Promotion of Rooting in Azukia Cuttings by Possible Glycoproteins Extracted from Lentinus edodes Culture

Macromolecules purified from Lentinus edodes mycelia cultureenhanced adventitious root formation in Azukia epicotyl cuttings.Partial purification by sequential column chromatographies gavematerial composed of 71% polysaccharides and 29% proteins. Thesugar moiety consisted of mainly xylose, glucose and arabinose,the sum of their contents being more than 76% of the total carbohydrates.The protein moiety consisted of mainly glycine and serine, whichaccounted for more than 40% of the total amino acid residues. (Received June 9, 1984; Accepted November 12, 1984)     

Effect of selenium and protein deficiency on selenium and glutathione peroxidase in rats

Twenty-four weanling male Wistar rats were divided into four groups fed diets containing adequate or deficient levels of selenium (0.5 ppm [+ Se] or <0.02 ppm [−Se] and protein (15% [+Pro] or 5% [−Pro]), but adequate levels of all other nutrients for 4 wk to determine the effects of Se deficiency and protein deficiency on tissue Se and glutathione peroxidase (GSHPx) activity in rats. Plasma, heart, liver, and kidney Se and GSHPx were significantly lower in Se-deficient groups in relation to Se-sufficient groups. In Se-deficient groups, Se and GSHPx were significantly higher in −Se−Pro rats in heart, liver, and kidney. Data analysis showed that there were significant interaction effects between dietary Se and protein on Se and GSHPx of rats. It is assumed that under the condition of Se deficiency. a low level of protein may decrease Se and GSHPx utilization, increase GSHPx synthesis, and result in Se redistribution. This could account for high levels of Se and GSHPx in the −Se−Pro rats compared to −Se+Pro rats.     

Synthetic sialyl glycolipids (sialo-cholesterol and sialo-diglyceride) induce granulocytic differentiation of human myelogenous leukemia cell line HL-60

When HL-60 cells were cultivated with synthetic sialyl glycolipids, sialo-cholesterol and sialo-diglyceride, the cells were found to be differentiated into mature granulocytes on morphological and functional criteria. The differentiation of cells was accompanied by inhibition of cell proliferation. The differentiation-inducing activity of sialo-cholesterol was greater than that of sialo-diglyceride on a molar basis, and the alpha-anomer of each compound was more potent than the beta-anomer, suggesting that the stereospecific structure of the compounds is important for the differentiation-inducing activity.     

Cloning, expression, and characterization of a lipolytic enzyme gene (lip8) from Pseudomonas aeruginosa LST-03

A lipolytic enzyme gene (lip8) was cloned from organic solvent-tolerant Pseudomonas aeruginosa LST-03 and sequenced. In the sequenced nucleotides, an open reading frame consisting of 1,173 nucleotides and encoding 391 amino acids was found. Lip8 is considered to belong to the family VIII of lipolytic enzymes whose serine in the consensus sequence of -Ser-Xaa-Xaa-Lys- acts as catalytic nucleophile. The gene was expressed in Escherichia coli and purified by a combination of ammonium sulfate fractionation and hydrophobic interaction and ion-exchange chromatographies to homogeneity on SDS-PAGE analysis. The optimum temperature and heat stability of Lip8 were not as high as those of Lip3 and LST-03 lipase, two other lipolytic enzymes from the same strain. Addition of glycerol to a solution containing Lip8 stabilized this enzyme. By measuring the activities against various triacylglycerols and fatty acid methyl esters having carbon chains of different lengths, Lip8 was categorized as an esterase which has higher activities against fatty acid methyl esters with short-chain fatty acids.     

Differential requirement for the N-terminal catalytic domain of the DNA polymerase ε p255 subunit in the mitotic cell cycle and the endocycle

In Drosophila, the 255kDa catalytic subunit (dpolεp255) and the 58kDa subunit of DNA polymerase ε (dpolεp58) have been identified. The N-terminus of dpolεp255 carries well-conserved six DNA polymerase subdomains and five 3'→5' exonuclease motifs as observed with Polε in other species. We here examined roles of dpolεp255 during Drosophila development using transgenic fly lines expressing double stranded RNA (dsRNA). Expression of dpolεp255 dsRNA in eye discs induced a small eye phenotype and inhibited DNA synthesis, indicating a role in the G1-S transition and/or S-phase progression of the mitotic cycle. Similarly, expression of dpolεp255 dsRNA in the salivary glands resulted in small size and endoreplication defects, demonstrating a critical role in endocycle progression. In the eye disc, defects induced by knockdown of dpolεp255 were rescued by overexpression of the C-terminal region of dpolεp255, indicating that the function of this non-catalytic domain is conserved between yeast and Drosophila. However, this was not the case for the salivary gland, suggesting that the catalytic N-terminal region is crucial for endoreplication and its defect cannot be complemented by other DNA polymerases. In addition, several genetic interactants with dpolεp255 including genes related to DNA replication such as RFC, DNA primase, DNA polη, Mcm10 and Psf2 and chromatin remodeling such as Iswi were also identified.     

