scholarly journals Evidence for the Presence of an Alternative Glucose Transport System in Clostridium beijerinckii NCIMB 8052 and the Solvent-Hyperproducing Mutant BA101

2005 ◽  
Vol 71 (6) ◽  
pp. 3384-3387 ◽  
Author(s):  
Jieun Lee ◽  
Wilfrid J. Mitchell ◽  
Martin Tangney ◽  
H. P. Blaschek
Keyword(s):  
Glucose Uptake ◽  
Transport System ◽  
Exponential Growth ◽  
Clostridium Beijerinckii ◽  
Uptake System ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Substrate Analogs ◽  
Glucose Transport System ◽  
Energy Inhibitors

ABSTRACT The effects of substrate analogs and energy inhibitors on glucose uptake and phosphorylation by Clostridium beijerinckii provide evidence for the operation of two uptake systems: a previously characterized phosphoenolpyruvate-dependent phosphotransferase system (PTS) and a non-PTS system probably energized by the transmembrane proton gradient. In both wild-type C. beijerinckii NCIMB 8052 and the butanol-hyperproducing mutant BA101, PTS activity declined at the end of exponential growth, while glucokinase activity increased in the later stages of fermentation. The non-PTS uptake system, together with enhanced glucokinase activity, may provide an explanation for the ability of the mutant to utilize glucose more effectively during fermentation despite the fact that it is partially defective in PTS activity.

scholarly journals Glucose Uptake in Clostridium beijerinckii NCIMB 8052 and the Solvent-Hyperproducing Mutant BA101

2001 ◽  
Vol 67 (11) ◽  
pp. 5025-5031 ◽  
Author(s):  
Jieun Lee ◽  
H. P. Blaschek
Keyword(s):  
Glucose Uptake ◽  
Clostridium Beijerinckii ◽  
Phosphotransferase System ◽  
Stages Of Growth ◽  
Cell Extracts ◽  
Glucose Phosphorylation ◽  
Phosphorylation Rate

ABSTRACT Glucose uptake and accumulation by Clostridium beijerinckii BA101, a butanol hyperproducing mutant, were examined during various stages of growth. Glucose uptake in C. beijerinckii BA101 was repressed 20% by 2-deoxyglucose and 25% by mannose, while glucose uptake in C. beijerinckii8052 was repressed 52 and 28% by these sugars, respectively. We confirmed the presence of a phosphoenolpyruvate (PEP)-dependent phosphotransferase system (PTS) associated with cell extracts ofC. beijerinckii BA101 by glucose phosphorylation by PEP. The PTS activity associated with C. beijerinckii BA101 was 50% of that observed for C. beijerinckii 8052.C. beijerinckii BA101 also demonstrated lower PTS activity for fructose and glucitol. Glucose phosphorylation by cell extracts derived from both C. beijerinckii BA101 and 8052 was also dependent on the presence of ATP, a finding consistent with the presence of glucokinase activity in C. beijerinckii extracts. ATP-dependent glucose phosphorylation was predominant during the solventogenic stage, when PEP-dependent glucose phosphorylation was dramatically repressed. A nearly twofold-greater ATP-dependent phosphorylation rate was observed for solventogenic stage C. beijerinckii BA101 than for solventogenic stage C. beijerinckii 8052. These results suggest that C. beijerinckii BA101 is defective in PTS activity and that C. beijerinckii BA101 compensates for this defect with enhanced glucokinase activity, resulting in an ability to transport and utilize glucose during the solventogenic stage.

scholarly journals Identification of a Phosphotransferase System of Escherichia coli Required for Growth on N-Acetylmuramic Acid

2004 ◽  
Vol 186 (8) ◽  
pp. 2385-2392 ◽  
Author(s):  
Ulrike Dahl ◽  
Tina Jaeger ◽  
Bao Trâm Nguyen ◽  
Julia M. Sattler ◽  
Christoph Mayer
Keyword(s):  
Escherichia Coli ◽  
Energy Analysis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Sole Source ◽  
Wild Type ◽  
Phosphotransferase System ◽  
E Coli ◽  
Glucose Transport System ◽  
Single Polypeptide

