The role of the trehalose system in regulating the maltose regulon of <i>Escherichia coli</i>

Decker, Katja; Gerhardt, Friederike; Boos, Winfried

doi:10.1046/j.1365-2958.1999.01395.x

Cited by 33 publications

(32 citation statements)

References 44 publications

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“…In a concerted way with the activity of the trehalose transporter, the activities of acidic and neutral trehalase as well as α-glucosidase were also increased during growth in maltose or trehalose media. For the first time we showed that in yeast cells trehalose and maltose cross-regulate each other's catabolism, as already reported to occur in Escherichia coli (13).…”

Section: Introductionsupporting

confidence: 73%

“…ity of the maltose transporter, which is undetectable during growth in glucose, is increased up to 3.5 and 7.1 nmol PNP min -1 mg cell (dry weight) -1 in cells harvested at the density of 1 mg (dry weight)/ml in trehalose and maltose medium, respectively, supporting our hypothesis. Interplay between the roles of these disaccharides in inducing the expression of the proteins necessary to promote each other's catabolism has already been shown to occur in E. coli (13) and Thermococcus litoralis (36). To examine the above hypothesis, maltose transporter and α-glucosidase activities were measured in C. utilis cells grown up to the stationary phase in glucose medium and up to 6 h after the transfer to fresh maltose, trehalose or glucose media (Figure 3).…”

Section: Trehalase Activity Is Increased During Growth In Maltose or mentioning

confidence: 96%

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Shared control of maltose and trehalose utilization in Candida utilis

Rolim

Araujo

Panek

et al. 2003

Braz J Med Biol Res

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Trehalose biosynthesis and its hydrolysis have been extensively studied in yeast, but few reports have addressed the catabolism of exogenously supplied trehalose. Here we report the catabolism of exogenous trehalose by Candida utilis. In contrast to the biphasic growth in glucose, the growth of C. utilis in a mineral medium with trehalose as the sole carbon and energy source is aerobic and exhibits the Kluyver effect. Trehalose is transported into the cell by an inducible trehalose transporter (K M of 8 mM and V MAX of 1.8 µmol trehalose min -1 mg cell (dry weight) -1 . The activity of the trehalose transporter is high in cells growing in media containing trehalose or maltose and very low or absent during the growth in glucose or glycerol. Similarly, total trehalase activity was increased from about 1.0 mU/mg protein in cells growing in glucose to 39.0 and 56.2 mU/mg protein in cells growing in maltose and trehalose, respectively. Acidic and neutral trehalase activities increased during the growth in trehalose, with neutral trehalase contributing to about 70% of the total activity. In addition to the increased activities of the trehalose transporter and trehalases, growth in trehalose promoted the increase in the activity of α-glucosidase and the maltose transporter. These results clearly indicate that maltose and trehalose promote the increase of the enzymatic activities necessary to their catabolism but are also able to stimulate each other's catabolism, as reported to occur in Escherichia coli. We show here for the first time that trehalose induces the catabolism of maltose in yeast. Correspondence

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Section: Introductionsupporting

confidence: 73%

Section: Trehalase Activity Is Increased During Growth In Maltose or mentioning

confidence: 96%

Shared control of maltose and trehalose utilization in Candida utilis

Rolim

Araujo

Panek

et al. 2003

Braz J Med Biol Res

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“…Thus, it is unclear what role glutamine transport might play in M. tuberculosis pathogenesis. In other species of bacteria, ABC transporters have been implicated in the transduction of information from the extracellular milieu, leading to adaptive changes in bacterial gene expression (16,23,35,44). We speculate that the very low levels of glutamine in the macrophage phagosome (26,43) might serve as an environmental cue that is transduced by the glutamine transporter to the appropriate cellular response pathways, resulting in adaptation of the organism to IFN-␥-dependent changes in the intracellular environment.…”

Section: Discussionmentioning

confidence: 94%

Identification ofMycobacterium tuberculosisCounterimmune (cim) Mutants in Immunodeficient Mice by Differential Screening

