51
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Le ATT, Schumann W. The Spo0E phosphatase of Bacillus subtilis is a substrate of the FtsH metalloprotease. MICROBIOLOGY-SGM 2009; 155:1122-1132. [PMID: 19332814 DOI: 10.1099/mic.0.024182-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In the absence of the ATP-dependent metalloprotease FtsH, the sporulation frequency of Bacillus subtilis cells is reduced by several orders of magnitude. This indicates that FtsH has to degrade or to regulate the steady-state level of one or more proteins that interfere with successful sporulation. Here, we show that the amount of the master regulator protein Spo0A is reduced in an ftsH knockout and the small amounts of Spo0A protein present are inactive. Phosphorylation of Spo0A occurs through a phosphorelay. Four negative regulators have been identified here which directly interfere with the phosphorelay through ftsH, namely the phosphatases RapA, RapB, RapE and Spo0E. If a null allele in any one of them was combined with an ftsH knockout, the sporulation frequency was increased by two to three orders of magnitude, but remained below 1 %. When purified Spo0E was incubated with FtsH, partial degradation of the phosphatase was observed. In contrast, two mutant versions of Spo0E with truncated C-termini remained stable. Transfer of the C-terminal 25 aa of Spo0E to a shorter homologue of Spo0E, YnzD, which is not a substrate of FtsH, conferred instability. When a mutant Spo0A was produced that was active in the absence of phosphorylation, spores were formed at a normal rate in an ftsH knockout, indicating that ftsH is needed only during phase 0.
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Affiliation(s)
- Ai Thi Thuy Le
- Institute of Genetics, University of Bayreuth, D-95440 Bayreuth, Germany
| | - Wolfgang Schumann
- Institute of Genetics, University of Bayreuth, D-95440 Bayreuth, Germany
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52
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Abstract
Two-component signal transduction based on phosphotransfer from a histidine protein kinase to a response regulator protein is a prevalent strategy for coupling environmental stimuli to adaptive responses in bacteria. In both histidine kinases and response regulators, modular domains with conserved structures and biochemical activities adopt different conformational states in the presence of stimuli or upon phosphorylation, enabling a diverse array of regulatory mechanisms based on inhibitory and/or activating protein-protein interactions imparted by different domain arrangements. This review summarizes some of the recent structural work that has provided insight into the functioning of bacterial histidine kinases and response regulators. Particular emphasis is placed on identifying features that are expected to be conserved among different two-component proteins from those that are expected to differ, with the goal of defining the extent to which knowledge of previously characterized two-component proteins can be applied to newly discovered systems.
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Affiliation(s)
- Rong Gao
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry, UMDNJ-Robert Wood Johnson Medical School and Howard Hughes Medical Institute, Piscataway, New Jersey 08854-5627
| | - Ann M. Stock
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry, UMDNJ-Robert Wood Johnson Medical School and Howard Hughes Medical Institute, Piscataway, New Jersey 08854-5627
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53
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Dubey GP, Narayan A, Mattoo AR, Singh GP, Kurupati RK, Zaman MS, Aggarwal A, Baweja RB, Basu-Modak S, Singh Y. Comparative genomic study of spo0E family genes and elucidation of the role of Spo0E in Bacillus anthracis. Arch Microbiol 2008; 191:241-53. [DOI: 10.1007/s00203-008-0446-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2008] [Revised: 09/05/2008] [Accepted: 11/03/2008] [Indexed: 11/30/2022]
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54
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A unique sensor histidine kinase. J Bacteriol 2008; 191:681-2. [PMID: 19028898 DOI: 10.1128/jb.01587-08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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55
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Mitrophanov AY, Groisman EA. Signal integration in bacterial two-component regulatory systems. Genes Dev 2008; 22:2601-11. [PMID: 18832064 DOI: 10.1101/gad.1700308] [Citation(s) in RCA: 265] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Two-component systems (TCSs) and phosphorelays are key mediators of bacterial signal transduction. The signals activating these systems promote the phosphorylated state of a response regulator, which is generally the form that carries out specific functions such as binding to DNA and catalysis of biochemical reactions. An emerging class of proteins-termed TCS connectors-modulate the output of TCSs by affecting the phosphorylation state of response regulators. TCS connectors use different mechanisms of action for signal integration, as well as in the coordination and fine-tuning of cellular processes. Present in both Gram-positive and Gram-negative bacteria, TCS connectors are critical for a variety of physiological functions including sporulation, competence, antibiotic resistance, and the transition to stationary phase.
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Affiliation(s)
- Alexander Y Mitrophanov
- Department of Molecular Microbiology, Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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56
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Thomas SA, Brewster JA, Bourret RB. Two variable active site residues modulate response regulator phosphoryl group stability. Mol Microbiol 2008; 69:453-65. [PMID: 18557815 DOI: 10.1111/j.1365-2958.2008.06296.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many signal transduction networks control their output by switching regulatory elements on or off. To synchronize biological response with environmental stimulus, switching kinetics must be faster than changes in input. Two-component regulatory systems (used for signal transduction by bacteria, archaea and eukaryotes) switch via phosphorylation or dephosphorylation of the receiver domain in response regulator proteins. Although receiver domains share conserved active site residues and similar three-dimensional structures, rates of self-catalysed dephosphorylation span a >or= 40,000-fold range in response regulators that control diverse biological processes. For example, autodephosphorylation of the chemotaxis response regulator CheY is 640-fold faster than Spo0F, which controls sporulation. Here we demonstrate that substitutions at two variable active site positions decreased CheY autodephosphorylation up to 40-fold and increased the Spo0F rate up to 110-fold. Particular amino acids had qualitatively similar effects in different response regulators. However, mutant proteins matched to other response regulators at the two key variable positions did not always exhibit similar autodephosphorylation kinetics. Therefore, unknown factors also influence absolute rates. Understanding the effects that particular active site amino acid compositions have on autodephosphorylation rate may allow manipulation of phosphoryl group stability for useful purposes, as well as prediction of signal transduction kinetics from amino acid sequence.
