Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, UFPR , P.O. Box 19046, 81531980 Curitiba , Paraná , Brazil.
Department of Biochemistry , University of Missouri, Bond Life Sciences Center , 1201 Rollins Street , Columbia , Missouri 65211 , United States.
J Proteome Res. 2020 Jan 3;19(1):92-105. doi: 10.1021/acs.jproteome.9b00397. Epub 2019 Oct 25.
is a diazotrophic microorganism capable of associating with roots of important grasses and cereals, promoting plant growth and increasing crop yields. Nitrogen levels and the Ntr regulatory system control the nitrogen metabolism in . This system comprises the nitrogen regulatory proteins GlnD, which is capable of adding uridylyl groups to the PII proteins, GlnB (PII-1) and GlnZ (PII-2), under limiting nitrogen levels. Under such conditions, the histidine kinase NtrB (nitrogen regulatory protein B) cannot interact with GlnB and phosphorylate NtrC (nitrogen regulatory protein C). The phosphorylated form of NtrC acts as a transcriptional activator of genes involved in the metabolism of alternative nitrogen sources. Considering the key role of NtrC in nitrogen metabolism in , in this work we evaluated the proteomic and metabolomic profiles of the wild-type FP2 strain and its mutant grown under high and low nitrogen. Analysis of the integrated data identifies novel NtrC targets, including proteins involved in the response against oxidative stress (i.e., glutathione -transferase and hydroperoxide resistance protein), underlining the importance of NtrC to bacterial survival under oxidative stress conditions.
是一种固氮微生物，能够与重要草类和谷类的根部共生，促进植物生长并提高作物产量。氮水平和 Ntr 调节系统控制 在氮代谢中的作用。该系统包括氮调节蛋白 GlnD，它能够在氮限制水平下向 PII 蛋白添加尿苷酰基。在这种情况下，组氨酸激酶 NtrB（氮调节蛋白 B）不能与 GlnB 相互作用并磷酸化 NtrC（氮调节蛋白 C）。磷酸化形式的 NtrC 作为参与替代氮源代谢的基因的转录激活剂。考虑到 NtrC 在 在氮代谢中的关键作用，在这项工作中，我们评估了野生型 FP2 菌株及其突变体 在高氮和低氮条件下生长的蛋白质组和代谢组图谱。综合数据分析确定了新的 NtrC 靶标，包括参与抗氧化应激反应的蛋白质（即谷胱甘肽 -转移酶和过氧化物抗性蛋白），这强调了 NtrC 在细菌应对氧化应激条件下生存的重要性。
