Keap1 modification and nuclear accumulation in response to S-nitrosocysteine
Keap1 modification and nuclear accumulation in response to S-nitrosocysteine
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DOI：
10.1016/j.freeradbiomed.2007.10.055
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发表时间：
2008-02-15
影响因子：
7.4
通讯作者：
Whorton, A. Richard
中科院分区：
文献类型：
--
作者：
Buckley, Barbara J.;Li, Sheng;Whorton, A. Richard
Keap 1是Nrf 2转录因子的关键调节因子，其反式激活抗氧化反应元件（ARE）并上调参与抗氧化防御的许多蛋白质。在基础条件下，Keap 1靶向Nrf 2进行泛素化和蛋白水解降解，因此负责Nrf 2的快速周转。响应于氧化剂和亲电体，Nrf 2被稳定并在细胞核中积累。已经提出这种效应的机制涉及Keap 1的巯基依赖性调节，导致其负调节Nrf 2的能力丧失。我们以前已经表明，一氧化氮和S-亚硝基硫醇导致核积累的Nrf 2和上调ARE调节基因HO-1。在这里，我们表明，一氧化氮和S-亚硝基半胱氨酸（CSNO）导致时间和剂量依赖性的Keap 1巯基修饰。这些研究在HEK 293细胞和过表达血凝素标记的Keap 1的HEK 293细胞中进行。此外，我们表明，在响应CSNO Keap 1积累在细胞核中的时间过程类似的Nrf 2。(c)2007年爱思唯尔公司All rights reserved.
Keap1 is a key regulator of the Nrf2 transcription factor, which transactivates the antioxidant response element (ARE) and upregulates numerous proteins involved in antioxidant defense. Under basal conditions, Keap1 targets Nrf2 for ubiquitination and proteolytic degradation and as such is responsible for the rapid turnover of Nrf2. In response to oxidants and electrophiles, Nrf2 is stabilized and accumulates in the nucleus. The mechanism for this effect has been proposed to involve thiol-dependent modulation of Keap1 leading to loss of its ability to negatively regulate Nrf2. We have previously shown that nitric oxide and S-nitrosothiols cause nuclear accumulation of Nrf2 and upregulation of the ARE-regulated gene HO-1. Here we show that nitric oxide and S-nitrosocysteine (CSNO) cause time- and dose-dependent Keap1 thiol modification. These studies were carried out in HEK293 cells and in HEK293 cells overexpressing hemagglutinin-tagged Keap1. Furthermore we demonstrate that in response to CSNO Keap1 accumulates in the nucleus with a time course similar to that of Nrf2. (c) 2007 Elsevier Inc. All rights reserved.