Screening and Identification of ClpE Interaction Proteins in Streptococcus pneumoniae by a Bacterial Two-Hybrid System and Co-immunoprecipitation

WenJuan Yan,YingYing Cai,Qun Zhang,YuSi Liu,WenChun Xu,YiBing Yin,YuJuan He,Hong Wang,XueMei Zhang 한국미생물학회 2013 The journal of microbiology Vol.51 No.4

Hsp100/Clp proteins have crucial functions in the protein quality control, stress tolerance, and virulence of many pathogenic bacteria. ClpE is an important virulence factor involved in adherence and invasion in Streptococcus pneumoniae. To explore the underlying mechanism, we screened ClpE interaction proteins using a bacterial two-hybrid system and co-immunoprecipitation. We used ClpE as bait and constructed the pBT-ClpE bait plasmid for two-hybrid screening. Then, we constructed ClpE::GFP fusion for co-immunoprecipitation screening using anti-GFP monoclonal antibody. We obtained eight potential ClpE interaction proteins,including carbamoyl-phosphate synthase, pyruvate oxidase (SpxB), phosphoenolpyruvate-protein phosphotransferase,aminopeptidase N (pepN), L-lactate dehydrogenase, ribosomal protein S4, sensor histidine kinase (SPD_2019), and FtsW (a cell division protein). FtsW, SpxB, pepN, and SPD_2019 were confirmed to interact with ClpE using Bacterial Two-hybrid or Co-immunoprecipitation. Morphologic observations found that ΔclpE strain existed in abnormal division. β-Galactosidase activity assay suggested that ClpE contributed to the degradation of FtsW. Furthermore, FtsW could be induced by heat shock. The results suggested that ClpE might affect cell division by regulating the level of FtsW. These data may provide new insights in studying the role of ClpE in S. pneumoniae.

SP0454, A Putative Threonine Dehydratase, Is Required For Pneumococcal Virulence In Mice

WenJuan Yan,Hong Wang,WenChun Xu,KaiFeng Wu,Run Yao,XiuYu Xu,Jie Dong,YanQing Zhang,Wen Zhong,XueMei Zhang 한국미생물학회 2012 The journal of microbiology Vol.50 No.3

Increasing pressure in antibiotic resistance and the requirement for the design of new vaccines are the objectives of clarifying the putative virulence factors in pneumococcal infection. In this study, the putative threonine dehydratase sp0454 was inactivated by erythromycin-resistance cassette replacement in Streptococcus pneumoniae CMCC 31203 strain. The sp0454 mutant was tested for cell growth, adherence, colonization, and virulence in a murine model. The Δsp0454 mutant showed decreased ability for colonization and impaired ability to adhere to A549 cells. However, the SP0454 polypeptide or its antiserum did not affect pneumococcal CMCC 31203 adhesion to A549 cells. The sp0454 deletion mutant was less virulent in a murine intranasal infection model. Real-time RT-PCR analysis revealed significant decrease of the pneumococcal surface antigen A expression in the sp0454 mutant. These results suggest that SP0454 contributes to virulence and colonization, which could be explained in part by modulating the expression of other virulence factors, such as psaA in pneumococcal infection.

Review : Characterizing LipR from Pseudomonas sp. R0-14 and Applying in Enrichment of Polyunsaturated Fatty Acids from Algal Oil

( Wenjuan Yang ),( Li Xu ),( Houjin Zhang ),( Yunjun Yan ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.11

