caa a22 4500 605503001 CHVBK 20210128100608.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s00253-015-6591-4 doi (NATIONALLICENCE)springer-10.1007/s00253-015-6591-4 Membrane-anchored MucR mediates nitrate-dependent regulation of alginate production in Pseudomonas aeruginosa [Elektronische Daten] [Yajie Wang, Iain Hay, Zahid Rehman, Bernd Rehm] 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. Springer-Verlag Berlin Heidelberg, 2015 Alginate production nationallicence Cystic fibrosis nationallicence Alginate regulation nationallicence c-di-GMP nationallicence Diguanylate cyclase nationallicence Phosphodiesterase nationallicence Nitrate nationallicence Wang Yajie Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand aut Hay Iain Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand aut Rehman Zahid Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand aut Rehm Bernd Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/17(2015-09-01), 7253-7265 0175-7598 99:17<7253 2015 99 253 https://doi.org/10.1007/s00253-015-6591-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-015-6591-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wang Yajie Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand aut NATIONALLICENCE 700 1- Hay Iain Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand aut NATIONALLICENCE 700 1- Rehman Zahid Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand aut NATIONALLICENCE 700 1- Rehm Bernd Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/17(2015-09-01), 7253-7265 0175-7598 99:17<7253 2015 99 253