Membrane-anchored MucR mediates nitrate-dependent regulation of alginate production in Pseudomonas aeruginosa
Type
ArticleKAUST Department
Water Desalination and Reuse Research Center (WDRC)Date
2015-04-29Online Publication Date
2015-04-29Print Publication Date
2015-09Permanent link to this record
http://hdl.handle.net/10754/566131
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Alginates exhibit unique material properties suitable for medical and industrial applications. However, if produced by Pseudomonas aeruginosa, it is an important virulence factor in infection of cystic fibrosis patients. The alginate biosynthesis machinery is activated by c-di-GMP imparted by the inner membrane protein, MucR. Here, it was shown that MucR impairs alginate production in response to nitrate in P. aeruginosa. Subsequent site-specific mutagenesis of MucR revealed that the second MHYT sensor motif (MHYT II, amino acids 121–124) of MucR sensor domain was involved in nitrate sensing. We also showed that both c-di-GMP synthesizing and degrading active sites of MucR were important for alginate production. Although nitrate and deletion of MucR impaired alginate promoter activity and global c-di-GMP levels, alginate yields were not directly correlated with alginate promoter activity or c-di-GMP levels, suggesting that nitrate and MucR modulate alginate production at a post-translational level through a localized pool of c-di-GMP. Nitrate increased pel promoter activity in the mucR mutant while in the same mutant the psl promoter activity was independent of nitrate. Nitrate and deletion of mucR did not impact on swarming motility but impaired attachment to solid surfaces. Nitrate and deletion of mucR promoted the formation of biofilms with increased thickness, cell density, and survival. Overall, this study provided insight into the functional role of MucR with respect to nitrate-mediated regulation of alginate biosynthesis. © 2015 Springer-Verlag Berlin HeidelbergCitation
Wang, Y., Hay, I. D., Rehman, Z. U., & Rehm, B. H. A. (2015). Membrane-anchored MucR mediates nitrate-dependent regulation of alginate production in Pseudomonas aeruginosa. Applied Microbiology and Biotechnology, 99(17), 7253–7265. doi:10.1007/s00253-015-6591-4Publisher
Springer Natureae974a485f413a2113503eed53cd6c53
10.1007/s00253-015-6591-4