Proteomic and microarray analyses of the Dictyostelium Zak1-GSK-3 signaling pathway reveal a role in early development

GskA, the Dictyostelium GSK-3 orthologue, is modified and activated by the dual-specificity tyrosine kinase Zak1, and the two kinases form part of a signaling pathway that responds to extracellular cyclic AMP. We identify potential cellular effectors for the two kinases by analyzing the corresponding null mutants. There are proteins and mRNAs that are altered in abundance in only one or the other of the two mutants, indicating that each kinase has some unique functions. However, proteomic and microarray analyses identified a number of proteins and genes, respectively, that are similarly misregulated in both mutant strains. The positive correlation between the array data and the proteomic data is consistent with the Zak1-GskA signaling pathway's functioning by directly or indirectly regulating gene expression. The discoidin 1 genes are positively regulated by the pathway, while the abundance of the H5 protein is negatively regulated. Two of the targets, H5 and discoidin 1, are well-characterized markers for early development, indicating that the Zak1-GskA pathway plays a role in development earlier than previously observed.     

Chromosome-Scale Genome Assembly of the Marine Oleaginous Diatom Fistulifera solaris

Marine Biotechnology - Microalgae including diatoms are of interest for environmentally friendly manufacturing such as production of biofuels, chemicals, and materials. The highly oil-accumulating...     

Production and characterization of recombinant P1 adhesin essential for adhesion,gliding, and antigenic variation in the human pathogenic bacterium,Mycoplasma pneumoniae

Mycoplasma pneumoniae forms an attachment organelle at one cell pole, binds to the host cell surface, and glides via a unique mechanism. A 170-kDa protein, P1 adhesin, present on the organelle surface plays a critical role in the binding and gliding process. In this study, we obtained a recombinant P1 adhesin comprising 1476 amino acid residues, excluding the C-terminal domain of 109 amino acids that carried the transmembrane segment, that were fused to additional 17 amino acid residues carrying a hexa-histidine (6?×?His) tag using an Escherichia coli expression system. The recombinant protein showed solubility, and chirality in circular dichroism (CD). The results of analytical gel filtration, ultracentrifugation, negative-staining electron microscopy, and small-angle X-ray scattering (SAXS) showed that the recombinant protein exists in a monomeric form with a uniformly folded structure. SAXS analysis suggested the presence of a compact and ellipsoidal structure rather than random or molten globule-like conformation. Structure model based on SAXS results fitted well with the corresponding structure obtained with cryo-electron tomography from a closely related species, M. genitalium. This recombinant protein may be useful for structural and functional studies as well as for the preparation of antibodies for medical applications.     

Koji glycosylceramide commonly contained in Japanese traditional fermented foods alters cholesterol metabolism in obese mice

ABSTRACT

Koji, which is manufactured by proliferating non-pathogenic fungus Aspergillus oryzae on steamed rice, is the base for Japanese traditional fermented foods. We have revealed that koji and related Japanese fermented foods and drinks such as amazake, shio-koji, unfiltered sake and miso contain abundant glycosylceramide. Here, we report that feeding of koji glycosylceramide to obese mice alters the cholesterol metabolism . Liver cholesterol was significantly decreased in obese mice fed with koji glycosylceramide. We hypothesized that their liver cholesterol was decreased because it was converted to bile acids. Consistent with the hypothesis, many bile acids were increased in the cecum and feces of obese mice fed with koji glycosylceramide. Expressions of CYP7A1 and ABCG8 involved in the metabolism of cholesterol were significantly increased in the liver of mice fed with koji glycosylceramide. Therefore, it was considered that koji glycosylceramide affects the cholesterol metabolism in obese mice.     

First record of the invasive woodwasp,Urocerus albicornis (Hymenoptera: Siricidae), from a local forest in Japan

The woodwasp Urocerus albicornis (Fabricius, 1781) (Hymenoptera: Siricidae) is a forest pest native to North America and occasionally introduced into European countries. One of these invasive woodwasps was collected in a local forest in Nagano Prefecture, Central Japan. The collected individual was an adult female ovipositing on a log from a Japanese larch (Larix kaempferi (Lamb.) Carrière). Although several of these woodwasps have been found on imported logs in Japan, this is the first record of the alien woodwasp in a local forest within Japan and Asia. This finding indicates that a population of this invasive woodwasp may be established in Japanese forests.     

