Tetrapyrrole-mediated regulation in the opportunistic pathogen Pseudomonas aeruginosa

在这个提议中，我们试图阐明细菌光敏色素BphP和铜绿假单胞菌中潜在的血红素调节剂的功能。光敏色素是植物中的胆蛋白感受器，但其在细菌中的作用尚不清楚。生物信息学分析和报告基因融合的结合建立了bphP的细胞密度依赖性表达，表明群体感应系统和/或替代sigma因子RpoS的参与。蛋白质组和转录组分析将在表达研究定义的条件下进行，以深入了解铜绿假单胞菌的光敏色素调控。光敏色素的作用依赖于将血红素降解为光敏色素的血红素加氧酶。我们的目的是研究血红素加氧酶的另一个可能的作用：通过降解调节细胞血红素水平。一个潜在的血红素调节剂已经确定，其参与调节血红素降解和生物合成将进行测试。

In this proposal we seek to elucidate the function of the bacterial phytochrome BphP and a potential heme regulator in Pseudomonas aeruginosa. Phytochromes are biliprotein photoreceptors in plants but their function in bacteria remains elusive. A combination of bioinformatics analyses and reporter gene fusions established a cell-density dependent expression of bphP indicating an involvement of the quorum sensing system and/or the alternative sigma factor RpoS. Proteome and transcriptome analyses will be performed under conditions defined by expression studies to gain insights into the phytochrome regulon of P. aeruginosa. Phytochrome action is dependent on the enzyme heme oxygenase which degrades heme to the phytochrome chromophore. We aim to investigate another possible role of heme oxygenases: the regulation of cellular heme levels through degradation. A potential heme regulator has been identified whose participation in regulating heme degradation and biosynthesis will be tested.