Effects of activated ADP-ribosylation factors on Golgi morphology require neither activation of phospholipase D1 nor recruitment of coatomer

Nine mutations in the switch I and switch II regions of human ADP-ribosylation factor 3 (ARF3) were isolated from loss-of-interaction screens, using two-hybrid assays with three different effectors. We then analyzed the ability of the recombinant proteins to (i) bind guanine nucleotides, (ii) activate phospholipase D1 (PLD1), (iii) recruit coatomer (COP-I) to Golgi-enriched membranes, and (iv) expand and vesiculate Golgi in intact cells. Correlations of activities in these assays were used as a means of testing specific hypotheses of ARF action, including the role of PLD1 activation in COP-I recruitment, the role of COP-I in Golgi vesiculation caused by expression of the dominant activating mutant [Q71L]ARF3, and the need for PLD1 activation in Golgi vesiculation. Because we were able to find at least one example of a protein that has lost each of these activities with retention of the others, we conclude that activation of PLD1, recruitment of COP-I to Golgi, and vesiculation of Golgi in cells are functionally separable processes. The ability of certain mutants of ARF3 to alter Golgi morphology without changes in PLD1 activity or COP-I binding is interpreted as evidence for at least one additional, currently unidentified, effector for ARF action at the Golgi.     

Activation of farnesoid X receptor (FXR) protects against fructose-induced liver steatosis via inflammatory inhibition and ADRP reduction

Fructose is a key dietary factor in the development of nonalcoholic fatty liver disease (NAFLD). Here we investigated whether WAY-362450 (WAY), a potent synthetic and orally active FXR agonist, protects against fructose-induced steatosis and the underlying mechanisms. C57BL/6J mice, fed 30% fructose for 8 weeks, were treated with or without WAY, 30 mg/kg, for 20 days. The elevation of serum and hepatic triglyceride in mice fed 30% fructose was reversed by WAY treatment. Histologically, WAY significantly reduced triglyceride accumulation in liver, attenuated microphage infiltration and protected the junction integrity in intestine. Moreover, WAY remarkably decreased portal endotoxin level, and lowered serum TNFα concentration. In lipopolysaccharide (LPS)-induced NAFLD model, WAY attenuated serum TNFα level. Moreover, WAY suppressed LPS-induced expression of hepatic lipid droplet protein adipose differentiation-related protein (ADRP), down-regulation of it in mice fed 30% fructose. Furthermore, WAY repressed lipid accumulation and ADRP expression in a dose-dependent manner in palmitic acid (PA)-treated HepG2 and Huh7 cells. WAY suppressed TNFα-induced ADRP up-regulation via competing with AP-1 for ADRP promoter binding region. Together, our findings suggest that WAY, an FXR agonist, attenuates liver steatosis through multiple mechanisms critically involved in the development of hepatosteatosis, and represents a candidate for NAFLD treatment.     

How to map ses, a mutant of Arabidopsis thaliana affecting pollen development

In Arabidopsis, map-based cloning has been developed to an effective method in mutant genetic analysis because high-density markers are available, candidate genes or genomic sequences can be amplified by PCR, and transgenic techniques are simplified. Mutant ses named from shortened early-stage siliques was used as an example to show how to map a mutant in this way. By the process of bulked segregants analysis, linkage testing, large-scale and fine-scale mapping, mutant ses was narrowed into a 67 kb interval from CER448792 (2000541 bp) to CER464544 (2067844 bp) crossing over the right of BAC F12K11 to the left of the BAC F4H5 including at most 22 putative genes on the top of chromosome 1. In sequence-based map of Arabidopsis genes with mutant phenotype (SMAGMP) mutant ses was between AT1g06150 (EMB1444) and AT1g08060 (MOM). The ses mapping also showed that developed markers on polymorphism site of CAPC not only were simplified but worked well. Twenty-four markers from CAPC used in the mapping maybe help Arabidopsis researchs with others and the methods related to ses mapping also gave an example of positional cloning. The text was submitted by the authors in English.     