In this study, Pseudomonas R0-14, which was isolated from Arctic soil samples, showed a clear halo when grown on M9 medium agarose plates containing olive oil-rhodamine B as substrate, suggesting that it expressed putative lipase(s). A putative lipase gene, lipR, was cloned from R0-14 by genome walking and Touchdown PCR. lipR encodes a 562-amino-acid polypeptide showing a typical α/β hydrolase structure with a catalytic triad consisting of Ser153-Asp202-His260 and one α-helical lid (residues 103-113). A phylogenetic analysis revealed that LipR belongs to the lipase subfamily I.3. LipR was successfully expressed in Escherichia coli, purified, and biochemically characterized. Recombinant LipR exhibited its maximum activity towards p-nitrophenyl butyrate at pH 8.5 and 60oC with a Km of 0.37 mM and a kcat of 6.42 s-1. It retained over 90% of its original activity after incubation at 50oC for 12 h. In addition, LipR was activated by Ca2+, Mg2+, Ba2+, and Sr2+, while strongly inhibited by Cu2+, Zn2+, Mn2+, and ethylenediaminetetraacetic acid. Moreover, it showed a certain tolerance to organic solvents, including acetonitrile, isopropanol, acetone, methanol, and tert-butanol. When algal oil was hydrolyzed by LipR for 24 h, there was an enrichment of n-3 long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (1.22%, 1.65-fold), docosapentaenoic acid (21.24%, 2.04-fold), and docosahexaenoic acid (36.98%, 1.33-fold), and even a certain amount of diacylglycerols was also produced. As a result, LipR has great prospect in industrial applications, especially in food and/or cosmetics applications.

Aerodynamic force characteristics and galloping analysis of iced bundled conductors

Wenjuan Lou,M.F. Huang,Jiang Lv,Lun Yang,Dong Yan 한국풍공학회 2014 한국풍공학회지 Vol.18 No.2

Aerodynamic characteristics of crescent and D-shape bundled conductors were measured by high frequency force balance technique in the wind tunnel. The drag and lift coefficients of each sub-conductor and the whole bundled conductors were presented under various attack angles of wind. The galloping possibility of bundled conductors is discussed based on the Den Hartog criterion. The influence of icing thickness, initial ice accretion angle and sub-conductor on the aerodynamic properties were investigated. Based on the measured aerodynamic force coefficients, a computationally efficient finite element method is also implemented to analyze galloping of iced bundled conductors. The analysis results show that each sub-conductor of the bundled conductor has its own galloping feature due to the use of aerodynamic forces measured separately for every single sub-conductors.

Investigation on Material Removal Mechanisms in Photocatalysis-Assisted Chemical Mechanical Polishing of 4H–SiC Wafers

Yan He,Zewei Yuan,Shuyuan Song,Xingjun Gao,Wenjuan Deng 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.5

Photocatalysis-assisted chemical mechanical polishing, in which the photocatalysis oxidation and silica abrasives polishing are combined, is a novel finishing technique for 4H–SiC wafer. This paper characterizes the effect of pressure and abrasives on the MRR and surface quality and discusses mechanical and chemical interaction based three slurries that resulted in maximum material removal rate (1.18 μm/h) with PCMP slurry. The polished silicon carbide wafer was examined with atomic force microscope, transmission electron microscope and X-ray photoelectron spectroscopy for surface quality and material removal mechanism. The results show that an atomically smooth and fl at 4H–SiC (0001) surface (Ra about 0.247 nm) was obtained by PCMP. The interface of crystal and amorphous layer of 4H–SiC wafer was flat without introducing crystallographic subsurface damage, and the atoms and lattice fringes of the crystal layer are arranged in regular order. The existence of a thin silicon oxycarbide layer, which are various forms of functional groups such as Si–C, Si–C–O, Si–O, Si 4 C 4 O 4 , C–O, and C = O, at the interface. And, it also demonstrates that the amorphous layer is composed of oxide layer (4–6 nm) and distorted layer. The silicon carbide surface is mechanically activated, oxidized and mechanically removed in turn, which is the main method of material removal.

