A shaE Deletion Mutant Showed Lower Na+ Sensitivity Compared to Other Deletion Mutants in the Bacillus subtilis Sodium/Hydrogen Antiporter (Sha) System

Yoshinaka, Toko; Takasu, Hirotoshi; Tomizawa, Rui; Kosono, Saori; Kudo, Toshiaki

doi:10.1263/jbb.95.306

Cited by 10 publications

(15 citation statements)

References 13 publications

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“…This species could be a labile sixprotein species that has low antiporter activity that accounts for the low activity of membranes from the ⌬mrpE transformant. In B. subtilis, an analogous pattern could account for the residual Na ϩ resistance and Na ϩ efflux capacity in a ⌬mrpE mutant (46).…”

Section: Discussionmentioning

confidence: 88%

“…In addition, a panel of site-directed mrpE mutants was prepared to more fully assess the impact of MrpE on the antiporter activity of the full Mrp system. Although early studies indicated that full Mrp activity depends upon the presence of every protein, MrpE was suggested to be dispensable, since a B. subtilis mutant carrying a deletion of mrpE retained significant Na ϩ resistance and Na ϩ efflux capacity (46).…”

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confidence: 99%

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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

et al. 2008

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Mrp antiporters catalyze secondary Na؉ (Li ؉ )/H ؉ antiport and/or K ؉ /H ؉ antiport that is physiologically important in diverse bacteria. An additional capacity for anion flux has been observed for a few systems. Mrp is unique among antiporters in that it requires all six or seven hydrophobic gene products (MrpA to MrpG) of the mrp operon for full antiporter activity, but MrpE has been reported to be dispensable. Here, the membrane complexes formed by Mrp proteins were examined using a cloned mrp operon from alkaliphilic Bacillus pseudofirmus OF4. The operon was engineered so that the seven Mrp proteins could be detected in single samples. Membrane extracts of an antiporter-deficient Escherichia coli strain expressing this construct were analyzed by blue native-sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Mrp complexes of two sizes were identified containing all seven Mrp proteins. Studies of the single nonpolar mrp gene deletions in the construct showed that a subcomplex of MrpA, MrpB, MrpC, and MrpD was formed in the absence of MrpE, MrpF, or MrpG. By contrast, MrpE, MrpF, and MrpG were not observed in membranes lacking MrpA, MrpB, MrpC, or MrpD. Although MrpA and MrpD have been hypothesized to be the antiporter proteins, the MrpA-to-D complex was inactive. Every Mrp protein was required for an activity level near that of the wild-type

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Section: Discussionmentioning

confidence: 88%

mentioning

confidence: 99%

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

et al. 2008

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“…We have studied multigeneencoded Na ϩ /H ϩ antiporters called Sha (14,15,35) and also known as Mrp (11,12), Pha (24), and Mnh (9). sha homologue genes are found as a cluster containing six or seven genes on the genomes of various bacteria.…”

Section: Namentioning

confidence: 99%

“…sha homologue genes are found as a cluster containing six or seven genes on the genomes of various bacteria. Several studies indicate that all genes in the sha cluster are necessary for ion transport and function, and Sha proteins most probably form a multisubunit transport complex (9,12,24,35). It is well mentioned that Sha proteins show similarity to membrane subunits of respiratory NADH:quinone oxydoreductase (complex I); i.e., ShaA, ShaC, and ShaD are related to NuoL, NuoK, and NuoM/NuoN of Escherichia coli complex I, respectively (6,9,11,18,24).…”

Section: Namentioning

confidence: 99%

Characterization of a Multigene-Encoded Sodium/Hydrogen Antiporter (Sha) from Pseudomonas aeruginosa : Its Involvement in Pathogenesis

