Disease relevance of ectoine

• Isolation and characterization of salt-sensitive mutants of the moderate halophile Halomonas elongata and cloning of the ectoine synthesis genes [1].
• To investigate the function of ectoine as a compatible solute in plant cells, the three genes were individually placed under the control of the cauliflower mosaic virus 35S promoter and introduced together into cultured tobacco (Nicotiana tabacum L.) cv Bright Yellow 2 (BY2) cells [2].
• Osmoprotection of Escherichia coli by ectoine: uptake and accumulation characteristics [3].
• To understand the mechanisms of ectoine-induced osmoprotection in Sinorhizobium meliloti, a proteomic examination of S. meliloti cells grown in minimal medium supplemented with ectoine was undertaken [4].
• Functional expression of the ectoine hydroxylase gene (thpD) from Streptomyces chrysomallus in Halomonas elongata [5].

High impact information on ectoine

• Finally, a cosmid from the H. elongata genomic library was isolated which complemented the Ect- phenotype of both mutants, indicating that it carried at least the genes ectB and ectC of the biosynthetic pathway of ectoine [1].
• Despite the presence of nuclear inclusions, apoptotic features were less frequently observed after ectoine application [6].
• (13)C-nuclear magnetic resonance analysis of cells grown in minimal medium at the limiting temperature of 45 degrees C revealed the presence of hydroxyectoine, ectoine, glutamate, trehalose (not present in cells grown at 37 degrees C), and the ectoine precursor, Ngamma-acetyldiaminobutyric acid [7].
• Hence, it is conceivable that SMCs such as ectoine and hydroxyectoine could be potential inhibitors against the aggregate formation of Alzheimer's Abeta, which has not been studied to date [8].
• The halophilic bacterium Halomonas elongata accumulates K+, glutamate, and the compatible solute ectoine as osmoprotectants [9].

Chemical compound and disease context of ectoine

• Sucrose and ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidine carboxylic acid) are very unusual osmoprotectants for Sinorhizobium meliloti because these compounds, unlike other bacterial osmoprotectants, do not accumulate as cytosolic osmolytes in salt-stressed S. meliloti cells [10].
• When expressed in the heterologous host E. coli, the permease is specific for glycine betaine and does not transport the other osmoprotectants previously described for T. halophila (i.e. carnitine, choline, dimethylsulfonioacetate, dimethylsulfoniopropionate, and ectoine) [11].
• The growth of a halotolerant Brevibacterium sp. JCM 6894 was examined in the presence of compatible solutes such as glycine betaine, ectoine (2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine) and ectoine derivatives [12].
• Calorimetrically obtained information about the efficiency of ectoine synthesis from glucose in Halomonas elongata [13].

Biological context of ectoine

• On the basis of sequence homologies, eutABCDE encode enzymes with putative and hypothetical functions in ectoine catabolism [4].
• This transporter was encoded by four genes (ehuA, ehuB, ehuC, and ehuD) that formed an operon with another gene cluster that contains five genes, named eutABCDE for ectoine utilization [4].
• By repeatedly performing this "bacterial milking" process (at least nine times) we were able to produce large amounts of ectoines with a biomass productivity of 155 mg of ectoine per cycle per gram cell dry weight [14].
• The ectoine transporter is encoded by an open reading frame of 1,578 bp named ectM [15].
• A 480-bp Marinococcus halophilus DNA-fragment upstream of the ectoine genes ectABC was linked to the reporter gene gfp(uv) in the stress probe plasmid pBRGFP(uv) [16].

Anatomical context of ectoine

• Therefore, the physiological role of TeaABC may be primarily to recover ectoine leaking through the cytoplasmic membrane [17].
• Ectoine from halophilic microorganisms induces the expression of hsp70 and hsp70B' in human keratinocytes modulating the proinflammatory response [18].
• Following a high-cell-density fermentation which provided biomass up to 48 g cell dry weight per liter, we applied alternating osmotic shocks in combination with crossflow filtration techniques to harvest the compatible solutes ectoine and hydroxyectoine [14].

Associations of ectoine with other chemical compounds

• EctP preferred ectoine (Km, 63 microM) to betaine (Km, 333 microM) and proline (Km, 1,200 microM) [19].
• They grew well under optimal conditions (29-35 degrees C, pH 7.5-8.5, 0.5-1.0 M NaCl) and accumulated intracellularly poly-beta-hydroxybutyrate and the compatible solute ectoine [20].
• HPLC determinations of the cytoplasmic solute content showed the accumulation of a biosynthetic precursor of ectoine, L-2,4-diaminobutyric acid [21].

Gene context of ectoine

• In addition, ectoine had no effect on proinflammatory cytokines interleukin (IL)-1alpha, IL-6, IL-8, and tumor necrosis factor-alpha and on NF-kappaB and IkappaB-alpha pathway, whereas it downregulated the expression of cited proinflammatory cytokines, in lipopolysaccharides-treated keratinocytes [18].
• Strain CHR63 is a salt-sensitive mutant of the moderately halophilic wild-type strain Halomonas elongata DSM 3043 that is affected in the ectoine synthase gene (ectC) [22].
• We constructed a deletion mutant of H. elongata, KB1, defective in ectoine synthesis and tolerating elevated salt concentrations only in the presence of external compatible solutes [17].
• The purified cyanophycin synthetase maintained the parental thermophilic character and was active even after prolonged incubation at 50 degrees C; in the presence of ectoine the enzyme retained 90% of its activity even after 2 h of incubation [23].
• In contrast, in the absence of heat shock, ectoine was unable to induce hsp70B' but had the ability to induce another member of the Hsp family, the hsp70 [18].

Analytical, diagnostic and therapeutic context of ectoine

• HPLC analysis of osmotically challenged B. pasteurii cells revealed that ectoine production within this bacterium is finely tuned and closely correlated with the osmolality of the growth medium [24].
• High-performance liquid chromatography analyses showed that the levels of ectoine and hydroxyectoine were maximal during the stationary phase of growth [7].
• We therefore investigated the effects that cyclic naturally occurring ectoine-type compatible solutes and their synthetic derivatives have on melting temperature of double-stranded DNA (dsDNA) and on PCR amplification of different templates [25].
• In this study, we evaluated the ability of ectoine, a novel natural biomolecule produced by halophilic microorganisms, to activate the hsp70 and hsp70B'. By reverse transcriptase-polymerase chain reaction and Western blot analysis, we demonstrated increased hsp70B' gene expression in human keratinocytes treated with ectoine and heat stressed [18].

References