Protein-protein interactions governing septin heteropentamer assembly and septin filament organization in Saccharomyces cerevisiae
Protein-protein interactions governing septin heteropentamer assembly and septin filament organization in Saccharomyces cerevisiae
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DOI：
10.1091/mbc.e04-04-0330
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发表时间：
2004-10-01
影响因子：
3.3
通讯作者：
Thorner, J
中科院分区：
文献类型：
--
作者：
Versele, M;Gullbrand, B;Thorner, J
有丝分裂酵母（酿酒酵母）细胞表达5个相关的septins（Cdc 3，Cdc 10，Cdc 11，Cdc 12，和Shs 1），形成一个皮质丝状衣领在母芽颈部所需的正常形态发生和胞质分裂。所有五个拥有一个N-末端GTdR结构域，除了Cdc 10，C-末端延伸（CTE）含有预测的卷曲螺旋。在这里，我们表明，Cdc 3和Cdc 12的CTE是必不可少的协会和两个septins在体内的功能。Cdc 10与Cdc 3-Cdc 12复合物相互作用，与任一蛋白质的CTE无关。与Cdc 3和Cdc 12相反，Cdc 11 CTE招募非必需的septin Shs 1，其在体内的功能是不确定的。此外，Cdc 11与Cdc 12形成化学计量复合物，与其CTE无关。各种multiseptin复合物的重建和电子显微镜分析表明，Cdc 3，Cdc 11，和Cdc 12都是必要的和足够的septin丝形成，和Cdc 10的存在下，丝配对。这些数据提供了新的见解之间的连接功能septin异五聚体和septin丝的组织的五个单独的septins。
Mitotic yeast (Saccharomyces cerevisiae) cells express five related septins (Cdc3, Cdc10, Cdc11, Cdc12, and Shs1) that form a cortical filamentous collar at the mother-bud neck necessary for normal morphogenesis and cytokinesis. All five possess an N-terminal GTPase domain and, except for Cdc10, a C-terminal extension (CTE) containing a predicted coiled coil. Here, we show that the CTEs of Cdc3 and Cdc12 are essential for their association and for the function of both septins in vivo. Cdc10 interacts with a Cdc3-Cdc12 complex independently of the CTE of either protein. In contrast to Cdc3 and Cdc12, the Cdc11 CTE, which recruits the nonessential septin Shs1, is dispensable for its function in vivo. In addition, Cdc11 forms a stoichiometric complex with Cdc12, independent of its CTE. Reconstitution of various multiseptin complexes and electron microscopic analysis reveal that Cdc3, Cdc11, and Cdc12 are all necessary and sufficient for septin filament formation, and presence of Cdc10 causes filament pairing. These data provide novel insights about the connectivity among the five individual septins in functional septin heteropentamers and the organization of septin filaments.