Molecular evolution of the reactive oxygen-generating NADPH oxidase (Nox/Duox) family of enzymes
Molecular evolution of the reactive oxygen-generating NADPH oxidase (Nox/Duox) family of enzymes
复制标题
DOI：
10.1186/147-2148-7-109
复制
发表时间：
2007-07-06
影响因子：
3.4
通讯作者：
Lambeth, J. David
中科院分区：
文献类型：
--
作者：
Kawahara, Tsukasa;Quinn, Mark T.;Lambeth, J. David
背景：NADPH-氧化酶(NOX)及其相关的双重氧化酶(DUOX)通过调节活性氧(ROS)的生成，发挥着不同的生物学和病理作用。NOX/DUOX家族成员广泛存在于哺乳动物、线虫、果蝇、绿色植物、真菌和黏菌中，但对这些酶的分子进化历史知之甚少。结果：我们组装并分析了脊椎动物、尾索动物、棘皮动物、昆虫、线虫、真菌、黏菌变形虫、藻类和植物等25个物种的101个NOX/DUOX同源物的氨基酸序列。与原核生物中存在的超氧化物歧化酶和过氧化氢酶等ROS防御酶不同，产生ROS的NOx/DUOX同源物只是在进化过程中较晚才出现。分子分类学揭示了Nox和Duoxes的7个不同的亚科。代表4个亚家族的钙调控同源基因很早就出现了分化，是生物学中分布最广泛的。亚基调节的NOX是第二个主要的亚类，最先出现在真菌和阿米巴中。Nox5在啮齿类动物中缺失，而Nox3是最近出现的，它在内耳中负责重力感知，对应于脊椎动物对陆地的全职适应。紫球海胆拥有脊椎动物Nox1、Nox2和Nox3最早的NOX2同源基因，而NOX4最早出现在尾索动物中。进化替换率的比较表明，在脊椎动物中，NOX2、调控亚基p47Phox和p67Phox以及DUOX比其他NOx和NOx调控亚基更严格保守。氨基酸序列比较确定了关键的催化或调节区，因为68个残基在所有NOX/DUOX同源基因中高度保守，其中14个与X连锁慢性肉芽肿疾病变异体中NOX2突变的残基相同。突变分析证实，除了典型基序外，B-环、TM6-FAD、VXGPFG-基序和极端C-末端区域对NOx活性也很重要。这些非经典但高度保守的区域的存在表明，所有的NOx/DUOX可能都具有一个长期存在于NOx/DUOX进化历史中的共同生物学功能。结论：本报告首次全面分析了NOX和DUOX家族成员的进化和保守功能，包括保守氨基酸残基的鉴定。这些结果为未来的结构-功能研究和了解这些酶的生物学功能的进化提供了指导。
Background: NADPH-oxidases (Nox) and the related Dual oxidases (Duox) play varied biological and pathological roles via regulated generation of reactive oxygen species (ROS). Members of the Nox/Duox family have been identified in a wide variety of organisms, including mammals, nematodes, fruit fly, green plants, fungi, and slime molds; however, little is known about the molecular evolutionary history of these enzymes.Results: We assembled and analyzed the deduced amino acid sequences of 101 Nox/Duox orthologs from 25 species, including vertebrates, urochordates, echinoderms, insects, nematodes, fungi, slime mold amoeba, alga and plants. In contrast to ROS defense enzymes, such as superoxide dismutase and catalase that are present in prokaryotes, ROS-generating Nox/Duox orthologs only appeared later in evolution. Molecular taxonomy revealed seven distinct subfamilies of Noxes and Duoxes. The calcium-regulated orthologs representing 4 subfamilies diverged early and are the most widely distributed in biology. Subunit-regulated Noxes represent a second major subdivision, and appeared first in fungi and amoeba. Nox5 was lost in rodents, and Nox3, which functions in the inner ear in gravity perception, emerged the most recently, corresponding to full-time adaptation of vertebrates to land. The sea urchin Strongylocentrotus purpuratus possesses the earliest Nox2 co-ortholog of vertebrate Nox1, 2, and 3, while Nox4 first appeared somewhat later in urochordates. Comparison of evolutionary substitution rates demonstrates that Nox2, the regulatory subunits p47phox and p67phox, and Duox are more stringently conserved in vertebrates than other Noxes and Nox regulatory subunits. Amino acid sequence comparisons identified key catalytic or regulatory regions, as 68 residues were highly conserved among all Nox/Duox orthologs, and 14 of these were identical with those mutated in Nox2 in variants of X-linked chronic granulomatous disease. In addition to canonical motifs, the B-loop, TM6-FAD, VXGPFG-motif, and extreme C-terminal regions were identified as important for Nox activity, as verified by mutational analysis. The presence of these non-canonical, but highly conserved regions suggests that all Nox/Duox may possess a common biological function remained in a long history of Nox/Duox evolution.Conclusion: This report provides the first comprehensive analysis of the evolution and conserved functions of Nox and Duox family members, including identification of conserved amino acid residues. These results provide a guide for future structure-function studies and for understanding the evolution of biological functions of these enzymes.