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The production of extracellular proteins is regulated by ribonuclease III via two different pathways in Staphylococcus aureus.

Liu Y, Dong J, Wu N, Gao Y, Zhang X, Mu C, Shao N, Fan M, Yang G - PLoS ONE (2011)

Bottom Line: It was found that the extracellular proteins of Δrnc were decreased.We found during the lag phase of the bacterial growth cycle RNase III could influence the extracellular protein secretion via regulating the expression of secY2, one component of accessory secretory (sec) pathway.Our results suggest that RNase III could regulate the pathogenicity of S. aureus by influencing the level of extracellular proteins via two different ways respectively at different growth phases.

View Article: PubMed Central - PubMed

Affiliation: Beijing Institute of Basic Medical Sciences, Beijing, People's Republic of China.

ABSTRACT
Staphylococcus aureus ribonuclease III belongs to the enzyme family known to degrade double-stranded RNAs. It has previously been reported that RNase III cannot influence cell growth but regulates virulence gene expression in S. aureus. Here we constructed an RNase III inactivation mutant (Δrnc) from S. aureus 8325-4. It was found that the extracellular proteins of Δrnc were decreased. Furthermore, we explored how RNase III regulated the production of the extracellular proteins in S. aureus. We found during the lag phase of the bacterial growth cycle RNase III could influence the extracellular protein secretion via regulating the expression of secY2, one component of accessory secretory (sec) pathway. After S. aureus cells grew to exponential phase, RNase III can regulate the expression of extracellular proteins by affecting the level of RNAIII. Further investigation showed that the mRNA stability of secY2 and RNAIII was affected by RNase III. Our results suggest that RNase III could regulate the pathogenicity of S. aureus by influencing the level of extracellular proteins via two different ways respectively at different growth phases.

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Detection of the protein profile from different phases of WT and Δrnc.Equal number of S. aureus cells was harvested at the indicated time points. The total proteins of whole-cell and supernatant proteins were extracted. The results showed that the supernatant proteins of the Δrnc were decreased significantly compared with WT, while the total proteins of whole-cell did not show the same change as the supernatant proteins. The experiment has been repeated for three times. 1,4,7: WT, wild type, S. aureus 8325-4; 2,5,8: Δrnc; 3,6,9: rncR.
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pone-0020554-g002: Detection of the protein profile from different phases of WT and Δrnc.Equal number of S. aureus cells was harvested at the indicated time points. The total proteins of whole-cell and supernatant proteins were extracted. The results showed that the supernatant proteins of the Δrnc were decreased significantly compared with WT, while the total proteins of whole-cell did not show the same change as the supernatant proteins. The experiment has been repeated for three times. 1,4,7: WT, wild type, S. aureus 8325-4; 2,5,8: Δrnc; 3,6,9: rncR.

Mentions: The extracellular proteins play an important role for the pathogenicity of S. aureus [11]. We compared the profiles of the extracellular proteins from the same number of cells between Δrnc and its parent strain at the different growth phases. According to the growth curve, S. aureus cultured for 1.5 h, 6 h and 12 h is at the lag phase, exponential phase and stationary phase respectively. The proteins in the supernatant at different time points (1.5 h, 6 h, and 12 h) were extracted as described in Material and methods and the profile of the extracellular proteins in the supernatant was determined by SDS-PAGE. It was surprising that the extracellular proteins of Δrnc decreased significantly compared with its parent strain at three time points (figure 2). At the same time, we compared the total proteins of whole-cell between Δrnc and its parent strain. However, we did not find obvious changes in the total proteins (figure 2).


The production of extracellular proteins is regulated by ribonuclease III via two different pathways in Staphylococcus aureus.

Liu Y, Dong J, Wu N, Gao Y, Zhang X, Mu C, Shao N, Fan M, Yang G - PLoS ONE (2011)

Detection of the protein profile from different phases of WT and Δrnc.Equal number of S. aureus cells was harvested at the indicated time points. The total proteins of whole-cell and supernatant proteins were extracted. The results showed that the supernatant proteins of the Δrnc were decreased significantly compared with WT, while the total proteins of whole-cell did not show the same change as the supernatant proteins. The experiment has been repeated for three times. 1,4,7: WT, wild type, S. aureus 8325-4; 2,5,8: Δrnc; 3,6,9: rncR.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3105085&req=5

pone-0020554-g002: Detection of the protein profile from different phases of WT and Δrnc.Equal number of S. aureus cells was harvested at the indicated time points. The total proteins of whole-cell and supernatant proteins were extracted. The results showed that the supernatant proteins of the Δrnc were decreased significantly compared with WT, while the total proteins of whole-cell did not show the same change as the supernatant proteins. The experiment has been repeated for three times. 1,4,7: WT, wild type, S. aureus 8325-4; 2,5,8: Δrnc; 3,6,9: rncR.
Mentions: The extracellular proteins play an important role for the pathogenicity of S. aureus [11]. We compared the profiles of the extracellular proteins from the same number of cells between Δrnc and its parent strain at the different growth phases. According to the growth curve, S. aureus cultured for 1.5 h, 6 h and 12 h is at the lag phase, exponential phase and stationary phase respectively. The proteins in the supernatant at different time points (1.5 h, 6 h, and 12 h) were extracted as described in Material and methods and the profile of the extracellular proteins in the supernatant was determined by SDS-PAGE. It was surprising that the extracellular proteins of Δrnc decreased significantly compared with its parent strain at three time points (figure 2). At the same time, we compared the total proteins of whole-cell between Δrnc and its parent strain. However, we did not find obvious changes in the total proteins (figure 2).

Bottom Line: It was found that the extracellular proteins of Δrnc were decreased.We found during the lag phase of the bacterial growth cycle RNase III could influence the extracellular protein secretion via regulating the expression of secY2, one component of accessory secretory (sec) pathway.Our results suggest that RNase III could regulate the pathogenicity of S. aureus by influencing the level of extracellular proteins via two different ways respectively at different growth phases.

View Article: PubMed Central - PubMed

Affiliation: Beijing Institute of Basic Medical Sciences, Beijing, People's Republic of China.

ABSTRACT
Staphylococcus aureus ribonuclease III belongs to the enzyme family known to degrade double-stranded RNAs. It has previously been reported that RNase III cannot influence cell growth but regulates virulence gene expression in S. aureus. Here we constructed an RNase III inactivation mutant (Δrnc) from S. aureus 8325-4. It was found that the extracellular proteins of Δrnc were decreased. Furthermore, we explored how RNase III regulated the production of the extracellular proteins in S. aureus. We found during the lag phase of the bacterial growth cycle RNase III could influence the extracellular protein secretion via regulating the expression of secY2, one component of accessory secretory (sec) pathway. After S. aureus cells grew to exponential phase, RNase III can regulate the expression of extracellular proteins by affecting the level of RNAIII. Further investigation showed that the mRNA stability of secY2 and RNAIII was affected by RNase III. Our results suggest that RNase III could regulate the pathogenicity of S. aureus by influencing the level of extracellular proteins via two different ways respectively at different growth phases.

Show MeSH
Related in: MedlinePlus