Several enzymes of the central metabolism are phosphorylated in<i>Staphylococcus aureus</i>

Lomas-Lopez, Rodrigo; Paracuellos, Patricia; Riberty, MylÃ ̈ne; Cozzone, Alain J.; Duclos, B.

doi:10.1111/j.1574-6968.2007.00742.x

Cited by 41 publications

(48 citation statements)

References 29 publications

(42 reference statements)

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“…Similarly, the kinase of Enterococcus faecalis is implicated in persistence in the intestine of mice (25). In contrast, PrkC of Staphylococcus aureus was reported to phosphorylate glycolytic enzymes (26).…”

Section: Discussionmentioning

confidence: 99%

“…This gene cluster is conserved in all firmicutes, i.e., in gram-positive bacteria with a low GC content of their genomic DNA (this group includes the mollicutes). In other firmicutes, PrkC has been shown to be a protein kinase involved in many functions, such as phosphorylation of glycolytic enzymes, virulence, and germination (11,25,26,30). However, the potential protein kinase PrkC of M. pneumoniae has so far not been the subject of any studies.…”

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confidence: 99%

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The Stability of Cytadherence Proteins in Mycoplasma pneumoniae Requires Activity of the Protein Kinase PrkC

et al. 2010

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Mycoplasma pneumoniae belongs to the mollicutes, a group of bacteria that have strongly reduced genomes but that are nevertheless capable of independent life. With only three transcription factors, the regulatory features of these bacteria are very limited. Thus, posttranslational regulation might be important for M. pneumoniae. In addition to the highly specific HPr kinase, the M. pneumoniae prkC gene encodes the serine/ threonine protein kinase C. In order to study the function(s) of this kinase, we isolated an M. pneumoniae mutant affected in PrkC. This mutation resulted in nonadherent growth and loss of cytotoxicity. Examination of the phosphorylation profile of the prkC mutant suggested that phosphorylation of cytadherence proteins was affected by the loss of this kinase. In contrast, inactivation of the prpC gene affecting the protein phosphatase that antagonizes PrkC-dependent phosphorylation resulted in more intensive phosphorylation of the cytadherence proteins HMW1 and HMW3 of the major adhesin P1 and of the surface protein MPN474. Moreover, loss of PrkC affects not only the phosphorylation state of the cytadherence proteins but also their intracellular accumulation. However, the expression of the corresponding genes was not affected by PrkC, suggesting that PrkC-dependent phosphorylation results in stabilization of the cytadherence proteins. The HMW proteins and P1 are part of the so-called terminal organelle of M. pneumoniae that is involved in gliding motility, cell division, and adhesion to host epithelial tissues. Our observations suggest that the posttranslational modification of cytadherence proteins by PrkC is essential for the development and function of the M. pneumoniae terminal organelle.Mycoplasma pneumoniae belongs to the mollicutes, i.e., cell wall-less bacteria. These organisms are among the smallest selfreplicating living beings capable of a host-independent existence. M. pneumoniae is a pathogenic bacterium that causes atypical pneumonia and extrapulmonary infections, such as autoimmune disorders, asthma, and arthritis (4,32,34).M. pneumoniae and its close relative Mycoplasma genitalium have recently attracted much attention, not only with respect to the elucidation of pathogenicity mechanisms but also because the small genomes of these bacteria define the lower limit of naturally existing independent life. The analysis of the minimal gene complement of M. pneumoniae and M. genitalium is one of the sources of synthetic biology, a new discipline of biology (12, 13).However, life is not static and not determined only by a defined set of genes. A very important feature is the control of biological activities in response to changing environmental conditions. Only this control enables organisms to adapt to different habitats and to survive suboptimal conditions. In M. pneumoniae, the regulatory potential seems to be rather limited. In bacteria, regulation of gene expression is achieved mainly at the level of transcription, by alternative sigma factors of the RNA polymerase, by transcriptio...

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The Stability of Cytadherence Proteins in Mycoplasma pneumoniae Requires Activity of the Protein Kinase PrkC

et al. 2010

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“…Recent work has demonstrated the functional kinase activity of PknB and has identified potential substrates. Most of the identified substrates of PknB are proteins which are involved in the central metabolism of bacteria, such as trigger factor, DnaK, enolase, pyruvate dehydrogenase, and the regulator MgrA (27,44). These observations suggest a broad regulatory role for PknB in S. aureus.…”

