...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Molecular and Cellular Biology >The molecular chaperone Ydj1 is required for the p34CDC28-dependent phosphorylation of the cyclin Cln3 that signals its degradation.
【24h】

The molecular chaperone Ydj1 is required for the p34CDC28-dependent phosphorylation of the cyclin Cln3 that signals its degradation.

机译：分子伴侣Ydj1是细胞周期蛋白Cln3的p34CDC28依赖性磷酸化所必需的，这指示其降解。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The G1 cyclin Cln3 of the yeast Saccharomyces cerevisiae is rapidly degraded by the ubiquitin-proteasome pathway. This process is triggered by p34CDC28-dependent phosphorylation of Cln3. Here we demonstrate that the molecular chaperone Ydj1, a DnaJ homolog, is required for this phosphorylation. In a ydj1 mutant at the nonpermissive temperature, both phosphorylation and degradation of Cln3 were deficient. No change was seen upon inactivation of Sis1, another DnaJ homolog. The phosphorylation defect in the ydj1 mutant was specific to Cln3, because no reduction in the phosphorylation of Cln2 or histone H1, which also requires p34CDC28, was observed. Ydj1 was required for Cln3 phosphorylation and degradation rather than for the proper folding of this cyclin, since Cln3 produced in the ydj1 mutant was fully active in the stimulation of p34CDC28 histone kinase activity. Moreover, Ydj1 directly associates with Cln3 in close proximity to the segment that is phosphorylated and signals degradation. Thus, binding of Ydj1 to this domain of Cln3 seems to be essential for the phosphorylation and breakdown of this cyclin. In a cell-free system, purified Ydj1 stimulated the p34CDC28-dependent phosphorylation of the C-terminal segment of Cln3 and did not affect phosphorylation of Cln2 (as was found in vivo). The reconstitution of this process with pure components provides evidence of a direct role for the chaperone in the phosphorylation of Cln3.
机译：酵母Saccharomyces cerevisiae的G1细胞周期蛋白Cln3通过泛素-蛋白酶体途径迅速降解。此过程由p34CDC28依赖的Cln3磷酸化触发。在这里，我们证明分子伴侣Ydj1，DnaJ同源，是这种磷酸化所必需的。在非容许温度下的ydj1突变体中，Cln3的磷酸化和降解均不足。另一个DnaJ同源物Sis1失活后未见变化。 ydj1突变体的磷酸化缺陷是Cln3特有的，因为未观察到也需要p34CDC28的Cln2或组蛋白H1的磷酸化降低。 Ydj1是Cln3磷酸化和降解而不是该细胞周期蛋白正确折叠所必需的，因为ydj1突变体中产生的Cln3在刺激p34CDC28组蛋白激酶活性中具有充分的活性。此外，Ydj1与Cln3直接缔合，紧邻被磷酸化并信号降解的片段。因此，Ydj1绑定到Cln3的这个域似乎是这种细胞周期蛋白的磷酸化和分解必不可少的。在无细胞系统中，纯化的Ydj1刺激了Cln3 C末端片段的p34CDC28依赖性磷酸化，并且不影响Cln2的磷酸化（如在体内发现的）。用纯组分重建该过程提供了伴侣在Cln3磷酸化中的直接作用的证据。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号