As an important generator of reactive oxygen species (ROS) in eukaryotic cells, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) is essential to antimicrobial host defense. NOX, a member of the NOX family, was identified in during the current investigation. It encodes a polypeptide with 571 amino acids, and it has an open reading frame of 1716 bp. The inferred amino acid sequence of NOX includes a transmembrane domain, a ferric reductase domain, a flavin adenine dinucleotide-binding-8 domain, and a NADPH-binding-6 domain. NOX shares 53.03%–42.39% sequence homology with other NOX proteins found in vertebrates and invertebrates in accordance with multiple sequence alignment. NOX was found in close proximity to the sea urchin NOX and the vertebrate NOX1–3 on the phylogenetic tree. The NOX gene was expressed in all of the test tissues including the body wall, muscle, intestine, respiratory tree, and coelomocytes. After being challenged with , sea cucumber coelomocytes showed a remarkable increase in the protein and mRNA levels of NOX. ROS was produced less remarkably in coelomocytes as a result of NOX RNA interference. When the expression of NOX was suppressed by siRNA or inhibitor, the ability of coelomocytes to remove bacteria was drastically decreased. Reducing NOX-derived ROS decreased the production of inflammatory cytokines and coelomocyte apoptosis. All of these findings indicate that NOX may be crucial to the antibacterial immune response against the invasive pathogen in sea cucumbers .

中文翻译：

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NOX 衍生的 ROS 调节仿刺参体腔细胞的抗菌免疫反应

作为真核细胞中活性氧 (ROS) 的重要产生者，烟酰胺腺嘌呤二核苷酸磷酸 (NADPH) 氧化酶 (NOX) 对于抗菌宿主防御至关重要。 NOX 是 NOX 家族的一员，在当前的调查中被发现。它编码571个氨基酸的多肽，具有1716 bp的开放阅读框。 NOX的推断氨基酸序列包括跨膜结构域、铁还原酶结构域、黄素腺嘌呤二核苷酸结合8结构域和NADPH结合6结构域。根据多重序列比对，NOX 与脊椎动物和无脊椎动物中发现的其他 NOX 蛋白具有 53.03%–42.39% 的序列同源性。在系统发育树上，NOX 与海胆 NOX 和脊椎动物 NOX1-3 非常接近。 NOX基因在所有测试组织中表达，包括体壁、肌肉、肠道、呼吸树和体腔细胞。受到 的攻击后，海参体腔细胞的 NOX 蛋白和 mRNA 水平显着增加。由于 NOX RNA 干扰，体腔细胞中 ROS 的产生量较少。当NOX的表达被siRNA或抑制剂抑制时，体腔细胞去除细菌的能力急剧下降。减少 NOX 衍生的 ROS 可减少炎症细胞因子的产生和体腔细胞凋亡。所有这些发现表明，NOX可能对于海参针对入侵病原体的抗菌免疫反应至关重要。