Serum response factor promotes axon regeneration following spinal cord transection injury

Studies have snown that serum response factor is beneficaial for axonar regeneration of peripheral herves.However,Its role after central nervous system injury remains unclear. In this study,we established a rat model of T9-T10 spinal cord transection injury.We found that the expression of serum response factor in injured spinal cord gray matter neurons gradually increased with time,reached its peak on the 7^(th) day,and then gradually decreased.To investigate the role of serum response factor,we used lentivirus vecto rs to ove rexpress and silence serum response factor in spinal cord tissue.We found that overexpression of serum response factor promoted motor function recovery in rats with spinal cord injury.Qualitative observation of biotinylated dextran amine anterograde tra cing showed that ove rexpression of serum response factor increased nerve fibers in the injured spinal co rd.Additionally,transmission electron microscopy showed that axon and myelin sheath morphology was restored.Silencing serum response factor had the opposite effects of ove rexpression.These findings suggest that serum response factor plays a role in the recovery of motor function after spinal cord injury.The underlying mechanism may be related to the regulation of axonal regeneration.

Light Promotes Protein Stability of Auxin Response Factor 7#

Light is an environmental signaling,whereas Aux/IAA proteins and Auxin Response Factors(ARFs)are regulators of auxin signalling.Aux/IAA proteins are unstable,and their degradation dependents on 26S ubiquitin-proteasome and is promoted by Auxin.Auxin binds directly to a SCF-type ubiquitin-protein ligase,TIR1,facilitates the interaction between Aux/IAA proteins and TIR1,and then the degradation of Aux/IAA proteins.A few studies have reported that some ARFs are also unstable proteins,and their degradation is also mediated by 26S proteasome.In this study,by using of antibodies recognizing endogenous ARF7 proteins,we found that protein stability of ARF7 was affected by light.By expressing MYC tagged ARF activators in protoplasts,we found that degradation of ARF7 was inhibited by 26 proteasome inhibitors.In addition,at least ARF5 and ARF19 were also unstable proteins,and degradation of ARF5 via 26S proteasome was further confirmed by using stable transformed plants overexpressing ARF5 with a GUS tag.

Overexpression of the Watermelon Ethylene Response Factor ClERF069 in Transgenic Tomato Resulted in Delayed Fruit Ripening

Watermelon fruit undergoes distinct development stages with dramatic changes during fruit ripening.To date,the molecular mechanics of watermelon ripening remain unclear.Genetic and transcriptome evidences suggested that the ethylene response factor(ERF)gene ClERF069 may be an important candidate factor affecting watermelon fruit ripening.To dissect the roles of ClERF069 in fruit ripening,structure and phylogenetic analysis were performed using the amplified full-length sequence.Normal-ripening watermelon 97103,non-ripening watermelon PI296341-FR and the RIL population were used to analyze ClERF069 expression dynamics and the correlation with fruit ripening indexs.The results indicated that ClERF069 belongs to ERF family group VI and show high homology(83%identity)to melon ERF069-like protein.ClERF069 expression in watermelon flesh was negatively correlated with fruit lycopene content and sugar content during fruit ripening progress.Further transgenic evidences indicated that overexpression of 35S:ClERF069 in tomato noticeably delayed the ripening process up to 5.2 days.Lycopene,β-carotenoid accumulation patterns were altered and ethylene production patterns in transgenic fruits was significantly delayed during fruit ripening.Taken together,watermelon ethylene response factor ClERF069 was concluded to be a negative regulator of fruit ripening.

Serum response factor:Look into the gut

Serum response factor(SRF) is a transcription factor that regulates many genes involved in cellular activities such as proliferation,migration,differentiation,angiogenesis,and apoptosis.Although it has only been known for about two decades,SRF has been studied extensively.To date,over a thousand SRF studies have been published,but it still remains a hot topic.Due to its critical role in mesoderm-derived tissues,most of the SRF studies focused on muscle structure/function,cardiovascular development/maintenance,and smooth muscle generation/repair.Recently,SRF has received more attention in the digestive field and several important discoveries have been made.This review will summarize what we have learned about SRF in the gastrointestinal tract and provide insights into possible future directions in this area.

