Identification of Multiple Substrates of the StkP Ser/Thr Protein Kinase in Streptococcus pneumoniae

ABSTRACT Monitoring the external environment and responding to its changes are essential for the survival of all living organisms. The transmission of extracellular signals in prokaryotes is mediated mainly by two-component systems. In addition, genomic analyses have revealed that many bacteria contain eukaryotic-type Ser/Thr protein kinases. The human pathogen Streptococcus pneumoniae encodes 13 two-component systems and has a single copy of a eukaryotic-like Ser/Thr protein kinase gene designated stkP. Previous studies demonstrated the pleiotropic role of the transmembrane protein kinase StkP in pneumococcal physiology. StkP regulates virulence, competence, and stress resistance and plays a role in the regulation of gene expression. To determine the intracellular signaling pathways controlled by StkP, we used a proteomic approach for identification of its substrates. We detected six proteins phosphorylated on threonine by StkP continuously during growth. We identified three new substrates of StkP: the Mn-dependent inorganic pyrophosphatase PpaC, the hypothetical protein spr0334, and the cell division protein DivIVA. Contrary to the results of a previous study, we did not confirm that the α-subunit of RNA polymerase is a target of StkP. We showed that StkP activation and substrate recognition depend on the presence of a peptidoglycan-binding domain comprising four extracellular penicillin-binding protein- and Ser/Thr kinase-associated domain (PASTA domain) repeats. We found that StkP is regulated in a growth-dependent manner and likely senses intracellular peptidoglycan subunits present in the cell division septa. In addition, stkP inactivation results in cell division defects. Thus, the data presented here suggest that StkP plays an important role in the regulation of cell division in pneumococcus.

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Two Component Regulatory Systems and Antibiotic Resistance in Gram-Negative Pathogens

International Journal of Molecular Sciences ◽

10.3390/ijms20071781 ◽

2019 ◽

Vol 20 (7) ◽

pp. 1781 ◽

Cited By ~ 22

Author(s):

Anjali Y. Bhagirath ◽

Yanqi Li ◽

Rakesh Patidar ◽

Katherine Yerex ◽

Xiaoxue Ma ◽

...

Keyword(s):

Antibiotic Resistance ◽

Antimicrobial Resistance ◽

Pathogenic Bacteria ◽

Current Knowledge ◽

Regulation Of Gene Expression ◽

Gram Negative ◽

Environmental Signals ◽

Component Systems ◽

Two Component ◽

Two Component Systems

Gram-negative pathogens such as Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa are the leading cause of nosocomial infections throughout the world. One commonality shared among these pathogens is their ubiquitous presence, robust host-colonization and most importantly, resistance to antibiotics. A significant number of two-component systems (TCSs) exist in these pathogens, which are involved in regulation of gene expression in response to environmental signals such as antibiotic exposure. While the development of antimicrobial resistance is a complex phenomenon, it has been shown that TCSs are involved in sensing antibiotics and regulating genes associated with antibiotic resistance. In this review, we aim to interpret current knowledge about the signaling mechanisms of TCSs in these three pathogenic bacteria. We further attempt to answer questions about the role of TCSs in antimicrobial resistance. We will also briefly discuss how specific two-component systems present in K. pneumoniae, A. baumannii, and P. aeruginosa may serve as potential therapeutic targets.

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Domain organization and molecular characterization of 13 two-component systems identified by genome sequencing of Streptococcus pneumoniae

Gene ◽

10.1016/s0378-1119(99)00266-8 ◽

1999 ◽

Vol 237 (1) ◽

pp. 223-234 ◽

Cited By ~ 140

Author(s):

Roland Lange ◽

Christian Wagner ◽

Antoine de Saizieu ◽

Nicholas Flint ◽

Juliette Molnos ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Molecular Characterization ◽

Genome Sequencing ◽

Domain Organization ◽

Component Systems ◽

Two Component ◽

Two Component Systems

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Vancomycin Stress Response in a Sensitive and a Tolerant Strain of Streptococcus pneumoniae

Journal of Bacteriology ◽

10.1128/jb.187.23.8205-8210.2005 ◽

2005 ◽

Vol 187 (23) ◽

pp. 8205-8210 ◽

Cited By ~ 45

Author(s):

Wolfgang Haas ◽

Deepak Kaushal ◽

Jack Sublett ◽

Caroline Obert ◽

Elaine I. Tuomanen

Keyword(s):