The Nedd8‐activating enzyme inhibitor MLN 4924 ( TAK ‐924/Pevonedistat) induces apoptosis via c‐Myc‐Noxa axis in head and neck squamous cell carcinoma

Zhang, Wenjuan,Liang, Yupei,Li, Lihui,Wang, Xiaofang,Yan, Zi,Dong, Changsheng,Zeng, Mu‐,Sheng,Zhong, Qian,Liu, Xue‐,Kui,Yu, Jinha,Sun, Shuyang,Liu, Xiaojun,Kang, Jihui,Zhao, Hu,Jeong, Lak BLACKWELL SCIENTIFIC PUBLICATIONS 2019 CELL PROLIFERATION Vol.52 No.2

Aerodynamic force characteristics and galloping analysis of iced bundled conductors

Lou, Wenjuan,Lv, Jiang,Huang, M.F.,Yang, Lun,Yan, Dong Techno-Press 2014 Wind and Structures, An International Journal (WAS Vol.18 No.2

Aerodynamic characteristics of crescent and D-shape bundled conductors were measured by high frequency force balance technique in the wind tunnel. The drag and lift coefficients of each sub-conductor and the whole bundled conductors were presented under various attack angles of wind. The galloping possibility of bundled conductors is discussed based on the Den Hartog criterion. The influence of icing thickness, initial ice accretion angle and sub-conductor on the aerodynamic properties were investigated. Based on the measured aerodynamic force coefficients, a computationally efficient finite element method is also implemented to analyze galloping of iced bundled conductors. The analysis results show that each sub-conductor of the bundled conductor has its own galloping feature due to the use of aerodynamic forces measured separately for every single sub-conductors.

LKB1 on POMC neurons affect the formation of diet-induced obesity by regulating the expression of HDAC1

Zhang Yan,Wu Zhaoxia,Xi Pengjiao,Wang Haomin,Zhu Wenjuan,Tian Derun 한국유전학회 2022 Genes & Genomics Vol.44 No.4

Background: Obesity is considered a major public health issue worldwide. Liver Kinase B1 (LKB1) is a serine/threonine kinase, peripheral LKB1 is involved in obesity by regulating adipogenesis, but the role of central LKB1 in the development of obesity remains unclear. Objective: This study aims to explore the main role of LKB1 in POMC neurons on obesity, and reveal the underlying mechanism of central LKB1 affecting obesity through quantitative proteomics. Methods: We constructed POMC neuron specific LKB1 knockout mice (PomcLkb1 KO) and exposed them to high fat diet intervention for three months. The effect of LKB1 knockout on obesity was evaluated by monitoring body weight, food intake and measuring fat content. The hypothalamus tissues were collected for proteomic analysis and validated by RT-PCR. Results: The degree of obesity was aggravated in PomcLkb1 KO mice fed with high fat diet. Proteomic results showed that only Histone deacetylase 1 (HDAC1) was down-regulated in the hypothalamus of PomcLkb1 KO mice. Our research also found that LKB1 knockout on POMC neurons led to reduction of Peroxisome proliferator-activated receptor γ (PPARγ). Meanwhile, the software predicted that the transcription factor PPARγ binds to the HDAC1 promoter. Therefore, we speculated that central LKB1 may regulate diet-induced obesity development by influencing HDAC1/PPARγ expression. Conclusion: We firstly found that central LKB1 may affect the development of obesity by regulating the expression of HDAC1, which provides a new idea for the central regulatory mechanism of obesity.

Synthesis of (Imido)vanadium(V) Complexes Containing 8-(2,6-Dimethylanilide)-5,6,7-trihydroquinoline Ligands: Highly Active Catalyst Precursors for Ethylene Dimerization

Tang, Xiao-Yan,Igarashi, Atsushi,Sun, Wen-Hua,Inagaki, Akiko,Liu, Jingyu,Zhang, Wenjuan,Li, Yue-Sheng,Nomura, Kotohiro American Chemical Society 2014 Organometallics Vol.33 No.4