ABSTRACT We report here that wild-type Escherichia coli grows on N-acetylmuramic acid (MurNAc) as the sole source of carbon and energy. Analysis of mutants defective in N-acetylglucosamine (GlcNAc) catabolism revealed that the catabolic pathway for MurNAc merges into the GlcNAc pathway on the level of GlcNAc 6-phosphate. Furthermore, analysis of mutants defective in components of the phosphotransferase system (PTS) revealed that a PTS is essential for growth on MurNAc. However, neither the glucose-, mannose/glucosamine-, nor GlcNAc-specific PTS (PtsG, ManXYZ, and NagE, respectively) was found to be necessary. Instead, we identified a gene at 55 min on the E. coli chromosome that is responsible for MurNAc uptake and growth. It encodes a single polypeptide consisting of the EIIB and C domains of a so-far-uncharacterized PTS that was named murP. MurP lacks an EIIA domain and was found to require the activity of the crr-encoded enzyme IIA-glucose (EIIAGlc), a component of the major glucose transport system for growth on MurNAc. murP deletion mutants were unable to grow on MurNAc as the sole source of carbon; however, growth was rescued by providing murP in trans expressed from an isopropylthiogalactopyranoside-inducible plasmid. A functional His6 fusion of MurP was constructed, isolated from membranes, and identified as a polypeptide with an apparent molecular mass of 37 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis. Close homologs of MurP were identified in the genome of several bacteria, and we believe that these organisms might also be able to utilize MurNAc.

Hyperpolarization as a mediator of insulin action: increased muscle glucose uptake induced electrically

1980 ◽  
Vol 239 (1) ◽  
pp. E21-E29 ◽  
Author(s):  
K. Zierler ◽  
E. M. Rogus
Keyword(s):  
Glucose Uptake ◽  
Glucose Transport ◽  
Transport System ◽  
Continuous Flow ◽  
Insulin Action ◽  
Interstitial Fluid ◽  
The Other ◽  
Glucose Transport System ◽  
Sucrose Gap ◽  
Whole Muscle

Insulin hyperpolarizes. This raises the questions: is hyperpolarization a means by which insulin exerts some of its other effects, and can electrically induced hyperpolarization mimic insulin action on membrane functions? A technique was devised to study the latter question. The technique permits electrical hyperpolarization of a segment of whole muscle. Rat caudofemoralis muscle was threaded into a triple sucrose-gap chamber. Continuous flow of sucrose displaced interstitial fluid of muscle segments in the gaps. In one electrolyte compartment between gaps was placed an anode and in the other a cathode. The muscle segment in the anodal compartment was hyperpolarized continuously for 30 min, probably by about 1.5 mV. Uptake of deoxyglucose was increased in the hyperpolarized muscle segment. This increase, by 39%, was highly significant. It was probably smaller than the twofold increase elicited by insulin (100 mU/ml), but not than the possible effect produced by 10 mU/ml. The effect of hyperpolarization was specific for the D-glucose transport system because uptake of L-glucose was not altered.

Rate-limiting steps for insulin-mediated glucose uptake into perfused rat hindlimb

1986 ◽  
Vol 250 (1) ◽  
pp. E100-E102 ◽  
Author(s):  
K. Kubo ◽  
J. E. Foley
Keyword(s):  
Glucose Uptake ◽  
Glucose Transport ◽  
Transport System ◽  
Glucose Concentration ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Glucose Transport System ◽  
Glucose Clearance ◽  
Rate Limiting ◽  
Uptake And Metabolism