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confidence: 88%

Transcriptome and Functional Analysis of the Eukaryotic-Type Serine/Threonine Kinase PknB inStaphylococcus aureus

et al. 2009

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The function of the Staphylococcus aureus eukaryotic-like serine/threonine protein kinase PknB was investigated by performing transcriptome analysis using DNA microarray technology and biochemical assays. The transcriptional profile revealed a strong regulatory impact of PknB on the expression of genes encoding proteins which are involved in purine and pyrimidine biosynthesis, cell wall metabolism, autolysis, and glutamine synthesis. Functional activity of overexpressed and purified PknB kinase was demonstrated using the myelin basic protein as a surrogate substrate. Phosphorylation occurred in a time-dependent manner with Mn 2؉ as a preferred cofactor. Furthermore, biochemical characterization revealed regulation of adenylosuccinate synthase (PurA) activity by phosphorylation. Phosphorylated PurA showed a 1.8-fold decrease in enzymatic activity compared to unphosphorylated PurA. Loss of PknB led to formation of larger cell clusters, and a pknB deletion strain showed 32-fold-higher sensitivity to the cell wall-active antibiotic tunicamycin. The results of this study strongly indicate that PknB has a role in regulation of purine biosynthesis, autolysis, and central metabolic processes in S. aureus.The phosphorylation of proteins is a key regulatory mechanism in the signal transduction pathways of both prokaryotes and eukaryotes. Typically, extracellular signals are translated into cellular responses. The phosphorylation of proteins is carried out by specific protein kinases and is coupled to dephosphorylation reactions catalyzed by protein phosphatases. In prokaryotes sensing of extracellular signals and transduction of information are usually mediated by two-component signal transduction systems consisting of histidine kinase sensors and their associated response regulators (42). In contrast, signal transduction in eukaryotes occurs via phosphorylation of serine, threonine, and tyrosine residues. Serine/threonine and tyrosine kinases and phosphatases control reversible phosphorylation of target proteins in eukaryotes and are essential for cell cycle control and differentiation (17,19).It has recently been shown in a number of studies that eukaryotic-type serine/threonine protein kinases (STPKs) and phosphatases are also expressed in many prokaryotes (2). Prokaryotic STPKs regulate various cellular functions, such as stress responses, biofilm formation, sporulation, and metabolic and developmental processes (20,23,30,34,37,39,46). STPKs also play a role in the virulence of many bacterial pathogens, such as streptococci, Mycobacterium tuberculosis, Yersinia pseudotuberculosis, and Pseudomonas aeruginosa (11,16,21,36,47). Although the functional roles of protein kinases have been described in previous studies, only a small number of target substrates have been identified so far. Moreover, the impact of phosphorylation and dephosphorylation of target protein functions has been investigated in only some cases (33,38).A single STPK has been found to be conserved in all sequenced strains of Staphylococcus aureus. Origi...

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“…pknB and stp are cotranscribed and translationally coupled (10,30). PknB, also called Stk1, can autophosphorylate as well as phosphorylate the serine and threonine residues of other proteins, including many glycolytic and protein synthetic enzymes, further placing PknB in central metabolic pathways, such as those for nucleotide biosynthesis, glycolysis, amino acid metabolism, and cell wall metabolism (10,24,30). The roles played by PknB are many.…”

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Phosphorylation of MgrA and Its Effect on Expression of the NorA and NorB Efflux Pumps of Staphylococcus aureus

Truong-Bolduc

Hooper

2010

J Bacteriol

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MgrA is a global regulator in Staphylococcus aureus that controls the expression of diverse genes encoding virulence factors and multidrug resistance (MDR) efflux transporters. We identified pknB, which encodes the (Ser/Thr) kinase PknB, in the S. aureus genome. PknB was able to autophosphorylate as well as phosphorylate purified MgrA. We demonstrated that rsbU, which encodes a Ser/Thr phosphatase and is involved in the activation of the SigB regulon, was able to dephosphorylate MgrA-P but not PknB-P. Serines 110 and 113 of MgrA were found to be phosphorylated, and Ala substitutions at these positions resulted in reductions in the level of phosphorylation of MgrA. DNA gel shift binding assays using norA and norB promoters showed that MgrA-P was able to bind the norB promoter but not the norA promoter, a pattern which was the reverse of that for unphosphorylated MgrA. The double mutant MgrA S110A-S113A bound to the norA promoter but not the norB promoter. The double mutant led to a 2-fold decrease in norA transcripts and a 2-fold decrease in the MICs of norfloxacin and ciprofloxacin in strain RN6390. Thus, phosphorylation of MgrA results in loss of binding to the norA promoter, but with a gain of the ability to bind the norB promoter. Loss of the ability to phosphorylate MgrA by Ala substitution resulted in increased repression of norA expression and in reductions in susceptibilities to NorA substrates.

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Several enzymes of the central metabolism are phosphorylated inStaphylococcus aureus

Cited by 41 publications

References 29 publications

The Stability of Cytadherence Proteins in Mycoplasma pneumoniae Requires Activity of the Protein Kinase PrkC

The Stability of Cytadherence Proteins in Mycoplasma pneumoniae Requires Activity of the Protein Kinase PrkC

Transcriptome and Functional Analysis of the Eukaryotic-Type Serine/Threonine Kinase PknB inStaphylococcus aureus

Phosphorylation of MgrA and Its Effect on Expression of the NorA and NorB Efflux Pumps of Staphylococcus aureus

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