Streptococcus Pneumoniae ◽

Stress Response ◽

Antibiotic Treatment ◽

Tolerant Strain ◽

Component Systems ◽

Two Component ◽

Genes Encoding ◽

Two Component Systems

ABSTRACT The vancomycin stress response was studied in Streptococcus pneumoniae strains T4 (TIGR4) and Tupelo. Vancomycin affected the expression of 175 genes, including genes encoding transport functions and enzymes involved in aminosugar metabolism. The two-component systems TCS03, TCS11, and CiaRH also responded to antibiotic treatment. We hypothesize that the three regulons are an important part of the bacterium's response to vancomycin stress.

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The ChrA-ChrS and HrrA-HrrS Signal Transduction Systems Are Required for Activation of the hmuO Promoter and Repression of the hemA Promoter in Corynebacterium diphtheriae

Infection and Immunity ◽

10.1128/iai.01821-06 ◽

2007 ◽

Vol 75 (5) ◽

pp. 2421-2431 ◽

Cited By ~ 45

Author(s):

Lori A. Bibb ◽

Carey A. Kunkle ◽

Michael P. Schmitt

Keyword(s):

Corynebacterium Diphtheriae ◽

Heme Iron ◽

Dependent Manner ◽

Two Component System ◽

Component System ◽

Regulatory Systems ◽

Component Systems ◽

Two Component ◽

Genes Encoding ◽

Two Component Systems

ABSTRACT Transcription of the Corynebacterium diphtheriae hmuO gene, which encodes a heme oxygenase involved in heme iron utilization, is activated in a heme- or hemoglobin-dependent manner in part by the two-component system ChrA-ChrS. Mutation of either the chrA or the chrS gene resulted in a marked reduction of hemoglobin-dependent activation at the hmuO promoter in C. diphtheriae; however, it was observed that significant levels of hemoglobin-dependent expression were maintained in the mutants, suggesting that an additional activator is involved in regulation. A BLAST search of the C. diphtheriae genome sequence revealed a second two-component system, encoded by DIP2268 and DIP2267, that shares similarity with ChrS and ChrA, respectively; we have designated these genes hrrS (DIP2268) and hrrA (DIP2267). Analysis of hmuO promoter expression demonstrated that hemoglobin-dependent activity was fully abolished in strains from which both the chrA-chrS and the hrrA-hrrS two-component systems were deleted. Similarly, deletion of the sensor kinase genes chrS and hrrS or the genes encoding both of the response regulators chrA and hrrA also eliminated hemoglobin-dependent activation at the hmuO promoter. We also show that the regulators ChrA-ChrS and HrrA-HrrS are involved in the hemoglobin-dependent repression of the promoter upstream of hemA, which encodes a heme biosynthesis enzyme. Evidence for cross talk between the ChrA-ChrS and HrrA-HrrS systems is presented. In conclusion, these findings demonstrate that the ChrA-ChrS and HrrA-HrrS regulatory systems are critical for full hemoglobin-dependent activation at the hmuO promoter and also suggest that these two-component systems are involved in the complex mechanism of the regulation of heme homeostasis in C. diphtheriae.

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Role of two-component systems in the virulence of Streptococcus pneumoniae

Journal of Medical Microbiology ◽

10.1099/jmm.0.46423-0 ◽

2006 ◽

Vol 55 (4) ◽

pp. 355-363 ◽

Cited By ~ 41

Author(s):

G. K. Paterson ◽

C. E. Blue ◽

T. J. Mitchell

Keyword(s):

Streptococcus Pneumoniae ◽

Cellular Response ◽

Fluorescence Induction ◽

Environmental Response ◽

Human Pathogen ◽

Component Systems ◽

Two Component ◽

Two Component Systems ◽

Insight Into

Understanding of how the human pathogen Streptococcus pneumoniae perceives and responds to its environment in the host offers insight into the pathogenesis of disease caused by this important bacterium and the potential for improved interventions. A central role in this environmental response is played by two-component systems (TCSs), which both sense the environment and drive the cellular response. Molecular advances in the form of genome sequencing, signature-tagged mutagenesis, differential fluorescence induction and microarray analysis have yielded considerable progress in the study of these systems in S. pneumoniae. These recent advances are discussed here, focusing in particular on the role of TCSs in the virulence of S. pneumoniae.

