Biochemical and spectroscopic properties of Brucella microti glutamate decarboxylase, a key component of the glutamate-dependent acid resistance system
Publication date: Available online 17 March 2015 Source:FEBS Open Bio Author(s): Gaia Grassini , Eugenia Pennacchietti , Francesca Cappadocio , Alessandra Occhialini , Daniela De Biase In orally acquired bacteria, the ability to counteract extreme acid stress (pH ⩽ 2.5) ensures survival during transit through the animal host stomach. In several neutralophilic bacteria, the glutamate-dependent acid resistance system (GDAR) is the most efficient molecular system in conferring protection from acid stress. In Escherichia coli its structural components are either of the two glutamate decarboxylase isoforms (GadA, Gad...
Source: FEBS Open Bio - March 17, 2015 Category: Molecular Biology Source Type: research
Design and evaluation of a peptide-based immunotoxin for breast cancer therapeutics
Publication date: Available online 14 March 2015 Source:FEBS Open Bio Author(s): Kelsey J. Weigel , Luqun Shen , Clayton L. Thomas , Daniel Alber , Lauren Drapalik , Zachary T. Schafer , Shaun W. Lee Immunotoxins are chimeric proteins comprising a specific cellular targeting domain linked to a cytotoxic factor. Here we describe the design and use of a novel, peptide-based immunotoxin that can initiate selective cytotoxicity on ErbB2-positive cells. ErbB2 is a receptor tyrosine kinase that is overexpressed in the tumor cells of approximately 30% of breast cancer patients. Immunotoxin candidates were designed to i...
Source: FEBS Open Bio - March 14, 2015 Category: Molecular Biology Source Type: research
Characterization of G protein coupling mediated by the conserved D1343.49 of DRY motif, M2416.34, and F2516.44 residues on human CXCR1
The objective of this study was to elucidate the role of critical amino acid residues on TM3 near intracellular loop 2 (i2) and TM6 near intracellular loop 3 (i3), including S1323.47 (Baldwin location), D1343.49, M2416.34, and F2516.44, in G protein coupling and CXCR1 activation. The results demonstrate that mutations of D1343.49 at DRY motif of CXCR1 (D134N and D134V) completely abolished the ligand binding and functional response of the receptor. Additionally, point mutations at positions 241 and 251 between TM6 and i3 loop generated mutant receptors with modest constitutive activity via Gα15 signaling activation. Our r...
Source: FEBS Open Bio - March 12, 2015 Category: Molecular Biology Source Type: research
Insertion of sequences at the original provirus integration site of mouse ROSA26 locus using the CRISPR/Cas9 system
This study also revealed that anomalous and mosaic sequence insertions can occur with the CRISPR/Cas9 system. Graphical abstract (Source: FEBS Open Bio)
Source: FEBS Open Bio - March 11, 2015 Category: Molecular Biology Source Type: research
A generalised enzyme kinetic model for predicting the behaviour of complex biochemical systems
Publication date: Available online 9 March 2015 Source:FEBS Open Bio Author(s): Martin Kin Lok Wong , James Robert Krycer , James Geoffrey Burchfield , David Ernest James , Zdenka Kuncic Quasi steady-state enzyme kinetic models are increasingly used in systems modelling. The Michaelis Menten model is popular due to its reduced parameter dimensionality, but its low-enzyme and irreversibility assumption may not always be valid in the in vivo context. While the total quasi-steady state assumption (tQSSA) model eliminates the reactant stationary assumptions, its mathematical complexity is increased. Here, we propose t...
Source: FEBS Open Bio - March 9, 2015 Category: Molecular Biology Source Type: research
Characterization of G protein coupling mediated by the conserved D134(3.49) of DRY motif, M241(6.34), and F251(6.44) residues on human CXCR1
The objective of this study was to elucidate the role of critical amino acid residues on TM3 near intracellular loop 2 (i2) and TM6 near intracellular loop 3 (i3), including S1323.47 (Baldwin location), D1343.49, M2416.34, and F2516.44, in G protein coupling and CXCR1 activation. The results demonstrate that mutations of D1343.49 at DRY motif of CXCR1 (D134N and D134V) completely abolished the ligand binding and functional response of the receptor. Additionally, point mutations at positions 241 and 251 between TM6 and i3 loop generated mutant receptors with modest constitutive activity via Gα15 signaling activation. Our r...
Source: FEBS Open Bio - March 7, 2015 Category: Molecular Biology Source Type: research
Oligomer-dependent and -independent chaperone activity of sHsps in different stressed conditions
Publication date: Available online 5 March 2015 Source:FEBS Open Bio Author(s): Liang Liu , Jiyun Chen , Bo Yang , Yonghua Wang A great number of studies have proven that sHsps protect cells by inhibiting protein aggregation under heat stress, while little is known about their function to protect cells under acid stress. In this work, we show that Hsp20.1 and Hsp14.1 oligomers dissociated to smaller oligomeric species or even dimer/monomer at low pH (pH 4.0 and pH 2.0), whereas no prominent quaternary structural changes were seen at 50 °C. Both oligomers and smaller oligomeric species exhibited abilities to suppre...
Source: FEBS Open Bio - March 5, 2015 Category: Molecular Biology Source Type: research
A novel FBN2 mutation in a Chinese family with congenital contractural arachnodactyly
Publication date: Available online 5 March 2015 Source:FEBS Open Bio Author(s): Wei Liu , Ning Zhao , Xue-fu Li , Hong Wang , Yu Sui , Yong-ping Lu , Wen-hua Feng , Chao Ma , Wei-tian Han , Miao Jiang Congenital contractural arachnodactyly (CCA, OMIM: 121050) is an autosomal dominant condition that shares skeletal features with Marfan syndrome (MFS, OMIM: 154700), including contractures, arachnodactyly, dolichostenomelia, scoliosis, crumpled ears and pectus deformities but excluding the ocular and cardiovascular complications that characterize MFS. These two similar syndromes result from mutations in two gene...