Assessment of seismic design response factors of concrete wall buildings

To verify the seismic design response factors of high-rise buildings, five reference structures, varying in height from 20- to 60-stories, were selected and designed according to modern design codes to represent a wide range of concrete wall structures. Verified fiber-based analytical models for inelastic simulation were developed, considering the geometric nonlinearity and material inelasticity of the structural members. The ground motion uncertainty was accounted for by employing 20 earthquake records representing two seismic scenarios, consistent with the latest understanding of the tectonic setting and seismicity of the selected reference region （UAE）. A large number of Inelastic Pushover Analyses （IPAs） and Incremental Dynamic Collapse Analyses （IDCAs） were deployed for the reference structures to estimate the seismic design response factors. It is concluded that the factors adopted by the design code are adequately conservative. The results of this systematic assessment of seismic design response factors apply to a wide variety of contemporary concrete wall buildings with various characteristics.

Advances in structure and function of auxin response factor in plants

Auxin is a crucial phytohormone that has various effects on the regulators of plant growth and development.Auxin signal transduction is mainly controlled by two gene families:auxin response factor(ARF)and auxin/indole-3-acetic acid(Aux/IAA).ARFs are plant-specific transcription factors that bind directly to auxin response elements in the promoters of auxinresponsive genes.ARF proteins contain three conserved regions:a conserved N-terminal B3DNA-binding domain,a variable intermediate middle region domain that functions in activation or repression,and a C-terminal domain including the Phox and Bem1p region for dimerization,similar to theⅢandⅣelements of Aux/IAA,which facilitate protein–protein interaction through homodimerization of ARF proteins or heterodimerization of ARF and Aux/IAA proteins.In the two decades following the identification of the first ARF,23 ARF members have been identified and characterized in Arabidopsis.Using whole-genome sequencing,22,25,23,25,and 36 ARF genes have been identified in tomato,rice,wheat,sorghum,and maize,respectively,in addition to which the related biofunctions of some ARFs have been reported.ARFs play crucial roles in regulating the growth and development of roots,leaves,flowers,fruits,seeds,responses to biotic and abiotic stresses,and phytohormone signal crosstalk.In this review,we summarize the research progress on the structures and functions of ARFs in Arabidopsis,tomato,and cereal crops,to provide clues for future basic research on phytohormone signaling and the molecular design breeding of crops.

Ethylene Response Factor TERF1 Enhances Glucose Sensitivity in Tobacco through Activating the Expression of Sugar-related Genes

Ethylene response factor （ERF） proteins are important plant-specific transcription factors. Increasing evidence shows that ERF proteins regulate plant pathogen resistance, abiotic stress response and plant development through interaction with different stress responsive pathways. Previously, we revealed that overexpression of TERF1 in tobacco activates a cluster gene expression through interacting with GCC box and dehydration responsive element （DRE）, resulting in enhanced sensitivity to abscisic acid （ABA） and tolerance to drought, and dark green leaves of mature plants, indicating that TERF1 participates in the integration of ethylene and osmotic responses. Here we further report that overexpression of TERF1 confers sugar response in tobacco. Analysis of the novel isolated tomato TERF1 promoter provides information indicating that there are many cis-acting elements, including sugar responsive elements （SURE） and W box, suggesting that TERF1 might be sugar inducible. This prediction is confirmed by results of reverse transcription-polymerase chain reaction amplification, indicating that transcripts of TERF1 are accumulated in tomato seedlings after application of glucose. Further investigation indicates that the expression of TERF1 in tobacco enhances sensitivity to glucose during seed germination, root and seedling development, showing a decrease of the fresh weight and root elongation under glucose treatment. Detailed investigations provide evidence that TERF1 interacts with the sugar responsive cis-acting element SURE and activates the expression of sugar response genes, establishing the transcriptional regulation of TERF1 in sugar response. Therefore, our results deepen our understanding of the glucose response mediated by the ERF protein TERF1 in tobacco.