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Affiliation(s)
- Stephanie A Thomas
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599-7290, USA
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57
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Diaz AR, Stephenson S, Green JM, Levdikov VM, Wilkinson AJ, Perego M. Functional Role for a Conserved Aspartate in the Spo0E Signature Motif Involved in the Dephosphorylation of the Bacillus subtilis Sporulation Regulator Spo0A. J Biol Chem 2008; 283:2962-72. [DOI: 10.1074/jbc.m709032200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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58
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Ul’yanova VV, Vershinina VI, Kharitonova MA, Sharipova MR. The effect of Spo0A and AbrB proteins on expression of the genes of guanyl-specific ribonucleases from Bacillus intermedius and Bacillus pumilus in Bacillus subtilis recombinant strains. Microbiology (Reading) 2007. [DOI: 10.1134/s0026261707050086] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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59
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Sharipova MR, Shagimardanova EI, Chastukhina IB, Shamsutdinov TR, Balaban NP, Mardanova AM, Rudenskaya GN, Demidyuk IV, Kostrov SV. The expression of Bacillus intermedius glutamyl endopeptidase gene in Bacillus subtilis recombinant strains. Mol Biol Rep 2007; 34:79-87. [PMID: 17387634 DOI: 10.1007/s11033-006-9017-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Accepted: 06/05/2006] [Indexed: 10/23/2022]
Abstract
The gene encoding for B. intermedius glutamyl endopeptidase (gseBi) has previously been cloned and its nucleotide sequence analyzed. In this study, the expression of this gene was explored in protease-deficient strain B. subtilis AJ73 during stationary phase of bacterial growth. We found that catabolite repression usually involved in control of endopeptidase expression during vegetative growth was not efficient at the late stationary phase. Testing of B. intermedius glutamyl endopeptidase gene expression with B. subtilis spo0-mutants revealed slight effect of these mutations on endopeptidase expression. Activity of glutamyl endopeptidase was partly left in B. subtilis ger-mutants. Probably, gseBi expression was not connected with sporulation. This enzyme might be involved in outgrowth of the spore, when germinating endospore converts into the vegetative cell. These data suggest complex regulation of B. intermedius glutamyl endopeptidase gene expression with contribution of several regulatory systems and demonstrate changes in control of enzyme biosynthesis at different stages of growth.
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Affiliation(s)
- M R Sharipova
- Department of Microbiology, Kazan State University, Kazan, Russia.
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60
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McLaughlin PD, Bobay BG, Regel EJ, Thompson RJ, Hoch JA, Cavanagh J. Predominantly buried residues in the response regulator Spo0F influence specific sensor kinase recognition. FEBS Lett 2007; 581:1425-9. [PMID: 17350627 PMCID: PMC1987376 DOI: 10.1016/j.febslet.2007.02.061] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Revised: 02/05/2007] [Accepted: 02/24/2007] [Indexed: 11/21/2022]
Abstract
Several alanine mutations in the response regulator Spo0F induce hypersporulation in Bacillus subtilis. L66A, I90A and H101A mutants are purported to be involved in contacts stabilizing the orientation of the alpha4-helix and hence the beta4-alpha4 kinase recognition loop. Y13A is thought to affect the orientation of the alpha1-helix and consequently phosphatase action. Using comparative NMR chemical shift analyses for these mutants, we have confirmed these suppositions and isolated residues in Spo0F critical in sensor kinases discrimination. In addition, we discuss how buried residues and intra-protein communication networks contribute to precise molecular recognition by ensuring that the correct surface is presented.
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Affiliation(s)
- Patrick D. McLaughlin
- Department of Molecular & Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Benjamin G. Bobay
- Department of Molecular & Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Erin J. Regel
- Department of Molecular & Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Richele J. Thompson
- Department of Molecular & Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - James A. Hoch
- Division of Cellular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - John Cavanagh
- Department of Molecular & Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- *correspondence should be addressed to: John Cavanagh, 128 Polk Hall, North Carolina State University, Department of Molecular and Structural Biochemistry, Raleigh, NC 27695, Phone number: 919-513-4349, Fax number: 919-515-2057,
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61
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Bongiorni C, Stoessel R, Perego M. Negative regulation of Bacillus anthracis sporulation by the Spo0E family of phosphatases. J Bacteriol 2007; 189:2637-45. [PMID: 17259308 PMCID: PMC1855805 DOI: 10.1128/jb.01798-06] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The initiation of sporulation in Bacillus species is controlled by the phosphorelay signal transduction system. Multiple regulatory elements act on the phosphorelay to modulate the level of protein phosphorylation in response to cellular, environmental, and metabolic signals. In Bacillus anthracis nine possible histidine sensor kinases can positively activate the system, while two response regulator aspartyl phosphate phosphatases of the Rap family negatively impact the pathway by dephosphorylating the Spo0F intermediate response regulator. In this study, we have characterized the B. anthracis members of the Spo0E family of phosphatases that specifically dephosphorylate the Spo0A response regulator of the phosphorelay and master regulator of sporulation. The products of four genes were able to promote the dephosphorylation of Spo0A approximately P in vitro. The overexpression of two of these B. anthracis Spo0E-like proteins from a multicopy vector consistently resulted in a sporulation-deficient phenotype. A third gene was found to be not transcribed in vivo. A fourth gene encoded a prematurely truncated protein due to a base pair deletion that nevertheless was subject to translational frameshift repair in an Escherichia coli protein expression system. A fifth Spo0E-like protein has been structurally and functionally characterized as a phosphatase of Spo0A approximately P by R. N. Grenha et al. (J. Biol. Chem. 281:37993-38003, 2006). We propose that these proteins may contribute to maintain B. anthracis in the transition phase of growth during an active infection and therefore contribute to the virulence of this organism.