et al. 2005

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Sha (also known as Mrp/Mnh/Pha) is a Na؉ /H ؉ antiporter encoded by a cluster of six or seven genes that probably form a multisubunit transport complex. The Sha system is important for the homeostasis of H ؉ , Na ؉ , and other monovalent cations and plays a critical role in various functions, including alkaliphily, sporulation, and symbiosis. Here, we characterized the sha homologue genes from the opportunistic pathogen Pseudomonas aeruginosa, which exist as a cluster of six genes (PA1054 to PA1059). The gene cluster PA1054 to PA1059, but not the cluster with a deletion of PA1054, complemented a growth defect in the presence of 0.2 M NaCl and a defect in Na ؉ /H ؉ antiport activity of the Escherichia coli TO114 mutant lacking the three major Na ؉ /H ؉ antiporters, indicating that genes PA1054 to PA1059 are responsible for Na ؉ /H ؉ antiport activity. We disrupted PA1054 (a shaA homologue gene) and determined its effect on Na ؉ tolerance during growth, Na ؉ efflux, and pathogenicity in mice. Disruption of PA1054 resulted in severe Na ؉ sensitivity during growth and decreased Na ؉ efflux activity. In mice, the deletion mutant of PA1054 also exhibited an attenuated virulence in systemic, pulmonary, and urinary tract infections and also a decrease in colonization of the infected organs. From these results, we conclude that the genes PA1054 to PA1059 encode a Na ؉ /H ؉ antiporter that is largely responsible for Na ؉ extrusion in P. aeruginosa and has a role in the infection of the pathogen. We propose to designate PA1054 to PA1059 as the sha (sodium hydrogen antiporter) genes, shaABCDEFG.

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“…The mrp operons are categorized into two major groups (Swartz et al, 2005): group 1, which includes mrp from Bacillus subtilis, contains seven genes (mrpABCDEFG); and group 2, which includes Vibrio cholerae Vc-mrp, contains six genes (mrpA9CDEFG) (Dzioba-Winogrodzki et al, 2009). It has been shown that all of the components are required for the Mrp antiporter to be fully functional (Ito et al, , 2000Putnoky et al, 1998;Yoshinaka et al, 2003). Recently, two groups have experimentally shown that gene products of the mrp operon from Bacillus species actually form complexes in B. subtilis cells (Kajiyama et al, 2007) and in heterologous Escherichia coli cells (Morino et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

pH-dependent regulation of the multi-subunit cation/proton antiporter Pha1 system from Sinorhizobium meliloti

et al. 2009

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The pha1 gene cluster (pha1A′-G) of Sinorhizobium meliloti has previously been characterized as a necessary component for proper invasion into plant root tissue. It has been suggested to encode a multi-subunit K+/H+ antiporter, since mutations in the pha1 region rendered S. meliloti cells sensitive to K+ and alkali, and because there is high amino acid sequence similarity to previously characterized multi-subunit cation/H+ antiporters (Mrp antiporters). However, the detailed transport properties of the Pha1 system are yet to be determined. Interestingly, most of the Mrp antiporters are highly selective for Na+, unlike the Pha1 system. Here, we report the functional expression of the Pha1 system in Escherichia coli and the measurement of cation/H+ antiport activity. We showed that the Pha1 system is indeed a K+/H+ antiporter with a pH optimum under mildly alkaline conditions. Moreover, we found that the Pha1 system can transport Na+; this was unexpected based on previous phenotypic analyses of pha1 mutants. Furthermore, we demonstrated that the cation selectivity of the Pha1 system was altered when the pH was lowered from the optimum. The downregulation of Na+/H+ and K+/H+ antiport activities upon acidic shift appeared to occur via different processes, which might indicate the presence of distinct mechanisms for the regulation of the K+/H+ and Na+/H+ antiport activities of the Pha1 system.

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A shaE Deletion Mutant Showed Lower Na+ Sensitivity Compared to Other Deletion Mutants in the Bacillus subtilis Sodium/Hydrogen Antiporter (Sha) System

Cited by 10 publications

References 13 publications

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

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

Characterization of a Multigene-Encoded Sodium/Hydrogen Antiporter (Sha) from Pseudomonas aeruginosa : Its Involvement in Pathogenesis

pH-dependent regulation of the multi-subunit cation/proton antiporter Pha1 system from Sinorhizobium meliloti

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A shaE Deletion Mutant Showed Lower Na+ Sensitivity Compared to Other Deletion Mutants in the Bacillus subtilis Sodium/Hydrogen Antiporter (Sha) System

Cited by 10 publications

References 13 publications

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

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

Characterization of a Multigene-Encoded Sodium/Hydrogen Antiporter (Sha) from Pseudomonas aeruginosa : Its Involvement in Pathogenesis

pH-dependent regulation of the multi-subunit cation/proton antiporter Pha1 system from Sinorhizobium meliloti

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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

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