...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >Arrestin with a single amino acid substitution quenches light-activated rhodopsin in a phosphorylation-independent fashion.
【24h】

Arrestin with a single amino acid substitution quenches light-activated rhodopsin in a phosphorylation-independent fashion.

机译：具有单个氨基酸取代的Arrestin以非磷酸化方式猝灭光激活的视紫红质。

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

Arrestins are members of a superfamily of regulatory proteins that participate in the termination of G protein-mediated signal transduction. In the phototransduction cascade of vertebrate rods, which serves as a prototypical G protein-mediated signaling pathway, the binding of visual arrestin is stimulated by phosphorylation of the C-terminus of photoactivated rhodopsin (Rh*). Arrestin is very selective toward light-activated phosphorhodopsin (P-Rh*). Previously we reported that a single amino acid substitution in arrestin, Arg175Gln, results in a dramatic increase in arrestin binding to Rh* [Gurevich, V. V., & Benovic, J. L. (1995) J. Biol. Chem. 270, 6010-6016]. Here we demonstrate that a similar mutant, arrestin(R175E), binds to light-activated rhodopsin independent of phosphorylation. Arrestin(R175E) binds with high affinity not only to P-Rh* and Rh* but also to light-activated truncated rhodopsin in which the C-terminus phosphorylation sites have been proteolytically removed. In an in vitro assay that monitored rhodopsin-dependent activation of cGMP phosphodiesterase (PDE), wild type arrestin quenched PDE response only when ATP was present to support rhodopsin phosphorylation. In contrast, as little as 30 nM arrestin(R175E) effectively quenched PDE activation in the absence of ATP. Arrestin(R175E) had no effect when the lifetime of Rh* no longer contributed to the time course of PDE activity, suggesting that it disrupts signal transduction at the level of rhodopsin-transducin interaction.
机译：抑制蛋白是调节蛋白超家族的成员，其参与G蛋白介导的信号转导的终止。在脊椎动物杆的光转导级联反应中，它作为原型G蛋白介导的信号传导途径，通过光活化视紫红质（Rh *）C端的磷酸化刺激视觉抑制蛋白的结合。 Arrestin对光激活的磷酸视紫红质（P-Rh *）具有很高的选择性。先前，我们报道了抑制蛋白Arg175Gln中的单个氨基酸取代导致抑制蛋白与Rh *的结合显着增加[Gurevich，V.V。，＆Benovic，J.L。（1995）J.Biol.Chem。，1987。化学270，6010-6016]。在这里，我们证明了一个类似的突变蛋白，restarin（R175E），与光激活的视紫红质结合，独立于磷酸化作用。 Arrestin（R175E）不仅与P-Rh *和Rh *具有高亲和力，而且还与光活化的截短的视紫红质结合，其中C-端磷酸化位点已被蛋白水解去除。在监测视紫红质依赖性cGMP磷酸二酯酶（PDE）活化的体外测定中，仅当存在ATP以支持视紫红质磷酸化时，野生型抑制蛋白才终止PDE反应。相反，在不存在ATP的情况下，低至30 nM的抑制蛋白（R175E）可以有效地淬灭PDE活化。当Rh *的寿命不再对PDE活性的时间进程有贡献时，Arrestin（R175E）没有作用，表明Arrestin（R175E）在视紫红质-转导蛋白相互作用的水平上破坏了信号转导。

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