Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Trehalose”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 505 records · Page 28Linked to original sources
PubMed2002

Disruption of the Candida albicans TPS2 gene encoding trehalose-6-phosphate phosphatase decreases infectivity without affecting hypha formation.

Deletion of trehalose-6-phosphate phosphatase, encoded by TPS2, in Saccharomyces cerevisiae results in accumulation of trehalose-6-phosphate (Tre6P) instead of trehalose under stress conditions. Since trehalose is an important stress protectant and Tre6P accumulation is toxic, we have investigated whether Tre6P phosphatase could be a useful target for antifungals in Candida albicans. We have cloned the C. albicans TPS2 (CaTPS2) gene and constructed heterozygous and homozygous deletion strains. As in S. cerevisiae, complete inactivation of Tre6P phosphatase in C. albicans results in 50-fold hyperaccumulation of Tre6P, thermosensitivity, and rapid death of the cells after a few hours at 44 degrees C. As opposed to inactivation of Tre6P synthase by deletion of CaTPS1, deletion of CaTPS2 does not affect hypha formation on a solid glucose-containing medium. In spite of this, virulence of the homozygous deletion mutant is strongly reduced in a mouse model of systemic infection. The pathogenicity of the heterozygous deletion mutant is similar to that of the wild-type strain. CaTPS2 is a new example of a gene not required for growth under standard conditions but required for pathogenicity in a host. Our results suggest that Tre6P phosphatase may serve as a potential target for antifungal drugs. Neither Tre6P phosphatase nor its substrate is present in mammals, and assay of the enzymes is simple and easily automated for high-throughput screening.

Amino Acid Sequence↗
PubMed1992

Molecular cloning and physical mapping of the otsBA genes, which encode the osmoregulatory trehalose pathway of Escherichia coli: evidence that transcription is activated by katF (AppR)

It has been shown previously that the otsA and otsB mutations block osmoregulatory trehalose synthesis in Escherichia coli. We report that the transcription of these osmoregulated ots genes is dependent on KatF (AppR), a putative sigma factor for certain stationary phase- and starvation-induced genes. The transcription of the osmoregulated bet and proU genes was not katF dependent. Our genetic analysis showed that katF carries an amber mutation in E. coli K-12 and many of its derivatives but that katF has reverted to an active form in the much-used strain MC4100. This amber mutation in katF leads to strain variations in trehalose synthesis and other katF-dependent functions of E. coli. We have performed a molecular cloning of the otsBA genes, and we present evidence that they constitute an operon encoding trehalose-6-phosphate phosphatase and trehalose-6-phosphate synthase. A cloning and restriction site analysis, performed by comparing the cloned fragments with the known physical map of the E. coli chromosome, revealed that the otsBA genes are situated on a 2.9-kb HindIII fragment located 8 to 11 kb clockwise of tar (41.6 min).

Chromosome Mapping↗
PubMed1999

AGT1, encoding an alpha-glucoside transporter involved in uptake and intracellular accumulation of trehalose in Saccharomyces cerevisiae.

The trehalose content in Saccharomyces cerevisiae can be significantly manipulated by including trehalose at an appropriate level in the growth medium. Its uptake is largely dependent on the expression of AGT1, which encodes an alpha-glucoside transporter. The trehalose found in a tps1 mutant of trehalose synthase may therefore largely reflect its uptake from the enriched medium that was employed.

Biological Transport↗
PubMed2000

Characterization of tpp1(+) as encoding a main trehalose-6P phosphatase in the fission yeast Schizosaccharomyces pombe.

