Calcium carbonate prevents Botryococcus braunii growth inhibition caused by medium acidification

Journal of Applied Phycology - Microalgae, Botryococcus braunii in particular, have received increasing interest owing to their potential as biofuel sources. Although the fertilizer components...     

Ontogenesis of α2-Adrenoceptor Coupling with GTP-Binding Proteins in the Rat Telencephalon

The ontogenesis of alpha 2-adrenoceptors and GTP-binding proteins and their coupling activity were investigated in telencephalon membranes of developing rats. The manganese-induced elevation of [3H]clonidine binding was increased in an age-dependent manner but the guanosine 5'-O-(3-thio)triphosphate-induced decrease in binding did not change. The extent of the binding of [3H]clonidine at 15 nM (saturable concentration) increased in an age-dependent manner and reached the adult level at 4 days after birth. Cholera toxin and pertussis toxin catalyzed ADP-ribosylation of proteins of 46 and 41/39 kilodaltons (kDa) in solubilized cholate extracts of the membranes. The 41/39-kDa proteins ADP-ribosylated by pertussis toxin (Gi alpha + Go alpha) were increased with age and reached the adult level at day 12, whereas the 46-kDa protein (Gs alpha) reached its peak on day 12 and then decreased to the fetal level at the adult stage. The immunoblot experiments of the homogenates with antiserum (specific antibody against alpha- and beta-subunit of GTP-binding proteins) demonstrated that the 39-kDa alpha-subunit of (Go alpha) and the 36-kDa beta-subunit of GTP-binding protein (beta 36) increased with postnatal age. In contrast, 35-kDa beta-subunit (beta 35) did not change. From these results, it is suggested that the coupling activity of alpha 2-adrenoceptor with GTP-binding protein gradually develops in a manner parallel with the increase of alpha 2-adrenoceptor and pertussis toxin sensitive GTP-binding proteins, Gi, and that alpha 39 beta 36 gamma may be related to the differentiation and/or growth of nerve cells in rat telencephalon.     

Engineering of Escherichia coli to facilitate efficient utilization of isomaltose and panose in industrial glucose feedstock

Industrial glucose feedstock prepared by enzymatic digestion of starch typically contains significant amounts of disaccharides such as maltose and isomaltose and trisaccharides such as maltotriose and panose. Maltose and maltosaccharides can be utilized in Escherichia coli fermentation using industrial glucose feedstock because there is an intrinsic assimilation pathway for these sugars. However, saccharides that contain α-1,6 bonds, such as isomaltose and panose, are still present after fermentation because there is no metabolic pathway for these sugars. To facilitate more efficient utilization of glucose feedstock, we introduced glvA, which encodes phospho-α-glucosidase, and glvC, which encodes a subunit of the phosphoenolpyruvate-dependent maltose phosphotransferase system (PTS) of Bacillus subtilis, into E. coli. The heterologous expression of glvA and glvC conferred upon the recombinant the ability to assimilate isomaltose and panose. The recombinant E. coli assimilated not only other disaccharides but also trisaccharides, including alcohol forms of these saccharides, such as isomaltitol. To the best of our knowledge, this is the first report to show the involvement of the microbial PTS in the assimilation of trisaccharides. Furthermore, we demonstrated that an l-lysine-producing E. coli harboring glvA and glvC converted isomaltose and panose to l-lysine efficiently. These findings are expected to be beneficial for industrial fermentation.

     

Increased tolerance to salt stress in the phosphate-accumulating <Emphasis Type="Italic">Arabidopsis</Emphasis> mutants <Emphasis Type="Italic">siz1</Emphasis> and <Emphasis Type="Italic">pho2</Emphasis>

High salinity is an environmental factor that inhibits plant growth and development, leading to large losses in crop yields. We report here that mutations in SIZ1 or PHO2, which cause more accumulation of phosphate compared with the wild type, enhance tolerance to salt stress. The siz1 and pho2 mutations reduce the uptake and accumulation of Na⁺. These mutations are also able to suppress the Na⁺ hypersensitivity of the sos3-1 mutant, and genetic analyses suggest that SIZ1 and SOS3 or PHO2 and SOS3 have an additive effect on the response to salt stress. Furthermore, the siz1 mutation cannot suppress the Li⁺ hypersensitivity of the sos3-1 mutant. These results indicate that the phosphate-accumulating mutants siz1 and pho2 reduce the uptake and accumulation of Na⁺, leading to enhanced salt tolerance, and that, genetically, SIZ1 and PHO2 are likely independent of SOS3-dependent salt signaling.     

Novel mutations of CDKN1C in Japanese patients with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is an imprinting-related human disease that is characterized by macrosomia, macroglossia, abdominal wall defects, and variable minor features. BWS is caused by several genetic/epigenetic alterations, such as loss of methylation at KvDMR1, gain of methylation at H19-DMR, paternal uniparental disomy of chromosome 11, CDKN1C mutations, and structural abnormalities of chromosome 11. CDKN1C is an imprinted gene with maternal preferential expression, encoding for a cyclin-dependent kinase (CDK) inhibitor. Mutations in CDKN1C are found in 40 % of familial BWS cases with dominant maternal transmission and in ~5 % of sporadic cases. In this study, we searched for CDKN1C mutations in 37 BWS cases that had no evidence for other alterations. We found five mutations—four novel and one known—from a total of six patients. Four were maternally inherited and one was a de novo mutation. Two frame-shift mutations and one nonsense mutation abolished the QT domain, containing a PCNA-binding domain and a nuclear localization signal. Two missense mutations occurred in the CDK inhibitory domain, diminishing its inhibitory function. The above-mentioned mutations were predicted by in silico analysis to lead to loss of function; therefore, we strongly suspect that such anomalies are causative in the etiology of BWS.     

