Identification of a protein kinase which phosphorylates a subunit of the 26S proteasome and changes in its activity during meiotic cell cycle in goldfish oocytes
Identification of a protein kinase which phosphorylates a subunit of the 26S proteasome and changes in its activity during meiotic cell cycle in goldfish oocytes
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DOI：
10.1016/j.cellsig.2004.07.002
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发表时间：
2005-02-01
影响因子：
4.8
通讯作者：
Tokumoto, T
中科院分区：
文献类型：
--
作者：
Horiguchi, R;Yoshikuni, M;Tokumoto, T
蛋白酶体参与鱼卵母细胞减数分裂细胞周期的进展。我们报道26S蛋白酶体的α4亚基是20S蛋白酶体外环的组成部分，在未成熟卵母细胞中被磷酸化，而在成熟卵母细胞中被去磷酸化。为了研究磷酸化的作用，我们使用重组 α4 亚基作为底物从未成熟卵母细胞中纯化了蛋白激酶。与激酶活性完全对应的蛋白质条带被鉴定为酪蛋白激酶Iα（CKIα）。二维 (2D) PAGE 分析表明，部分 alpha4 亚基在体外被 CKIalpha 磷酸化。该点在纯化的未成熟 26S 蛋白酶体中检测到，但在成熟 26S 蛋白酶体中未检测到，证明 α4 亚基被 CKIα 减数分裂细胞周期依赖性磷酸化。 (C) 2004 Elsevier Inc. 保留所有权利。
The proteasome is involved in the progression of the meiotic cell cycle in fish oocytes. We reported that the alpha4 subunit of the 26S proteasome, which is a component of the outer rings of the 20S proteasome, is phosphorylated in immature oocytes and dephosphorylated in mature oocytes. To investigate the role of the phosphorylation, we purified the protein kinase from immature oocytes using a recombinant alpha4 subunit as substrate. A protein band which well corresponded to the kinase activity was identified as casein kinase Ialpha (CKIalpha). Two-dimensional (2D) PAGE analysis showed that part of the alpha4 subunit was phosphorylated by CKIalpha in vitro. This spot was detected in purified immature 26S proteasome but not in mature 26S proteasome, demonstrate that the alpha4 subunit is phosphorylated by CKIalpha meiotic cell cycle dependently. (C) 2004 Elsevier Inc. All rights reserved.