scholarly journals Regulation of Inducible Potassium Transporter KdpFABC by the KdpD/KdpE Two-Component System in Mycobacterium smegmatis

2017 ◽  
Vol 8 ◽  
Author(s):  
Maria K. Ali ◽  
Xinfeng Li ◽  
Qing Tang ◽  
Xiaoyu Liu ◽  
Fang Chen ◽  
...  
Keyword(s):  
Mycobacterium Smegmatis ◽  
Two Component System ◽  
Component System ◽  
Potassium Transporter ◽  
Two Component

Modeling the Interplay of Pseudomonas putida EIIANtr with the Potassium Transporter KdpFABC

2015 ◽  
Vol 25 (2-3) ◽  
pp. 178-194 ◽  
Author(s):  
S. Wolf ◽  
K. Pflüger-Grau ◽  
A. Kremling
Keyword(s):  
Pseudomonas Putida ◽  
Physiological Mechanism ◽  
Cell Number ◽  
Potassium Uptake ◽  
Phosphotransferase System ◽  
Two Component System ◽  
Component System ◽  
Potassium Transporter ◽  
Starting Point ◽  
Two Component

The nitrogen phosphotransferase system (PTS<sup>Ntr</sup>) of <i>Pseudomonas putida</i> is a key regulatory device that participates in controlling many physiological processes in a posttranscriptional fashion. One of the target functions of the PTS<sup>Ntr</sup> is the regulation of potassium transport. This is mediated by the direct interaction of one of its components with the sensor kinase KdpD of the two-component system controlling transcription of the <i>kdpFABC</i> genes. From a detailed experimental analysis of the activity of the <i>kdpF</i> promoter in <i>P. putida</i> wild-type and <i>pts</i> mutant strains with varying potassium concentrations, we had highly time-resolved data at hand, describing the influence of the PTS<sup>Ntr</sup> on the transcription of the KdpFABC potassium transporter. Here, this data was used to construct a mathematical model based on a black box approach. The model was able to describe the data quantitatively with convincing accuracy. The qualitative interpretation of the model allowed the prediction of two general points describing the interplay between the PTS<sup>Ntr</sup> and the KdpFABC potassium transporter: (1) the influence of cell number on the performance of the <i>kdpF</i> promoter is mainly by dilution by growth and (2) potassium uptake is regulated not only by the activity of the KdpD/KdpE two-component system (in turn influenced by PtsN). An additional controller with integrative behavior is predicted by the model structure. This suggests the presence of a novel physiological mechanism during regulation of potassium uptake with the KdpFABC transporter and may serve as a starting point for further investigations.

scholarly journals MnoSR Is a Bona Fide Two-Component System Involved in Methylotrophic Metabolism in Mycobacterium smegmatis

2019 ◽  
Vol 85 (13) ◽  
Author(s):  
Abhishek Anil Dubey ◽  
Vikas Jain
Keyword(s):  
Carbon Source ◽  
Mycobacterium Smegmatis ◽  
Sole Carbon Source ◽  
Specific Binding ◽  
Two Component System ◽  
Methanol Metabolism ◽  
Component System ◽  
Content Type ◽  
Two Component

ABSTRACT Mycobacterium smegmatis and several other mycobacteria are able to utilize methanol as the sole source of carbon and energy. We recently showed that N,N-dimethyl-p-nitrosoaniline (NDMA)-dependent methanol dehydrogenase (Mno) is essential for the growth of M. smegmatis on methanol. Although Mno from this bacterium shares high homology with other known methanol dehydrogenases, methanol metabolism in M. smegmatis differs significantly from that of other described methylotrophs. In this study, we dissect the regulatory mechanism involved in the methylotrophic metabolism in M. smegmatis. We identify a two-component system (TCS), mnoSR, that is involved in the regulation of mno expression. We show that the MnoSR TCS is comprised of a sensor kinase (MnoS) and a response regulator (MnoR). Our results demonstrate that MnoS undergoes autophosphorylation and is able to transfer its phosphate to MnoR by means of phosphotransferase activity. Furthermore, MnoR shows specific binding to the putative mno promoter region in vitro, thus suggesting its role in the regulation of mno expression. Additionally, we find that the MnoSR system is involved in the regulation of MSMEG_6239, which codes for a putative 1,3-propanediol dehydrogenase. We further show that M. smegmatis lacking mnoSR is unable to utilize methanol and 1,3-propanediol as the sole carbon source, which confirms the role of MnoSR in the regulation of alcohol metabolism. Our data, thus, suggest that the regulation of mno expression in M. smegmatis provides new insight into the regulation of methanol metabolism, which furthers our understanding of methylotrophy in mycobacteria. IMPORTANCE Methylotrophic metabolism has gained huge attention considering its broad application in ecology, agriculture, industries, and human health. The genus Mycobacterium comprises both pathogenic and nonpathogenic species. Several members of this genus are known to utilize methanol as the sole carbon source for growth. Although various pathways underlying methanol utilization have been established, the regulation of methylotrophic metabolism is not well studied. In the present work, we explore the regulation of methanol metabolism in M. smegmatis and discover a dedicated two-component system (TCS), MnoSR, that is involved in its regulation. We show that the loss of MnoSR renders the bacterium incapable of utilizing methanol and 1,3-propanediol as the sole carbon sources. Additionally, we establish that MnoS acts as the common sensor for the alcohols in M. smegmatis.

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