Sec16 influences transitional ER sites by regulating rather than organizing COPII.
Sec16 influences transitional ER sites by regulating rather than organizing COPII.
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DOI：
10.1091/mbc.e13-04-0185
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发表时间：
2013-11
影响因子：
3.3
通讯作者：
Glick BS
中科院分区：
文献类型：
--
作者：
Bharucha N;Liu Y;Papanikou E;McMahon C;Esaki M;Jeffrey PD;Hughson FM;Glick BS
有人提出，在COPII囊泡从过渡性ER（tER）位点萌发期间，Sec16发挥着两种不同的作用：负调节COPII转换和组织COPII组装。新的数据表明，Sec16实际上并没有组织COPII，COPII营业额的调节可以解释Sec16对tER网站的影响。在从过渡型内质网（tER）位点出芽的外壳蛋白复合物II（COPII）囊泡过程中，Sec16被认为起着两种不同的作用：负调节COPII周转和组织COPII在tER位点的组装。我们用毕赤酵母检验了这些想法。Sec16重新分布到胞质溶胶加速tER动力学，支持Sec16的负调节作用。为了评估一个可能的COPII组织角色，我们解剖了Sec16的功能区域。中央保守结构域，这已经涉及协调COPII组装，实际上是正常的tER结构的。上游保守区（UCR）将Sec16定位于tER位点。UCR结合COPII组分，从tER位点去除COPII也会去除Sec16，表明COPII招募Sec16，而不是相反。我们建议Sec16实际上并不组织COPII。相反，COPII营业额的调节可以解释Sec16对tER网站的影响。
It has been proposed that during the budding of COPII vesicles from transitional ER (tER) sites, Sec16 plays two distinct roles: negatively regulating COPII turnover and organizing COPII assembly. New data suggest that Sec16 does not in fact organize COPII and that regulation of COPII turnover can explain the influence of Sec16 on tER sites. During the budding of coat protein complex II (COPII) vesicles from transitional endoplasmic reticulum (tER) sites, Sec16 has been proposed to play two distinct roles: negatively regulating COPII turnover and organizing COPII assembly at tER sites. We tested these ideas using the yeast Pichia pastoris. Redistribution of Sec16 to the cytosol accelerates tER dynamics, supporting a negative regulatory role for Sec16. To evaluate a possible COPII organization role, we dissected the functional regions of Sec16. The central conserved domain, which had been implicated in coordinating COPII assembly, is actually dispensable for normal tER structure. An upstream conserved region (UCR) localizes Sec16 to tER sites. The UCR binds COPII components, and removal of COPII from tER sites also removes Sec16, indicating that COPII recruits Sec16 rather than the other way around. We propose that Sec16 does not in fact organize COPII. Instead, regulation of COPII turnover can account for the influence of Sec16 on tER sites.