TY  - JOUR
AU  - Bertani, I
AU  - Sevo, M
AU  - Kojić, Milan
AU  - Venturi, V
PY  - 2003
UR  - http://intor.torlakinstitut.com/handle/123456789/799
AB  - RpoS is the stationary phase sigma factor responsible for increased transcription of a set of genes when bacterial cells enter stationary phase and under stress conditions. In Escherichia coli, RpoS expression is modulated at the level of transcription, translation, and post-translational stability whereas in Pseudomonas, previous studies have implicated four genetic loci (psrA, gacA, lasI and rhlI) involved in rpoS transcription. In this report, the transcription, translation and proteins profiles of rpoS/RpoS were analyzed in response to growth phase of knockout genomic mutants in the P. aeruginosa transcriptional regulatory loci psrA, gacA, vfr, and in the las and rhl quorum-sensing systems. Gene expression and protein profiles were also analyzed in the ppk genomic mutant. This gene is responsible for the biosynthesis of polyphosphate, an alarmone involved in the regulation of RpoS accumulation in E. coli. Finally, the role of the ClpXP protease in RpoS regulation was also studied; in E. coli, this protease has been shown to rapidly degrade RpoS during exponential growth. These studies confirm the significant role of PsrA in rpoS transcription during the late-exponential and stationary growth phases, the probable role of Vfr in transcriptional repression during exponential phase, and the function of the ClpXP protease in RpoS degradation during exponential phase. GacA/GacS, the quorum-sensing systems, and the polyphosphate alarmone molecule were not significant in rpoS/RpoS regulation. These results demonstrate important similarities and differences with the regulation of this sigma factor in E. coli and in Pseudomonas.
PB  - Springer-Verlag, New York
T2  - Archives of Microbiology
T1  - Role of GacA, LasI, RhlI, ppk, PsrA, vfr and ClpXP in the regulation of the stationary-phase sigma factor rpoS/RpoS in Pseudomonas
EP  - 271
IS  - 4
SP  - 264
VL  - 180
DO  - 10.1007/s00203-003-0586-8
ER  - 

@article{
author = "Bertani, I and Sevo, M and Kojić, Milan and Venturi, V",
year = "2003",
abstract = "RpoS is the stationary phase sigma factor responsible for increased transcription of a set of genes when bacterial cells enter stationary phase and under stress conditions. In Escherichia coli, RpoS expression is modulated at the level of transcription, translation, and post-translational stability whereas in Pseudomonas, previous studies have implicated four genetic loci (psrA, gacA, lasI and rhlI) involved in rpoS transcription. In this report, the transcription, translation and proteins profiles of rpoS/RpoS were analyzed in response to growth phase of knockout genomic mutants in the P. aeruginosa transcriptional regulatory loci psrA, gacA, vfr, and in the las and rhl quorum-sensing systems. Gene expression and protein profiles were also analyzed in the ppk genomic mutant. This gene is responsible for the biosynthesis of polyphosphate, an alarmone involved in the regulation of RpoS accumulation in E. coli. Finally, the role of the ClpXP protease in RpoS regulation was also studied; in E. coli, this protease has been shown to rapidly degrade RpoS during exponential growth. These studies confirm the significant role of PsrA in rpoS transcription during the late-exponential and stationary growth phases, the probable role of Vfr in transcriptional repression during exponential phase, and the function of the ClpXP protease in RpoS degradation during exponential phase. GacA/GacS, the quorum-sensing systems, and the polyphosphate alarmone molecule were not significant in rpoS/RpoS regulation. These results demonstrate important similarities and differences with the regulation of this sigma factor in E. coli and in Pseudomonas.",
publisher = "Springer-Verlag, New York",
journal = "Archives of Microbiology",
title = "Role of GacA, LasI, RhlI, ppk, PsrA, vfr and ClpXP in the regulation of the stationary-phase sigma factor rpoS/RpoS in Pseudomonas",
pages = "271-264",
number = "4",
volume = "180",
doi = "10.1007/s00203-003-0586-8"
}

Bertani, I., Sevo, M., Kojić, M.,& Venturi, V.. (2003). Role of GacA, LasI, RhlI, ppk, PsrA, vfr and ClpXP in the regulation of the stationary-phase sigma factor rpoS/RpoS in Pseudomonas. in Archives of Microbiology
Springer-Verlag, New York., 180(4), 264-271.
https://doi.org/10.1007/s00203-003-0586-8

Bertani I, Sevo M, Kojić M, Venturi V. Role of GacA, LasI, RhlI, ppk, PsrA, vfr and ClpXP in the regulation of the stationary-phase sigma factor rpoS/RpoS in Pseudomonas. in Archives of Microbiology. 2003;180(4):264-271.
doi:10.1007/s00203-003-0586-8 .

Bertani, I, Sevo, M, Kojić, Milan, Venturi, V, "Role of GacA, LasI, RhlI, ppk, PsrA, vfr and ClpXP in the regulation of the stationary-phase sigma factor rpoS/RpoS in Pseudomonas" in Archives of Microbiology, 180, no. 4 (2003):264-271,
https://doi.org/10.1007/s00203-003-0586-8 . .

