...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Chloroplast Protein Targeting Involves Localized Translation In Chlamydomonas
【24h】

Chloroplast Protein Targeting Involves Localized Translation In Chlamydomonas

机译：靶向叶绿体蛋白涉及衣藻的局部翻译

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The compartmentalization of eukaryotic cells requires that newly synthesized proteins be targeted to the compartments in which they function. In chloroplasts, a few thousand proteins function in photosynthesis, expression of the chloroplast genome, and other processes. Most chloroplast proteins are synthesized in the cytoplasm, imported, and then targeted to a specific chloroplast compartment. The remainder are encoded by the chloroplast genome, synthesized within the organelle, and targeted by mechanisms that are only beginning to be elucidated. We used fluorescence confocal microscopy to explore the targeting mechanisms used by several chloroplast proteins in the green alga Chlamydomonas. These include the small subunit of ribulose bisphosphate carbox-ylase (rubisco) and the light-harvesting complex II (LHCII) subunits, which are imported from the cytoplasm, and 2 proteins synthesized in the chloroplast: the D1 subunit of photosystem II and the rubisco large subunit. We determined whether the targeting of each protein involves localized translation of the mRNA that encodes it. When this was the case, we explored whether the targeting sequence was in the nascent polypeptide or in the mRNA, based on whether the localization was translation-dependent or -independent, respectively. The results reveal 2 novel examples of targeting by localized translation, in LHCII subunit import and the targeting of the rubisco large subunit to the pyrenoid. They also demonstrate examples of each of the three known mechanisms-posttranslational, cotranslational (signal recognition particle-mediated), and mRNA-based-in the targeting of specific chloroplast proteins. Our findings can help guide the exploration of these pathways at the biochemical level.
机译：真核细胞的区室化要求将新合成的蛋白质靶向它们在其中起作用的区室。在叶绿体中，数千种蛋白质在光合作用，叶绿体基因组表达和其他过程中起作用。大多数叶绿体蛋白在细胞质中合成，输入，然后靶向特定的叶绿体区室。其余的由叶绿体基因组编码，在细胞器内合成，并由刚刚开始阐明的机制靶向。我们使用荧光共聚焦显微镜探索绿藻衣藻中几种叶绿体蛋白所使用的靶向机制。这些包括核糖二磷酸羧化酶的小亚基（rubisco）和从细胞质中导入的光捕获复合物II（LHCII）亚基，以及在叶绿体中合成的2种蛋白质：光系统II的D1亚基和rubisco大亚基。我们确定了每种蛋白质的靶向作用是否涉及编码它的mRNA的局部翻译。在这种情况下，我们根据定位分别是翻译依赖性还是非依赖性来探讨靶向序列是在新生多肽中还是在mRNA中。结果揭示了在LHCII亚基输入和rubisco大亚基靶向类胡萝卜素方面通过局部翻译靶向的2个新实例。他们还展示了针对特定叶绿体蛋白的三种已知机制（翻译后，共翻译（信号识别粒子介导）和基于mRNA）中每种机制的实例。我们的发现可以帮助指导在生化水平上探索这些途径。

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