Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, James-Franck-Ring N27, D-89081 Ulm, Germany.
J Cell Sci. 2013 Aug 1;126(Pt 15):3390-400. doi: 10.1242/jcs.125302. Epub 2013 Jun 7.
The mechanisms of the coordinated assembly and disassembly of the septin/myosin ring is central for the understanding of polar growth and cytokinesis in yeast and other organisms. The septin- and myosin-binding protein Bni5p provides a dual function during the formation and disassembly of septin/myosin rings. Early in the cell cycle, Bni5p captures Myo1p at the incipient bud site and actively transforms it into higher-order structures. Additionally, Bni5p stabilizes the septin/myosin ring and is released from the septins shortly before the onset of cytokinesis. If this Bni5p dissociation from the septins is artificially prevented, ring disassembly is impaired and the untimely appearance of septin/myosin ring is induced. The prematurely formed septin/myosin rings delay the establishment of a new polarity axis and the progression into a new cell cycle. This observation suggests a negative feedback between septin/myosin ring formation and polarity establishment that might help to guarantee the singular assembly of this structure and the synchronization of its formation with the cell cycle.
协调装配和拆卸的机制在理解极性生长和有丝分裂酵母和其他生物体中是中央的。 septin- 和肌球蛋白结合蛋白 Bni5p 在 septin/myosin 环的形成和拆卸过程中提供双重功能。在细胞周期的早期，Bni5p 在初始芽位点捕获 Myo1p，并将其积极转化为高级结构。此外，Bni5p 稳定 septin/myosin 环，并在有丝分裂开始前不久从 septin 上释放。如果 septin 与 septin 的这种分离被人为地阻止，环的拆卸就会受到损害，并且会过早地出现 septin/myosin 环。过早形成的 septin/myosin 环会延迟新极性轴的建立和进入新的细胞周期。这一观察结果表明 septin/myosin 环形成与极性建立之间存在负反馈，这可能有助于保证该结构的单一装配及其形成与细胞周期的同步。
