Role of the Group 2 Mrp sodium/proton antiporter in rapid response to high alkaline shock in the alkaline- and salt-tolerant Dietzia sp. DQ12-45-1b
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The six- and seven-subunit Na+/H+ antiporters (Mrp) are widely distributed in bacteria. They are reported to be integral for pH homeostasis in alkaliphilic bacteria when adapting to high pH environments. In this study, operons encoding for the six-subunit Na+/H+ antiporters were found in the genomes of all studied Dietzia strains, which have different alkaline-resistant abilities. Disruption of the operon in the strain Dietzia sp. DQ12-45-1b which leads to declined growth in presence of hypersaline and alkaline conditions suggested that the six-subunit Na+/H+ antiporter played an important role in hypersaline and alkaline resistance. Although the complexes DqMrp from DQ12-45-1b (strain with high alkaline resistance) and DaMrp from D. alimentaria 72T (strain with low alkaline resistance) displayed Na+(Li+)/H+ antiport activities, they functioned optimally at different pH levels (9.0 for DQ12-45-1b and 8.0 for 72T). While both antiporters functioned properly to protect Escherichia coli cells from salt shock, only the DqMrp-containing strain survived the high alkaline shock. Furthermore, real-time PCR results showed that the expression of mrpA and mrpD induced only immediately after DQ12-45-1b cells were subjected to the alkaline shock. These results suggested that the expression of DqMrp might be induced by a pH gradient across the cell membrane, and DqMrp mainly functioned at an early stage to respond to the alkaline shock.
KeywordsSodium/proton antiporter Dietzia Alkaline stress responses Alkaline tolerant
The authors would like to thank Prof. Lei Wang from China Agricultural University for kindly providing E. coli KNabc.
This work was supported by the National Natural Science Foundation of China (31225001 to XLW, and 31300108 to YN) and the National Basic Research Program of China (“973” Program, 2014CB846002).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
- Blanco-Rivero A, Leganes F, Fernandez-Valiente E, Calle P, Fernandez-Pinas F (2005) mrpA, a gene with roles in resistance to Na+ and adaptation to alkaline pH in the cyanobacterium Anabaena sp. PCC7120. Microbiology 151(5):1671–1682. https://doi.org/10.1099/mic.0.27848-0 CrossRefPubMedGoogle Scholar
- Dzioba-Winogrodzki J, Winogrodzki O, Krulwich TA, Boin MA, Hase CC, Dibrov P (2009) The Vibrio cholerae Mrp system: cation/proton antiport properties and enhancement of bile salt resistance in a heterologous host. J Mol Microbiol Biotechnol 16(3–4):176–186. https://doi.org/10.1159/000119547 CrossRefPubMedGoogle Scholar
- Hamamoto T, Hashimoto M, Hino M, Kitada M, Seto Y, Kudo T, Horikoshi K (1994) Characterization of a gene responsible for the Na+/H+ antiporter system of alkalophilic Bacillus species strain C-125. Mol Microbiol 14(5):939–946. https://doi.org/10.1111/j.1365-2958.1994.tb01329.x CrossRefPubMedGoogle Scholar
- Jiang J, Wang L, Zhang H, Wu H, Huang H, Yang L (2013a) Putative paired small multidrug resistance family proteins PsmrAB, the homolog of YvdSR, actually function as a novel two-component Na+/H+ antiporter. FEMS Microbiol Lett 338(1):31–38. https://doi.org/10.1111/1574-6968.12008 CrossRefPubMedGoogle Scholar
- Kosono S, Haga K, Tomizawa R, Kajiyama Y, Hatano K, Takeda S, Wakai Y, Hino M, Kudo T (2005) Characterization of a multigene-encoded sodium/hydrogen antiporter (Sha) from Pseudomonas aeruginosa: its involvement in pathogenesis. J Bacteriol 187(15):5242–5248. https://doi.org/10.1128/JB.187.15.5242-5248.2005 CrossRefPubMedPubMedCentralGoogle Scholar
- Morino M, Natsui S, Swartz TH, Krulwich TA, Ito M (2008) Single gene deletions of mrpA to mrpG and mrpE point mutations affect activity of the Mrp Na+/H+ antiporter of alkaliphilic Bacillus and formation of hetero-oligomeric Mrp complexes. J Bacteriol 190(12):4162–4172. https://doi.org/10.1128/JB.00294-08 CrossRefPubMedPubMedCentralGoogle Scholar
- Nie Y, Liang J, Fang H, Tang YQ, Wu XL (2011) Two novel alkane hydroxylase-rubredoxin fusion genes isolated from a Dietzia bacterium and the functions of fused rubredoxin domains in long-chain n-alkane degradation. Appl Environ Microbiol 77(20):7279–7288. https://doi.org/10.1128/aem.00203-11 CrossRefPubMedPubMedCentralGoogle Scholar
- Sperling E, Górecki K, Drakenberg T (2016) Functional differentiation of antiporter-like polypeptides in complex I; a site-directed mutagenesis study of residues conserved in MrpA and NuoL but not in MrpD, NuoM, and NuoN. PLoS One 11(7):e0158972. https://doi.org/10.1371/journal.pone.0158972 CrossRefPubMedPubMedCentralGoogle Scholar
- Teruo K, Toshi S, Kei I, Masaaki T, Tomofusa T (1994) Properties and sequence of the NhaA Na+/H+ antiporter of Vibrio parahaemolyticus. J Biochem 116(5):1030–1038. https://doi.org/10.1093/oxfordjournals.jbchem.a124624 CrossRefGoogle Scholar
- Toshiaki H, Kazuyo K, Teruo K, Tohru M, Tomofusa T (1998) A putative multisubunit Na+/H+ antiporter from Staphylococcus aureus. J Bacteriol 180(24):6642–6648Google Scholar
- Yang L, Jiang J, Wei W, Zhang B, Wang L, Yang S (2006) The pha2 gene cluster involved in Na+ resistance and adaption to alkaline pH in Sinorhizobium fredii RT19 encodes a monovalent cation/proton antiporter. FEMS Microbiol Lett 262(2):172–177. https://doi.org/10.1111/j.1574-6968.2006.00385.x CrossRefPubMedGoogle Scholar