Phosphorylation of an ethylene response factor by MPK3/MPK6 mediates negative feedback regulation of pathogen-induced ethylene biosynthesis in Arabidopsis

Plants under pathogen attack produce high levels of the gaseous phytohormone ethylene to induce plant defense responses via the ethylene signaling pathway.The 1-aminocyclopropane-1-carboxylate synthase(ACS)is a critical rate-limiting enzyme of ethylene biosynthesis.Transcriptional and post-translational upregulation of ACS2 and ACS6 by the mitogen-activated protein kinases MPK3 and MPK6 are previously shown to be crucial for pathogen-induced ethylene biosynthesis in Arabidopsis.Here,we report that the fungal pathogen Botrytis cinerea-induced ethylene biosynthesis in Arabidopsis is under the negative feedback regulation by ethylene signaling pathway.The ethylene response factor ERF1 A is further found to act downstream of ethylene signaling to negatively regulate the B.cinerea-induced ethylene biosynthesis via indirectly suppressing the expression of ACS2 and ACS6.Interestingly,ERF1 A is shown to also upregulate defensin genes directly and therefore promote Arabidopsis resistance to B.cinerea.Furthermore,ERF1 A is identified to be a substrate of MPK3 and MPK6,which phosphoactivate ERF1 A to enhance its functions in suppressing ethylene biosynthesis and inducing defensin gene expression.Taken together,our data reveal that ERF1 A and its phosphorylation by MPK3/MPK6 not only mediate the negativefeedback regulation of the B.cinerea-induced ethylene biosynthesis,but also upregulate defensin gene expression to increase Arabidopsis resistance to B.cinerea.

Research Progresses on Auxin Response Factors

Auxin response factors （ARFs）, a family of transcription factors, have been discovered recently. The ARFs bind specifically to the auxin response elements （AuxREs） within promoters of primary auxin responsive genes and function as activators or repressors. The ARFs contain three domains, namely a conserved Nterminal DNA-binding domain, a non-conserved middle region, and a conserved C-termlnal dlmerlzatlon domaln. The ARFs can form a protein complex with auxin/indoleacetic acid through homodimerization or heterodlmerization. The particular protein-protein interaction may play a key role in moduiating the expression of early auxin responsive genes. The identification of ARF mutations in Arabidopsis helps to demonstrate/dissect the function of ARFs in the normal growth and development of plants. Phylogenetic analysis also reveals some interesting protein evolution points in the ARF family.

INVESTIGATION ON THE RESPONSE FACTORS OF CONCENTRATION DETECTORS WITHIN SEC PROCESS

The response factors of refractive index（RI） and ultraviolet（UV） detectors of size exclusion chromatography （SEC） defined as the ratio of area of output signal to the mass of injected sample are studied and analyzed by using five narrowly distributed polystyrene（PS） standard samples with known molar masses.It is found that the individual response factor for a given sample varies with the concentration of the injected solution within a limited range bounded by an upper and a lower limiting response factor values.This variation reveals the conformational change of the polymer chains with the concentration of the injected solution.The dynamic contact concentrations c_s of the PS samples derived from the response factor data are in good accordance with those reported earlier by other methods.The physical meanings of the signals of the two detectors are further analyzed and theoretically formulated.The solvation of the polymer chain and the conformation changes play an important role in these detecting systems.Both of the solvation number of the structural repeating unit and the extra embedded solvent due to cluster forming in higher concentrations could be deduced from the variation of response factor with the concentration of the injected solution.

Response reduction factor of irregular RC buildings in Kathmandu valley

Most current seismic design includes the nonlinear response of a structure through a response reduction factor （R）. This allows the designer to use a linear elastic force-based approach while accounting for nonlinear behavior and deformation limits. In fact, the response reduction factor is used in modem seismic codes to scale down the elastic response of a structure. This study focuses on estimating the actual ＇R＇ value for engineered design/construction of reinforced concrete （RC） buildings in Kathmandu valley. The ductility and overstrength of representative RC buildings in Kathmandu are investigated. Nonlinear pushover analysis was performed on structural models in order to evaluate the seismic performance of buildings. Twelve representative engineered irregular buildings with a variety of characteristics located in the Kathmandu valley were selected and studied. Furthermore, the effects of overstrength on the ductility factor, beam column capacity ratio on the building ductility, and load path on the response reduction factor, are examined. Finally, the results are further analyzed and compared with different structural parameters of the buildings.

