Phosphorylation and activation of 13S condensin by Cdc2 in vitro
Phosphorylation and activation of 13S condensin by Cdc2 in vitro
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DOI：
10.1126/science.282.5388.487
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发表时间：
1998-10-16
期刊：
影响因子：
56.9
通讯作者：
Hirano, T
中科院分区：
文献类型：
--
作者：
Kimura, K;Hirano, M;Hirano, T
13S 凝缩蛋白是爪蟾卵提取物中有丝分裂染色体凝缩所必需的多亚基蛋白质复合物。在体外拓扑异构酶 I 和三磷酸腺苷存在下，纯化的 135 凝缩蛋白将正超螺旋引入 DNA。 13S 凝缩蛋白的超螺旋活性受到有丝分裂特异性磷酸化的调节。免疫耗竭、体外磷酸化和肽图谱实验表明，Cdc2 很可能是磷酸化和激活 135 凝缩蛋白的激酶。多个 Cdc2 磷酸化位点聚集在 XCAP-D2（非洲爪蟾染色体相关多肽 D2）亚基的羧基末端结构域中。这些结果表明，Cdc2 对 135 凝缩蛋白的磷酸化可能会在体外触发有丝分裂染色体凝缩。
13S condensin is a multisubunit protein complex essential for mitotic chromosome condensation in Xenopus egg extracts. Purified 135 condensin introduces positive supercoils into DNA in the presence of topoisomerase I and adenosine triphosphate in vitro. The supercoiling activity of 13S condensin was regulated by mitosis-specific phosphorylation. Immunodepletion, in vitro phospholylation, and peptide-mapping experiments indicated that Cdc2 is Likely to be the kinase that phosphorylates and activates 135 condensin. Multiple Cdc2 phosphorylation sites are clustered in the carboxyl-terminal domain of the XCAP-D2 (Xenopus chromosome-associated polypeptide D2) subunit. These results suggest that phosphorylation of 135 condensin by Cdc2 may trigger mitotic chromosome condensation in vitro.