Cloning and expression trait of UDP-glucose:flavonoid 3-O-glucosyltransferase gene (UF3GT) in turnip

Anthocyanin is a class of important secondary metabolites in plants. UDP-glucose:flavonoid  3-O-glucosyltransferase (UF3GT) is a committed catalytic enzyme in the late stage of anthocyanin  biosynthesis. BrUF3GT1 and BrUF3GT2 genes were cloned by reverse transcription polymerase chain reaction  (RT-PCR) method from ‘Tsuda’ and ‘Yurugi Akamaru’ turnips. The open reading frame (ORF) of BrUF3GT1 and  BrUF3GT2 genes contained 1407 bp encoding proteins of 468 amino acids. Amino acid sequence analysis  showed that BrUF3GT1 and BrUF3GT2 had 87% identity to UF3GT of Arabidopsis thaliana, and the  glycosyltransferase protein family domain was in the amino acids sequence from 16 to 453. The nucleotide  sequence of BrUF3GT1 and BrUF3GT2 genes showed only seven nucleotide differences, and one common  deduced amino acid sequence. The northern blotting results showed that the expression of BrUF3GT1 and BrUF3GT2 genes could be induced by irradiation of ultra-violet A (UV-A), and the expression of the genes was correlated with light-exposure time. The 51.88 and 51.89 KDa proteins of BrUF3GT1 and BrUF3GT2 were  successfully purified after prokaryotic induced expression.Key words: Turnip, UDP-glucose:flavonoid 3-O-glucosyltransferase (UF3GT) gene, gene clone, sequence analysis, gene expression

Hydrothermal Synthesis of Nitrogen-Doped Titanium Dioxide and Evaluation of Its Visible Light Photocatalytic Activity

Nitrogen-doped titanium dioxide (N-doped TiO2) photocatalyst was synthesized from nanotube titanic acid (denoted as NTA; molecular formula H2Ti2O5·H2O ) precursor via a hydrothermal route in ammonia solution. As-synthesized N-doped TiO2 catalysts were characterized by means of X-ray diffraction, transmission electron microscopy, diffuse reflectance spectrometry, X-ray photoelectron spectroscopy, electron spin resonance spectrometry and Fourier transform infrared spectrometry. It was found that nanotube ammonium titanate (NAT) was produced as an intermediate during the preparation of N-doped TiO2 from NTA, as evidenced by the N1s X-ray photoelectron spectroscopic peak of NH4 + at 401.7 eV. The catalyst showed much higher activities to the degradation of methylene blue and p-chlorophenol under visible light irradiation than Degussa P25. This could be attributed to the enhanced absorption of N-doped TiO2 in visible light region associated with the formation of single-electron-trapped oxygen vacancies and the inhibition of recombination of photo-generated electron-hole pair by doped nitrogen

Intrachromosomal Looping Is Required for Activation of Endogenous Pluripotency Genes during Reprogramming

SummaryGeneration of induced pluripotent stem cells (iPSCs) by defined factors is an extremely inefficient process, because there is a strong epigenetic block preventing cells from achieving pluripotency. Here we report that virally expressed factors bound to the promoters of their target genes to the same extent in both iPSCs and unreprogrammed cells (URCs). However, expression of endogenous pluripotentcy genes was observed only in iPSCs. Comparison of local chromatin structure of the OCT4 locus revealed that there was a cohesin-complex-mediated intrachromosomal loop that juxtaposes a downstream enhancer to the gene’s promoter, enabling activation of endogenous stemness genes. None of these long-range interactions were observed in URCs. Knockdown of the cohesin-complex gene SMC1 by RNAi abolished the intrachromosomal interaction and affected pluripotency. These findings highlight the importance of the SMC1-orchestrated intrachromosomal loop as a critical epigenetic barrier to the induction of pluripotency

