Bartz René, Seemann Joachim
Merck & Co. Inc., RNA Therapeutics, West Point, Pennsylvania, USA.
Cell Cycle. 2008 Jul 15;7(14):2100-5. doi: 10.4161/cc.7.14.6327. Epub 2008 May 22.
The highly organized structure of the Golgi apparatus becomes compromised during mitosis. The Golgi cisternae unstack and form vesicles, which are then partitioned into the daughter cells. Here, we analyzed the fate of the SREBP and ATF6, two key transcription factors of sterol biogenesis and the unfolded protein response, respectively. During interphase the precursors of both transcription factors are silent in the ER, but upon activation signals SREBP and ATF6 move to the Golgi where they are activated by proteolytic cleavage by S1P and S2P. Since the spatial separation between the ER and the Golgi is the basis for the regulated activation, we investigated whether mitosis is sufficient to trigger activation. We found that the strict compartmentalization of the ER and the Golgi is maintained during mitosis to inhibit the activation of SREBP and ATF6.
高尔基体高度有序的结构在有丝分裂期间会受到破坏。高尔基体潴泡解堆叠并形成囊泡，然后这些囊泡被分配到子细胞中。在此，我们分析了固醇生物合成和未折叠蛋白反应的两个关键转录因子——固醇调节元件结合蛋白（SREBP）和活化转录因子6（ATF6）的命运。在间期，这两种转录因子的前体在内质网中处于沉默状态，但在激活信号作用下，SREBP和ATF6会移动到高尔基体，在那里它们被位点1蛋白酶（S1P）和位点2蛋白酶（S2P）的蛋白水解切割所激活。由于内质网和高尔基体之间的空间分隔是调节激活的基础，我们研究了有丝分裂是否足以触发激活。我们发现，在有丝分裂期间，内质网和高尔基体的严格区室化得以维持，以抑制SREBP和ATF6的激活。
