Sipiczki Matthias
Department of Genetics, University of Debrecen, Debrecen, Hungary.
FEMS Yeast Res. 2007 Sep;7(6):761-70. doi: 10.1111/j.1567-1364.2007.00266.x. Epub 2007 Jun 27.
In cell-walled organisms, a cross wall (septum) is produced during cytokinesis, which then splits in certain organisms to allow the daughter cells to separate. The formation and the subsequent cleavage of the septum require wall synthesis and wall degradation, which need to be strictly coordinated in order to prevent cell lysis. The dividing fission yeast (Schizosaccharomyces) cell produces a three-layered septum in which the middle layer and a narrow band of the adjacent cell wall can be degraded without threatening the integrity of the separating daughter cells. This spatially very precise process requires the activity of the Agn1p 1,3-alpha-glucanase and the Eng1p 1,3-beta-glucanase, which are localized to the septum by a complex mechanism involving the formation of a septin ring and the directed activity of the exocyst system. The Sep1p-Ace2p transcription-factor cascade regulates the expression of many genes producing proteins for this complex process. Recent advances in research into the molecular mechanisms of separation and its regulation are discussed in this review.
在有细胞壁的生物体中，胞质分裂期间会产生横壁（隔膜），然后在某些生物体中横壁会裂开，使子细胞分离。隔膜的形成及随后的裂开需要细胞壁合成和细胞壁降解，为防止细胞裂解，这两者需严格协调。正在分裂的裂殖酵母细胞会产生一个三层隔膜，其中间层和相邻细胞壁的一条窄带可被降解，而不会威胁到正在分离的子细胞的完整性。这个在空间上非常精确的过程需要Agn1p 1,3-α-葡聚糖酶和Eng1p 1,3-β-葡聚糖酶的活性，它们通过一种复杂机制定位于隔膜，该机制涉及 septin 环的形成和外泌体系统的定向活性。Sep1p-Ace2p转录因子级联反应调节许多为此复杂过程产生蛋白质的基因的表达。本文综述了分离及其调控分子机制研究的最新进展。