<P>A series of (imido)vanadium(V) dichloride complexes containing 8-(2,6-dimethylanilide)-5,6,7-trihydroquinoline ligands of the type V(NR)Cl<SUB>2</SUB>[8-(2,6-Me<SUB>2</SUB>C<SUB>6</SUB>H<SUB>3</SUB>)N(C<SUB>9</SUB>H<SUB>10</SUB>N)] (R = Ad (<B>3</B>), 2-MeC<SUB>6</SUB>H<SUB>4</SUB> (<B>4</B>), 2,6-Me<SUB>2</SUB>C<SUB>6</SUB>H<SUB>3</SUB> (Ar, <B>5</B>)) have been prepared and identified, and their structures have been determined by X-ray crystallographic analysis. The ethylene dimerization catalyst generated from complex <B>3</B> upon treatment with an excess amount of MAO exhibited remarkable catalytic activities (e.g. TOF = 9600000 h<SUP>–1</SUP> (2670 s<SUP>–1</SUP>), Al/V = 4000 (molar ratio)), affording 1-butene as the major product (95.0–99.4%). The activities of <B>3</B> and <B>4</B> were higher than those exhibited by the corresponding 2-(anilide)methylpyridine analogues; <B>3</B> showed higher 1-butene selectivity than the others and the activity did not decrease remarkably at 50 °C. Complex <B>5</B> afforded a mixture of polymer and oligomers with low activities, suggesting that a fine tuning of both the imido and the anionic donor ligands plays an essential role in this catalysis.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orgnd7/2014/orgnd7.2014.33.issue-4/om401119y/production/images/medium/om-2013-01119y_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/om401119y'>ACS Electronic Supporting Info</A></P>

Effects of supplemented culture media from solid-state fermented Isaria cicadae on performance, serum biochemical parameters, serum immune indexes, antioxidant capacity and meat quality of broiler chickens

Liu, Shaoshuai,Yan, Wenjuan,Ma, Chang,Liu, Yajing,Gong, Limin,Levesque, Crystal,Dong, Bing Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.4

Objective: The objective of this study was to investigate effects of supplementation of culture media from solid-state fermented Isaria cicadae (I. cicadae) on performance, serum biochemical parameters, serum immune indexes, antioxidant capacity and meat quality of broiler chickens. Methods: A total of 648 Arbor Acres male broiler chickens(1 d; average body weight, 42.93±0.47 g) were randomly assigned to 6 treatments, each with six replicates and 18 broiler chickens per replicate. Broiler chickens were fed phase I (d 1 to 21) and phase II (d 22 to 42) diets. The phase I diets were corn and soybean-meal based diets supplemented with 0%, 2%, 4%, 6%, 8%, or 10% culture media from solid-state fermented I. cicadae respectively. The phase II diets were corn and soybean-meal based diets supplemented with 0%, 1.33%, 2.67%, 4.00%, 5.32%, or 6.67% culture media from solid-state fermented I. cicadae respectively. Results: In phase I, the broiler chickens with the supplementation of culture media had increased body weight gain and feed intake (linear and quadratic, p<0.05) with increasing inclusion of culture media. The levels of serum total antioxidant capacity (T-AOC), glutathione (GSH) and superoxide dismutase (SOD) increased linearly (p<0.05). In phase II, levels of serum T-AOC and interleukin-1β increased linearly (p<0.05), and GSH increased (p<0.05). In the kidney, GSH and glutathione peroxidase (GSH-Px) concentrations increased (linear and quadratic, p<0.05) and SOD concentration increased linearly (p<0.05). Compared to the control, shear force and drip loss of breast muscle decreased (linear and quadratic, p<0.05). Drip loss of leg muscle decreased linearly and quadratically (p<0.05). Conclusion: Dietary supplementation of culture media from solid-state fermented I.cicadae which was enriched in both wheat and residual bioactive components of I. cicadae enhanced the growth performance of broiler chickens. It also improved body anti-oxidative status and contributed to improve broiler meat quality.