SIRT5 脱乙化碳酸合成酶1并调节尿素循环
Takashi Nakagawa1, David J Lomb, Marcia C Haigis
1Department of Biology, Massachusetts Institute of Technology, Cambridge, 02139, USA.
Cell
|May 5, 2009
概括
塞尔图因5 (SIRT5) 激活了线粒体中的碳酸合成酶1 (CPS1),这对氨解毒至关重要. 缺少SIRT5会损害这一过程,导致在禁食和改变饮食期间氨水平升高.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 代谢调节 代谢调节 代谢调节 代谢调节
背景情况:
- 锡尔图因是依赖NAD的脱乙酶,将新陈代谢与衰老联系在一起.
- 哺乳动物的sirtuins (SIRT1-7) 包括线粒体和非线粒体成员.
- 线粒体sirtuins在细胞能量恒温中发挥关键作用.
研究的目的:
- 研究SIRT5在线粒体功能和代谢适应中的作用.
- 为了确定肝脏中SIRT5的基质和调节机制.
- 为了阐明SIRT5对氨解毒路径的贡献.
主要方法:
- 线粒体蛋白质局部化研究.
- 对CPS1.1的酶活性测定.
- 使用生物化学方法进行Sirtuin-基质相互作用分析.
- 在各种饮食条件下 (禁食,卡路里限制,高蛋白饮食) 分析SIRT5淘汰赛 (KO) 鼠标模型.
主要成果:
- SIRT5定位在线粒体基质中,并与CPS1.1相互作用.
- SIRT5去乙基化并提高CPS1的活性,这是一个关键的尿素循环酶.
- 在禁食期间,线粒体NAD+的增加引发了CPS1的SIRT5激活.
- 在禁食,卡路里限制或高蛋白饮食期间,SIRT5 KO小鼠表现出CPS1活性受损和血氨水平升高.
结论:
- SIRT5是CPS1活动和氨排毒的关键调节者.
- 通过调节尿素循环,SIRT5促进新陈代谢适应营养的可用性.
- 对SIRT5的调节失调会影响氨平衡,突出显示其对代谢健康的重要性.
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