To determine the glucose and insulin concentrations at which glucose transport is rate limiting for insulin-mediated glucose uptake and metabolism in muscle, glucose clearance was determined in the presence of glucose concentrations ranging from trace to 20 mM and in the absence or presence of insulin in the perfused rat hindlimb. In the absence of insulin and at submaximally stimulating insulin concentrations glucose clearance was constant up to 7 mM glucose and then decreased as the glucose concentration was raised. At maximally stimulating insulin concentrations glucose clearance was constant up to 2 mM glucose and then decreased. The decrease in glucose clearance between 2 and 7 mM glucose in the presence of maximally stimulating insulin concentrations could not be accounted for by competition among glucose molecules for the glucose transport system. The results suggest that at physiological glucose concentrations in the presence of maximally stimulating insulin concentrations the rate-limiting step for insulin-mediated glucose uptake and metabolism in muscle shifts from glucose transport to some step beyond transport.

scholarly journals Regulation and Properties of PstSCAB, a High-Affinity, High-Velocity Phosphate Transport System of Sinorhizobium meliloti

2006 ◽  
Vol 188 (3) ◽  
pp. 1089-1102 ◽  
Author(s):  
Ze-Chun Yuan ◽  
Rahat Zaheer ◽  
Turlough M. Finan
Keyword(s):  
Transport System ◽  
High Velocity ◽  
Sinorhizobium Meliloti ◽  
Protein Transport ◽  
Root Nodules ◽  
Phosphate Transport ◽  
Site Directed Mutagenesis ◽  
Uptake System ◽  
Wild Type ◽  
High Affinity

ABSTRACT The properties and regulation of the pstSCAB-encoded Pi uptake system from the alfalfa symbiont Sinorhizobium meliloti are reported. We present evidence that the pstSCAB genes and the regulatory phoUB genes are transcribed from a single promoter that contains two PhoB binding sites and that transcription requires PhoB. S. meliloti strain 1021 (Rm1021) and its derivatives were found to carry a C deletion frameshift mutation in the pstC gene (designated pstC1021) that severely impairs activity of the PstSCAB Pi transport system. This mutation is absent in RCR2011, the parent of Rm1021. Correction of the pstC1021 mutation in Rm1021 by site-directed mutagenesis revealed that PstSCAB is a Pi-specific, high-affinity (Km , 0.2 μM), high-velocity (V max, 70 nmol/min/mg protein) transport system. The pstC1021 allele was shown to generate a partial pho regulon constitutive phenotype, in which transcription is activated by PhoB even under Pi-excess conditions that render PhoB inactive in a wild-type background. The previously reported symbiotic Fix− phenotype of phoCDET mutants was found to be dependent on the pstC1021 mutation, as Rm1021 phoCDET mutants formed small white nodules on alfalfa that failed to reduce N2, whereas phoCDET mutant strains with a corrected pstC allele (RmP110) formed pink nodules on alfalfa that fixed N2 like the wild type. Alfalfa root nodules formed by the wild-type RCR2011 strain expressed the low-affinity orfA-pit-encoded Pi uptake system and neither the pstSCAB genes nor the phoCDET genes. Thus, metabolism of alfalfa nodule bacteroids is not Pi limited.

scholarly journals Utilization of gluconate by Escherichia coli. Induction of gluconate kinase and 6-phosphogluconate dehydratase activities

1973 ◽  
Vol 134 (2) ◽  
pp. 489-498 ◽  
Author(s):  
H. L. Kornberg ◽  
Anne K. Soutar
Keyword(s):  
Escherichia Coli ◽  
Glucose Uptake ◽  
Uptake System ◽  
Glucosephosphate Isomerase ◽  
Wild Type ◽  
E Coli ◽  
Phosphogluconate Dehydrogenase ◽  
Aldolase Activity

