Project description:An incompatibility P-7 plasmid pCAR1 can be efficiently transferred among artificial microcosms in the presence of divalent cations Ca2+ and Mg2+. One on one mating assays between Pseudomonas strains with different plasmids showed that the promotion of transfer efficiency by divalent cations was also found in other plasmids including pB10 and NAH7, whereas the impacts were larger in IncP-7 plasmids. The impact on pCAR1 transfer altered by different pairs of donor and recipient strains, and the promotion of transfer efficiency was clearly detected between donors P. resinovorans CA10dm4 and P. fluorescens Pf0-1 to the recipients P. putida KT2440 and CA10dm4. Transcriptome analyses showed that genes on the pCAR1 did not respond to the presence of cations, including the tra/trh genes involved in its transfer. Notably, transcriptions of oprH genes, encoding a putative outer membrane proteins, in both of donor and recipient were commonly upregulated under the cation-limited condition. Transfer frequency of the pCAR1 to the transposon mutant of oprH in KT2440 was not promoted by the cations. This effect was partially recovered by the complementation with oprH gene, suggesting that OprH is involved in the promotion the pCAR1 transfer by divalent cations.
Project description:MvaT proteins are recognized as a member of H-NS family proteins in pseudomonads. IncP-7 conjugative plasmid pCAR1, which was originally found in Pseudomonas resinovorans, carries an mvaT homologous gene, pmr. In Pseudomonas putida KT2440 bearing pCAR1, it was previously reported that pmr and chromosomally-encoded homologous genes, turA and turB, are majorly transcribed, and that Pmr interacts with TurA and TurB in vitro (Yun et al. J. Bacteriol. 192:4720-4731, 2010). In the present study, we clarified how the three MvaT proteins regulate the transcriptome of P. putida KT2440(pCAR1). Modified ChIP-chip analyses suggested that the binding sites of Pmr, TurA, and TurB in P. putida KT2440(pCAR1) genome were almost identical; nevertheless, transcriptome analyses using deletion mutants of each MvaT protein gene at the log and early-stationary growth phases clearly suggested that their regulons were different with one another. Especially, significant dissimilarity of regulons was found between Pmr and other two proteins. Transcriptions of the larger number of genes were affected by Pmr deletion at the early-stationary phase than at the log phase, suggesting that Pmr minimizes the pCAR1 effects on host fitness more effectively at the early-stationary phase. On the other hand, similarity found between the regulons of TurA and TurB implied that they may have complementary roles as global transcriptional regulators in response to the plasmid carriage.
Project description:MvaT proteins are recognized as a member of H-NS family proteins in pseudomonads. IncP-7 conjugative plasmid pCAR1, which was originally found in Pseudomonas resinovorans, carries an mvaT homologous gene, pmr. In Pseudomonas putida KT2440 bearing pCAR1, it was previously reported that pmr and chromosomally-encoded homologous genes, turA and turB, are majorly transcribed, and that Pmr interacts with TurA and TurB in vitro (Yun et al. J. Bacteriol. 192:4720-4731, 2010). In the present study, we clarified how the three MvaT proteins regulate the transcriptome of P. putida KT2440(pCAR1). Modified ChIP-chip analyses suggested that the binding sites of Pmr, TurA, and TurB in P. putida KT2440(pCAR1) genome were almost identical; nevertheless, transcriptome analyses using deletion mutants of each MvaT protein gene at the log and early-stationary growth phases clearly suggested that their regulons were different with one another. Especially, significant dissimilarity of regulons was found between Pmr and other two proteins. Transcriptions of the larger number of genes were affected by Pmr deletion at the early-stationary phase than at the log phase, suggesting that Pmr minimizes the pCAR1 effects on host fitness more effectively at the early-stationary phase. On the other hand, similarity found between the regulons of TurA and TurB implied that they may have complementary roles as global transcriptional regulators in response to the plasmid carriage.
Project description:Broad-host-range plasmids play a critical role in the spread of antibiotic resistance and other traits. In spite of increasing information about the genomic diversity of closely related plasmids, the relationship between sequence divergence and host range remains unclear. IncP-1 plasmids are currently classified into six subgroups based on the genetic distance of backbone genes. We investigated whether plasmids from two subgroups exhibit a different host range, using two IncP-1γ plasmids, an IncP-1β plasmid and their minireplicons. Efficiencies of plasmid establishment and maintenance were compared using five species that belong to the Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria. The IncP-1β plasmid replicated and persisted in all five hosts in the absence of selection. Of the two IncP-1γ plasmids, both were unable to replicate in alphaproteobacterial host Sphingobium japonicum, and one established itself in Agrobacterium tumefaciens but was very unstable. In contrast, both IncP-1γ minireplicons, which produced higher levels of replication initiation protein than the wild-type plasmids, replicated in all strains, suggesting that poor establishment of the native plasmids is in part due to suboptimal replication initiation gene regulation. The findings suggest that host ranges of distinct IncP-1 plasmids only partially overlap, which may limit plasmid recombination and thus result in further genome divergence.
