The mitotic phosphorylation cycle of the cis-Golgi matrix protein GM130
The mitotic phosphorylation cycle of the cis-Golgi matrix protein GM130
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DOI：
10.1083/jcb.149.2.341
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发表时间：
2000-04-17
影响因子：
7.8
通讯作者：
Warren, G
中科院分区：
文献类型：
--
作者：
Lowe, M;Gonatas, NK;Warren, G
在有丝分裂中，顺式高尔基体基质蛋白GM 130在丝氨酸25上被磷酸化，磷酸化抑制与p115（囊泡束缚蛋白）的结合，并且被认为是有丝分裂高尔基体片段化过程中的重要步骤。我们已经产生了一种抗体，特异性地识别GM130磷酸化丝氨酸25，并使用这种抗体来研究体内磷酸化的时间调节。GM130在高尔基体复合体开始分解的前期被磷酸化，并且在中期和后期的进一步分解和高尔基体片段的分配期间保持磷酸化。在末期，随着高尔基体片段开始重组，GM130被去磷酸化。磷酸化和去磷酸化的时间与p115与高尔基体膜的解离和再结合相关。GM130磷酸化和p115解离似乎特异于有丝分裂，因为它们不是由触发非有丝分裂高尔基体片段化的几种药物诱导的。负责有丝分裂GM 130去磷酸化的磷酸酶被鉴定为PP2A。活性物质被鉴定为含有B α调节亚基的异源三聚体磷酸酶，这表明该亚型在有丝分裂结束时有丝分裂高尔基体膜的重新组装中的作用。
The cis-Golgi matrix protein GM130 is phosphorylated in mitosis on serine 25, Phosphorylation inhibits binding to p115, a vesicle-tethering protein, and has been implicated as an important step in the mitotic Golgi fragmentation process. We have generated an antibody that specifically recognizes GM130 phosphorylated on serine 25, and used this antibody to study the temporal regulation of phosphorylation in vivo. GM130 is phosphorylated in prophase as the Golgi complex starts to break down, and remains phosphorylated during further breakdown and partitioning of the Golgi fragments in metaphase and anaphase. In telophase, GM130 is dephosphorylated as the Golgi fragments start to reassemble. The timing of phosphorylation and dephosphorylation correlates with the dissociation and reassociation of p115 with Golgi membranes. GM130 phosphorylation and p115 dissociation appear specific to mitosis, since they are not induced by several drugs that trigger nonmitotic Golgi fragmentation. The phosphatase responsible for dephosphorylation of mitotic GM130 was identified as PP2A. The active species was identified as heterotrimeric phosphatase containing the B alpha regulatory subunit, suggesting a role for this isoform in the reassembly of mitotic Golgi membranes at the end of mitosis.