Source: FEBS Open Bio - March 5, 2015 Category: Molecular Biology Source Type: research
Krüppel-like factor 4 induces apoptosis and inhibits tumorigenic progression in SK-BR-3 breast cancer cells
Publication date: Available online 2 March 2015 Source:FEBS Open Bio Author(s): Bing Wang , Ming-zhi Zhao , Nai-peng Cui , Dan-dan Lin , An-yi Zhang , Yan Qin , Cai-yun Liu , Wei-tao Yan , Jian-hong Shi , Bao-ping Chen Krüppel-like factor4 (KLF4) functions as either a tumor suppressor or an oncogene in different tissues by regulating the expression of various genes. The aim of this study was to reveal the functions of KLF4 in regulating breast cancer apoptosis, proliferation, and tumorigenic progression. KLF4 expression levels in breast cancer tissues and breast cancer cell lines were found to be much lower ...
Source: FEBS Open Bio - March 4, 2015 Category: Molecular Biology Source Type: research
Analysis of a temperature-sensitive mutation in Uba1: effects of the click reaction on subsequent immunolabeling of proteins involved in DNA replication
Publication date: Available online 3 March 2015 Source:FEBS Open Bio Author(s): Kimihiko Sugaya , Yoshie Ishihara , Sonoe Inoue In our previous study, a Met-to-Ile substitution at amino acid 256 in the catalytic domain of Uba1 was determined in temperature-sensitive CHO-K1 mutant tsTM3 cells, which exhibited chromosomal instability and cell-cycle arrest in the S to G2 phases with decreased DNA synthesis at the nonpermissive temperature, 39°C. Mutant cells were also characterized by a significant decrease of Uba1 in the nucleus with decreased ubiquitination activity at 39°C. Defects of ubiquitination activity in th...
Source: FEBS Open Bio - March 4, 2015 Category: Molecular Biology Source Type: research
Structure-based identification of functional residues in the nucleoside-2′-O-methylase domain of Bluetongue virus VP4 capping enzyme
In this study, we have exploited the structural information to identify the residues that are important for the catalytic activity of 2′-O MTase of VP4 and their influence on BTV replication. The effect of these mutations on GMP binding, guanylyltransferase (GTase) and methylase activities were analysed by a series of in vitro biochemical assays using recombinant mutant proteins; subsequently their effects on virus replication were assessed by introducing the same mutations in replicating viral genome using a reverse genetics system. Our data showed that single substitution mutations in the catalytic tetrad K-D-K-E were ...
Source: FEBS Open Bio - February 28, 2015 Category: Molecular Biology Source Type: research
Genome-wide analysis of the AP2/ERF gene family in Salix arbutifolia
In this study, a comprehensive computational analysis identified 173 AP2/ERF superfamily genes in willow (Salix arbutifolia), by using in silico cloning methods with the use of the AP2/ERF conserved domain amino acid sequence of Arabidopsis thaliana as a probe. Based on the results of phylogenetic analyses and the number of AP2/ERF domains, the AP2/ERF genes were classified into four groups: AP2, RAV, ERF and Soloist. The expression profile was analyzed using transcriptome data from different tissues. A comparative analysis of AP2/ERF superfamily genes among Salix, Populus and Arabidopsis was performed. The Salix DREB, AP2...
Source: FEBS Open Bio - February 26, 2015 Category: Molecular Biology Source Type: research
Structure-based identification of functional residues in the nucleoside-2’-O-methylase domain of Bluetongue virus VP4 capping enzyme
In this study, we have exploited the structural information to identify the residues that are important for the catalytic activity of 2’-O MTase of VP4 and their influence on BTV replication. The effect of these mutations on GMP binding, guanylyltransferase (GTase) and methylase activities were analysed by a series of in vitro biochemical assays using recombinant mutant proteins; subsequently their effects on virus replication were assessed by introducing the same mutations in replicating viral genome using a reverse genetics system. Our data showed that single substitution mutations in the catalytic tetrad K-D-K-E were ...
Source: FEBS Open Bio - February 24, 2015 Category: Molecular Biology Source Type: research
NADH oxidase and alkyl hydroperoxide reductase subunit C (peroxiredoxin) from Amphibacillus xylanus form an oligomeric assembly
In this study, we analyzed the effects of ammonium sulfate (AS) on the interaction between NADH oxidase and Prx by surface plasmon resonance analysis. The interaction between NADH oxidase and Prx was observed in the presence of AS. Dynamic light scattering assays were conducted while altering the concentration of AS and the ratio of NADH oxidase to Prx in the solutions. The results revealed that the two proteins formed a large oligomeric assembly, the size of which depended on the ionic strength of AS. The molecular mass of the assembly converged at approximately 300 kDa above 240 mM AS. The observed reduction rate of hydr...
Source: FEBS Open Bio - February 8, 2015 Category: Molecular Biology Source Type: research
Regulation of a serine protease homolog by the JNK pathway during thoracic development of Drosophila melanogaster
In this study, data are presented on a serine protease homolog (SPH), scarface. These data show that scarface is under regulatory control of the JNK pathway and that this pathway is both necessary and sufficient for its expression within the context of thoracic development. Consequently, down-regulation of scarface results in a thoracic-cleft phenotype that phenocopies the JNK pathway defect. A possible role of scarface during thoracic development in Drosophila is discussed. (Source: FEBS Open Bio)
Source: FEBS Open Bio - February 7, 2015 Category: Molecular Biology Source Type: research
