Involvement of Rac1 in Activation of Multicomponent Nox1- and Nox3-Based NADPH Oxidases
Involvement of Rac1 in Activation of Multicomponent Nox1- and Nox3-Based NADPH Oxidases
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DOI：
10.1128/mcb.26.6.2160-2174.2006
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发表时间：
2006-03
影响因子：
5.3
通讯作者：
T. Ueyama;M. Geiszt;Thomas L. Leto
中科院分区：
文献类型：
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作者：
T. Ueyama;M. Geiszt;Thomas L. Leto
Nox家族NADPH氧化酶是一个多组分酶系统。我们探讨了多组分氧化酶Nox 1和Nox 3的组装决定因素，并研究了Rac 1参与其调节。这两种酶都由p47 phox和p67 phox或称为Noxo1和Noxa1的同源调节因子支持，尽管Nox3对这些辅因子的活性依赖性较低。Noxa1的质膜靶向依赖于Noxo1，通过这些蛋白质之间的尾对尾相互作用。Noxa1可以支持Nox1没有Noxo1，当通过融合膜结合序列从Rac1（氨基酸183至192）的Noxa1的C末端的质膜。然而，Noxa1的膜靶向不足以激活Nox1。Noxo1独立和依赖的Nox1系统都涉及Rac 1，因为它们受到Rac 1突变体或Rac结合缺陷的Noxa1突变体或短干扰RNA介导的Rac 1沉默的影响。Nox 1或Nox 3表达促进p22 phox转运至质膜，并且这两种氧化酶都被Nox组织者（p47 phox或Noxo1）的p22 phox结合位点（SH3结构域）中的突变抑制。Rac1对Nox3的调节也可以从突变型Rac1或突变型Nox3激活剂（p67 phox或Noxa1）或Rac1沉默的影响中看出。在没有Nox组织者的情况下，Nox激活剂（p67 phox或Noxa1）与Rac1共定位在皱褶膜内，与它们结合Rac1的能力无关。因此，Rac1通过Nox激活剂调节两种氧化酶，尽管它似乎并不指导这些激活剂的亚细胞定位。
ABSTRACT Several Nox family NADPH oxidases function as multicomponent enzyme systems. We explored determinants of assembly of the multicomponent oxidases Nox1 and Nox3 and examined the involvement of Rac1 in their regulation. Both enzymes are supported by p47 phox and p67 phox or homologous regulators called Noxo1 and Noxa1, although Nox3 is less dependent on these cofactors for activity. Plasma membrane targeting of Noxa1 depends on Noxo1, through tail-to-tail interactions between these proteins. Noxa1 can support Nox1 without Noxo1, when targeted to the plasma membrane by fusing membrane-binding sequences from Rac1 (amino acids 183 to 192) to the C terminus of Noxa1. However, membrane targeting of Noxa1 is not sufficient for activation of Nox1. Both the Noxo1-independent and -dependent Nox1 systems involve Rac1, since they are affected by Rac1 mutants or Noxa1 mutants defective in Rac binding or short interfering RNA-mediated Rac1 silencing. Nox1 or Nox3 expression promotes p22 phox transport to the plasma membrane, and both oxidases are inhibited by mutations in the p22 phox binding sites (SH3 domains) of the Nox organizers (p47 phox or Noxo1). Regulation of Nox3 by Rac1 was also evident from the effects of mutant Rac1 or mutant Nox3 activators (p67 phox or Noxa1) or Rac1 silencing. In the absence of Nox organizers, the Nox activators (p67 phox or Noxa1) colocalize with Rac1 within ruffling membranes, independently of their ability to bind Rac1. Thus, Rac1 regulates both oxidases through the Nox activators, although it does not appear to direct the subcellular localization of these activators.