Bisel Blaine, Wang Yanzhuang, Wei Jen-Hsuan, Xiang Yi, Tang Danming, Miron-Mendoza Miguel, Yoshimura Shin-ichiro, Nakamura Nobuhiro, Seemann Joachim
Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
J Cell Biol. 2008 Sep 8;182(5):837-43. doi: 10.1083/jcb.200805045. Epub 2008 Sep 1.
Directed cell migration requires the orientation of the Golgi and centrosome toward the leading edge. We show that stimulation of interphase cells with the mitogens epidermal growth factor or lysophosphatidic acid activates the extracellular signal-regulated kinase (ERK), which phosphorylates the Golgi structural protein GRASP65 at serine 277. Expression of a GRASP65 Ser277 to alanine mutant or a GRASP65 1-201 truncation mutant, neither of which can be phosphorylated by ERK, prevents Golgi orientation to the leading edge in a wound assay. We show that phosphorylation of GRASP65 with recombinant ERK leads to the loss of GRASP65 oligomerization and causes Golgi cisternal unstacking. Furthermore, preventing Golgi polarization by expressing mutated GRASP65 inhibits centrosome orientation, which is rescued upon disassembly of the Golgi structure by brefeldin A. We conclude that Golgi remodeling, mediated by phosphorylation of GRASP65 by ERK, is critical for the establishment of cell polarity in migrating cells.
定向细胞迁移需要高尔基体和中心体朝向迁移前沿定向排列。我们发现，用有丝分裂原表皮生长因子或溶血磷脂酸刺激间期细胞会激活细胞外信号调节激酶（ERK），ERK会使高尔基体结构蛋白GRASP65的丝氨酸277位点发生磷酸化。将GRASP65丝氨酸277突变为丙氨酸的突变体或GRASP65 1 - 201截短突变体表达出来，这两种突变体都不能被ERK磷酸化，在伤口实验中可阻止高尔基体向迁移前沿定向排列。我们发现，用重组ERK使GRASP65磷酸化会导致GRASP65寡聚化丧失，并引起高尔基体扁平囊解聚。此外，通过表达突变的GRASP65来阻止高尔基体极化会抑制中心体定向排列，在用布雷菲德菌素A拆解高尔基体结构后这种抑制作用会得到挽救。我们得出结论，由ERK介导的GRASP65磷酸化所介导的高尔基体重塑对于迁移细胞中细胞极性的建立至关重要。