We have characterized an open reading frame of 2,454 bp on chromosome I of Schizosaccharomyces pombe as the gene encoding trehalose-6P phosphatase (tpp1(+)). Disruption of tpp1(+) caused in vivo accumulation of trehalose-6P upon heat shock and prevented cell growth at 37 to 40 degrees C. Accumulation of trehalose-6P in cells bearing a chromosomal disruption of the tpp1(+) gene and containing a plasmid with tpp1(+) under the control of the thiamine-repressible promotor correlated with tpp1(+) repression. The level of tpp1(+) mRNA rose upon heat shock, osmostress, or oxidative stress and was negatively controlled by cyclic AMP-dependent protein kinase activity. Expression of tpp1(+) during oxidative or osmotic stress, but not during heat shock, was under positive control by the wis1-sty1 (equivalent to phh1 and spc1) mitogen-activated protein kinase pathway. Analysis of Tpp1 protein levels suggests that the synthesis of trehalose-6P phosphatase may also be subjected to translational or posttranslational control.

Chromosomes, Fungal↗
PubMed1989

Usefulness of trehalose fermentation and L-glutamic acid decarboxylation for identification of biochemically aberrant Providencia stuartii strains.

A total of 849 Providencia isolates were collected during a 4-year period when an increased incidence of nosocomial Providencia stuartii infection was noted in urologic wards. Of these isolates, 630 were identified as P. stuartii, 206 were identified as Providencia rettgeri, and 1 was identified as Providencia alcalifaciens. Twelve inositol-positive isolates from 10 patients (10 strains) resembled P. stuartii in fermenting trehalose but resembled P. rettgeri in fermenting D-arabitol or meso-erythritol or both. The latter traits, however, were not stable in all cases. These aberrant strains were identified as P. stuartii on the basis of their O antigens and DNA hybridization experiments. All isolates were tested for L-glutamic acid decarboxylase activity by a qualitative thin-layer chromatography method. All P. stuartii isolates, including the aberrant ones, were trehalose positive and L-glutamic acid decarboxylase negative. None of the P. rettgeri isolates fermented trehalose, while 99.0% of them and the single P. alcalifaciens strain were L-glutamic acid decarboxylase positive. Thus, trehalose fermentation and L-glutamic acid decarboxylation are more useful for separating P. stuartii from P. rettgeri than are D-arabitol and meso-erythritol fermentation.

DNA, Bacterial↗
PubMed1995

Increased thermal stability of the enzyme content in permeabilized whole cells from the fission yeast Schizosaccharomyces pombe by exogenous trehalose and other compounds.

Cells of the fission yeast Schizosaccharomyces pombe were permeabilized by treatment with toluene-ethanol. The permeabilized cells lost the bulk of the internal trehalose pool while most of the alkaline phosphatase, invertase, alpha-glucosidase, or neutral trehalase activities located inside the cells remained unaffected. This system was used as an in situ assay to determine the involvement of trehalose in enzyme protection during thermal treatments. The addition of trehalose to suspensions of permeabilized cells resulted in a sugar-dependent thermoprotection of the internal marker enzymes. This approach demonstrates that in whole cells of the fission yeast trehalose plays a physiological role as a protective molecule against thermal denaturation of cellular enzymes.

Alkaline Phosphatase↗
PubMed1998

Transcriptional and translational regulation of major heat shock proteins and patterns of trehalose mobilization during hyperthermic recovery in repressed and derepressed Saccharomyces cerevisiae.

Patterns of heat shock gene transcription and translation, as well as trehalose content, were investigated in both glucose (repressed) and acetate (derepressed) grown cells of Saccharomyces cerevisiae during heat shock and subsequent return of cells to 25 degrees C. Heat-shocked cells (37 degrees C for 30 min), grown in either glucose- or acetate-supplemented media, initially acquired high thermotolerance to a 50 degrees C heat stress, which was progressively lost when cultures were allowed to recover at 25 degrees C and subsequently exposed to a second heat stress. In all cases, with the notable exception of repressed cells of a relatively thermosensitive strain, inhibition of protein synthesis and coincident decrease in trehalose accumulation during the heat shock had little effect on the kinetics of loss of thermotolerance. Heat shock at 37 degrees C elicited a marked increase in transcription and translation of genes encoding major heat shock proteins (hsps). During recovery at 25 degrees C, both metabolic activities were suppressed followed by a gradual increase in hsp mRNA transcription to levels observed prior to heat shock. De novo translation of hsp mRNAs, however, was no longer observed during the recovery phase, although immunodetection analyses demonstrated persistence of high levels of hsps 104, 90, 70, and 60 in cells throughout the 240-min recovery period. In addition, while heat shock induced trehalose was rapidly degraded during recovery in repressed cells, levels remained high in derepressed cells. Results therefore indicated that the progressive loss of induced thermotolerance exhibited by glucose- and acetate-grown cells was not closely correlated with levels of hsp or trehalose. It was concluded that both constitutive and de novo synthesized hsps require heat shock associated activation to confer thermotolerance and this modification is progressively reversed upon release from the heat-shocked state.