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Affiliation(s)
- Cristina Bongiorni
- Division of Cellular Biology, Mail Code MEM-116, Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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62
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Muff TJ, Ordal GW. Assays for CheC, FliY, and CheX as Representatives of Response Regulator Phosphatases. Methods Enzymol 2007; 423:336-48. [PMID: 17609139 DOI: 10.1016/s0076-6879(07)23015-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Much study of two-component systems deals with the excitation of the histidine kinase, activation of the response regulator, and the ultimate target of the signal. Removal of the message is of great importance to these signaling systems. Many methods have evolved in two-component systems to this end. These include autodephosphorylation of the response regulator, hydrolysis of the phosphoryl group by the kinase, or a dedicated phosphatase protein. It has long been known that CheZ is the phosphatase in the chemotaxis system of Escherichia coli and related bacteria. Most bacteria and archaea, however, do not have a cheZ gene, but instead rely on the CheC, CheX, and FliY family of CheY-P phosphatases. Here, we describe assays to test these chemotactic phosphatases, applicable to many other response regulator phosphatases.
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Affiliation(s)
- Travis J Muff
- Department of Biochemistry, University of Illinois, Urbana, IL, USA
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63
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Grenha R, Rzechorzek NJ, Brannigan JA, de Jong RN, Ab E, Diercks T, Truffault V, Ladds JC, Fogg MJ, Bongiorni C, Perego M, Kaptein R, Wilson KS, Folkers GE, Wilkinson AJ. Structural Characterization of Spo0E-like Protein-aspartic Acid Phosphatases That Regulate Sporulation in Bacilli. J Biol Chem 2006; 281:37993-8003. [PMID: 17001075 DOI: 10.1074/jbc.m607617200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Spore formation is an extreme response of many bacterial species to starvation. In the case of pathogenic species of Bacillus and Clostridium, it is also a component of disease transmission. Entry into the pathway of sporulation in Bacillus subtilis and its relatives is controlled by an expanded two-component system in which starvation signals lead to the activation of sensor kinases and phosphorylation of the master sporulation response regulator Spo0A. Accumulation of threshold concentrations of Spo0A approximately P heralds the commitment to sporulation. Countering the activities of the sensor kinases are phosphatases such as Spo0E, which dephosphorylate Spo0A approximately P and inhibit sporulation. Spo0E-like protein-aspartic acid-phosphate phosphatases, consisting of 50-90 residues, are conserved in sporeforming bacteria and unrelated in sequence to proteins of known structure. Here we determined the structures of the Spo0A approximately P phosphatases BA1655 and BA5174 from Bacillus anthracis using nuclear magnetic resonance spectroscopy. Each is composed of two anti-parallel alpha-helices flanked by flexible regions at the termini. The signature SQELD motif (SRDLD in BA1655) is situated in the middle of helix alpha2 with its polar residues projecting outward. BA5174 is a monomer, whereas BA1655 is a dimer. The four-helix bundle structure in the dimer is reminiscent of the phosphotransferase Spo0B and the chemotaxis phosphatase CheZ, although in contrast to these systems, the subunits in BA1655 are in head-to-tail rather than head-to-head apposition. The implications of the structures for interactions between the phosphatases and their substrate Spo0A approximately P are discussed.
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MESH Headings
- Amino Acid Motifs
- Amino Acid Sequence
- Bacillus anthracis/enzymology
- Bacillus anthracis/genetics
- Bacillus anthracis/physiology
- Bacterial Proteins/chemistry
- Bacterial Proteins/genetics
- Bacterial Proteins/physiology
- Base Sequence
- DNA, Bacterial/genetics
- Dimerization
- Genes, Bacterial
- Models, Molecular
- Molecular Sequence Data
- Nuclear Magnetic Resonance, Biomolecular
- Phosphoric Monoester Hydrolases/chemistry
- Phosphoric Monoester Hydrolases/genetics
- Phosphoric Monoester Hydrolases/physiology
- Protein Structure, Quaternary
- Protein Structure, Secondary
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Sequence Homology, Amino Acid
- Spores, Bacterial/enzymology
- Spores, Bacterial/genetics
- Spores, Bacterial/physiology
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Affiliation(s)
- Rosa Grenha
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, United Kingdom
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64
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Cashin P, Goldsack L, Hall D, O'Toole R. Contrasting signal transduction mechanisms in bacterial and eukaryotic gene transcription. FEMS Microbiol Lett 2006; 261:155-64. [PMID: 16907715 DOI: 10.1111/j.1574-6968.2006.00295.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
All known cell types use signal transduction systems to respond to an extracellular or intracellular event. The role of these systems can be to adapt to environmental changes or simply to maintain homeostasis. Cells detect and respond to stimuli in a number of ways. Here we review the mechanisms involved in the transmission of a signal from point of detection to site of action. In particular, a comparison is made between the signalling networks which function in gene transcription in bacterial and eukaryotic cells. Knowledge of the similarities between the systems found in the two types of cells can provide a better understanding of the function and origin of signalling components. In addition, the divergence evident can be exploited by molecules that modulate or disrupt the function of differential signalling mechanisms.
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Affiliation(s)
- Phillipa Cashin
- School of Biological Sciences, Victoria University of Wellington, New Zealand
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65
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Bongiorni C, Stoessel R, Shoemaker D, Perego M. Rap phosphatase of virulence plasmid pXO1 inhibits Bacillus anthracis sporulation. J Bacteriol 2006; 188:487-98. [PMID: 16385039 PMCID: PMC1347315 DOI: 10.1128/jb.188.2.487-498.2006] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
This study shows that the Bacillus anthracis pXO1 virulence plasmid carries a Rap-Phr system, BXA0205, which regulates sporulation initiation in this organism. The BXA0205Rap protein was shown to dephosphorylate the Spo0F response regulator intermediate of the phosphorelay signal transduction system that regulates the initiation of the developmental pathway in response to environmental, metabolic, and cell cycle signals. The activity of the Rap protein was shown to be inhibited by the carboxy-terminal pentapeptide generated through an export-import processing pathway from the associated BXA0205Phr protein. Deregulation of the Rap activity by either overexpression or lack of the Phr pentapeptide resulted in severe inhibition of sporulation. Five additional Rap-Phr encoding systems were identified on the chromosome of B. anthracis, one of which, BA3790-3791, also affected sporulation initiation. The results suggest that the plasmid-borne Rap-Phr system may provide a selective advantage to the virulence of B. anthracis.
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Affiliation(s)
- Cristina Bongiorni
- Division of Cellular Biology, Mail Code: MEM-116, Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037.
