Chaperone requirements for de novo folding of Saccharomyces cerevisiae septins.
Chaperone requirements for de novo folding of Saccharomyces cerevisiae septins.
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DOI：
10.1091/mbc.e22-07-0262
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发表时间：
2022-10-01
影响因子：
3.3
通讯作者：
McMurray, Michael
中科院分区：
文献类型：
--
作者：
Hassell, Daniel;Denney, Ashley;Singer, Emily;Benson, Aleyna;Roth, Andrew;Ceglowski, Julia;Steingesser, Marc;McMurray, Michael
septin蛋白复合物的聚合物在真核细胞中起细胞骨架作用。复合物中特定的亚基组成控制着功能和高阶结构特性。所有的蛋白酶都有球状的GTPase结构域。其他真核细胞骨架NTPases严格需要细胞质分子伴侣蛋白的帮助，特别是笼状伴侣蛋白，才能折叠成寡聚化的构象。我们之前发现了结合septin并影响携带与人类疾病相关突变的septin的寡聚化能力的细胞质伴侣，但尚不清楚野生型septin在多大程度上需要伴侣协助其天然折叠。在这里，我们使用体内和体外方法的组合来证明通过出芽酵母蛋白酶从头折叠和复杂组装的伴侣要求。单独纯化的蛋白酶采用非天然构象，形成非天然同型二聚体。在伴侣蛋白缺乏或hsp70缺陷的细胞中，septin折叠速度较慢，并且无法在翻译后组装成天然复合物。一种septin， Cdc12，非常依赖于协同翻译伴侣蛋白的帮助，没有它，翻译就失败了。我们的研究结果指出，不同septin的不同翻译延伸率可能是指导逐步的共翻译组装途径的机制，其中一般细胞质伴侣蛋白作为关键中介。
Polymers of septin protein complexes play cytoskeletal roles in eukaryotic cells. The specific subunit composition within complexes controls functions and higher-order structural properties. All septins have globular GTPase domains. The other eukaryotic cytoskeletal NTPases strictly require assistance from molecular chaperones of the cytosol, particularly the cage-like chaperonins, to fold into oligomerization-competent conformations. We previously identified cytosolic chaperones that bind septins and influence the oligomerization ability of septins carrying mutations linked to human disease, but it was unknown to what extent wild-type septins require chaperone assistance for their native folding. Here we use a combination of in vivo and in vitro approaches to demonstrate chaperone requirements for de novo folding and complex assembly by budding yeast septins. Individually purified septins adopted nonnative conformations and formed nonnative homodimers. In chaperonin- or Hsp70-deficient cells, septins folded slower and were unable to assemble posttranslationally into native complexes. One septin, Cdc12, was so dependent on cotranslational chaperonin assistance that translation failed without it. Our findings point to distinct translation elongation rates for different septins as a possible mechanism to direct a stepwise, cotranslational assembly pathway in which general cytosolic chaperones act as key intermediaries.
表达SSA1，SSA2，SSA3或SSA4的酵母细胞的全局转录本和表型分析是胞质HSP70-SSA伴侣活性的唯一来源。
影响因子：
4.4
作者：
Hasin N;Cusack SA;Ali SS;Fitzpatrick DA;Jones GW
通讯作者：
Jones GW
DOI：
10.1093/g3journal/jkaa006
发表时间：
2021-01-18
期刊：
G3 (Bethesda, Md.)
影响因子：
--
作者：
Takagi J;Cho C;Duvalyan A;Yan Y;Halloran M;Hanson-Smith V;Thorner J;Finnigan GC
通讯作者：
Finnigan GC