Acetates↗
PubMed2002

Trehalose augments osteoprotegerin production in the FHs74Int human intestinal epithelial cell line.

The disaccharide trehalose has been shown to inhibit both bone loss in ovariectomized mice and excessive osteoclastogenesis in lipopolysaccharide-injected mice. However, the mechanism of osteoclastogenesis inhibition by oral administration of trehalose is still unclear. We report here for the first time that a human intestinal epithelial cell line, FHs74Int, also produces osteoprotegerin (OPG) and that trehalose augments OPG production by this cell line. Thus, these results suggest that trehalose promotes the production of OPG by intestinal epithelial cells, which then acts on bone marrow cells, resulting in the suppression of osteoclastogenesis.

Base Sequence↗
PubMed2006

Role of selenium supplementation and heat stress on trehalose and glutathione content in Saccharomyces cerevisiae.

The role of selenium (Se) supplementation on glutathione, a potent intracellular redox buffer, and trehalose, a well-known stress protectant molecule, was studied. The amount of glutathione decreased significantly while that of trehalose showed a minor decrease in the cells grown in Se-supplemented medium. After heat shock, glutathione content diminished further, whereas that of trehalose increased significantly in control and Se-supplemented cells. These findings suggest the importance of trehalose as an antioxidant molecule.

Glutathione↗
PubMedDate not supplied

Marine biosurfactants, II. Production and characterization of an anionic trehalose tetraester from the marine bacterium Arthrobacter sp. EK 1.

Within a screening for biosurfactants we could isolate various n-alkanes utilizing marine bacteria which were capable of synthesizing glycolipids. One strain was identified as Arthrobacter sp. EK 1 which produced trehalose lipids. After purification by column and thick layer chromatography the main fraction, an anionic 2,3,4,2'-trehalose tetraester, was obtained. The chain lengths of fatty acids ranged from 8 up to 14, furthermore succinate could be detected. Since the place of substitution of succinate has so far not been cited in literature, a definitive structural elucidation was carried out chemically by hydroboration and by 1H, 2D1H, 13C and 13C-1H correlation NMR measurements. All investigations confirmed the exact position of succinate at C 2 atom of trehalose. After improvement of growth conditions the production of the trehalose tetraester increased up to 4.8 milligrams during a fermentation in 20 l bioreactor under nitrogen limitation.

Animals↗
PubMed2006

Cytochrome C in a dry trehalose matrix: structural and dynamical effects probed by x-ray absorption spectroscopy.

We report on the structure and dynamics of the Fe ligand cluster of reduced horse heart cytochrome c in solution, in a dried polyvinyl alcohol (PVA) film, and in two trehalose matrices characterized by different contents of residual water. The effect of the solvent/matrix environment was studied at room temperature using Fe K-edge x-ray absorption fine structure (XAFS) spectroscopy. XAFS data were analyzed by combining ab initio simulations and multi-parameter fitting in an attempt to disentangle structural from disorder parameters. Essentially the same structural and disorder parameters account adequately for the XAFS spectra measured in solution, both in the absence and in the presence of glycerol, and in the PVA film, showing that this polymer interacts weakly with the embedded protein. Instead, incorporation in trehalose leads to severe structural changes, more prominent in the more dried matrix, consisting of 1), an increase up to 0.2 A of the distance between Fe and the imidazole N atom of the coordinating histidine residue and 2), an elongation up to 0.16 A of the distance between Fe and the fourth-shell C atoms of the heme pyrrolic units. These structural distortions are accompanied by a substantial decrease of the relative mean-square displacements of the first ligands. In the extensively dried trehalose matrix, extremely low values of the Debye Waller factors are obtained for the pyrrolic and for the imidazole N atoms. This finding is interpreted as reflecting a drastic hindering in the relative motions of the Fe ligand cluster atoms and an impressive decrease in the static disorder of the local Fe structure. It appears, therefore, that the dried trehalose matrix dramatically perturbs the energy landscape of cytochrome c, giving rise, at the level of local structure, to well-resolved structural distortions and restricting the ensemble of accessible conformational substates.