TY  - JOUR
AU  - Bertani, I
AU  - Kojić, Milan
AU  - Venturi, V
PY  - 2001
UR  - http://intor.torlakinstitut.com/handle/123456789/794
AB  - The regulation of the p-hydroxybenzoate hydroxylase gene (pobA) of Pseudomonas putida WC5358 involved in the catabolism of p-hydroxybenzoic acid (PHB) to the central intermediate protocatechuate was studied. Protocatechuic acid (PCA) is then degraded via the beta -ketoadipate pathway to form tricarboxylic acid intermediates. In several Gram-negative bacteria pobA has been found genetically linked to a regulator called pobR which activates pobA expression in response to PHB, In this study the identification and characterization of the pobC-pobA locus of P, putida WCS358 is presented. The p-hydroxybenzoate hydroxylase (PobA) is highly identical to other identified PobA proteins, whereas the regulatory protein PobC did not display very high identity to other PobR proteins studied and belonged to the AraC family of regulatory proteins, hence it has been designated PobC, Using the pobA promoter transcriptionally fused to a promoterless lad gene it was observed that induction via PobC occurred very efficiently when PHB was present and to a lesser but still significant level also in the presence of PCA, This PobC-PCA response was genetically demonstrated by making use of pobC::Tn5 and pcaH::Tn5 mutants of strain WC5358 constructed in this study. In pobC mutants both the p-hydroxybenzoic and PCA response were not observed, whereas in the pcaH mutant, which lacks a functional protocatechuate 3,4-dioxygenase, the protocatechuic-acid-dependent pobA activation was still observed. Finally, the activation of pobA by PHB varied according to the concentration and it was observed that in the pcaR::Tn5 regulatory mutant of strain WCS358 the pobA promoter activity was reduced. PcaR is a regulator involved in the regulation of several loci of the beta -ketoadipate pathway, one of which is pcaK, It was postulated that the reduction of pobA activation in pcaR::Tn5 mutants was because there was no expression of the pcaK gene encoding the PHB transport protein resulting in lower levels of PHB present inside the cell.
PB  - Soc General Microbiology, Reading
T2  - Microbiology-Sgm
T1  - Regulation of the p-hydroxybenzoic acid hydroxylase gene (pobA) in plant-growth-promoting Pseudomonas putida WCS358
EP  - 1620
SP  - 1611
VL  - 147
DO  - 10.1099/00221287-147-6-1611
ER  - 

@article{
author = "Bertani, I and Kojić, Milan and Venturi, V",
year = "2001",
abstract = "The regulation of the p-hydroxybenzoate hydroxylase gene (pobA) of Pseudomonas putida WC5358 involved in the catabolism of p-hydroxybenzoic acid (PHB) to the central intermediate protocatechuate was studied. Protocatechuic acid (PCA) is then degraded via the beta -ketoadipate pathway to form tricarboxylic acid intermediates. In several Gram-negative bacteria pobA has been found genetically linked to a regulator called pobR which activates pobA expression in response to PHB, In this study the identification and characterization of the pobC-pobA locus of P, putida WCS358 is presented. The p-hydroxybenzoate hydroxylase (PobA) is highly identical to other identified PobA proteins, whereas the regulatory protein PobC did not display very high identity to other PobR proteins studied and belonged to the AraC family of regulatory proteins, hence it has been designated PobC, Using the pobA promoter transcriptionally fused to a promoterless lad gene it was observed that induction via PobC occurred very efficiently when PHB was present and to a lesser but still significant level also in the presence of PCA, This PobC-PCA response was genetically demonstrated by making use of pobC::Tn5 and pcaH::Tn5 mutants of strain WC5358 constructed in this study. In pobC mutants both the p-hydroxybenzoic and PCA response were not observed, whereas in the pcaH mutant, which lacks a functional protocatechuate 3,4-dioxygenase, the protocatechuic-acid-dependent pobA activation was still observed. Finally, the activation of pobA by PHB varied according to the concentration and it was observed that in the pcaR::Tn5 regulatory mutant of strain WCS358 the pobA promoter activity was reduced. PcaR is a regulator involved in the regulation of several loci of the beta -ketoadipate pathway, one of which is pcaK, It was postulated that the reduction of pobA activation in pcaR::Tn5 mutants was because there was no expression of the pcaK gene encoding the PHB transport protein resulting in lower levels of PHB present inside the cell.",
publisher = "Soc General Microbiology, Reading",
journal = "Microbiology-Sgm",
title = "Regulation of the p-hydroxybenzoic acid hydroxylase gene (pobA) in plant-growth-promoting Pseudomonas putida WCS358",
pages = "1620-1611",
volume = "147",
doi = "10.1099/00221287-147-6-1611"
}

Bertani, I., Kojić, M.,& Venturi, V.. (2001). Regulation of the p-hydroxybenzoic acid hydroxylase gene (pobA) in plant-growth-promoting Pseudomonas putida WCS358. in Microbiology-Sgm
Soc General Microbiology, Reading., 147, 1611-1620.
https://doi.org/10.1099/00221287-147-6-1611

Bertani I, Kojić M, Venturi V. Regulation of the p-hydroxybenzoic acid hydroxylase gene (pobA) in plant-growth-promoting Pseudomonas putida WCS358. in Microbiology-Sgm. 2001;147:1611-1620.
doi:10.1099/00221287-147-6-1611 .

Bertani, I, Kojić, Milan, Venturi, V, "Regulation of the p-hydroxybenzoic acid hydroxylase gene (pobA) in plant-growth-promoting Pseudomonas putida WCS358" in Microbiology-Sgm, 147 (2001):1611-1620,
https://doi.org/10.1099/00221287-147-6-1611 . .