Transcriptional profiling of ParA and ParB mutants in actively dividing cells of an opportunistic human pathogen Pseudomonas aeruginosa.
Accurate chromosome segregation to progeny cells is a fundamental process ensuring proper inheritance of genetic material. In bacteria with simple cell cycle, chromosome segregation follows replication initiation since duplicated oriC domains start segregating to opposite halves of the cell soon after they are made. ParA and ParB proteins together with specific DNA sequences are parts of the segregation machinery. ParA and ParB proteins in Pseudomonas aeruginosa are important for optimal growth, nucleoid segregation, cell division and motility. Comparative transcriptome analysis of parA null and parB null mutants versus parental P. aeruginosa PAO1161 strain demonstrated global changes in gene expression pattern in logarithmically growing planktonic cultures. The set of genes similarly affected in both mutant strains is designated Par regulon and comprises 536 genes. The Par regulon includes genes controlled by two sigma factors (RpoN and PvdS) as well as known and putative transcriptional regulators. In the absence of Par proteins, a large number of genes from RpoS regulon is induced, reflecting the need for slowing down the cell growth rate and decelerating the metabolic processes. Changes in the expression profiles of genes involved in c-di-GMP turnover point out the role of this effector in such signal transmission. Microarray data for chosen genes were confirmed by RT-qPCR analysis. The promoter regions of selected genes were cloned upstream of the promoter-less lacZ gene and analyzed in the heterologous host E. coliΔlac. Regulation by ParA and ParB of P. aeruginosa was confirmed for some of the tested promoters. Our data demonstrate that ParA and ParB besides their role in accurate chromosome segregation may act as modulators of genes expression. Directly or indirectly, Par proteins are part of the wider regulatory network in P. aeruginosa linking the process of chromosome segregation with the cell growth, division and motility.
Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
Aneta A
AA
Bartosik
Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
Krzysztof
K
Glabski
Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
Paulina
P
Jecz
Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
Sylwia
S
Mikulska
Laboratory of Microarray Analysis, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
Anna
A
Fogtman
Laboratory of Microarray Analysis, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland ; Department of Systems Biology, Faculty of Biology, University of Warsaw, Warsaw, Poland.
Marta
M
Koblowska
Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
Grazyna
G
Jagura-Burdzy
D001426:Bacterial Proteins / Q000235:genetics*; D002455:Cell Division / Q000235:genetics; D016000:Cluster Analysis; D004926:Escherichia coli / Q000235:genetics; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D007763:Lac Operon / Q000235:genetics; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D001426:Bacterial Proteins; C052883:chromosome partition proteins, bacterial