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66
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Howell A, Dubrac S, Noone D, Varughese KI, Devine K. Interactions between the YycFG and PhoPR two-component systems in Bacillus subtilis: the PhoR kinase phosphorylates the non-cognate YycF response regulator upon phosphate limitation. Mol Microbiol 2006; 59:1199-215. [PMID: 16430694 DOI: 10.1111/j.1365-2958.2005.05017.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Two-component signal transduction systems (TCS) are an important mechanism by which bacteria sense and respond to their environment. Although each two-component system appears to detect and respond to a specific signal(s), it is now evident that they do not always act independently of each other. In this paper we present data indicating regulatory links between the PhoPR two-component system that participates in the cellular response to phosphate limitation, and the essential YycFG two-component system in Bacillus subtilis. We show that the PhoR sensor kinase can activate the YycF response regulator during a phosphate limitation-induced stationary phase, and that this reaction occurs in the presence of the cognate YycG sensor kinase. Phosphorylation of YycF by PhoR also occurs in vitro, albeit at a reduced level. However, the reciprocal cross-phosphorylation does not occur. A second level of interaction between PhoPR and YycFG is indicated by the fact that cells depleted for YycFG have a severely deficient PhoPR-dependent phosphate limitation response and that YycF can bind directly to the promoter of the phoPR operon. YycFG-depleted cells neither activate expression of phoA and phoPR nor repress expression of the essential tagAB and tagDEF operons upon phosphate limitation. This effect is specific to the PhoPR-dependent phosphate limitation response because PhoPR-independent phosphate limitation responses can be initiated in YycFG-depleted cells.
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Affiliation(s)
- Alistair Howell
- Department of Genetics, Smurfit Institute, Trinity College Dublin, Dublin 2, Ireland
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67
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Brunsing RL, La Clair C, Tang S, Chiang C, Hancock LE, Perego M, Hoch JA. Characterization of sporulation histidine kinases of Bacillus anthracis. J Bacteriol 2005; 187:6972-81. [PMID: 16199567 PMCID: PMC1251614 DOI: 10.1128/jb.187.20.6972-6981.2005] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The initiation of sporulation in Bacillus species is regulated by the phosphorelay signal transduction pathway, which is activated by several histidine sensor kinases in response to cellular and metabolic signals. Comparison of the protein components of the phosphorelay between Bacillus subtilis and Bacillus anthracis revealed high homology in the phosphorelay orthologs of Spo0F, Spo0B, and Spo0A. The sensor domains of sensor histidine kinases are poorly conserved between species, making ortholog recognition tenuous. Putative sporulation sensor histidine kinases of B. anthracis were identified by homology to the HisKA domain of B. subtilis sporulation sensor histidine kinases, which interacts with Spo0F. Nine possible kinases were uncovered, and their genes were assayed for complementation of kinase mutants of B. subtilis, for ability to drive lacZ expression in B. subtilis and B. anthracis, and for the effect of deletion of each on the sporulation of B. anthracis. Five of the nine sensor histidine kinases were inferred to be capable of inducing sporulation in B. anthracis. Four of the sensor kinases could not be shown to induce sporulation; however, the genes for two of these were frameshifted in all B. anthracis strains and one of these was also frameshifted in the pathogenic pXO1-bearing Bacillus cereus strain G9241. It is proposed that acquisition of plasmid pXO1 and pathogenicity may require a dampening of sporulation regulation by mutational selection of sporulation sensor histidine kinase defects. The sporulation of B. anthracis ex vivo appears to result from any one or a combination of the sporulation sensor histidine kinases remaining.
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Affiliation(s)
- Ryan L Brunsing
- Division of Cellular Biology, Mail Code MEM-116, Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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68
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Anderson I, Sorokin A, Kapatral V, Reznik G, Bhattacharya A, Mikhailova N, Burd H, Joukov V, Kaznadzey D, Walunas T, Larsen N, Pusch G, Liolios K, Grechkin Y, Lapidus A, Goltsman E, Chu L, Fonstein M, Ehrlich SD, Overbeek R, Kyrpides N, Ivanova N. Comparative genome analysis ofBacillus cereusgroup genomes withBacillus subtilis. FEMS Microbiol Lett 2005; 250:175-84. [PMID: 16099605 DOI: 10.1016/j.femsle.2005.07.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 06/22/2005] [Accepted: 07/01/2005] [Indexed: 11/24/2022] Open
Abstract
Genome features of the Bacillus cereus group genomes (representative strains of Bacillus cereus, Bacillus anthracis and Bacillus thuringiensis sub spp. israelensis) were analyzed and compared with the Bacillus subtilis genome. A core set of 1381 protein families among the four Bacillus genomes, with an additional set of 933 families common to the B. cereus group, was identified. Differences in signal transduction pathways, membrane transporters, cell surface structures, cell wall, and S-layer proteins suggesting differences in their phenotype were identified. The B. cereus group has signal transduction systems including a tyrosine kinase related to two-component system histidine kinases from B. subtilis. A model for regulation of the stress responsive sigma factor sigmaB in the B. cereus group different from the well studied regulation in B. subtilis has been proposed. Despite a high degree of chromosomal synteny among these genomes, significant differences in cell wall and spore coat proteins that contribute to the survival and adaptation in specific hosts has been identified.