1. A mutant of Escherichia coli, devoid of phosphopyruvate synthetase, glucosephosphate isomerase and 6-phosphogluconate dehydrogenase activities, grew readily on gluconate and inducibly formed an uptake system for gluconate, gluconate kinase and 6-phosphogluconate dehydratase while doing so. 2. This mutant also grew on glucose 6-phosphate and inducibly formed 6-phosphogluconate dehydratase; however, the formation of the gluconate uptake system and gluconate kinase was not induced under these conditions. 3. The use of the Entner–Doudoroff pathway for the dissimilation of 6-phosphogluconate, derived from either gluconate or glucose 6-phosphate, by this mutant was also demonstrated by the accumulation of 2-keto-3-deoxy-6-phosphogluconate (3-deoxy-6-phospho-l-glycero-2-hexulosonate) from both these substrates in a similar mutant that also lacked phospho-2-keto-3-deoxygluconate aldolase activity. 4. Glucose 6-phosphate inhibits the continued utilization of fructose by cultures of the mutants growing on fructose, as it does in wild-type E. coli. 5. The mutants do not use glucose for growth. This is shown to be due to insufficiency of phosphopyruvate, which is required for glucose uptake.

scholarly journals In vitro analysis of the glucose-transport system in GLUT4-null skeletal muscle

1999 ◽  
Vol 342 (2) ◽  
pp. 321-328 ◽  
Author(s):  
Jeffrey W. RYDER ◽  
Yuichi KAWANO ◽  
Alexander V. CHIBALIN ◽  
Jorge RINCÓN ◽  
Tsu-Shuen TSAO ◽  
...  
Keyword(s):  
Cell Surface ◽  
Glucose Transport ◽  
Transport System ◽  
Soleus Muscle ◽  
Cytochalasin B ◽  
Transport Activity ◽  
Wild Type ◽  
Glucose Transport System ◽  
Vitro Analysis

We have characterized the glucose-transport system in soleus muscle from female GLUT4-null mice to determine whether GLUT1, 3 or 5 account for insulin-stimulated glucose-transport activity. Insulin increased 2-deoxyglucose uptake 2.8- and 2.1-fold in soleus muscle from wild-type and GLUT4-null mice, respectively. Cytochalasin B, an inhibitor of GLUT1- and GLUT4-mediated glucose transport, inhibited insulin-stimulated 2-deoxyglucose uptake by > 95% in wild-type and GLUT4-null soleus muscle. Addition of 35 mM fructose to the incubation media was without effect on insulin-stimulated 3-O-methylglucose transport activity in soleus muscle from either genotype, whereas 35 mM glucose inhibited insulin-stimulated (20 nM) 3-O-methylglucose transport by 65% in wild-type and 99% in GLUT4-null mice. We utilized the 2-N-4-1-(1-azi-2,2,2-t r i f l u o r o e t h y l ) b e n z o y l - 1, 3 - b i s (D - m a n n o s e - 4 - y l o x y ) - 2 - p ro p y lamine (ATB-BMPA) exofacial photolabel to determine if increased cell-surface GLUT1 or GLUT4 content accounted for insulin-stimulated glucose transport in GLUT4-null muscle. In wild-type soleus muscle, cell-surface GLUT4 content was increased by 2.8-fold under insulin-stimulated conditions and this increase corresponded to the increase in 2-deoxyglucose uptake. No detectable cell-surface GLUT4 was observed in soleus muscle from female GLUT4-null mice under either basal or insulin-stimulated conditions. Basal cell-surface GLUT1 content was similar between wild-type and GLUT4-null mice, with no further increase noted in either genotype with insulin exposure. Neither GLUT3 nor GLUT5 appeared to account for insulin-stimulated glucose-transport activity in wild-type or GLUT4-null muscle. In conclusion, insulin-stimulated glucose-transport activity in female GLUT4-null soleus muscle is mediated by a facilitative transport process that is glucose- and cytochalasin B-inhibitable, but which is not labelled strongly by ATB-BMPA.

scholarly journals Characterization of Streptococcus mutans Strains Deficient in EIIABMan of the Sugar Phosphotransferase System

2003 ◽  
Vol 69 (8) ◽  
pp. 4760-4769 ◽  
Author(s):  
Jacqueline Abranches ◽  
Yi-Ywan M. Chen ◽  
Robert A. Burne
Keyword(s):  
Streptococcus Mutans ◽  
Type Strain ◽  
Wild Type Strain ◽  
Sugar Transport ◽  
Fold Increase ◽  
Sugar Uptake ◽  
Uptake System ◽  
Oral Streptococci ◽  
Wild Type ◽  
Phosphotransferase System

