继续积累，尽管速度有所降低，直到细胞质分裂开始时，颈部局部间隔素的数量迅速减少。讨论了septin环组装机理的启示。
Although the septin ring and collar in budding yeast were described over 20 years ago, there is still controversy regarding the organization of septin filaments within these structures and about the way in which the ring first forms and about how it converts into a collar at the mother-bud neck. Here we present quantitative analyses of the recruitment of fluorescently-tagged septins to the ring and collar through the cell cycle. Septin ring assembly began several minutes after polarity establishment and this interval was longer in daughter than in mother cells, suggesting asymmetric inheritance of septin regulators. Septins formed an initial faint and irregular ring, which became more regular as septins were recruited at a constant rate. This steady rate of septin recruitment continued for several minutes after the ring converted to a collar at bud emergence. We did not detect a stepwise change in septin fluorescence during the ring-to-collar transition. After collar formation, septins continued to accumulate at the bud neck, though at a reduced rate, until the onset of cytokinesis when the amount of neck-localized septins rapidly decreased. Implications for the mechanism of septin ring assembly are discussed.