Adaptive mutation related to cellulose producibility in <Emphasis Type="Italic">Komagataeibacter medellinensis</Emphasis> (<Emphasis Type="Italic">Gluconacetobacter xylinus</Emphasis>) NBRC 3288

Gluconacetobacter xylinus (formerly Acetobacter xylinum and presently Komagataeibacter medellinensis) is known to produce cellulose as a stable pellicle. However, it is also well known to lose this ability very easily. We investigated the on and off mechanisms of cellulose producibility in two independent cellulose-producing strains, R1 and R2. Both these strains were isolated through a repetitive static culture of a non-cellulose-producing K. medellinensis NBRC 3288 parental strain. Two cellulose synthase operons, types I and II, of this strain are truncated by the frameshift mutation in the bcsBI gene and transposon insertion in the bcsCII gene, respectively. The draft genome sequencing of R1 and R2 strains revealed that in both strains the bcsBI gene was restored by deletion of a nucleotide in its C-rich region. This result suggests that the mutations in the bcsBI gene are responsible for the on and off mechanism of cellulose producibility. When we looked at the genomic DNA sequences of other Komagataeibacter species, several non-cellulose-producing strains were found to contain similar defects in the type I and/or type II cellulose synthase operons. Furthermore, the phylogenetic relationship among cellulose synthase genes conserved in other bacterial species was analyzed. We observed that the cellulose genes in the Komagataeibacter shared sequence similarities with the γ-proteobacterial species but not with the α-proteobacteria and that the type I and type II operons could be diverged from a same ancestor in Komagataeibacter.     

Recent developments in yeast cell surface display toward extended applications in biotechnology

Yeasts are promising hosts for industrial bio-refinery applications. In yeast cell surface displays, functional proteins, such as cellulases or lipases, are genetically fused to an anchor protein and expressed on the cell surface. Saccharomyces cerevisiae is the most commonly used yeast for cell surface display. Engineered yeasts have been utilized for a variety of applications, such as bioethanol production, chemicals synthesis, adsorption of environmental pollutants, and protein evolution. Here, we summarize recent developments in yeast cell surface display techniques for bio-refinery applications, including methods using hosts such as Pichia pastoris, Yarrowia lipolytica, and S. cerevisiae, focusing on the characteristics of anchor proteins and applications.     

Hsk1-Dfp1/Him1, the Cdc7-Dbf4 kinase in Schizosaccharomyces pombe, associates with Swi1, a component of the replication fork protection complex

The protein kinase Hsk1 is essential for DNA replication in Schizosaccharomyces pombe. It associates with Dfp1/Him1 to form an active complex equivalent to the Cdc7-Dbf4 protein kinase in Saccharomyces cerevisiae. Swi1 and Swi3 are subunits of the replication fork protection complex in S. pombe that is homologous to the Tof1-Csm3 complex in S. cerevisiae. The fork protection complex helps to preserve the integrity of stalled replication forks and is important for activation of the checkpoint protein kinase Cds1 in response to fork arrest. Here we describe physical and genetic interactions involving Swi1 and Hsk1-Dfp1/Him1. Dfp1/Him1 was identified in a yeast two-hybrid screen with Swi1. Hsk1 and Dfp1/Him1 both co-immunoprecipitate with Swi1. Swi1 is required for growth of a temperature-sensitive hsk1 (hsk1ts) mutant at its semi-permissive temperature. Hsk1ts cells accumulate Rad22 (Rad52 homologue) DNA repair foci at the permissive temperature, as previously observed in swi1 cells, indicating that abnormal single-stranded DNA regions form near the replication fork in hsk1ts cells. hsk1ts cells were also unable to properly delay S-phase progression in the presence of a DNA alkylating agent and were partially defective in mating type switching. These data suggest that Hsk1-Dfp1/Him1 and Swi1-Swi3 complexes have interrelated roles in stabilization of arrested replication forks.     

Muscle mechanoreceptor modulation of sweat rate during recovery from moderate exercise.

The objective of this study was to identify whether muscle mechanoreceptor stimulation is capable of modulating sweat rate. Seven healthy subjects performed two 20-min bouts of supine exercise on a tandem cycle ergometer (60 rpm at 65% of maximal heart rate). After one bout, the subject stopped exercising (i.e., no pedaling), whereas, after the other bout, the subject's legs were passively cycled (at 60 rpm) via a second person cycling the tandem ergometer. This allows for mechanical stimulation of muscle with minimal activation of central command. Esophageal temperature (T(es)), mean skin temperature (T(sk)), heart rate, mean arterial blood pressure, oxygen consumption, cutaneous vascular conductance (CVC), and sweat rate were not different during the two exercise bouts. Regardless of the mode of exercise recovery, there were no differences in T(es), T(sk), or CVC. In contrast, early in the recovery period, chest and forearm sweat rate were significantly greater in the passive cycling recovery mode relative to the no-pedaling condition (chest: 0.57 +/- 0.13 vs. 0.39 +/- 0.14, forearm: 0.30 +/- 0.05 vs. 0.12 +/- 0.02 mg.cm(-2).min(-1); both P < 0.05). These results suggested that muscle mechanoreceptor stimulation to the previously activated muscle is capable of modulating sweat rate.