Animals↗
PubMed2005

Stabilization of cold-adapted protease MCP-01 promoted by trehalose: prevention of the autolysis.

Protease MCP-01 is similar to other cold-adapted enzymes in that it is a cold-adapted serine protease having high specific activity and low thermostability at low and moderate temperature. Its thermolability and self-autolysis has resulted in difficulties in its purification, preservation and research on its structure and function. The disaccharide trehalose is known to effectively stabilize proteins. Its prevention effect on the autolysis of cold-adapted protease MCP-01 was monitored by capillary electrophoresis. In the absence of trehalose, protease MCP-01 autolyzed rapidly at 35 degrees C. However, when trehalose was added, autolysis was remarkably prevented and the loss of activity reduced. MCP-01 may be a useful model for basic research on the interaction of protein and trehalose.

Electrophoresis, Capillary↗
PubMed2001

Cutinase unfolding and stabilization by trehalose and mannosylglycerate.

The unfolding of cutinase at pH 4.5 was induced by increasing the temperature and guanidine hydrochloride concentration in the presence of potassium chloride, trehalose, and mannosylglycerate potassium salt. Protein thermal unfolding approached a two-state process, since the unfolding transitions were coincident within experimental error when assessed by near-ultraviolet (UV) difference, tryptophyl, and 8-anilino-1-naphthalene sulfonic acid (ANS) fluorescence spectroscopy. Trehalose at 0.5 M increased the temperature at which 50% of cutinase is unfolded by 3 degrees C. Unfolding induced by guanidine hydrochloride is clearly a non-two-state process. The presence of a stable intermediate was detected because unfolding assessed by near-UV difference spectroscopy occurs earlier than unfolding assessed by tryptophyl fluorescence. The intermediate is molten globule in character: the ANS fluorescence is higher than in the presence of the folded or unfolded state, showing native-like secondary structure and losing many tertiary interactions of the folded state, i.e., those surrounding the tyrosyl microenvironment. The stabilization effect of trehalose and mannosylglycerate was quantified by fitting the unfolding transitions to a model proposed by Staniforth et al. (Biochemistry 1993;32:3842-3851). This model takes into consideration the increase in solvation energies of the amino acid side-chains as the denaturant concentration was increased and the fraction of amino acid side-chains that become exposed in the unfolded structure of cutinase. Trehalose and mannosylglycerate stabilize the folded state relative to the intermediate by 1.4-1.6 and 1.6 kcal/mol and the intermediate relative to the unfolded state by 1.0 and 1.5 kcal/mol, respectively.

Carboxylic Ester Hydrolases↗
PubMed2001

[The metabolism of trehalose and intracellular glycerol in Candida krusei responding to high osmosis].

The trehalose and intracellular glycerol contents of osmotolerant yeast Candida krusei cells rapidly increased in response to the medium containing NaCl. Addition of NaCl at early exponential phase or steady phase increased trehalose content only, but the content of extracellular glycerol increased gradually. Development of resistance was accompanied by accumulation of trehalose and was apparently unrelated to intracellular glycerol content which was always low under these conditions. There seems to be an overlap function between trehalose and glycerol in Candida krusei cells in response to the osmotic conditions.