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Affiliation(s)
- Iain Anderson
- Integrated Genomics, 2201 W. Campbell Park Dr., Chicago, IL 60612, USA
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69
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Bongiorni C, Ishikawa S, Stephenson S, Ogasawara N, Perego M. Synergistic regulation of competence development in Bacillus subtilis by two Rap-Phr systems. J Bacteriol 2005; 187:4353-61. [PMID: 15968044 PMCID: PMC1151770 DOI: 10.1128/jb.187.13.4353-4361.2005] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The 11 Rap proteins of Bacillus subtilis comprise a conserved family of tetratricopeptide (TPR)-containing regulatory proteins. Their activity is inhibited by specific Phr pentapeptides produced from the product of phr genes through an export-import maturation process. We found that one of the proteins, namely RapF, is involved in the regulation of competence to DNA transformation. The ComA response regulator and transcription factor for initiation of competence development is the target of RapF. Specific binding of RapF to the carboxy-terminal DNA-binding domain of ComA inhibits the response regulator's ability to bind its target DNA promoters. The PhrF C-terminal pentapeptide, QRGMI, inhibits RapF activity. The activity of RapF and PhrF in regulating competence development is analogous to the previously described activity of RapC and PhrC (L. J. Core and M. Perego, Mol. Microbiol. 49:1509-1522, 2003). In fact, the RapF and PhrF pair of proteins acts synergistically with RapC and PhrC in the overall regulation of the ComA transcription factor. Since the transcription of the RapC- and RapF-encoding genes is positively regulated by their own target ComA, an autoregulatory circuit must exist for the competence transcription factor in order to modulate its activity.
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Affiliation(s)
- Cristina Bongiorni
- Division of Cellular Biology, Mail Code MEM-116, Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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70
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Gottig N, Pedrido ME, Méndez M, Lombardía E, Rovetto A, Philippe V, Orsaria L, Grau R. The Bacillus subtilis SinR and RapA developmental regulators are responsible for inhibition of spore development by alcohol. J Bacteriol 2005; 187:2662-72. [PMID: 15805512 PMCID: PMC1070374 DOI: 10.1128/jb.187.8.2662-2672.2005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Even though there is a large body of information concerning the harmful effects of alcohol on different organisms, the mechanism(s) that affects developmental programs, at a single-cell level, has not been clearly identified. In this respect, the spore-forming bacterium Bacillus subtilis constitutes an excellent model to study universal questions of cell fate, cell differentiation, and morphogenesis. Here, we demonstrate that treatment with subinhibitory concentrations of alcohol that did not affect vegetative growth inhibited the initiation of spore development through a selective blockage of key developmental genes under the control of the master transcription factor Spo0A approximately P. Isopropyl-beta-D-thiogalactopyranoside-directed expression of a phosphorylation-independent form of Spo0A (Sad67) and the use of an in vivo mini-Tn10 insertional library permitted the identification of the developmental SinR repressor and RapA phosphatase as the effectors that mediated the inhibitory effect of alcohol on spore morphogenesis. A double rapA sinR mutant strain was completely resistant to the inhibitory effects of different-C-length alcohols on sporulation, indicating that the two cell fate determinants were the main or unique regulators responsible for the spo0 phenotype of wild-type cells in the presence of alcohol. Furthermore, treatment with alcohol produced a significant induction of rapA and sinR, while the stationary-phase induction of sinI, which codes for a SinR inhibitor, was completely turned off by alcohol. As a result, a dramatic repression of spo0A and the genes under its control occurred soon after alcohol addition, inhibiting the onset of sporulation and permitting the evaluation of alternative pathways required for cellular survival.
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Affiliation(s)
- Natalia Gottig
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario and Instituto de Biología Molecular y Celular de Rosario, IBR-CONICET, Suipacha 531, Rosario (2000), Argentina
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71
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Abstract
Differentiation of vegetative Bacillus subtilis into heat resistant spores is initiated by the activation of the key transcription regulator Spo0A through the phosphorelay. Subsequent events depend on the cell compartment-specific action of a series of RNA polymerase sigma factors. Analysis of genes in the Spo0A regulon has helped delineate the mechanisms of axial chromatin formation and asymmetric division. There have been considerable advances in our understanding of critical controls that act to regulate the phosphorelay and to activate the sigma factors.
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Affiliation(s)
- Patrick J Piggot
- Department of Microbiology and Immunology, Temple University School of Medicine. 3400N. Broad St., Philadelphia, Pennsylvania 19140, USA
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72
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Hutchings MI, Hoskisson PA, Chandra G, Buttner MJ. Sensing and responding to diverse extracellular signals? Analysis of the sensor kinases and response regulators of Streptomyces coelicolor A3(2). Microbiology (Reading) 2004; 150:2795-2806. [PMID: 15347739 DOI: 10.1099/mic.0.27181-0] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Streptomyces coelicolor is a Gram-positive soil bacterium that undergoes a complex developmental life cycle. The genome sequence of this organism was recently completed and has revealed the presence of over 60 sigma factors and a multitude of other transcriptional regulators, with a significant number of these being putative two-component signal transduction proteins. The authors have used the criteria established by Hoch and co-workers (Fabret et al., 1999, J Bacteriol 181, 1975-1983) to identify sensor kinase and response regulator genes encoded within the S. coelicolor genome. This analysis has revealed the presence of 84 sensor kinase genes, 67 of which lie adjacent to genes encoding response regulators. This strongly suggests that these paired genes encode two-component systems. In addition there are 13 orphan response regulators encoded in the genome, several of which have already been characterized and are implicated in development and antibiotic production, and 17 unpaired and as yet uncharacterized sensor kinases. This article attempts to infer useful information from sequence analysis and reviews what is currently known about the two-component systems, unpaired sensor kinases and orphan response regulators of S. coelicolor from both published reports and the authors' own unpublished data.
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Affiliation(s)
- Matthew I Hutchings
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK
| | - Paul A Hoskisson
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK
| | - Mark J Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK
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73
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Hilbert DW, Piggot PJ. Compartmentalization of gene expression during Bacillus subtilis spore formation. Microbiol Mol Biol Rev 2004; 68:234-62. [PMID: 15187183 PMCID: PMC419919 DOI: 10.1128/mmbr.68.2.234-262.2004] [Citation(s) in RCA: 252] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gene expression in members of the family Bacillaceae becomes compartmentalized after the distinctive, asymmetrically located sporulation division. It involves complete compartmentalization of the activities of sporulation-specific sigma factors, sigma(F) in the prespore and then sigma(E) in the mother cell, and then later, following engulfment, sigma(G) in the prespore and then sigma(K) in the mother cell. The coupling of the activation of sigma(F) to septation and sigma(G) to engulfment is clear; the mechanisms are not. The sigma factors provide the bare framework of compartment-specific gene expression. Within each sigma regulon are several temporal classes of genes, and for key regulators, timing is critical. There are also complex intercompartmental regulatory signals. The determinants for sigma(F) regulation are assembled before septation, but activation follows septation. Reversal of the anti-sigma(F) activity of SpoIIAB is critical. Only the origin-proximal 30% of a chromosome is present in the prespore when first formed; it takes approximately 15 min for the rest to be transferred. This transient genetic asymmetry is important for prespore-specific sigma(F) activation. Activation of sigma(E) requires sigma(F) activity and occurs by cleavage of a prosequence. It must occur rapidly to prevent the formation of a second septum. sigma(G) is formed only in the prespore. SpoIIAB can block sigma(G) activity, but SpoIIAB control does not explain why sigma(G) is activated only after engulfment. There is mother cell-specific excision of an insertion element in sigK and sigma(E)-directed transcription of sigK, which encodes pro-sigma(K). Activation requires removal of the prosequence following a sigma(G)-directed signal from the prespore.