A NEW METHOD TO PREPARE THE NOVEL ANATASE TiO2

In this paper, a kind of novel anatase TiO2 nanoparticle with single-electron-trapped oxygen vacancies was prepared by hydrothermal treated nanotube titanic acid. The morphology, structure, and properties of the products were characterized by transmission electron microscope, X-ray diffraction, electron spin resonance, and photoluminescence. Photocatalytic decolorization of the Methylene Blue solution was carried out in the visible light region and showed a high photocatalytic activity.Nanotube titanic acid, novel TiO2, single-electron-trapped oxygen vacancies, hydrothermal method

Effects and Mechanism of Plasma-Activated Medium on Angiogenesis of Vascular Endothelial Cells

After cell culture medium is treated with low temperature plasma (LTP), the liquid is rich in reactive oxygen and nitrogen species (RONS), and becomes plasma-activated medium (PAM). PAM, as the supplier of RONS, can affect the angiogenesis of cells. The purpose of this study is to investigate the effects and related mechanism of PAM on human umbilical vein endothelial cells (HUVECs). Cell viability and cell cycle were evaluated after HUVECs were treated with PAM for 24 h. Changes in cell angiogenesis, migration and adhesion, secretion of cytokines such as VEGF and bFGF, expression of VEGFR-2 and phosphorylation of the key proteins in the MEK/ERK signaling pathway, concentrations of H2O2 and NO2− in PAM and in cells were also investigated. The results showed that PAM obtained by LTP treatment had dual effects on the angiogenesis of HUVECs: PAM obtained by short-term LTP treatment promoted the angiogenesis of HUVECs, while PAM obtained by long-term LTP treatment inhibited the angiogenesis of HUVECs. The mechanism may be that PAM treatment changes the content of RONS, affects the VEGF-VEGFR-2 signaling pathway, and ultimately affects the angiogenesis of HUVECs

Infrared Photodissociation Spectroscopic and Theoretical Study of Homoleptic Dinuclear Chromium Carbonyl Cluster Cations with a Linear Bridging Carbonyl Group

Infrared spectra of mass-selected homoleptic dinuclear chromium carbonyl cluster cations Cr₂(CO)_<i>n</i>⁺ with <i>n</i> = 7–9 are measured via infrared photodissociation spectroscopy in the carbonyl stretching frequency region in the gas phase. The structures are established by comparison of the experimental spectra with the simulated spectra derived from density functional calculations. The Cr₂(CO)_<i>n</i>⁺ cluster cations are characterized to have the (OC)₅Cr–C–O–Cr­(CO)_<i>n</i>−6⁺ structures with a linear bridging carbonyl group bonded to one chromium atom through its carbon atom and to the other chromium atom through its oxygen atom. The cluster cations all have a sextet ground state with the positive charge and the unpaired electrons located on the Cr­(CO)_<i>n</i>−6 moiety. The formation of the linear bridging structures without Cr–Cr bonding can be rationalized that chromium forms strong Cr–CO bonds but weak Cr–Cr bonds

Inhibition of HIV-1 Viral Infection by an Engineered CRISPR Csy4 RNA Endoribonuclease

<div><p>The bacterial defense system CRISPR (clustered regularly interspaced short palindromic repeats) has been explored as a powerful tool to edit genomic elements. In this study, we test the potential of CRISPR Csy4 RNA endoribonuclease for targeting HIV-1. We fused human codon-optimized Csy4 endoribonuclease with VPR, a HIV-1 viral preintegration complex protein. An HIV-1 cell model was modified to allow quantitative detection of active virus production. We found that the <i>trans</i>-expressing VPR-Csy4 almost completely blocked viral infection in two target cell lines (SupT1, Ghost). In the MAGI cell assay, where the HIV-1 LTR β-galactosidase is expressed under the control of the <i>tat</i> gene from an integrated provirus, VPR-Csy4 significantly blocked the activity of the provirus-activated HIV-1 reporter. This proof-of-concept study demonstrates that Csy4 endoribonuclease is a promising tool that could be tailored further to target HIV-1.</p></div

Optimal LDR to Protect the Kidney From Diabetes: Whole-Body Exposure to 25 mGy X-rays Weekly for 8 Weeks Efficiently Attenuates Renal Damage in Diabetic Mice