Project description:MvaT proteins are recognized as a member of H-NS family proteins in pseudomonads. IncP-7 conjugative plasmid pCAR1, which was originally found in Pseudomonas resinovorans, carries an mvaT homologous gene, pmr. In Pseudomonas putida KT2440 bearing pCAR1, it was previously reported that pmr and chromosomally-encoded homologous genes, turA and turB, are majorly transcribed, and that Pmr interacts with TurA and TurB in vitro (Yun et al. J. Bacteriol. 192:4720-4731, 2010). In the present study, we clarified how the three MvaT proteins regulate the transcriptome of P. putida KT2440(pCAR1). Modified ChIP-chip analyses suggested that the binding sites of Pmr, TurA, and TurB in P. putida KT2440(pCAR1) genome were almost identical; nevertheless, transcriptome analyses using deletion mutants of each MvaT protein gene at the log and early-stationary growth phases clearly suggested that their regulons were different with one another. Especially, significant dissimilarity of regulons was found between Pmr and other two proteins. Transcriptions of the larger number of genes were affected by Pmr deletion at the early-stationary phase than at the log phase, suggesting that Pmr minimizes the pCAR1 effects on host fitness more effectively at the early-stationary phase. On the other hand, similarity found between the regulons of TurA and TurB implied that they may have complementary roles as global transcriptional regulators in response to the plasmid carriage. ChIP-chip: Pseudomonas putida KT2440 harboring plasmid pCAR1 cells were ChIPed with His-tag (C-terminus of each MvaT homologs) and compared with input control. Transcriptome analysis: pCAR1 RNA maps of mvaT deletion mutants were compared with those of wild-type cells.
Project description:MvaT proteins are recognized as a member of H-NS family proteins in pseudomonads. IncP-7 conjugative plasmid pCAR1, which was originally found in Pseudomonas resinovorans, carries an mvaT homologous gene, pmr. In Pseudomonas putida KT2440 bearing pCAR1, it was previously reported that pmr and chromosomally-encoded homologous genes, turA and turB, are majorly transcribed, and that Pmr interacts with TurA and TurB in vitro (Yun et al. J. Bacteriol. 192:4720-4731, 2010). In the present study, we clarified how the three MvaT proteins regulate the transcriptome of P. putida KT2440(pCAR1). Modified ChIP-chip analyses suggested that the binding sites of Pmr, TurA, and TurB in P. putida KT2440(pCAR1) genome were almost identical; nevertheless, transcriptome analyses using deletion mutants of each MvaT protein gene at the log and early-stationary growth phases clearly suggested that their regulons were different with one another. Especially, significant dissimilarity of regulons was found between Pmr and other two proteins. Transcriptions of the larger number of genes were affected by Pmr deletion at the early-stationary phase than at the log phase, suggesting that Pmr minimizes the pCAR1 effects on host fitness more effectively at the early-stationary phase. On the other hand, similarity found between the regulons of TurA and TurB implied that they may have complementary roles as global transcriptional regulators in response to the plasmid carriage. ChIP-chip: Pseudomonas putida KT2440 harboring plasmid pCAR1 cells were ChIPed with His-tag (C-terminus of each MvaT homologs) and compared with input control. Transcriptome analysis: Chromosomal RNA maps of mvaT deletion mutants were compared with those of wild-type cells.
Project description:Plasmid carriage requires appropriate expression of the genes on the plasmid or host chromosome through cooperative transcriptional regulation. To clarify the impact of plasmid carriage on the host chromosome, we compared the chromosomal RNA maps of plasmid-free and plasmid-containing host strains using the incompatibility group P-7 archetype plasmid pCAR1, which is involved in carbazole degradation, and three distinct Pseudomonas strains. The possession of pCAR1 altered gene expression related to the iron acquisition systems in each host. Expression of the major siderophore pyoverdine was greater in plasmid-containing P. putida KT2440 and P. aeruginosa PAO1 than in the plasmid-free host strains, in part due to the expression of carbazole-degradative genes on pCAR1. The mexEFoprN operon encoding an efflux pump of the resistance-nodulation-cell division (RND) family was specifically upregulated by the carriage of pCAR1 in P. putida KT2440, whereas the expression of orthologous genes in the other species remained unaltered. Induction of the mexEFoprN genes increased the resistance of pCAR1-containing KT2440 to chloramphenicol compared to pCAR1-free KT2440. Our findings indicate that the possession of pCAR1 altered the growth rate of the host via the expression of genes on pCAR1 and the host chromosomes.
Project description:The plasmids of the incompatibility (Inc) group IncP-1, also called IncP, as extrachromosomal genetic elements can transfer and replicate virtually in all Gram-negative bacteria. They are composed of backbone genes that encode a variety of essential functions and accessory genes that have implications for human health and environmental bioremediation. Broad-host-range IncP plasmids are known to spread genes between distinct phylogenetic groups of bacteria. These genes often code for resistances to a broad spectrum of antibiotics, heavy metals, and quaternary ammonium compounds used as disinfectants. The backbone of these plasmids carries modules that enable them to effectively replicate, move to a new host via conjugative transfer and to be stably maintained in bacterial cells. The adaptive, resistance, and virulence genes are mainly located on mobile genetic elements integrated between the functional plasmid backbone modules. Environmental studies have demonstrated the wide distribution of IncP-like replicons in manure, soils and wastewater treatment plants. They also are present in strains of pathogenic or opportunistic bacteria, which can be a cause for concern, because they may encode multiresistance. Their broad distribution suggests that IncP plasmids play a crucial role in bacterial adaptation by utilizing horizontal gene transfer. This review summarizes the variety of genetic information and physiological functions carried by IncP plasmids, which can contribute to the spread of antibiotic and heavy metal resistance while also mediating the process of bioremediation of pollutants. Due to the location of the resistance genes on plasmids with a broad-host-range and the presence of transposons carrying these genes it seems that the spread of these genes would be possible and quite hazardous in infection control. Future studies are required to determine the level of risk of the spread of resistance genes located on these plasmids.