Amyloplasts and vacuolar membrane dynamics in the living graviperceptive cell of the Arabidopsis inflorescence stem

We developed an adequate method for the in vivo analysis of organelle dynamics in the gravity-perceptive cell (endodermis) of the Arabidopsis thaliana inflorescence stem, revealing behavior of amyloplasts and vacuolar membranes in those cells. Amyloplasts in the endodermis showed saltatory movements even before gravistimulation by reorientation, and these movements were confirmed as microfilament dependent. From our quantitative analysis in the wild type, the gravity-oriented movement of amyloplasts mainly occurred during 0 to 3 min after gravistimulation by reorientation, supporting findings from our previous physiological study. Even after microfilament disruption, the gravity-oriented movement of amyloplasts remained. By contrast, in zig/sgr4 mutants, where a SNARE molecule functioning in vacuole biogenesis has been disrupted, the movement of amyloplasts in the endodermis is severely restricted both before and after gravistimulation by reorientation. Here, we describe vacuolar membrane behavior in these cells in the wild-type, actin filament-disrupted, and zig/sgr4 mutants and discuss its putatively important features for the perception of gravity. We also discuss the data on the two kinds of movements of amyloplasts that may play an important role in gravitropism: (1) the leading edge amyloplasts and (2) the en mass movement of amyloplasts.     

Dissecting the basis of nongenomic activation of endothelial nitric oxide synthase by estradiol: role of ERalpha domains with known nuclear functions

Estradiol stimulates endothelial nitric oxide synthase (eNOS) via the activation of plasma membrane (PM)-associated estrogen receptor (ER) alpha. The process requires Src and erk signaling and eNOS phosphorylation by phosphoinositide 3-kinase (PI3 kinase)-Akt kinase, with Src and PI3 kinase associating with ERalpha upon ligand activation. To delineate the basis of nongenomic eNOS stimulation, the potential roles of ERalpha domains necessary for classical nuclear function were investigated in COS-7 cells. In cross-linking studies, estradiol-17beta (E2) caused PM-associated ERalpha to form dimers. However, eNOS activation by E2 was unaltered for a dimerization-deficient mutant ERalpha (ERalphaL511R). In contrast, ERalpha mutants lacking the nuclear localization signals (NLS), NLS2,3 (ERalphaDelta250-274) or the DNA binding domain (ERalphaDelta185-251), which targeted normally to PM and caveolae/rafts, were incapable of activating eNOS. The loss of NLS2/NLS3 prevented Src and erk activation, and it altered ligand-induced PI3 kinase-ERalpha interaction and prevented eNOS phosphorylation. Loss of the DNA binding domain did not change E2 activation of Src or erk, but ligand-induced PI3 kinase-ERalpha binding and eNOS phosphorylation did not occur. Thus, dimerization is not required for ERalpha coupling to eNOS; however, NLS2/NLS3 plays a role in Src activation, and the DNA binding region is involved in the dynamic interaction between ERalpha and PI3 kinase.     

Establishment and characterization of a human malignant choroids plexus papilloma cell line (HIBCPP)

A cell line designated "HIBSPP" was established from a human malignant choroids plexus papilloma of 29-year-old Japanese woman. This line grew well without interruption for 3 years and was subcultivated over 70 times. The cells were spindle, oval, and polygonal in shape, and neoplastic and pleomorphic features, a jigsaw puzzle-like arrangement, multilayering and forming papillary structures without contact inhibition. The cells proliferated slowly, and the population doubling time was about 69 hours. The chromosome number showed a wide distribution of aneuploidy. The mode was in the hypotetraploid range, and many marker chromosomes were observed. The culture cells were easily transplanted into the subcutis of nude mice and produced the tumor resembling the original tumor.     

Establishment and characterization of a human thyroid carcinoma cell line (HOTHC) producing colony stimulating factor

A cell line designated HOTHC was established from an anaplastic carcinoma (giant cell type) of the thyroid gland of 80-year-old woman. The HOTHC line grew rapidly in multilayer without contact inhibition, and more than 120 serial passages were made within 27 months. The cells were spindle or polygonal in shape and revealed neoplastic and pleomorphic features. These cells were characterized as containing coloid droplets and poorly developed rough-endoplasmic reticulum in the cytoplasm. Doubling time was about 24 hours and plating efficiency was about 70%. The karyotype exhibits hyperploidy and marker chromosomes, and the modal chromosome number ranged between 77-90. The HOTHC cells were transplanted into the subcutis of BALB/c nude mice and produced anaplatic carcinomas (giant cell type) resembling the original tumor. The HOTHC cells produced colony stimulating factor (CSF) and caused granulocytosis in the mice.     