ABSTRACT The phosphoenolpyruvate:sugar phosphotransferase system (PTS) is the major sugar uptake system in oral streptococci. The role of EIIABMan (encoded by manL) in gene regulation and sugar transport was investigated in Streptococcus mutans UA159. The manL knockout strain, JAM1, grew more slowly than the wild-type strain in glucose but grew faster in mannose and did not display diauxic growth, indicating that EIIABMan is involved in sugar uptake and in carbohydrate catabolite repression. PTS assays of JAM1, and of strains lacking the inducible (fruI) and constitutive (fruCD) EII fructose, revealed that S. mutans EIIABMan transported mannose and glucose and provided evidence that there was also a mannose-inducible or glucose-repressible mannose PTS. Additionally, there appears to be a fructose PTS that is different than FruI and FruCD. To determine whether EIIABMan controlled expression of the known virulence genes, glucosyltransferases (gtfBC) and fructosyltransferase (ftf) promoter fusions of these genes were established in the wild-type and EIIABMan-deficient strains. In the manL mutant, the level of chloramphenicol acetyltransferase activity expressed from the gtfBC promoter was up to threefold lower than that seen with the wild-type strain at pH 6 and 7, indicating that EIIABMan is required for optimal expression of gtfBC. No significant differences were observed between the mutant and the wild-type background in ftf regulation, with the exception that under glucose-limiting conditions at pH 7, the mutant exhibited a 2.1-fold increase in ftf expression. Two-dimensional gel analysis of batch-grown cells of the EIIABMan-deficient strain indicated that the expression of at least 38 proteins was altered compared to that seen with the wild-type strain, revealing that EIIABMan has a pleiotropic effect on gene expression.

Glucose transport in Streptococcus salivarius. Evidence for the presence of a distinct phosphoenolpyruvate: glucose phosphotransferase system which catalyses the phosphorylation of α-methyl glucoside

1982 ◽  
Vol 28 (2) ◽  
pp. 190-199 ◽  
Author(s):  
Christian Vadeboncoeur ◽  
Luc Trahan
Keyword(s):  
Glucose Transport ◽  
Transport System ◽  
Facilitated Diffusion ◽  
Spontaneous Mutant ◽  
Streptococcus Salivarius ◽  
Phosphotransferase System ◽  
Methyl Glucoside ◽  
Glucose Transport System ◽  
Uptake Studies ◽  
Active Transport System

A spontaneous mutant of Streptococcus salivarius ATCC 25975 was isolated by inoculating an agar medium containing 11 mM lactose and 0.5 mM 2-deoxyglucose. This mutant grew poorly on 5 mM glucose but almost as well as the parental strain on 110 mM glucose. Uptake of 2-deoxyglucose was abolished by the mutation, and phosphoenolpyruvate:glucose phosphotransferase activity could not be detected with toluenized cells under normal conditions when the glucose concentration was below 5 mM. Data from growth experiments, glycolysis, and uptake studies indicated the presence of a second phosphoenolpyruvate: glucose phosphotransferase system that could catalyze the phosphorylation of α-methyl glucoside. The activity of this system was detected by a spectrophotometric assay coupled with lactate dehydrogenase and by a radioactive isotope method using methyl α-D-[U-14C]glucoside. The phosphorylation was phosphoenolpyruvate dependent. The apparent Km of the system for glucose and α-methyl glucoside was approximately 20 mM. Studies with energy poisons ruled out the possibility of an active transport system, and accumulation of α-methyl glucoside argued against facilitated diffusion. It was concluded that the other glucose transport system which allowed growth of the mutant strain of S. salivarius was a second phosphoenolpyruvate:glucose phosphotransferase system.

Sign in / Sign up

Export Citation Format

Share Document