Poly(ADP-ribosyl)ation of Apoptosis Antagonizing Transcription Factor Involved in Hydroquinone-Induced DNA Damage Response

The molecular mechanism of DNA damage induced by hydroquinone （HQ） remains unclear. Poly（ADP-ribose） polymerase-1 （PARP-1） usually works as a DNA damage sensor, and hence, it is possible that PARP-1 is involved in the DNA damage response induced by HQ. In TK6 cells treated with HQ, PARP activity as well as the expression of apoptosis antagonizing transcription factor （AATF）, PARP-1, and phosphorylated H2AX （v-H2AX） were maximum at 0.5 h, 6 h, 3 h, and 3 h, respectively. To explore the detailed mechanisms underlying the prompt DNA repair reaction, the above indicators were investigated in PARP-l-silenced cells. PARP activity and expression of AATF and PARP-1 decreased to 36%, 32%, and 33%, respectively, in the cells; however, y-H2AX expression increased to 265%. Co-immunoprecipitation （co-IP） assays were employed to determine whether PARP-1 and AATF formed protein complexes. The interaction between these proteins together with the results from IP assays and confocal microscopy indicated that poly（ADP-ribosyl）ation {PARylation） regulated AATF expression, in conclusion, PARP-1 was involved in the DNA damage repair induced by HQ via increasing the accumulation of AATF through PARylation.

Identification and characterization of MeERF genes and their targets in pathogen response by cassava(Manihot esculenta)

Cassava,Manihot esculenta Crantz (Me),is a major dietary source of calories for over 700 million people in tropical regions.The production of cassava is constantly threatened by cassava bacterial blight (CBB),caused by Xanthomonas axonopodis pv.manihotis (Xam).The gene resources for CBB-resistant breeding of cassava are limited.In model plant species,ethylene response factors play important roles in response to pathogen infection.In this study,cassava ethylene response factors (MeERFs) were identified and characterized as the first step in studying their potential for CBB-resistant breeding of cassava.In the cassava genome 155 MeERFs were identified,of which 23 were induced by Xam infection.The promoter regions of204 genes harbored GCC-box that had the potential to interact with MeERFs.Using 37 transcriptomes derived from Xam infection treatment,four gene co-expression modules for the MeERFs and GCC-box containing genes were constructed.Six MeERFs were associated with two GCC-box containing genes:transcription initiation factor TFIIE subunit beta (MeTFIIE),and histone-lysine N-methyltransferase ASHR1 (MeASHR1).Dual-luciferase reporter assays showed that MeERF10 and MeERF58 positively regulated Me TFIIE;MeERF137 negatively regulated Me TFIIE;MeERF10 and MeERF137 positively regulated Me ASHR1;and MeERF35 negatively regulated Me ASHR1.The four MeERFs may mediate pathogen response by regulating the expression of the two GCC-box containing genes.

Predictive active control of building structures using LQR and artificial intelligence

This study presents a neural network-based model for predicting linear quadratic regulator(LQR)weighting matrices for achieving a target response reduction.Based on the expected weighting matrices,the LQR algorithm is used to determine the various responses of the structure.The responses are determined by numerically analyzing the governing equation of motion using the state-space approach.For training a neural network,four input parameters are considered:the time history of the ground motion,the percentage reduction in lateral displacement,lateral velocity,and lateral acceleration,Output parameters are LQR weighting matrices.To study the effectiveness of an LQR-based neural network(LQRNN),the actual percentage reduction in the responses obtained from using LQRNN is compared with the target percentage reductions.Furthermore,to investigate the efficacy of an active control system using LQRNN,the controlled responses of a system are compared to the corresponding uncontrolled responses.The trained neural network effectively predicts weighting parameters that can provide a percentage reduction in displacement,velocity,and acceleration close to the target percentage reduction.Based on the simulation study,it can be concluded that significant response reductions are observed in the active-controlled system using LQRNN.Moreover,the LQRNN algorithm can replace conventional LQR control with the use of an active control system.

The Openness Degree Study of the Jiaoshiba Shale Gas, Sichuan Basin, China–Potential Factor Responsible for Reversed Isotope Series

Objective Reversed alkane δ;C and δ;H values in many prolific shale plays all over the world have aroused much attention in the study of the formation mechanism of reversed isotope series in alkanes in the past few years（Zou Caineng et al., 2016）. Although many researchers have put forward different hypotheses, the mechanism has not been well understood yet. The openness degree of oil and gas system

Extreme value of wind-excited response considering influence of bandwidth

This paper addresses the peak factors of wind- excited responses including alongwind, acrosswind tall building responses and vortex-induced vibration considering the bandwidth parameter. The influence of bandwidth parameter on the peak factor is investigated using advanced upcrossing theory taking the bandwidth influence into account. Results show that Davenport＇s formula without consideration of bandwidth parameter servers well in general. However, the advanced upcrossing theory leads to a better prediction of the peak factor of wind-induced response of very lightly damped buildings.

