Notch signalling in the nucleus: roles of Mastermind-like (MAML) transcriptional coactivators
Notch signalling plays pivotal roles in development and homeostasis of all metazoan species. Notch is a receptor molecule that directly translates information of cell–cell contact to gene expression in the nucleus. Mastermind is a conserved and essential nuclear factor that supports the activity of Notch. Here, the past and current studies of the interplay between these factors are reviewed. (Source: Journal of Biochemistry)
Source: Journal of Biochemistry - February 22, 2016 Category: Biochemistry Authors: Kitagawa, M. Tags: JB Reviews Source Type: research
Regulation of antiviral innate immune signaling by stress-induced RNA granules
Activation of antiviral innate immunity is triggered by cellular pattern recognition receptors. Retinoic acid inducible gene-I (RIG-I)-like receptors (RLRs) detect viral non-self RNA in cytoplasm of virus-infected cells and play a critical role in the clearance of the invaded viruses through production of antiviral cytokines. Among the three known RLRs, RIG-I and melanoma differentiation-associated gene 5 recognize distinct non-self signatures of viral RNA and activate antiviral signaling. Recent reports have clearly described the molecular machinery underlying the activation of RLRs and interactions with the downstream ad...
Source: Journal of Biochemistry - February 22, 2016 Category: Biochemistry Authors: Yoneyama, M., Jogi, M., Onomoto, K. Tags: JB Reviews Source Type: research
Structure-based molecular design for thermostabilization of N-acetyltransferase Mpr1 involved in a novel pathway of L-arginine synthesis in yeast
Previously, N-Acetyltransferase Mpr1 was suggested to be involved in a novel pathway of l-arginine biosynthesis in yeast. Our recent crystallographic analysis demonstrated that the overall structure of Mpr1 is a typical folding among proteins in the Gcn5-related N-acetyltransferase superfamily, and also provided clues to the design of mutations for improvement of the enzymatic functions. Here, we constructed new stable variants, Asn203Lys- and Asn203Arg-Mpr1, which exhibited 2.4-fold and 2.2-fold longer activity half-lives than wild-type Mpr1, respectively, by structure-based molecular design. The replacement of Asn203 wit...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Nasuno, R., Hirase, S., Norifune, S., Watanabe, D., Takagi, H. Tags: Regular Papers Source Type: research
High-level expression and preparation of recombinant human fibrinogen as biopharmaceuticals
Fibrinogen is a large and complex glycoprotein containing two sets of each of three different chains (α, β and ). There have been no reports of high-level expression of fibrinogen at commercial levels using mammalian cultured cells such as CHO cells because of the difficulty in highly expressing a protein with such a complex structure. We achieved high-level (1.3 g/l or higher) expression of recombinant human fibrinogen using CHO DG44 cells by optimizing the expression system and culture conditions. We also succeeded in establishing a high-recovery preparation method for recombinant fibrinogen that rarely yields...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Hirashima, M., Imamura, T., Yano, K., Kawamura, R., Meta, A., Tokieda, Y., Nakashima, T. Tags: Regular Papers Source Type: research
Structural basis of Cu, Zn-superoxide dismutase amyloid fibril formation involves interaction of multiple peptide core regions
Cu, Zn-superoxide dismutase (SOD1), an enzyme implicated in the progression of familial amyotrophic lateral sclerosis (fALS), forms amyloid fibrils under certain experimental conditions. As part of our efforts to understand ALS pathogenesis, in this study we found that reduction of the intramolecular disulfide bond destabilized the tertiary structure of metal free wild-type SOD1 and greatly enhanced fibril formation in vitro. We also identified fibril core peptides that are resistant to protease digestion by using mass spectroscopy and Edman degradation analyses. Three regions dispersed throughout the sequence were detecte...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Ida, M., Ando, M., Adachi, M., Tanaka, A., Machida, K., Hongo, K., Mizobata, T., Yamakawa, M. Y., Watanabe, Y., Nakashima, K., Kawata, Y. Tags: Regular Papers Source Type: research
Sensitive, nonradioactive assay of phosphorylase kinase through measurement of enhanced phosphorylase activity towards fluorogenic dextrin