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Affiliation(s)
- David W Hilbert
- Department of Microbiology and Immunology, Temple University School of Medicine, 3400 N. Broad St., Philadelphia, PA 19140, USA
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74
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Ansaldi M, Théraulaz L, Méjean V. TorI, a response regulator inhibitor of phage origin in Escherichia coli. Proc Natl Acad Sci U S A 2004; 101:9423-8. [PMID: 15197250 PMCID: PMC438992 DOI: 10.1073/pnas.0401927101] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The torI gene has been identified by using a genetic multicopy approach as a negative regulator of the torCAD operon that encodes the trimethylamine N-oxide reductase respiratory system in Escherichia coli. The negative effect was due to a previously unidentified small ORF (66 aa) of phage origin that we called torI for Tor inhibition. Overexpression of torI led to an 8-fold decrease of the torCAD operon transcription. This operon is positively regulated, in the presence of trimethylamine N-oxide, by a four-step phosphorelay involving the TorS sensor and the TorR response regulator. Epistatic experiments showed that TorI acts downstream of TorS and needs the presence of TorR. In vitro experiments showed that it is neither a TorR phosphatase nor a histidine kinase inhibitor and that it binds to the effector domain of TorR. Unexpectedly, TorI did not impede TorR DNA binding, and we propose that it may prevent RNA polymerase recruitment to the torC promoter. This study thus reveals a previously uncharacterized class of response regulator inhibitors.
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Affiliation(s)
- Mireille Ansaldi
- Laboratoire de Chimie Bactérienne, Institut de Biologie Structurale et Microbiologie, Centre National de la Recherche Scientifique, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
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75
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Abstract
Quorum sensing is a signaling mechanism through which bacteria modulate a number of cellular functions (genes), including sporulation, biofilm formation, bacteriocin production, virulence responses, as well as others. Quorum sensing is a mechanism of cell-to-cell communication and is mediated by extracellular chemical signals generated by the bacteria when specific cell densities are reached. When the concentration of the signal (and cell population) is sufficiently high, the target gene or genes are either activated or repressed. Quorum sensing increases the ability of the bacteria to have access to nutrients or to more favorable environmental niches and enhances bacterial defenses against eukaryotic hosts, competing bacteria, and environmental stresses. The physiological and clinical aspects of quorum sensing have received considerable attention and have been studied at the molecular level. Little is known, however, on the role of quorum sensing in food spoilage or in the growth and/or toxin production of pathogens present in food. A number of compounds have been isolated or synthesized that antagonize quorum sensors, and application of these antagonists may potentially be useful in inhibiting the growth or virulence mechanisms of bacteria in different environments, including food. It is important that food microbiologists have an awareness and an understanding of the mechanisms involved in bacterial quorum sensing, since strategies targeting quorum sensing may offer a means to control the growth of undesirable bacteria in foods.
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Affiliation(s)
- James L Smith
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA.
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76
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Depardieu F, Courvalin P, Msadek T. A six amino acid deletion, partially overlapping the VanSB G2 ATP-binding motif, leads to constitutive glycopeptide resistance in VanB-type Enterococcus faecium. Mol Microbiol 2004; 50:1069-83. [PMID: 14617162 DOI: 10.1046/j.1365-2958.2003.03771.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Enterococcus faecium clinical isolate BM4524, resistant to vancomycin and susceptible to teicoplanin, harboured a chromosomal vanB cluster, including the vanSB/vanRB two-component system regulatory genes. Enterococcus faecium strain BM4525, isolated two weeks later from the same patient, was resistant to high levels of both glycopeptides. The ddl gene of BM4525 had a 2 bp insertion leading to an impaired d-alanine:d-alanine ligase. Sequencing of the vanB operon in BM4525 also revealed an 18 bp deletion in the vanSB gene designated vanSBDelta. The resulting six amino acid deletion partially overlapped the G2 ATP-binding domain of the VanSBDelta histidine kinase leading to constitutive expression of the resistance genes. Sequence analysis indicated that the deletion occurred between two tandemly arranged heptanucleotide direct repeats, separated by 11 base-pairs. The VanSB, VanSBDelta and VanRB proteins were overproduced in Escherichia coli and purified. In vitro autophosphorylation of the VanSB and VanSBDelta histidine kinases and phosphotransfer to the VanRB response regulator did not differ significantly. However, VanSBDelta was deficient in VanRB phosphatase activity leading to accumulation of phosphorylated VanRB. Increased glycopeptide resistance in E. faecium BM4525 was therefore a result of the lack of production of d-alanyl-d-alanine ending pentapeptide and to constitutive synthesis of d-alanyl-d-lactate terminating peptidoglycan precursors, following loss of d-alanine:d-alanine ligase and of VanSB phosphatase activity respectively. We suggest that the heptanucleotide direct repeat in vanSB may favour the appearance of high level constitutively expressed vancomycin resistance through a 'slippage' type of genetic rearrangement in VanB-type strains.
