Targeting and functional mechanisms of the cytokinesis-related F-BAR protein Hof1 during the cell cycle.
Targeting and functional mechanisms of the cytokinesis-related F-BAR protein Hof1 during the cell cycle.
复制标题
细胞周期中胞质分裂相关 F-BAR 蛋白 Hof1 的靶向和功能机制。
DOI：
10.1091/mbc.e12-11-0804
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发表时间：
2013
影响因子：
3.3
通讯作者：
Bi,Erfei
中科院分区：
文献类型：
--
作者：
Oh,Younghoon;Schreiter,Jennifer;Nishihama,Ryuichi;Wloka,Carsten;Bi,Erfei
F-BAR蛋白是膜相关蛋白，据信在胞质分裂和内吞等细胞过程中将质膜与肌动蛋白细胞骨架连接起来。在芽殖酵母酿酒酵母中，F-BAR蛋白Hof 1在细胞周期中以复杂的模式定位于分裂位点，并在胞质分裂中发挥重要作用。然而，其定位和功能的机制知之甚少。在这里，我们表明，Hof 1包含三个不同的靶向结构域，有助于细胞质分裂的差异。Hof 1的N末端的一半定位于芽颈和细胞周期中极化生长的位点。颈部定位主要由N端的第二卷曲螺旋区域和隔蛋白Cdc 10之间的相互作用介导，而极化生长位点的定位完全由F-BAR结构域介导。相比之下，Hof 1的C-末端一半与芽殖酵母中唯一的肌球蛋白-II重链Myo 1相互作用，并从胞质分裂的开始到完成以Myo 1-依赖的方式定位于芽颈。我们还表明，在C-末端的SH 3结构域在维持胞质分裂期间Myo 1环收缩的对称性方面起着重要作用，并且Hof 1与Chs 2相互作用，Chs 2是初级隔膜形成所需的几丁质合酶。这些数据共同定义了一个机制，占本地化的Hof 1在细胞周期中，并建议Hof 1可能在胞质分裂耦合肌动球蛋白环收缩初级隔膜形成通过与Myo 1和Chs 2的相互作用。
F-BAR proteins are membrane‑associated proteins believed to link the plasma membrane to the actin cytoskeleton in cellular processes such as cytokinesis and endocytosis. In the budding yeastSaccharomyces cerevisiae, the F‑BAR protein Hof1 localizes to the division site in a complex pattern during the cell cycle and plays an important role in cytokinesis. However, the mechanisms underlying its localization and function are poorly understood. Here we show that Hof1 contains three distinct targeting domains that contribute to cytokinesis differentially. The N‑terminal half of Hof1 localizes to the bud neck and the sites of polarized growth during the cell cycle. The neck localization is mediated mainly by an interaction between the second coiled‑coil region in the N‑terminus and the septin Cdc10, whereas the localization to the sites of polarized growth is mediated entirely by the F‑BAR domain. In contrast, the C‑terminal half of Hof1 interacts with Myo1, the sole myosin‑II heavy chain in budding yeast, and localizes to the bud neck in a Myo1‑dependent manner from the onset to the completion of cytokinesis. We also show that the SH3 domain in the C‑terminus plays an important role in maintaining the symmetry of Myo1 ring constriction during cytokinesis and that Hof1 interacts with Chs2, a chitin synthase that is required for primary septum formation. Together these data define a mechanism that accounts for the localization of Hof1 during the cell cycle and suggest that Hof1 may function in cytokinesis by coupling actomyosin ring constriction to primary septum formation through interactions with Myo1 and Chs2.