Mitotic phosphorylation of Golgi reassembly stacking protein 55 by mitogen-activated protein kinase ERK2
Mitotic phosphorylation of Golgi reassembly stacking protein 55 by mitogen-activated protein kinase ERK2
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DOI：
10.1091/mbc.12.6.1811
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发表时间：
2001-06-01
影响因子：
3.3
通讯作者：
Linstedt, AD
中科院分区：
文献类型：
--
作者：
Jesch, SA;Lewis, TS;Linstedt, AD
有丝分裂原活化蛋白激酶激酶（MKK）/细胞外活化蛋白激酶（ERK）通路在有丝分裂高尔基体解体中的作用是有争议的，部分原因是高尔基体定位的靶点尚未确定。我们观察到高尔基体重组堆积蛋白35（GRASP 55）在有丝分裂细胞和提取物中被磷酸化，产生由MPM 2 mAb识别的有丝分裂特异性磷酸化表位。GRASP 55中ERK共有位点的突变阻止了这种磷酸化。GRASP 55有丝分裂磷酸化显着减少，在体外和体内，通过治疗与U 0126，一种有效的和特异性的抑制剂MKK，从而ERK激活。此外，ERK 2直接磷酸化GRASP 55上产生MPM 2磷酸化表位的相同残基。这些结果是GRASP 55有丝分裂磷酸化的首次证明，并表明MKK/ERK途径在有丝分裂期间直接磷酸化高尔基体。
The role of the mitogen-activated protein kinase kinase (MKK)/extracellular-activated protein kinase (ERK) pathway in mitotic Golgi disassembly is controversial, in part because Golgi-localized targets have not been identified. We observed that Golgi reassembly stacking protein 35 (GRASP55) was phosphorylated in mitotic cells and extracts, generating a mitosis-specific phospho-epitope recognized by the MPM2 mAb. This phosphorylation was prevented by mutation of ERK consensus sites in GRASP55. GRASP55 mitotic phosphorylation was significantly reduced, both in vitro and in vivo, by treatment with U0126, a potent and specific inhibitor of MKK and thus ERK activation. Furthermore, ERK2 directly phosphorylated GRASP55 on the same residues that generated the MPM2 phospho-epitope. These results are the first demonstration of GRASP55 mitotic phosphorylation and indicate that the MKK/ERK pathway directly phosphorylates the Golgi during mitosis.