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Affiliation(s)
- Florence Depardieu
- Centre National de la Recherche Scientifique, Institut Pasteur, Paris, France
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77
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Szurmant H, Bunn MW, Cannistraro VJ, Ordal GW. Bacillus subtilis hydrolyzes CheY-P at the location of its action, the flagellar switch. J Biol Chem 2003; 278:48611-6. [PMID: 12920116 DOI: 10.1074/jbc.m306180200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this report we show that in Bacillus subtilis the flagellar switch, which controls direction of flagellar rotation based on levels of the chemotaxis primary response regulator, CheY-P, also causes hydrolysis of CheY-P to form CheY and Pi. This task is performed in Escherichia coli by CheZ, which interestingly enough is primarily located at the receptors, not at the switch. In particular we have identified the phosphatase as FliY, which resembles E. coli switch protein FliN only in its C-terminal part, while an additional N-terminal domain is homologous to another switch protein FliM and to CheC, a protein found in the archaea and many bacteria but not in E. coli. Previous E. coli studies have localized the CheY-P binding site of the switch to FliM residues 6-15. These residues are almost identical to the residues 6-15 in both B. subtilis FliM and FliY. We were able to show that both of these proteins are capable of binding CheY-P in vitro. Deletion of this binding region in B. subtilis mutant fliM caused the same phenotype as a cheY mutant (clockwise flagellar rotation), whereas deletion of it in fliY caused the opposite. We showed that FliY increases the rate of CheY-P hydrolysis in vitro. Consequently, we imagine that the duration of enhanced CheY-P levels caused by activation of the CheA kinase upon attractant binding to receptors, is brief due both to adaptational processes and to phosphatase activity of FliY.
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Affiliation(s)
- Hendrik Szurmant
- Department of Biochemistry, Colleges of Medicine and Liberal Arts and Sciences, University of Illinois, Urbana, Illinois 61801, USA
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78
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Bijlsma JJE, Groisman EA. Making informed decisions: regulatory interactions between two-component systems. Trends Microbiol 2003; 11:359-66. [PMID: 12915093 DOI: 10.1016/s0966-842x(03)00176-8] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Jetta J E Bijlsma
- Department of Molecular Microbiology, Howard Hughes Medical Institute, Washington University School of Medicine, Campus Box 8230, 660 S. Euclid Avenue, St Louis, MO 63110, USA
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79
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Stephenson S, Mueller C, Jiang M, Perego M. Molecular analysis of Phr peptide processing in Bacillus subtilis. J Bacteriol 2003; 185:4861-71. [PMID: 12897006 PMCID: PMC166482 DOI: 10.1128/jb.185.16.4861-4871.2003] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Bacillus subtilis, an export-import pathway regulates production of the Phr pentapeptide inhibitors of Rap proteins. Processing of the Phr precursor proteins into the active pentapeptide form is a key event in the initiation of sporulation and competence development. The PhrA (ARNQT) and PhrE (SRNVT) peptides inhibit the RapA and RapE phosphatases, respectively, whose activity is directed toward the Spo0F approximately P intermediate response regulator of the sporulation phosphorelay. The PhrC (ERGMT) peptide inhibits the RapC protein acting on the ComA response regulator for competence with regard to DNA transformation. The structural organization of PhrA, PhrE, and PhrC suggested a role for type I signal peptidases in the processing of the Phr preinhibitor, encoded by the phr genes, into the proinhibitor form. The proinhibitor was then postulated to be cleaved to the active pentapeptide inhibitor by an additional enzyme. In this report, we provide evidence that Phr preinhibitor proteins are subject to only one processing event at the peptide bond on the amino-terminal end of the pentapeptide. This processing event is most likely independent of type I signal peptidase activity. In vivo and in vitro analyses indicate that none of the five signal peptidases of B. subtilis (SipS, SipT, SipU, SipV, and SipW) are indispensable for Phr processing. However, we show that SipV and SipT have a previously undescribed role in sporulation, competence, and cell growth.
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Affiliation(s)
- Sophie Stephenson
- Division of Cellular Biology, Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
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80
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Ladds JC, Muchová K, Blaskovic D, Lewis RJ, Brannigan JA, Wilkinson AJ, Barák I. The response regulator Spo0A from Bacillus subtilis is efficiently phosphorylated in Escherichia coli. FEMS Microbiol Lett 2003; 223:153-7. [PMID: 12829280 DOI: 10.1016/s0378-1097(03)00321-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
The response regulator proteins of two-component systems mediate many adaptations of bacteria to their ever-changing environment. Most response regulators are transcription factors that alter the level of transcription of specific sets of genes. Activation of response regulators requires their phosphorylation on a conserved aspartate residue by a cognate sensor kinase. For this reason, expression of a recombinant response regulator in the absence of the requisite sensor kinase is expected to yield an unphosphorylated product in the inactive state. For Spo0A, the response regulator controlling sporulation in Bacillus subtilis however, we have found that a significant fraction of the purified recombinant protein is phosphorylated. This phosphorylated component is dimeric and binds to Spo0A recognition sequences in DNA. Treatment with the Spo0A-specific phosphatase, Spo0E, leads to dissociation of the dimers and loss of DNA binding. It is therefore necessary to pre-treat recombinant Spo0A preparations with the cognate phosphatase, to generate the fully inactive state of the molecule.
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Affiliation(s)
- Joanne C Ladds
- Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, UK
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81
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Arabolaza AL, Nakamura A, Pedrido ME, Martelotto L, Orsaria L, Grau RR. Characterization of a novel inhibitory feedback of the anti-anti-sigma SpoIIAA on Spo0A activation during development in Bacillus subtilis. Mol Microbiol 2003; 47:1251-63. [PMID: 12603732 DOI: 10.1046/j.1365-2958.2003.03376.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Compartmentalized gene expression during sporulation is initiated after asymmetric division by cell-specific activation of the transcription factors sigmaF and sigmaE. Synthesis of these sigma factors, and their regulatory proteins, requires the activation (phosphorylation) of Spo0A by the phosphorelay signalling system. We report here a novel regulatory function of the anti-anti-sigmaF SpoIIAA as inhibitor of Spo0A activation. This effect did not require sigmaF activity, and it was abolished by expression of the phosphorelay-independent form Spo0A-Sad67 indicating that SpoIIAA directly interfered with Spo0A approximately P generation. IPTG-directed synthesis of the SpoIIE phosphatase in a strain carrying a multicopy plasmid coding for SpoIIAA and its specific inhibitory kinase SpoIIAB blocked Spo0A activation suggesting that the active form of the inhibitor was SpoIIAA and not SpoIIAA-P. Furthermore, expression of the non-phosphorylatable mutant SpoIIAAS58A (SpoIIAA-like), but not SpoIIAAS58D (SpoIIAA-P-like), completely blocked Spo0A-dependent gene expression. Importantly, SpoIIAA expressed from the chromosome under the control of its normal spoIIA promoter showed the same negative effect regulated not only by SpoIIAB and SpoIIE but also by septum morphogenesis. These findings are discussed in relation to the potential contribution of this novel inhibitory feedback with the proper activation of sigmaF and sigmaE during development.