In this study, we developed a highly sensitive and nonradioactive assay for PhK activity by measuring the enhanced GP activity towards a pyridylaminated maltohexaose. The enhanced GP activity (A) was calculated by the following formula: A = A+ – A0, where A+ and A0 represent the GP activities of the PhK-treated and PhK-nontreated samples, respectively. Using a high-performance liquid chromatograph equipped with a fluorescence spectrophotometer, the product of GP activity could be isolated and quantified at 10 fmol. This method does not require the use of any radioactive compounds and only 1 µg of GPb per sample...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Miyagawa, D., Makino, Y., Sato, M. Tags: Regular Papers Source Type: research
Intracellular accumulation of indium ions released from nanoparticles induces oxidative stress, proinflammatory response and DNA damage
In this study, we evaluated the cellular effects of ITO nanoparticles (NPs), indium chloride (InCl3) and tin chloride (SnCl3) using human lung epithelial A549 cells. Transmission electron microscopy and inductively coupled plasma mass spectrometry were employed to study cellular ITO NP uptake. Interestingly, greater uptake of ITO NPs was observed, as compared with soluble salts. ITO NP species released could be divided into two types: ‘indium release ITO’ or ‘tin release ITO’. We incubated A549 cells with indium release ITO, tin release ITO, InCl3 or SnCl2 and investigated oxidative stress, proinfla...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Tabei, Y., Sonoda, A., Nakajima, Y., Biju, V., Makita, Y., Yoshida, Y., Horie, M. Tags: Regular Papers Source Type: research
Functional analysis of CedA based on its structure: residues important in binding of DNA and RNA polymerase and in the cell division regulation
In this study, we searched for the specific sites of CedA in binding of DNA and RNA polymerase and in repression of cell division inhibition. First, DNA sequence to which CedA preferentially binds was determined. Next, the several residues and β4 region in CedA C-terminal domain was suggested to specifically interact with the DNA. Moreover, we found that the flexible N-terminal region was required for tight binding to longer DNA as well as interaction with RNA polymerase. Based on these results, several cedA mutants were examined in ability for repressing dnaAcos cell division inhibition. We found that the N-terminal ...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Abe, Y., Fujisaki, N., Miyoshi, T., Watanabe, N., Katayama, T., Ueda, T. Tags: Regular Papers Source Type: research
Ethrel-stimulated prolongation of latex flow in the rubber tree (Hevea brasiliensis Muell. Arg.): an Hev b 7-like protein acts as a universal antagonist of rubber particle aggregating factors from lutoids and C-serum
In this study, a latex allergen Hev b 7-like protein in C-serum was identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI TOF MS). In vitro analysis showed that the protein acted as a universal antagonist of RP aggregating factors from lutoids and C-serum. Ethrel treatment obviously weakened the effect of C-serum on RP aggregation, which was closely associated with the increase in the level of the Hev b 7-like protein and the decrease in the level of the 37 kDa protein, as revealed by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE), western blotting an...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Shi, M.-J., Cai, F.-G., Tian, W.-M. Tags: Regular Papers Source Type: research
Class I Arfs (Arf1 and Arf3) and Arf6 are localized to the Flemming body and play important roles in cytokinesis
Small GTPases play important roles in various aspects of cell division as well as membrane trafficking. We and others previously showed that ADP-ribosylation factor 6 (Arf6) is locally activated around the ingressing cleavage furrow and recruited to the Flemming body in late cytokinesis phases, and involved in faithful completion of cytokinesis. However, knockout of the Arf6 gene or Arf6 depletion by siRNAs did not drastically influence cytokinesis. We here show that, in addition to Arf6, Class I Arfs (Arf1 and Arf3) are localized to the Flemming body, and that double knockdown of Arf1 and Arf3 moderately increases the pro...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Hanai, A., Ohgi, M., Yagi, C., Ueda, T., Shin, H.-W., Nakayama, K. Tags: Regular Papers Source Type: research
