Engineered sorbitol accumulation induces dwarfism in Japanese persimmon

A cDNA encoding sorbitol-6-phosphate dehydrogenase (S6PDH), which is a key enzyme in sorbitol biosynthesis in Rosaceae, was introduced into the Japanese persimmon (Diospyros kaki) to increase the environmental stress tolerance. Resultant transformants exhibited salt-tolerance with dwarfing phenotypes. Therefore, we studied two transgenic lines to understand the physiological mechanism of this dwarfism: lines PS1 and PS6 accumulated high and moderate levels of sorbitol, respectively. The average length of shoots was significantly shorter as compared with the wild-type in line PS1, while no such decrease was observed in line PS6. The myo-inositol and glucose 6-phosphate (G6P) contents were measured in the transgenic lines because previous work with tobacco transformed with S6PDH had suggested that growth inhibition was due to depletion of these metabolites. Although the myo-inositol content was decreased in PS1 plants, the decrease was much smaller than that observed in transgenic tobacco that accumulates sorbitol. The G6P contents were the same in PS1 plants and phenotypically normal PS6 plants. The level of indole-3-acetic acid (IAA), which affects stem elongation, in line PS1 was similar to the levels in the other lines. A decrease in gibberellin (GA) content generally induces dwarfism in plants. However, GA was not decreased in PS1 plants compared with wild-type or control plants. Therefore, we focused on sorbitol accumulation as the most remarkable feature of PS1 plants. As one possibility, the observed growth inhibition was likely caused by an osmotic imbalance between the cytosol and vacuole.     

Nickel(II) and cobalt(II) complexes of hydroxyl-substituted triazamacrocyclic ligand as potential antitumor agents

The stability constants for the formation of nickel(II) and cobalt(II) complexes of the ligand [1,4,7]triazecan-9-ol (L) were presented. Antitumor activity of two complexes was reported. Nuclei of [NiL]-stimulated BEL-7402 cells clearly exhibited condensation and break down into chromatin clumps typical of apoptosis. Also it exhibited perturbation effects to cell cycle, and optimal induction of apoptosis was found by Flow-Cytometric analysis. But CoL complex did not exhibit introduction effects to BEL-7402 cells apoptosis; and could not perturb cell cycle. NiL and CuL complexes could cleave supercoiled DNA (pBR 322 DNA) to nicked and linear DNA, and DNA of cells treated with NiL or CuL complex was obviously damaged; while CoL complex only could cleave supercoiled DNA (pBR 322 DNA) to nicked DNA, and DNA of cells treated with CoL complex had no significant difference with control.     

Design and synthesis of 3'-ureidoadenosine-5'-uronamides: effects of the 3'-ureido group on binding to the A3 adenosine receptor

On the basis of high binding affinity at the A(3) adenosine receptor of 3'-aminoadenosine derivatives with hydrogen bonding donor ability, novel 3'-ureidoadenosine analogues were synthesized from 1,2:5,6-di-O-isopropylidene-d-glucose in order to lead to stronger hydrogen bonding than the corresponding 3'-aminoadenosine derivatives. However, the synthesized 3'-ureidoadenosine analogues were totally devoid of binding affinity, because 3'-urea moiety caused steric and electrostatic repulsions at the binding site of the A(3) adenosine receptor, leading to conformational distortion.     

Mitochondrial proteins and complexes in Leishmania and Trypanosoma involved in U-insertion/deletion RNA editing

A number of mitochondrial proteins have been identified in Leishmania sp. and Trypanosoma brucei that may be involved in U-insertion/deletion RNA editing. Only a few of these have yet been characterized sufficiently to be able to assign functional names for the proteins in both species, and most have been denoted by a variety of species-specific and laboratory-specific operational names, leading to a terminology confusion both within and outside of this field. In this review, we summarize the present status of our knowledge of the orthologous and unique putative editing proteins in both species and the functional motifs identified by sequence analysis and by experimentation. An online Supplemental sequence database (http://164.67.60.200/proteins/protsmini1.asp) is also provided as a research resource.     

Early anti-apoptosis treatment reduces myocardial infarct size after a prolonged reperfusion

OBJECTIVE : Significant myocardial apoptosis occurs in ischemia/reperfused hearts. However, the contribution of apoptosis to the development of myocardial injury remains controversial. The present study attempted to obtain evidence that inhibition of apoptosis at early reperfusion can reduce myocardial infarction after prolonged reperfusion. METHODS : Adult male rats were subjected to 30 min ischemia and 4 (apoptosis assay) or 24 h (myocardial infarction determination) of reperfusion and treated with vehicle, SB 239063, insulin or insulin plus wortmannin. RESULTS : Treatment with SB 239063 or insulin markedly decreased myocardial apoptosis (10.6 +/- 1.5% and 7.9 +/- 0.9% respectively, P < 0.01 vs. vehicle) and significantly reduced infarct size (43 +/- 3.6% and 35 +/- 2.9%, respectively, P < 0.01 vs. vehicle). Most interestingly, inhibition of insulin signaling with wortmannin to block insulin signaling not only blocked insulin's anti-apoptotic effect, but also abolished its infarct reduction property. CONCLUSION : These data indicate that apoptosis contributes to the development of myocardial infarction, and inhibition of apoptosis at early reperfusion reduces the myocardial infarction.     

Intein-mediated rapid purification of recombinant human pituitary adenylate cyclase activating polypeptide

In order to obtain the recombinant human PACAP efficiently by intein-mediated single column purification, a gene encoding human PACAP was synthesized and cloned into Escherichia coli expression vector pKYB. The recombinant vector pKY-PAC was transferred into E. coli ER2566 cells and the target protein was over-expressed as     

Expression of a modified Cry1Ie gene in E. coli and in transgenic tobacco confers resistance to corn borer

The wild-type Crylle gene from Bacillus thuringiensis was modified for its efficient expression in transgenic plants. Modified Crylle gene (designated as Cryllem) was cloned into prokaryotic expressionvector pET28b and its expression in E.coli was confirmed by SDS-PAGE analysis. Bioassays using crude expression products in E.coli revealed that CrylIem protein had a similar toxicity to corn borer as wild-type CrylIe. CrylIem gene was then inserted downstream of the maize ubiquitin-1 promoter in plant expression vector p3301. Transgenic tobacco plants carrying Cryllem showed insecticidal activity against corn borer.     

Effect of degree of acetylation on gelation of konjac glucomannan

Effect of the degree of acetylation (DA) on the gelation behaviors on addition of sodium carbonate for native and acetylated konjac glucomannan (KGM) samples with a DA range from 1.38 to 10.1 wt % synthesized using acetic anhydride in the presence of pyridine as catalyst was studied by dynamic viscoelastic measurements. At a fixed alkaline concentration (CNa), both the critical gelation times (tcr) and the plateau values of storage moduli (G'sat) of the KGM gels increased with increasing DA, while at a fixed ratio of alkaline concentrations to values of DA (CNa/DA), similar tcr and values independent of DA were observed. On the whole, increasing KGM concentration or temperature shortened the gelation time and enhanced the elastic modulus for KGM gel. The effect of deacetylation rate related to the CNa/DA on the gelation kinetics of the KGM samples was discussed.