Electricity production by an overflow-type wetted-wall microbial fuel cell

An overflow-type wetted-wall MFC (WWMFC) was developed to generate a stable voltage from acetate-based substrates. The maximum power density of 18.21 W/m³ was obtained. The power generation showed a saturation-type relationship as a function of initial COD, with a maximum power density (P_max) of 18.82 W/m³ and a saturation constant (K_s) of 227.4 mg/l. Forced air flowing through the cathode chamber had a negligible effect on power generation. Influent flow rate could greatly affect the power generation. The maximum power density was increased by 72.8% when the influent flow rate increased from 5 to 30 ml/min. In addition, increasing ionic strength did not affect the power density and internal resistance. Oxygen could be restrained to diffuse into the anode chamber effectively in the overflow-type WWMFC. And the overflow-type WWMFC could be scaled up conveniently in practical application.     

Ectopic overexpression of AtHDG11 in tall fescue resulted in enhanced tolerance to drought and salt stress

Tall fescue (Festuca arundinacea Schreb.) is a cool-season perennial grass, which has been conventionally grown in the temperate area. However, as a major type of cool-season turf grass, its growth has been extended to the sub-tropical climate or even to the transitional climate between the sub-tropical and the tropical, and, in some cases, to heavily salinized lands. The extended growth imposes a serious challenge to its tolerance to the abiotic stress, particularly to drought, salt and high temperature. Here, we report a successful introduction of Arabidopsis AtHDG11 into the tall fescue via Agrobacterium-mediated transformation. The ectopic overexpression of AtHDG11 under the control of CaMV 35S promoter with four enhancers resulted in significantly enhanced tolerance to drought and salt stress. No obvious adverse effects on growth and development were observed in the transgenic plants. The enhanced stress tolerance was associated with a more extensive root system, a lower level of malondialdehyde, a nearly normal Na⁺/K⁺ ratio, a higher level of proline and a kinetically accelerated induction of SOD and CAT activities observed in the transgenic plants during drought and/or salt stress, indicating that an enhanced ROS scavenging capability might play a significant role in the acquired tolerance to the abiotic stress. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Ya-Jun Cao and Qiang Wei contributed equally to this work.     

Boosting the Activity of BaCo0.4Fe0.4Zr0.1Y0.1O3−δ Perovskite for Oxygen Reduction Reactions at Low‐to‐Intermediate Temperatures through Tuning B‐Site Cation Deficiency

Doped perovskite oxides with the general formula of A_xA′_1?xB_yB′_1?yO₃ have been extensively exploited as the cathode materials of solid oxide fuel cells (SOFCs), but the performance at low‐to‐medium temperatures still needs improvement. BaCo_0.4Fe_0.4Zr_0.1Y_0.1O_3?δ (BCFZY) has been recently reported to show promising oxygen reduction reaction (ORR) activity under SOFCs' operating conditions. Here, it is reported that the activity of BCFZY can be further boosted via introducing a slight B‐site cation deficiency into the oxide lattice, and such an improvement is assigned to an increase in oxygen mobility that brings enhancement in both surface exchange and bulk diffusion kinetics. Specifically, materials with the nominal composition of Ba(Co_0.4Fe_0.4Zr_0.1Y_0.1)_0.975O_3?δ and Ba(Co_0.4Fe_0.4Zr_0.1Y_0.1)_0.95O_3?δ show significantly improved activity for ORR at reduced temperatures with the area specific resistances of 0.011 and 0.024 Ω cm² at 600 °C, as a comparison of 0.042 Ω cm² for the cation stoichiometric BCFZY. Excessive B‐site deficiencies, however, lead to the formation of impurity phases, which cause a block for charge transfer and, consequently, a reduction in electrode performance. Introducing a B‐site cation deficiency is a promising way to optimize the activity of perovskite oxides for ORR at reduced temperatures, but the degree of deficiency shall be carefully tuned.