Azide anions inhibit GH-18 endochitinase and GH-20 Exo {beta}-N-acetylglucosaminidase from the marine bacterium Vibrio harveyi
Vibrio harveyi is a bioluminescent marine bacterium that utilizes chitin as its sole source of energy. In the course of chitin degradation, the bacterium primarily secretes an endochitinase A (VhChiA) to hydrolyze chitin, generating chitooligosaccharide fragments that are readily transported into the cell and broken down to GlcNAc monomers by an exo β-N-acetylglucosaminidase (VhGlcNAcase). Here we report that sodium salts, especially sodium azide, inhibit two classes of these chitin-degrading enzymes (VhChiA and VhGlcNAcase) with distinct modes of action. Kinetic analysis of the enzymatic hydrolysis of pNP-glycoside s...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Sirimontree, P., Fukamizo, T., Suginta, W. Tags: Regular Papers Source Type: research
Electron microscopic imaging revealed the flexible filamentous structure of the cell attachment protein P2 of Rice dwarf virus located around the icosahedral 5-fold axes
The minor outer capsid protein P2 of Rice dwarf virus (RDV), a member of the genus Phytoreovirus in the family Reoviridae, is essential for viral cell entry. Here, we clarified the structure of P2 and the interactions to host insect cells. Negative stain electron microscopy (EM) showed that P2 proteins are monomeric and flexible L-shaped filamentous structures of ~20 nm in length. Cryo-EM structure revealed the spatial arrangement of P2 in the capsid, which was prescribed by the characteristic virion structure. The P2 proteins were visualized as partial rod-shaped structures of ~10 nm in length in the cryo-EM map and accom...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Miyazaki, N., Higashiura, A., Higashiura, T., Akita, F., Hibino, H., Omura, T., Nakagawa, A., Iwasaki, K. Tags: Regular Papers Source Type: research
Characterization of WWP1 protein expression in skeletal muscle of muscular dystrophy chickens
A missense mutation in the gene encoding WWP1 was identified as the most promising candidate responsible for chicken muscular dystrophy (MD) by genetic linkage analysis. WWP1 is a HECT-type E3 ubiquitin protein ligase composed of 922 amino acids, which contains 4 tandem WW domains that interact with the proline-rich peptide motifs of target proteins. The missense mutation changes arginine 441 that is located in the centre of the WW domains into glutamine (R441Q), which potentially affects the function of the WWP1 protein. Here, we show that WWP1 is detected as ~130-kDa protein that localizes to various structures, such as ...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Imamura, M., Nakamura, A., Mannen, H., Takeda, S. Tags: Regular Papers Source Type: research
Lysine 206 in Arabidopsis phytochrome A is the major site for ubiquitin-dependent protein degradation
Phytochrome A (phyA) is a light labile phytochrome that mediates plant development under red/far-red light condition. Degradation of phyA is initiated by red light-induced phyA-ubiquitin conjugation through the 26S proteasome pathway. The N-terminal of phyA is known to be important in phyA degradation. To determine the specific lysine residues in the N-terminal domain of phyA involved in light-induced ubiquitination and protein degradation, we aligned the amino acid sequence of the N-terminal domain of Arabidopsis phyA with those of phyA from other plant species. Based on the alignment results, phytochrome over-expressing ...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Rattanapisit, K., Cho, M.-H., Bhoo, S. H. Tags: Regular Papers Source Type: research
Intestinal M cells
We have an enormous number of commensal bacteria in our intestine, moreover, the foods that we ingest and the water we drink is sometimes contaminated with pathogenic microorganisms. The intestinal epithelium is always exposed to such microbes, friend or foe, so to contain them our gut is equipped with specialized gut-associated lymphoid tissue (GALT), literally the largest peripheral lymphoid tissue in the body. GALT is the intestinal immune inductive site composed of lymphoid follicles such as Peyer’s patches. M cells are a subset of intestinal epithelial cells (IECs) residing in the region of the epithelium coveri...
Source: Journal of Biochemistry - January 25, 2016 Category: Biochemistry Authors: Ohno, H. Tags: JB Special Reviews-Crosstalk between the Intestinal Immune System and Gut Commensal Microbiota Source Type: research