EML4 promotes the loading of NUDC to the spindle for mitotic progression

Echinoderm microtubule-associated protein (EMAP)-like (EML) family proteins are microtubule-associated proteins that have a conserved hydrophobic EMAP-like protein (HELP) domain and multiple WD40 domains. In this study, we examined the role of EML4, which is a member of the EML family, in cell division. Time-lapse microscopy analysis demonstrated that EML4 depletion induced chromosome misalignment during metaphase and delayed anaphase initiation. Further analysis by immunofluorescence showed that EML4 was required for the organization of the mitotic spindle and for the proper attachment of kinetochores to microtubules. We searched for EML4-associating proteins by mass spectrometry analysis and found that the nuclear distribution gene C (NUDC) protein, which is a critical factor for the progression of mitosis, was associated with EML4. This interaction was mediated by the WD40 repeat of EML4 and by the C-terminus of NUDC. In the absence of EML4, NUDC was no longer able to localize to the mitotic spindle, whereas NUDC was dispensable for EML4 localization. Our results show that EML4 is critical for the loading of NUDC onto the mitotic spindle for mitotic progression.     

Decreased apoptosis of beta 2- integrin-deficient bovine neutrophils

Stimulant-induced viability of neutrophils, nuclear-fragmentation, increase in intracellular calcium ([Ca2+]i), expression of annexin V on neutrophils and proteolysis of a fluorogenic peptide substrate Ac-DEVD-MCA (acetyl Asp-Glu-Val-Asp alpha-[4-methyl-coumaryl-7-amide]) by neutrophil lysates from five normal calves and three calves with leucocyte adhesion deficiency were determined to evaluate the apoptosis of normal and CD18-deficient neutrophils. Viability was markedly decreased in control neutrophils stimulated with opsonized zymosan (OPZ), compared to CD18-deficient neutrophils at 37 degrees C after incubation periods of 6 and 24 hours. The rate of apoptosis of control neutrophils stimulated with OPZ increased significantly depending on the incubation time, whereas no apparent increase in apoptosis was found in CD18-deficient neutrophils under the same conditions. Aggregated bovine (Agg) IgG-induced apoptosis of control neutrophils was not significantly different from that of CD18-deficient neutrophils. The expression of annexin V on OPZ-stimulated control neutrophils was greater than that of unstimulated ones 6 h after stimulation. No apparent increase in annexin V expression on CD18-deficient neutrophils was found with OPZ stimulation. A delay in apoptosis was demonstrated in CD18-deficient bovine neutrophils and this appeared to be closely associated with lowered signalling via [Ca2+]i, diminished annexin V expression on the cell surface, and decreased caspase 3 activity in lysates.     

Three-dimensional structure of the inclusion complex between phloridzin and beta-cyclodextrin

The inclusion of phloridzin into beta-cyclodextrin was studied as a model of molecular recognition in membranes. Effects on 1H NMR spectra and NOE correlational peaks between phloridzin and beta-cyclodextrin were observed in the complex. Strong NOEs were observed between hydrogens of a phenol group in phloridzin and beta-cyclodextrin. The three-dimensional structure of the inclusion complex between phloridzin and beta-cyclodextrin was simulated with distance constraints estimated by the intensity of NOE peaks using the DADAS90 programs. Two inclusion possibilities were suggested-the large rim of beta-cyclodextrin as an entrance of the inclusion and the small rim of beta-cyclodextrin as the entrance. In both cases, the phenol group of phloridzin was included in the hydrophobic space of beta-cyclodextrin.     

Hormonal regulation of fruit set, parthenogenesis induction and fruit expansion in Japanese pear

The effects of applied gibberellins (GAs), GA₁, GA₃, GA₄ and GA₇ with a cytokinin, N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) and indole-3-acetic acid (IAA) on fruit set, parthenogenesis induction and fruit expansion of a number of Rosaceae species were assessed. These included Japanese pear cv. ‘Akibae’ (self-compatible) and cv. ‘Iwate yamanashi’ (a seedless cultivar). Other Rosaceae species (Pyrus communis, Chaenomeles sinensis, Cydonia oblonga, and Malus pumila) were also investigated. GA₄, GA₇ and CPPU are very effective in inducing parthenocarpic fruit growth, whereas GA₁, GA₃ and IAA, have no ability to induce parthenogenesis in Japanese pear. GA₄- and GA₇-induced parthenocarpic fruit tended to be smaller in size, higher in flesh hardness, and showed advanced fruit ripening in comparison to pollinated fruit and to parthenocarpic fruit induced by CPPU. GA₄- and GA₇-induced parthenocarpic fruit also had an increased pedicel length and fruit shape index and also showed a slight protrusion of the calyx end. CPPU, GA₄ and GA₇ alone or combination with uniconazole were also active in inducing parthenogenesis in three other Rosaceae species, although final fruit set was extremely low. GA₁ was essentially inactive in promoting fruit expansion unlike the other bioactive GAs, whose effectiveness in promoting fruit cell expansion was as follow: GA₄ ≈ GA₇ > GA₃ > GA₁.