Methylmalonate-semialdehyde dehydrogenase is induced in auxin-stimulated and zinc-stimulated root formation in rice

Proteins induced in rice by auxin and zinc were determined by proteome analysis. Cultured suspension cells of rice were treated with 2,4-dichlorophenoxyacetic acid and ZnSO₄ and then proteins were separated by two-dimensional polyacrylamide gel electrophoresis; seven proteins were found to be induced by auxin and zinc. Of these seven, methylmalonate-semialdehyde dehydrogenase (MMSDH) was elevated by treatment with auxin alone. MMSDH was detected in cultured suspension cells, root and leaf sheath, but not in leaf blades. MMSDH responded to auxin and gibberellin, but did not respond to brassinolide and cytokinin. Furthermore, the amount of MMSDH in slr1, a constitutive gibberellin response mutant, was 2-fold that of wild type. MMSDH mRNA and protein were stimulated in root formation induced by auxin and/or zinc over a 4-week period. These results suggest that MMSDH may be necessary for root formation in rice induced by auxin and/or zinc.Abbreviations BA 6-Benzylaminopurine - BL Brassinolide - CBB Coomassie Brilliant Blue - 2,4-D 2,4-Dichlorophenoxyacetic acid - GA Gibberellic acid - IAA Indole-3-acetic acid - MALDI-TOF MS Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry - MMSDH Methylmalonate-semialdehyde dehydrogenase - 2D-PAGE Two-dimensional polyacrylamide gel electrophoresis - PVDF Polyvinylidene difluoride     

Characterization of transcriptional oscillation of an Arabidopsis homolog of PnC401 related to photoperiodic induction of flowering in Pharbitis nil

AtC401 is an Arabidopsis homolog of PnC401 that is related to photoperiodic induction of flowering in Pharbitis nil. These genes show free-running rhythms. To study the free-running rhythm of AtC401, we fused a firefly luciferase reporter to the AtC401 promoter and transformed it into Arabidopsis plants. The observed bioluminescence oscillated under continuous light and continuous dark only with sucrose supplementation. The free-running period of bioluminescence was temperature-compensated between 22 degrees C and 30 degrees C. Light-pulse experiments under continuous darkness produced a phase-response curve typical of circadian rhythms. We conclude that rhythmic expression of AtC401 is controlled by a circadian oscillator.     

Syntheses of novel diphenyl piperazine derivatives and their activities as inhibitors of dopamine uptake in the central nervous system

A new series of diphenyl piperazine derivatives containing the phenyl substituted aminopropanol moiety, which were modified at sites between the diphenyl and piperazine moieties, was prepared and evaluated for dopamine transporter binding affinity with [(3)H]GBR12935 in rat striatal membranes. These synthesized compounds showed apparent dopamine transporter binding affinities (IC(50)<30 nM) and some of them were approximately equivalent in activity to GBR12909 known as a potent dopamine uptake inhibitor, showing the activities with IC(50) values of nanomolar range. Among them, 1-[4,4-bis(4-fluorophenyl)butyl]-4-[2-hydroxy-3-(phenylamino)propyl]piperazine 2 was evaluated for extracellular dopamine levels in rat striatum using in vivo brain microdialysis. The intraperitoneal administration of 2 (0.01, 0.03, or 0.1 mmol/kg) induced dose-dependent increases of dopamine levels in rat striatal dialysates. The maximum increases in dopamine levels induced by 2 were greater than those by GBR12909. The pharmacological data of these novel diphenyl piperazine derivatives show that the compounds have potent dopamine uptake inhibitory activities in the central nervous system.     

A novel Cys-214-Ser mutation in the peripherin/RDS gene in a Japanese family with autosomal dominant retinitis pigmentosa

We have screened for possible disease-causing mutations in the peripherin/retinal degeneration slow (RDS) gene in 13 Japanese families with autosomal dominant retinitis pigmentosa (ADRP). Using polymerase chain reaction-single strand conformation polymorphism analysis, a novel mutation at codon 214 was found in which the highly conserved cysteine was replaced with a serine in one family. The mutation at codon 214 was found in all three affected siblings of this family, but none of the 40 normal control individuals had this mutation. These results strongly suggest, that the mutation is pathogenic for RP in this family. The clinical phenotype for this family is a late-onset form of ADRP.     

Tetraborate concentration on Morgan-Elson reaction and an improved method for hexosamine determination.

Effect of tetraborate concentration on the determination of hexosamine by Morgan-Elson color reaction according to Levvy and McAllan [(1959) Biochem. J., 73, 127–232] was studied using the three different preparations of the tetraborate solution. The concentration of the previous report during the chromogen formation (0.29 m) was too high comparing to the optimum concentration of the present experiment (0.175 m). An improved method is now proposed which is excellent on the ground of convenience and reproducibility; same readings were obtained with the tetraborate solution from various preparations which were stable at least for two years. It showed same molar extinction coefficient as obtained before.     

Reconstituted HDL containing human apolipoprotein A-1 reduces VCAM-1 expression and neointima formation following periadventitial cuff-induced carotid injury in apoE null mice.

Arterial injury triggers an inflammatory response in part mediated by induction of adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) and is implicated in neointimal thickening. Since HDL is known to reduce cytokine-activated VCAM-1 expression, we tested the hypothesis that VCAM-1 expression and neontimal thickening following arterial injury are inhibited by reconstituted human HDL containing plasma-derived apoA-1 (rHDL). We used the carotid cuff injury in apoE (-/-) mice fed high cholesterol. Mice received rHDL (40 mg/kg) intravenously every other day for 3 weeks. Compared to control, rHDL treatment inhibited neointima formation (0. 008 +/- 0.004 mm(2) vs. 0.037 +/- 0.019 mm(2); P < 0.01) 21 days after injury, reduced VCAM-1 expression, and decreased monocyte/macrophage infiltration as assessed by histomorphometric analysis within the first week after injury. These changes occurred without any effect on plasma total and HDL cholesterol levels as well as the arterial tissue cholesterol levels. rHDL treatment also reduced the formation of modified lipoprotein in the arterial wall compared to control within the first week after injury. This finding suggests an antioxidant effect of rHDL associated with reduced VCAM-1 expression and neointimal formation after arterial injury.     

Myocilin expression in the astrocytes of the optic nerve head

We investigated the expression of myocilin in the optic nerve head of porcine eyes by Western blotting and immunohistochemical staining. Myocilin was localized in the nucleus, centrosome, glial filament, mitochondria, and some parts of the cell membranes of the astrocytes. Myocilin was also detected at the edge-feet portion of the processes of astrocytes adjacent to the inner limiting membrane and blood vessel wall. The astrocytes are the major cell population in the optic nerve head, contributing to the architecture of the nerve axon and blood vessels. Therefore, myocilin gene mutation and change of myocilin protein are likely to affect the architecture of the optic nerve head and induce various forms of glaucomatous optic nerve damage.