et al. 2004

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Tuberculosis (TB) is characterized by lifetime persistence of Mycobacterium tuberculosis. Despite the induction of a vigorous host immune response that curtails disease progression in the majority of cases, the organism is not eliminated. Subsequent immunosuppression can lead to reactivation after a prolonged period of clinical latency. Thus, while it is clear that protective immune mechanisms are engaged during M. tuberculosis infection, it also appears that the pathogen has evolved effective countermechanisms. Genetic studies with animal infection models and with patients have revealed a key role for the cytokine gamma interferon (IFN-␥) in resistance to TB. IFN-␥ activates a large number of antimicrobial pathways. Three of these IFN-␥-dependent mechanisms have been implicated in defense against M. tuberculosis: inducible nitric oxide synthase (iNOS), phagosome oxidase (phox), and the phagosome-associated GTPase LRG-47. In order to identify bacterial genes that provide protection against specific host immune pathways, we have developed the strategy of differential signature-tagged transposon mutagenesis. Using this approach we have identified three M. tuberculosis genes that are essential for progressive M. tuberculosis growth and rapid lethality in iNOS-deficient mice but not in IFN-␥-deficient mice. We propose that these genes are involved in pathways that allow M. tuberculosis to counter IFN-␥-dependent immune mechanisms other than iNOS.Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is capable of long-term survival in vivo despite a vigorous host immune response. Although 90 to 95% of infected individuals initially control bacterial replication and do not manifest clinical signs and symptoms, reactivation of latent TB infection (LTBI) can occur many years after infection (42). Human immunodeficiency virus infection has become the most important risk factor for reactivation of LTBI, increasing the risk of reactivation from 5 to 10% per lifetime to 5% per year (9). Immunosuppressive agents, such as Infliximab, an antitumor necrosis factor alpha antibody used to treat chronic inflammatory conditions, have also been associated with reactivation of LTBI (42). Approximately half of all active cases of pulmonary TB are thought to result from endogenous reactivation of LTBI (40).Exogenous reinfection of asymptomatic individuals also appears to be common in areas where TB is endemic, despite the presence of detectable antigen-specific immune responses established by the previous infection (6,17,46). Similarly, vaccination with live-attenuated Mycobacterium bovis BCG has yielded highly variable and generally poor efficacy in prevention of pulmonary TB in adults despite eliciting robust antigenspecific immune responses in the majority of vaccinated individuals (4).A key component of antimycobacterial immunity is provided by the cytokine gamma interferon (IFN-␥), as evidenced by infection of IFN-␥-deficient mice (12, 19) and IFN-␥R1-deficient mice (25) and by naturally occurring mutations in IFN-...

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“…The production of MD-1P is not common in bacteria. Intracellular maltose-1-P was shown in E. coli but its origin and role were not elucidated (20). The phosphorylation of maltose and longer maltodextrins (DP up to 6), was also shown in Actinoplanes missouriensis (21).…”

Section: Production Of Phosphorylated Oligosaccharidesmentioning

confidence: 99%

Carbohydrate metabolism inFibrobacter succinogenes: What NMR tells us

Forano

Delort

Matulovà

2008

Microbial Ecology in Health and Disease

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Fibrobacter succinogenes is a major rumen fibrolytic bacterium found in high numbers when ruminants are fed cellulose-rich diets. It produces a very efficient fibrolytic system comprising numerous enzymes, but the organization and catalytic features of this system remain unclear. We were using nuclear magnetic resonance (NMR) to study carbohydrate metabolism by Fibrobacter spp. well before the term 'metabolomics' was coined. We first analyzed in detail the NMR spectra arising from resting cells of F. succinogenes provided with glucose, cellobiose or cellulose as a substrate. We were able to show carbohydrate cycling and reversibility of some steps. The use of 1D and 2D 1 H and 13 C NMR showed the synthesis by the cells of unexpected oligosaccharides: maltodextrins, maltodextrin-1-phosphate, and other glucose derivatives. We also showed that maltodextrins and maltodextrins-1-phosphate were synthesized and excreted out of the cell, and could originate from exogenous sugars or endogenous glycogen. According to the substrate and the physiological state of the bacterium (resting or growing cells), metabolic deviations toward the synthesis of these oligosaccharides were observed. We have also used liquid-and solid-state NMR to monitor wheat straw degradation by F. succinogenes. The originality of this NMR approach was to investigate the activity of an entire fibrolytic system on an intact complex substrate (wheat straw). No preferential degradation of amorphous versus crystalline cellulose was observed, nor of cellulose versus hemicelluloses. We showed for the first time a sequential activity of some enzymes of F. succinogenes S85 on wheat straw. In conclusion, our studies illustrate the utility of various NMR approaches to study and better understand sugar and polysaccharide metabolism in rumen bacteria.

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The role of the trehalose system in regulating the maltose regulon of Escherichia coli

Cited by 33 publications

References 44 publications

Shared control of maltose and trehalose utilization in Candida utilis

Shared control of maltose and trehalose utilization in Candida utilis

Identification ofMycobacterium tuberculosisCounterimmune (cim) Mutants in Immunodeficient Mice by Differential Screening

Carbohydrate metabolism inFibrobacter succinogenes: What NMR tells us

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