Regulation of Na+/K+-ATPase by Nuclear Respiratory Factor 1 IMPLICATION IN THE TIGHT COUPLING OF NEURONAL ACTIVITY, ENERGY GENERATION, AND ENERGY CONSUMPTION
Regulation of Na+/K+-ATPase by Nuclear Respiratory Factor 1 IMPLICATION IN THE TIGHT COUPLING OF NEURONAL ACTIVITY, ENERGY GENERATION, AND ENERGY CONSUMPTION
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DOI：
10.1074/jbc.m112.414573
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发表时间：
2012-11-23
影响因子：
4.8
通讯作者：
Wong-Riley, Margaret T. T.
中科院分区：
文献类型：
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作者：
Johar, Kaid;Priya, Anusha;Wong-Riley, Margaret T. T.
能量产生和能量消耗与细胞水平的神经元活动紧密相关。 Na+/K+-ATP酶是一种主要的能量消耗酶，在富含细胞色素c氧化酶（能量产生机制的重要酶）和谷氨酸受体（神经元活动的介质）的神经元中良好表达。本研究试图检验我们的假设，即耦合延伸到分子水平，即 Na+/K+-ATP 酶亚基受到相同转录因子核呼吸因子 1 (NRF-1) 的调节，我们的实验室最近发现 NRF-1 可以调节所有细胞色素 c 氧化酶亚基基因以及一些 NMDA 和 AMPA 受体亚基基因。通过计算机分析、电泳迁移率变动和超移测定、体内染色质免疫沉淀、启动子突变分析和实时定量 PCR 等多种方法，发现 NRF-1 与神经元中 Atp1a1 和 Atp1b1 基因的启动子功能性结合，但不与 Atp1a3 基因的启动子结合。 Atp1a1 和 Atp1b1 亚基基因的转录本受 KCl 上调，受河鲀毒素下调。 Atp1b1 受到 NRF-1 的正向调节，用小干扰 RNA 沉默 NRF-1 可以阻断 KCl 诱导的 Atp1b1 上调，而 NRF-1 的过表达可以使这些转录物免受河豚毒素的抑制。另一方面，Atp1a1 受到 NRF-1 的负调控。 NRF-1 在 Atp1a1 和 Atp1b1 上的结合位点在小鼠、大鼠和人类中是保守的。因此，NRF-1 调节关键的 Na+/K+-ATP 酶亚基，并在分子水平上介导能量消耗、能量产生和神经元活动之间的紧密耦合中发挥重要作用。
Energy generation and energy consumption are tightly coupled to neuronal activity at the cellular level. Na+/K+-ATPase, a major energy-consuming enzyme, is well expressed in neurons rich in cytochrome c oxidase, an important enzyme of the energy-generating machinery, and glutamatergic receptors that are mediators of neuronal activity. The present study sought to test our hypothesis that the coupling extends to the molecular level, whereby Na+/K+-ATPase subunits are regulated by the same transcription factor, nuclear respiratory factor 1 (NRF-1), found recently by our laboratory to regulate all cytochrome c oxidase subunit genes and some NMDA and AMPA receptor subunit genes. By means of multiple approaches, including in silico analysis, electrophoretic mobility shift and supershift assays, in vivo chromatin immunoprecipitation, promoter mutational analysis, and real-time quantitative PCR, NRF-1 was found to functionally bind to the promoters of Atp1a1 and Atp1b1 genes but not of the Atp1a3 gene in neurons. The transcripts of Atp1a1 and Atp1b1 subunit genes were up-regulated by KCl and down-regulated by tetrodotoxin. Atp1b1 is positively regulated by NRF-1, and silencing of NRF-1 with small interference RNA blocked the up-regulation of Atp1b1 induced by KCl, whereas overexpression of NRF-1 rescued these transcripts from being suppressed by tetrodotoxin. On the other hand, Atp1a1 is negatively regulated by NRF-1. The binding sites of NRF-1 on Atp1a1 and Atp1b1 are conserved among mice, rats, and humans. Thus, NRF-1 regulates key Na+/K+-ATPase subunits and plays an important role in mediating the tight coupling between energy consumption, energy generation, and neuronal activity at the molecular level.