To explore an optimal frequency of whole-body low-dose radiation (LDR) to protect the kidney from diabetes, type 1 diabetic mice were induced with multiple injections of low-dose streptozotocin in male C57BL/6J mice. Diabetic or age-matched normal mice received whole-body exposure to 12.5 or 25 mGy either every other day or weekly for 4 or 8 weeks. Diabetes decreased the urinary creatinine and increased the microalbumin in urine, renal accumulation of 3-nitrotyrosine and 4-hydroxynonenal, and renal expression of collagen IV and fibronectin. All these renal pathological and functional changes in diabetic mice were significantly attenuated by exposure to LDR at all regimens. However, whole-body exposure of diabetic mice to 25 mGy weekly and to 12.5 mGy every other day for 8 weeks provided a better prevention of diabetic nephropathy than other LDR regimens. Furthermore, whole-body exposure to 25 mGy weekly for 8 weeks showed no detectable effect on the kidney of normal mice, but whole-body exposure to normal mice at 12.5 mGy every other day for 8 weeks increased urinary microalbumin and renal expression of collagen IV and fibronectin. These results suggest that whole-body exposure to LDR at 25 mGy weekly is the optimal condition of LDR to protect the kidney from diabetes

Infrared Photodissociation Spectroscopy of Mass Selected Homoleptic Copper Carbonyl Cluster Cations in the Gas Phase

Infrared spectra of mass-selected homoleptic copper carbonyl cluster cations including dinuclear Cu₂(CO)₆⁺ and Cu₂(CO)₇⁺, trinuclear Cu₃(CO)₇⁺, Cu₃(CO)₈⁺, and Cu₃(CO)₉⁺, and tetranuclear Cu₄(CO)₈⁺ are measured via infrared photodissociation spectroscopy in the carbonyl stretching frequency region. The structures are established by comparison of the experimental spectra with simulated spectra derived from density functional calculations. The Cu₂(CO)₆⁺ cation is characterized to have an unbridged <i>D</i>_3<i>d</i> structure with a Cu–Cu half bond. The Cu₂(CO)₇⁺ cation is determined to be a weakly bound complex involving a Cu₂(CO)₆⁺ core ion. The trinuclear Cu₃(CO)₇⁺ and Cu₃(CO)₈⁺ cluster cations are determined to have triangle Cu₃ core structures with <i>C</i>₂ symmetry involving two Cu­(CO)₃ groups and one Cu­(CO)_<i>x</i> group (<i>x</i> = 1 or 2). In contrast, the trinuclear Cu₃(CO)₉⁺ cluster cation is determined to have an open chain-like (OC)₃Cu–Cu­(CO)₃–Cu­(CO)₃ structure. The tetranuclear Cu₄(CO)₈⁺ cluster cation is characterized to have a tetrahedral Cu₄⁺ core structure with all carbonyl groups terminally bonded

Infrared Photodissociation Spectroscopy of Mass-Selected Heteronuclear Iron–Copper Carbonyl Cluster Anions in the Gas Phase

Mass-selected heteronuclear iron–copper carbonyl cluster anions CuFe­(CO)_<i>n</i>^– (<i>n</i> = 4–7) are studied by infrared photodissociation spectroscopy in the carbonyl stretching frequency region in the gas phase. The cluster anions are produced via a laser vaporization supersonic cluster ion source. Their geometric structures are determined by comparison of the experimental spectra with those calculated by density functional theory. The experimentally observed CuFe­(CO)_<i>n</i>^– (<i>n</i> = 4–7) cluster anions are characterized to have (OC)₄Fe–Cu­(CO)_<i>n</i>−4 structures, each involving a <i>C</i>_3<i>v</i> symmetry Fe­(CO)₄^– building block. Bonding analysis indicates that the Fe–Cu bond in the CuFe­(CO)_<i>n</i>^– (<i>n</i> = 4–7) cluster anions is a σ type single bond with the iron center possessing the most favored 18-electron configuration. The results provide important new insight into the structure and bonding of hetronuclear transition metal carbonyl cluster anions