Dynamics of FtsZ assembly during sporulation in Streptomyces coelicolor A3(2)
Dynamics of FtsZ assembly during sporulation in Streptomyces coelicolor A3(2)
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DOI：
10.1128/jb.187.9.3227-3237.2005
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发表时间：
2005-05-01
影响因子：
3.2
通讯作者：
Flärdh, K
中科院分区：
文献类型：
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作者：
Grantcharova, N;Lustig, U;Flärdh, K
FtsZ 是细菌微管蛋白同源物，在天蓝色链霉菌 A3(2) 发育过程中的至少两个不同的细胞分裂过程中起主要作用。它形成细胞因子环，是在基质菌丝体中形成广泛间隔的菌丝横壁和将产孢气生菌丝转化为孢子的专门分隔的形成所必需的。后者发育控制的分隔涉及每个孢子菌丝细胞中大量 FtsZ 环的协调组装。我们使用 FtsZ 增强型绿色荧光蛋白 (EGFP) 翻译融合来可视化气生菌丝孢子形成过程中体内 FtsZ 环组装的进展。这表明多个 FtsZ 环的规则放置和胞质分裂的启动之前是一个延长的阶段，在此期间沿着气生菌丝细胞的长度检测到螺旋形 FtsZ 中间体。时程实验表明它们被改造并逐渐被规则间隔的 FtsZ 环取代。这种螺旋形细丝也可以通过使用抗 FtsZ 抗血清的免疫荧光显微镜来检测。根据我们的观察，我们提出了天蓝色链球菌孢子形成过程中 Z 环组装进展的模型。此外，还研究了缺乏发育调控基因whi4、whiB、whiG、whiH 和whiI 的突变体。他们未能上调气生菌丝中 FtsZ-EGFP 的表达，这与这些基因对 ftsZ 转录的已知影响一致。
FtsZ, the bacterial tubulin homologue, is the main player in at least two distinct processes of cell division during the development of Streptomyces coelicolor A3(2). It forms cytokinetic rings and is required for the formation of both the widely spaced hyphal cross walls in the substrate mycelium and the specialized septation that converts sporogenic aerial hyphae into spores. The latter developmentally controlled septation involves the coordinated assembly of large numbers of FtsZ rings in each sporulating hyphal cell. We used an FtsZ-enhanced green fluorescent protein (EGFP) translational fusion to visualize the progression of FtsZ ring assembly in vivo during sporulation of aerial hyphae. This revealed that the regular placement of multiple FtsZ rings and initiation of cytokinesis was preceded by a protracted phase during which spiral-shaped FtsZ intermediates were detected along the length of the aerial hyphal cell. Time course experiments indicated that they were remodeled and gradually replaced by regularly spaced FtsZ rings. Such spiral-shaped filaments could also be detected with immunofluorescence microscopy using an antiserum against FtsZ. Based on our observations, we propose a model for the progression of Z-ring assembly during sporulation of S. coelicolor. Furthermore, mutants lacking the developmental regulatory genes whi4, whiB, whiG, whiH, and whiI were investigated. They failed in up-regulation of the expression of FtsZ-EGFP in aerial hyphae, which is consistent with the known effects of these genes on ftsZ transcription.