Candida↗
PubMed2002

The enzymes of glycogen and trehalose catabolism from Hysterothylacium aduncum (Nematoda: Anisakidae).

The activity of alpha-amylase, glucoamylase, maltase, trehalase, glycogen phosphorylase and trehalose phosphorylase was measured in extracts from larval and adult Hysterothylacium aduncum (Rudolphi, 1802), parasitic nematode of marine fish. The content of glycogen and trehalose in the worm's body was also determined. Both the hydrolytic and phosphorolytic paths of sugar decomposition are present in H. aduncum. In the larvae glycogen was utilised mainly via the hydrolytic path. In the adults the activities of phosphorolytic enzymes were higher than in the larvae. In both stages the activity of trehalose phosphorylase is present. In adult nematodes it is uncommonly high. The dominating sugars in the adults were glucose and glycogen, while in the larvae it was trehalose.

Animals↗
PubMed2001

[Detection of trehalose in transgenic tobacco by HPLC with ELSD].

The E. coli trehase synthalose gene(otsA) was transferred into Nicotiana tabacum mediated by Agrobacterium, but the method for detecting low concentration of trehalose in transgenic plant was not available. The high performance liquid chromatograph(HPLC) with evaporative light-scatting detector(ELSD) using water: methyl cyanide(1:2.6 v/v) as mobile phase was established in this work. An ODS column Zorbax RX-SIL was employed. the trehalose detection limits of ELSD was 5 mg/L. From the linear relationship between the logarithm of trehalose concentration and the logarithm of peak area, it was shown there was 14.7 micrograms.(g FW)-1 in transgenic plant. The data strongly confirmed that trehalose was responsible for the improved stress tolerance of the tobacco.

Chromatography, High Pressure Liquid↗
PubMed1992

Differentiation of HT-29 human colonic adenocarcinoma cells correlates with increased expression of mitochondrial RNA: effects of trehalose on cell growth and maturation.

The HT-29 human adenocarcinoma cell line has been used extensively in the study of colonic cell differentiation and colon cancer. We report here that substitution of glucose with trehalose (alpha-D-glucopyranosyl-alpha-D-glucopyranoside) depresses growth and promotes mucin-producing, goblet-like maturation of HT-29. An initial characterization of this process was made by analyzing several cDNA clones whose RNA templates were differentially expressed at elevated levels in cells grown in trehalose-containing medium. Seven of the 9 clones examined corresponded to 6 mitochondrial genes whose expression levels, relative to those from glucose-grown cells, ranged from approximately 3-fold for 16S rRNA to 8-23-fold for NADH dehydrogenase subunit 4. On the other hand, levels of mitochondrial DNA copy, measured by using NADH dehydrogenase subunit 4 cDNA as probe, were shown to be unaffected by trehalose treatment. Elevation of cellular NADH dehydrogenase subunit 4 RNA in HT-29 cultures grown in medium containing different components (sodium butyrate, galactose, no-sugar, glucose, cellobiose) generally correlated with depressed growth levels and specifically with increased numbers of mucin-producing cells present. Like butyrate, the sugar, trehalose, is an effective inducer of HT-29 differentiation, and may prove useful as a dietary therapeutic, and as a probe for elucidating mitochondrial involvement in colonic cell differentiation and transformation.

Adenocarcinoma↗
PubMedDate not supplied

[Thermal resistance in fungi: the role of heat shock proteins and trehalose].

The parallel synthesis of heat shock proteins and trehalose in response to heat shock did not allow the role of these compounds in the acquisition of thermotolerance by fungal cells to be established for a long time. This review analyses experimental data obtained with the use of mutant fungal strains and shows differences in the thermoprotective functions of trehalose and heat shock proteins in relation to cell membranes and macromolecules. The main emphasis has been placed on data demonstrating the thermoprotective role of trehalose in fungi, the present-day understanding of its biological functions, and mechanisms of trehalose interaction with subcellular structures and cell macromolecules.

Adaptation, Physiological↗