Effect of dentures wearing on motor reaction time and balance function in elderly people

OBJECTIVE: To investigate the influence of dentures wearing on the parameters of physical fitness, particularly on agility and balance function in elderly people. DESIGN: A case control study.Setting: Motohachiohjimachi, Hachiohji, Tokyo, Japan. METHODS: Motor reaction time was measured in the presence and absence of dentures in the subjects who were 1) in a sitting position and lifted the lower limbs as fast as possible in response to a stimulus (Sitting Group) and those who were 2) in a standing position and jumped upright as fast as possible in response to a light stimulus (Jumping Group). The effects of dentures wearing on balance function were investigated by comparing the measured values of static and dynamic body sway. RESULTS AND CONCLUSIONS: Light-reaction time was not significantly influenced by dentures wearing in Sitting Group performing a light body movement that required little muscular force.In a relatively heavy body movement that required agility (i.e., jumping from the standing position), the reactivity changed depending on the muscular force; which might result in the difference of the reactivity due to dentures wearing (i.e., t-test showed a significant difference in the light-reaction time under clenching posture between with and without wearing dentures (p < 0.01)).No significant difference was observed in body sway under clenching posture between with and without wearing dentures.Therefore, we assumed that reaction speed varied depending upon dentures wearing.     

Identification of neuropeptide W as the endogenous ligand for orphan G-protein-coupled receptors GPR7 and GPR8

The structurally related orphan G-protein-coupled receptors GPR7 and GPR8 are expressed in the central nervous system, and their ligands have not been identified. Here, we report the identification of the endogenous ligand for both of these receptors. We purified the peptide ligand from porcine hypothalamus using stable Chinese hamster ovary cell lines expressing human GPR8 and cloned the cDNA encoding its precursor protein. The cDNA encodes two forms of the peptide ligand with lengths of 23 and 30 amino acid residues as mature peptides. We designated the two ligands neuropeptide W-23 (NPW23) and neuropeptide W-30 (NPW30). The amino acid sequence of NPW23 is completely identical to that of the N-terminal 23 residues of NPW30. Synthetic NPW23 and NPW30 activated and bound to both GPR7 and GPR8 at similar effective doses. Intracerebroventricular administration of NPW23 in rats increased food intake and stimulated prolactin release. These findings indicate that neuropeptide W is the endogenous ligand for both GPR7 and GPR8 and acts as a mediator of the central control of feeding and the neuroendocrine system.     

Cloning and nucleotide sequence analysis of the Streptococcus sobrinus gtfU gene that produces a highly branched water-soluble glucan

Streptococcus sobrinus has four gtf genes, gtfI, gtfS, gtfT, and gtfU, on the chromosome. These genes correspond respectively to the enzymes GTF-I, GTF-S1, GTF-S2, and GTF-S3. An Escherichia coli MD66 clone that contained the S. sobrinus gtfU gene was characterized. Immunological properties showed that the protein produced by the E. coli MD66 clone was similar to S. sobrinus GTF-S1. Biological properties and a linkage analysis of the glucans by 13C NMR spectrometry revealed that the protein produced by the E. coli MD66 clone was GTF-S1.     

Isolation, structure and biological activity of the Trp-containing pentapeptide from uremic fluid.

Trp-containing pentapeptide was isolated from uremic fluid of an uremic patient by ultrafiltration with Amicon membranes followed by gel filtrations. The peptide thus obtained was identified as H-Asp-Leu-Trp-Gln-Lys-OH by amino acid analysis, manual Edman degradation method, physical constants and analytical data of synthetic pentapeptide. Structural similarity was soon realized between this peptide and pentapeptide moiety corresponding to position 123 through 127 of β-chain of fibrinogen. E-rosettes inhibition test was shown this pentapeptide to have an inhibition activity by amount more than l.Omg/ml.     

Identification and characterization of quantitative trait loci for root elongation by using introgression lines with genetic background of Indica-type rice variety IR64

The root is the sole organ taking up water and nutrients from soils. Hence, root system architecture (RSA) is important for enhancing high-level and stable rice (Oryza sativa L.) production. However, the genetic improvement of RSA has received less attention than yield and yield components. Here, we aimed to identify and characterize quantitative trait loci (QTLs) for RSA by determining the maximum root length (MRL) of seedlings grown hydroponically under various concentrations of NH₄ ⁺. We used a total of 280 introgression lines (ILs) with an Indica-type variety IR64 genetic background, consisting of ten sibling ILs groups, to detect the QTLs. Greater variation of MRL was found in three sibling ILs groups. In total, five QTLs were detected by single marker analyses: two each on chromosomes 5 and 6 and one on chromosome 7. Among them, the most effective QTL was detected on a segment derived from IR69093-41-2-3-2 (YP5), which was localized to the long-arm of chromosome 6. The QTL, designated as qRL6.4-YP5, concerned in root elongation. MRL and total root length of a near-isogenic line (NIL) for qRL6.4-YP5 were significantly (15.2–24.6 %) higher than those of IR64 over a wide range of NH₄ ⁺ concentrations. Root number and weight of the NIL were the same as those of IR64. These results indicated that qRL6.4-YP5 was a constitutive QTL for root length in response to change in nitrogen concentrations. To enhance yield potential by improving RSA, qRL6.4-YP5 might help to improve root development in rice molecular breeding programs with marker-assisted selection.