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Cys303 in the Histidine Kinase PhoR Is Crucial for the Phosphotransfer Reaction in the PhoPR Two-Component System in Bacillus subtilis

Journal of Bacteriology ◽

10.1128/jb.01205-06 ◽

2006 ◽

Vol 189 (2) ◽

pp. 410-421 ◽

Cited By ~ 5

Author(s):

Amr Eldakak ◽

F. Marion Hulett

Keyword(s):

Inorganic Phosphate ◽

Efficient Production ◽

Dependent Manner ◽

Two Component System ◽

Component System ◽

Terminal Oxidases ◽

Component Systems ◽

Two Component ◽

Two Component Systems

ABSTRACT The PhoPR two-component system activates or represses Pho regulon genes to overcome a phosphate deficiency. The Pho signal transduction network is comprised of three two-component systems, PhoPR, ResDE, and Spo0A. Activated PhoP is required for expression of ResDE from the resA promoter, while ResD is essential for 80% of Pho induction, establishing a positive feedback loop between these two-component systems to amplify the signal received by the Pho system. The role of ResD in the Pho response is via production of terminal oxidases. Reduced quinones inhibit PhoR autophosphorylation in vitro, and it was proposed that the expression of terminal oxidases leads to oxidation of the quinone pool, thereby relieving the inhibition. We show here that the reducing environment generated by dithiothreitol (DTT) in vivo inhibited Pho induction in a PhoR-dependent manner, which is in agreement with our previous in vitro data. A strain containing a PhoR variant, PhoRC303A, exhibited reduced Pho induction and remained sensitive to inhibition by DTT, suggesting that the mechanisms for Pho reduction via PhoRC303A and DTT are different. PhoR and PhoRC303A were similar with regard to cellular concentration, limited proteolysis patterns, rate of autophosphorylation, stability of PhoR∼P, and inhibition of autophosphorylation by DTT. Phosphotransfer between PhoR∼P or PhoRC303A∼P and PhoP occurred rapidly; most label from PhoR∼P was transferred to PhoP, but only 10% of the label from PhoRC303A∼P was associated with PhoP, while 90% was released as inorganic phosphate. No difference in PhoP∼P or PhoR autophosphatase activity was observed between PhoR and PhoRC303A that would explain the release of inorganic phosphate. Our data are consistent with a role for PhoRC303 in PhoR activity via stabilization of the phosphoryl-protein intermediate(s) during phosphotransfer from PhoR∼P to PhoP, which is stabilization that is required for efficient production of PhoP∼P.

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Faculty Opinions recommendation of Essential Two-Component Systems Regulating Cell Envelope Functions: Opportunities for Novel Antibiotic Therapies.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.732072878.793568806 ◽

2019 ◽

Author(s):

Ann Stock

Keyword(s):

Cell Envelope ◽

Component Systems ◽

Two Component ◽

Two Component Systems ◽

Envelope Functions

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Growth Promotion or Osmotic Stress Response: How SNF1-Related Protein Kinase 2 (SnRK2) Kinases Are Activated and Manage Intracellular Signaling in Plants

Plants ◽

10.3390/plants10071443 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1443

Author(s):

Yoshiaki Kamiyama ◽

Sotaro Katagiri ◽

Taishi Umezawa

Keyword(s):

Protein Kinase ◽

Plant Growth ◽

Osmotic Stress ◽

Protein Function ◽

Intracellular Signaling ◽

Growth Promotion ◽

Research Field ◽

Dependent Manner ◽

Related Protein ◽

Wide Range

Reversible phosphorylation is a major mechanism for regulating protein function and controls a wide range of cellular functions including responses to external stimuli. The plant-specific SNF1-related protein kinase 2s (SnRK2s) function as central regulators of plant growth and development, as well as tolerance to multiple abiotic stresses. Although the activity of SnRK2s is tightly regulated in a phytohormone abscisic acid (ABA)-dependent manner, recent investigations have revealed that SnRK2s can be activated by group B Raf-like protein kinases independently of ABA. Furthermore, evidence is accumulating that SnRK2s modulate plant growth through regulation of target of rapamycin (TOR) signaling. Here, we summarize recent advances in knowledge of how SnRK2s mediate plant growth and osmotic stress signaling and discuss future challenges in this research field.

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