Edaravone protects against oxygen-glucose-serum deprivation/restoration-induced apoptosis in spinal cord astrocytes by inhibiting integrated stress response

We previously found that oxygen-glucose-serum deprivation/restoration（OGSD/R） induces apoptosis of spinal cord astrocytes, possibly via caspase-12 and the integrated stress response, which involves protein kinase R-like endoplasmic reticulum kinase（PERK）, eukaryotic initiation factor 2-alpha（eIF2α） and activating transcription factor 4（ATF4）. We hypothesized that edaravone, a low molecular weight, lipophilic free radical scavenger, would reduce OGSD/R-induced apoptosis of spinal cord astrocytes. To test this, we established primary cultures of rat astrocytes, and exposed them to 8 hours/6 hours of OGSD/R with or without edaravone（0.1, 1, 10, 100 μM） treatment. We found that 100 μM of edaravone significantly suppressed astrocyte apoptosis and inhibited the release of reactive oxygen species. It also inhibited the activation of caspase-12 and caspase-3, and reduced the expression of homologous CCAAT/enhancer binding protein, phosphorylated（p）-PERK, p-eIF2α, and ATF4. These results point to a new use of an established drug in the prevention of OGSD/R-mediated spinal cord astrocyte apoptosis via the integrated stress response.

Plant fertility defects induced by the enhanced expression of microRNA167

The plant hormone auxin plays a critical role in regulating plant growth and development. Recent advances have been made in the understanding of auxin response pathways, primarily by the characterization of auxin response mutants in Arabidopsis. In addition, microRNAs （miRNAs） have been shown to be critical regulators of genes important for normal plant development and physiology. However, little is known about possible interactions between miRNAs and hormonal signaling during normal development. Here we show that an Arabidopsis microRNA, miR167, which has a complementary sequence to a portion of the A UXINRESPONSE FACTOR6 （ARF6） and ARF8 mRNAs, can cause transcript degradation for ARF8, but not for ARF6. We report phenotypic characterizations of 35S：：MIR167b transgenic lines, and show that severe 35S：：MIR167b transgenic lines had phenotypes similar to those of an arf6 arf8 double mutant. The transgenic phenotypes suggest that miR167 may repress ARF6 at the level of translation. We demonstrate that the transgenic plants are defective in all four whods of floral organs. In the transgenic flowers, filaments were abnormally short, anthers could not properly release pollen, and pollen grains did not germinate. Our results provide an important link between the miRNA-mediated regulatory pathway of gene expression and the auxin signaling network promoting plant reproductive development.

COMPOSITION DETERMINATION OF BINARY POLYMER MIXTURES BY SIZE EXCLUSION CHROMATOGRAPHY WITH LIGHT SCATTERING DETECTION

Base on the principle of absolute quantification of size exclusion chromatography （SEC）, a light scattering （LS） detector coupled with a concentration detector （refractive index detector） is utilized to determine the compositions of complicated binary mixtures. A theoretical analysis predicts that the response factors for both LS and RI detectors are linear functions with the composition of any specified polymer mixtures in the binary polymer mixtures. Two pairs of complicated binary mixtures were used to test the theory mentioned in the present paper, and the experimental results show an excellent accordance with the theory.

New Role for an Old Rule: N-end Rule-Mediated Degradation of Ethylene Responsive Factor Proteins Governs Low Oxygen Response in Plants

The N-end rule pathway regulates protein degradation, which depends on exposed N-terminal sequences in prokaryotes and eukaryotes. In plants, conserved and specific enzymes stimulate selective proteolysis. Although a number of developmental and growth phenotypes have been reported for mutants in the N-end rule, its function has remained unrelated to specific physiological pathways. The first report of the direct involvement of the N-end rule in stress responses focused on hypoxic signaling and how the oxygen-dependent oxidation of cystein promotes the N-end rule-mediated degradation of ethylene responsive factor （ERF）-VII proteins, the master regulators of anaerobic responses. It has been suggested that plants have evolved specific mechanisms to tune ERF-VII availability in the nucleus. In this review, we speculate that ERF-VII proteins are reversibly protected from degradation via membrane sequestration. The oxidative response in plants subjected to anoxic conditions suggests that reactive oxygen and nitrogen species （reactive oxygen species and reactive nitrogen species） may interact or interfere with the N-end rule pathway-mediated response to hypoxia.