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MESH Headings
- Amino Acid Substitution
- Bacillus subtilis/genetics
- Bacillus subtilis/metabolism
- Bacillus subtilis/physiology
- Bacterial Proteins/biosynthesis
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- Bacterial Proteins/physiology
- Cell Compartmentation
- Feedback, Physiological
- Gene Expression Regulation, Bacterial/drug effects
- Genes, Reporter
- Isopropyl Thiogalactoside/pharmacology
- Lac Operon
- Models, Genetic
- Mutation, Missense
- Phosphorylation
- Promoter Regions, Genetic/drug effects
- Promoter Regions, Genetic/genetics
- Protein Processing, Post-Translational
- Recombinant Fusion Proteins/physiology
- Sigma Factor/metabolism
- Spores, Bacterial
- Transcription Factors/metabolism
- Transcription, Genetic
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Affiliation(s)
- Ana L Arabolaza
- Department of Microbiology, Rosario University School of Biochemistry and Pharmacy, and Institute for Molecular and Cellular Biology of Rosario, IBR-CONICET. Suipacha 531, Sala 9, Rosario-2000, Argentina
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82
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Berry C, O'Neil S, Ben-Dov E, Jones AF, Murphy L, Quail MA, Holden MTG, Harris D, Zaritsky A, Parkhill J. Complete sequence and organization of pBtoxis, the toxin-coding plasmid of Bacillus thuringiensis subsp. israelensis. Appl Environ Microbiol 2002; 68:5082-95. [PMID: 12324359 PMCID: PMC126441 DOI: 10.1128/aem.68.10.5082-5095.2002] [Citation(s) in RCA: 244] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2002] [Accepted: 06/18/2002] [Indexed: 11/20/2022] Open
Abstract
The entire 127,923-bp sequence of the toxin-encoding plasmid pBtoxis from Bacillus thuringiensis subsp. israelensis is presented and analyzed. In addition to the four known Cry and two known Cyt toxins, a third Cyt-type sequence was found with an additional C-terminal domain previously unseen in such proteins. Many plasmid-encoded genes could be involved in several functions other than toxin production. The most striking of these are several genes potentially affecting host sporulation and germination and a set of genes for the production and export of a peptide antibiotic.
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Affiliation(s)
- Colin Berry
- Cardiff School of Biosciences, Cardiff University, Cardiff, United Kingdom.
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83
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Abstract
Spo0A~P is the essential response regulator and transcription factor for sporulation initiation in Bacillus subtilis. The phosphorylation level of Spo0A in the cell is determined by the sensor kinase activity of the phosphorelay, donating phosphoryl groups, and the antagonistic effects of dephosphorylation mediated by the Rap and Spo0E families of phosphatases. In this study, spo0A mutations were generated that encoded proteins less sensitive to the activity of Spo0E than the wild-type protein. The Spo0A substitutions N12K, P60S, L62P and F88L are surface exposed and localize to the same face of the molecule as the active site and in its close proximity on the beta1-alpha1, beta3-alpha3 and beta4-alpha4 loops. The corresponding surface in the Spo0F response regulator was shown previously to be involved in the interaction with the RapB phosphatase, as well as the KinA histidine kinase and the Spo0B phosphotransferase. Thus, residues occupying the same position (N12:Q12, F88:Y84) and the same loops in Spo0A or Spo0F are involved in the interaction with the structurally unrelated Spo0E and RapB phosphatases, respectively, in addition to kinases and phosphotransferase. The specificity in phosphatase target recognition must be the result of side-chain variability within the response regulators and the interactions they promote. The residues involved in Spo0E interaction are identical in all Spo0A orthologues from spore-forming Bacilli encoding Spo0E phosphatases.
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Affiliation(s)
- Sophie J Stephenson
- Division of Cellular Biology, Department of Molecular and Experimental Medicine, MEM-116, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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84
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Kanamaru K, Stephenson S, Perego M. Overexpression of the PepF oligopeptidase inhibits sporulation initiation in Bacillus subtilis. J Bacteriol 2002; 184:43-50. [PMID: 11741842 PMCID: PMC134765 DOI: 10.1128/jb.184.1.43-50.2002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The yjbG gene encoding the homologue of the PepF1 and PepF2 oligoendopeptidases of Lactococcus lactis (Monnet et al., J. Biol. Chem. 269:32070-32076, 1994; Nardi et al., J. Bacteriol. 179:4164-4171, 1997) has been identified in Bacillus subtilis as an inhibitor of sporulation initiation when present in the cells on a multicopy plasmid. Genetic analysis suggested that the inhibitory effect is due to hydrolysis of the PhrA peptide in a form as small as the pentapeptide (ARNQT). Inactivation of PhrA results in deregulation of the RapA phosphatase and thus dephosphorylation of the Spo0F approximately P response regulator component of the phosphorelay for sporulation initiation. When overexpressed, the B. subtilis PepF is most likely hydrolyzing additional peptides of the Phr family, as is the case for PhrC involved in control of competence development. Chromosomal inactivation of the yjbG/pepF gene did not give rise to any detectable phenotype. The function of PepF in B. subtilis remains unknown. Limited experiments with a yjbG paralogue called yusX indicated that a frameshift is present, making the corresponding gene product inactive.
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Affiliation(s)
- Kyoko Kanamaru
- Division of Cellular Biology, Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
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