Metabolic activation of carcinogenic 1-nitropyrene by human cytochrome P450 1B1 in Salmonella typhimurium strain expressing an O-acetyltransferase in SOS/umu assay

Metabolic activation of 1-nitropyrene (1-NP) by human cytochrome P450 (P450) family 1 enzymes co-expressed with NADPH-cytochrome P450 reductase (NPR) in Escherichia coli membranes was investigated. 1-NP induced umu gene expression in Salmonella typhimurium TA1535/pSK1002 in the absence of any P450 system, but the activities were influenced by the levels of bacterial O-acetyltransferase (OAT) and nitroreductase. Metabolic activation of 1-NP by human P450 1B1/NPR membranes was observed and was influenced by the levels of OAT levels in tester strains. Metabolic activation of 1-NP (0.3microM) by P450 1B1 was 750 umu units/min/nmol P450 1B1 in an OAT-overexpressing strain NM2009. The metabolic activation of 1-NP (3-30microM) was similar (approximately 300 umu units/min/nmol P450 1B1) using TA1535/pSK1002 or OAT-deficient strain NM2000. P450 1B1 had the highest catalytic activities among P450 family 1 enzymes for the activation of 1-aminopyrene (1-AP) in the OAT-overexpressing strain NM2009, suggesting nitrenium ion formation via N-hydroxylation/O-acetylation. High-performance liquid chromatography (HPLC) analyses revealed the formation of 1-nitropyrene-6-ol and also 1-nitropyrene-3-ol, 1-nitropyrene-8-ol, and trans-4,5-dihydroxy-4,5-diol-1-nitropyrene from 1-NP (10microM), catalyzed by P450 1B1. These results indicate that 1-NP can be activated by human P450 1B1 to a genotoxic agent by nitroreduction/O-acetylation at low substrate concentrations and probably by epoxidation (independent of OAT) at high concentrations.     

Population structure and dynamics of an evergreen shade herb, Ainsliaea apiculata (Asteraceae), with special reference to herbivore effects

The population structure and dynamics of Ainsliaea apiculata, a forest understory evergreen herb widely distributed in Japan, was examined in a Chamaecyparis obtusa forest in Ibaraki Prefecture, central Japan (36°51N, 140°33E; 750 m a.s.l.). The mean population growth rate () calculated from the transition matrices for 4 years was 0.69 per year, predicting that the population size will decrease remarkably. There was a significant positive correlation between the survival of old leaves and the growth of new shoots in the following year. The shoots, especially new leaves, were damaged severely by herbivores (caterpillars of Leioptilus sp.). The survival rate of leaves formed in the previous spring to the next spring was remarkably low (41–54%). The growth of new shoots depended mainly on the reserves contained in old shoots, especially those in old leaves. New shoots of A. apiculata began to develop in spring, even though they were formed in autumn of the previous year. A defoliation experiment also showed that the removal of old shoots at the beginning of the growing season significantly inhibited the growth of new shoots. Damage to old shoots by herbivores severely influenced the growth and population dynamics of A. apiculata.     

Angiopoietin-3, a novel member of the angiopoietin family

A cDNA clone encoding angiopoietin-3 protein (Ang3), a novel member of the angiopoietin family, was identified. Ang3 cDNA was cloned from a human aorta cDNA library. Ang3 is a 503 amino acid protein having 45.1% and 44.7% identity with human angiopoietin-1 and human angiopoietin-2, respectively. Ang3 mRNA is expressed in lung and cultured human umbilical vein endothelial cells (HUVECs). Ang3 mRNA expression in HUVECs was slightly decreased by vascular endothelial cell growth factor treatment, suggesting that the regulation of Ang3 mRNA expression is different from that of Ang2.     

Management of the hairline using a local flap in total reconstruction for microtia

In cases of microtia with a low hairline, the manner in which hair is removed from the reconstructed auricle must be taken into consideration. This is one of the most common but difficult problems with reconstruction for microtia. The authors describe a new technique that uses a simple regional flap to resolve this problem. The hair-bearing skin in the estimated auricular region and its covering are removed using a local flap from the hairless mastoid region. This is done in the first stage of auricular reconstruction, the costal cartilage grafting is done in the second stage, and elevation of the auricle is done in the last stage. In 38 auricles of 36 patients who were treated from 1993 to 1995, eight auricles of eight patients were treated with this technique. In all cases, the hairless flap healed well, without vascular stasis or skin necrosis. In addition, no complications from using this technique occurred in the later stages of auricular reconstruction. With this technique, the skin of the flap provides a good texture and color match to the auricle. In addition, the skin of the flap has good elasticity for the cutaneous pocket for cartilage grafting. The harvested area of the flap can be hidden behind the reconstructed auricle. The authors initially wondered whether the marginal scar of the transposed flap's position in the auricle would be conspicuous. However, all of the scar became inconspicuous because it was positioned in the scaphoid fossa.