Diallyl disulfide inhibits p34cdc2 kinase activity through changes in complex formation and phosphorylation
Diallyl disulfide inhibits p34cdc2 kinase activity through changes in complex formation and phosphorylation
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DOI：
10.1093/carcin/21.6.1129
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发表时间：
2000-06-01
期刊：
影响因子：
4.7
通讯作者：
Milner, JA
中科院分区：
文献类型：
--
作者：
Knowles, LM;Milner, JA
我们实验室的先前研究表明，二烯丙基二硫化物（DADS），一种在加工大蒜中发现的油溶性烯丙基硫化合物，显著抑制p34（cdc 2）激酶活性，并诱导培养的人结肠肿瘤（HCT-15）细胞的G（2）/M期阻滞。目前的研究表明，抑制p34（cdc 2）激酶活性的DADS不直接与蛋白质的相互作用，但通过影响酶的形成和转化为其活性形式的因素的变化。流式细胞仪分析显示DADS处理后G（2）/M期细胞比例增加，同时细胞周期蛋白B-1蛋白表达增加。在DADS处理的细胞中观察到细胞周期蛋白B-1表达的时间和剂量依赖性反应。Western blot分析显示，50 μ M DADS对p34（cdc 2）蛋白表达量无影响，但使cyclin B-1蛋白表达量降低26%（P < 0.05）。暴露于25或50 μ M DADS的非同步化细胞导致p34（cdc 2）过度磷酸化（分别为17%和22%）增加的趋势。100 μ M DADS使同步化细胞p34（cdc 2）过度磷酸化增加15%（P < 0.05）。与其略微增加超磷酸化p34（cdc 2）数量的能力一致，25或50 μ M的DADS分别使cdc 25 C蛋白表达降低23%和46%（P < 0.05）。目前的研究表明，DADS抑制p34（cdc 2）激酶活化的能力是由于减少p34（cdc 2）/细胞周期蛋白B-1复合物的形成和适度的p34（cdc 2）过度磷酸化。
Previous studies from our laboratory demonstrated that diallyl disulfide (DADS), an oil-soluble allyl sulfur compound found in processed garlic, markedly suppressed p34(cdc2) kinase activity and induced a G(2)/M phase arrest in cultured human colon tumor (HCT-15) cells. The present studies reveal that suppression of p34(cdc2) kinase activity by DADS does not result from direct interactions with the protein, but through changes in factors influencing the formation and conversion of the enzyme to its active form. Flow cytometric analyses showed that the increased proportion of cells in the G(2)/M phase following DADS treatment was accompanied by an increase in cyclin B-1 protein expression. A temporal and dose-dependent response in cyclin B-1 expression was observed in cells treated with DADS. Western blot analysis revealed that 50 mu M DADS did not influence the quantity of p34(cdc2) protein expressed, but did decrease the amount associated with cyclin B-1 by 26% (P < 0.05). Exposure of unsynchronized cells to 25 or 50 mu M DADS caused a trend towards increased p34(cdc2) hyperphosphorylation (17 and 22%, respectively). Exposure of synchronized cells to 100 mu M DADS increased p34(cdc2) hyperphosphorylation by 15% (P < 0.05). Consistent with its ability to slightly increase the quantity of hyperphosphorylated p34(cdc2), DADS, 25 or 50 mu M, decreased cdc25C protein expression by 23 and 46%, respectively (P < 0.05). The present studies suggest that the ability of DADS to inhibit p34(cdc2) kinase activation occurs because of decreased p34(cdc2)/cyclin B-1 complex formation and modest p34(cdc2) hyperphosphorylation.