...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biology Open >Assisted protein folding at low temperature: evolutionary adaptation of the Antarctic fish chaperonin CCT and its client proteins
【24h】

Assisted protein folding at low temperature: evolutionary adaptation of the Antarctic fish chaperonin CCT and its client proteins

机译：辅助蛋白质在低温下折叠：南极鱼伴侣蛋白CCT及其客户蛋白质的进化适应

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

摘要

Eukaryotic ectotherms of the Southern Ocean face energetic challenges to protein folding assisted by the cytosolic chaperonin CCT. We hypothesize that CCT and its client proteins (CPs) have co-evolved molecular adaptations that facilitate CCT–CP interaction and the ATP-driven folding cycle at low temperature. To test this hypothesis, we compared the functional and structural properties of CCT–CP systems from testis tissues of an Antarctic fish, Gobionotothen gibberifrons (L?nnberg) (habitat/body T?=??1.9 to +2°C), and of the cow (body T?=?37°C). We examined the temperature dependence of the binding of denatured CPs (β-actin, β-tubulin) by fish and bovine CCTs, both in homologous and heterologous combinations and at temperatures between ?4°C and 20°C, in a buffer conducive to binding of the denatured CP to the open conformation of CCT. In homologous combination, the percentage of G. gibberifrons CCT bound to CP declined linearly with increasing temperature, whereas the converse was true for bovine CCT. Binding of CCT to heterologous CPs was low, irrespective of temperature. When reactions were supplemented with ATP, G. gibberifrons CCT catalyzed the folding and release of actin at 2°C. The ATPase activity of apo-CCT from G. gibberifrons at 4°C was ～2.5-fold greater than that of apo-bovine CCT, whereas equivalent activities were observed at 20°C. Based on these results, we conclude that the catalytic folding cycle of CCT from Antarctic fishes is partially compensated at their habitat temperature, probably by means of enhanced CP-binding affinity and increased flexibility of the CCT subunits.
机译：南大洋的真核等温线在胞质伴侣蛋白CCT的辅助下面临着蛋白质折叠的巨大挑战。我们假设CCT及其客户蛋白（CP）具有共同进化的分子适应性，可促进CCT-CP相互作用和低温下ATP驱动的折叠循环。为了验证这一假设，我们比较了南极鱼类睾丸组织中的CCT-CP系统的功能和结构特性，该生物体的生境/体温T == 1.9至+ 2°C，并且牛的体温（体温T？=？37°C）。我们研究了鱼类和牛CCT变性和CPs（β-肌动蛋白，β-微管蛋白）结合的温度依赖性，包括同源和异源组合以及在？4°C和20°C之间的温度下，在有助于变性的CP与CCT的开放构象的结合。在同源组合中，与CP结合的赤霉菌CCT的百分比随温度升高线性下降，而牛CCT则相反。无论温度如何，CCT与异源CP的结合均很低。当反应中补充有ATP时，赤霉素CCT在2°C时催化肌动蛋白的折叠和释放。赤霉菌的apo-CCT的ATPase活性在4°C时是apo-牛CCT的〜2.5倍，而在20°C时观察到了相同的活性。基于这些结果，我们得出结论，南极鱼类的CCT催化折叠周期在其栖息温度下得到了部分补偿，这可能是通过增强CP结合亲和力和增强CCT亚基的柔性来实现的。

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