Stipe elongation during basidiocarp maturation in Coprinus macrorhizus: Mechanical properties of stipe cell wall

Stipe elongation during basidiocarp maturation in the wild-type,#5026+5132, and the elongationless mutant, NG0398, of Coprinusmacrorhizus was studied, and the following results were obtained.

1. In the wild-type the middle zone of the stipe elongated 8.4times in 15 hr during maturation, while in the mutant it elongatedoaiy 2.2 times.
2. Component cells of the stipe elongated inparallel with thestipe elongation in both the wild-type andthe mutant. The widthof stipe cells was almost constant duringelongation in thewild-type, while it increased 2 times in themutant. Cell volumeincreased ca. 8 times in both stocks.
3. Theosmotic value of stipe cells was almost constant (0.45–0.50M) throughout elongation of both the wild-type and the elongationlessstipes.
4. Mechanical properties of the cell wall were examinedby measuringshrinkage, extensibility and minimum stress-relaxationtime(To) of the stipe during maturation. These parameters weredirectlyproportional to the elongation rate to follow.
5. Whenthe wild-type stipes were incubated in various concentrationsof mannitol solution and then in plain buffer solution, theextensibility of the stipe after the incubation in mannitolsolutions changed proportionally with the stipe length afterthe mannitol treatment, and To with the elongation capacityin plain buffer solution.

(Received March 3, 1977; )     

Discovery of TAK-960: An orally available small molecule inhibitor of polo-like kinase 1 (PLK1)

Using structure-based drug design, we identified and optimized a novel series of pyrimidodiazepinone PLK1 inhibitors resulting in the selection of the development candidate TAK-960. TAK-960 is currently undergoing Phase I evaluation in adult patients with advanced solid malignancies.     

An oxygen-evolving complex with a simple subunit structure - ‘a water-plastoquinone oxidoreductase” - from the thermophilic cyanobacterium Synechococcus sp.

An oxygen-evolving complex has been highly purified from the thermophilic cyanobacterium Synechococcus sp. The complex, which reproducibly showed 5 major polypeptide bands of 47, 40, 35, 30 and 9 kDa on SDS-polyacrylamide gel electrophoresis and contained 3.2 Mn per Q_A, had an oxygen-evolving activity of 300–400 μmol/mg chl per h in the presence of 5 mM MnCl₂; or CaCl₂. The complex most likely represents a minimum functional unit of the photosynthetic oxygen evolution.     

Ameliorative effects of mulberry (Morus alba L.) leaves on hyperlipidemia in rats fed a high-fat diet: induction of fatty acid oxidation, inhibition of lipogenesis, and suppression of oxidative stress

To determine the effects of mulberry (Morus alba L.) leaves on hyperlipidemia, we performed gene expression profiling of the liver. Rats were fed a high-fat diet and administered mulberry leaves for 7 weeks. Plasma triglyceride and non-esterified fatty acid levels were significantly lower in the rats treated with mulberry leaves as compared with the untreated rats. DNA microarray analysis revealed that mulberry leaves upregulated expression of the genes involved in α-, β- and ω-oxidation of fatty acids, mainly related to the peroxisome proliferator-activated receptor signaling pathway, and downregulated the genes involved in lipogenesis. Furthermore, treatment with mulberry leaves upregulated expression of the genes involved in the response to oxidative stress. These results indicate that consumption of fatty acids and inhibition of lipogenesis are responsible for the reduction in plasma lipids caused by mulberry administration. In addition, mulberry treatment maintains the body's oxidative state at a low level despite enhancing fatty acid oxidation.     

Localization of laminin α3B chain in vascular and epithelial basement membranes of normal human tissues and its down-regulation in skin cancers

The basement membrane (BM) proteins laminins, which consist of alpha, beta and gamma chains, play critical roles in the maintenance of tissue structures. One of laminin alpha chains, alpha3 has two isoforms, the truncated form alpha3A and the full-sized form alpha3B. In contrast to alpha3A laminins, little is known about alpha3B laminins. To show the histological distribution of the laminin alpha3B chain, we prepared alpha3B-specific monoclonal antibodies. Immunohistochemical analysis showed that the alpha3B chain was colocalized with the alpha3A, beta3 and gamma2 chains in the epithelial BMs of the skin, esophagus, breast and lung, suggesting the presence of laminin-3B32 (laminin-5B) and laminin-3A32 (laminin-5A). In the lung alveoli, laminin-3B32 was dominant over laminin-3A32, but vice versa in other epithelial BMs. In contrast, the BMs of blood vessels including capillaries were strongly positive for alpha3B, but almost or completely negative for alpha3A, beta3 and gamma2. alpha3B was colocalized with beta1 and gamma1 in these BMs. The alpha3B chain was scarcely detected in the vessels of malignant skin cancers, though the gamma2 and beta3 chains were highly expressed in the cancer cells. These results strongly suggest that the laminin alpha3B chain is widely expressed in vascular BMs of normal tissues, probably as laminin-3B11/3B21 (laminin-6B/7B).     

Purification and Properties of Penicillin Acylase from Kluyvera citrophila

Penicillin acylase (EC 3.5.1.11) of Kluyvera citrophila KY7844 was purified approximately 120-fold by DEAE-cellulose chromatography, hydroxyapatite chromatography and isoelectro-focusing fractionation. The purified enzyme, with an approximate molecular weight of 63,000, appeared to be homogeneous in disc electrophoretic analysis, and showed isoelectric point (Ip) 8.12 and 13.0 units/mg of specific activity for cephalexin hydrolysis. The Michaelis constant (Km) for cephalexin and for 7-[1-(1H)-tetrazolylacetamido]-desacetoxycephalosporanic acid ((1H) T-7ADCA) was 1.4 mM and 3.6 mM, respectively. This enzyme was capable of producing (1H) T-7ADCA in 80% yield from 1-(1H)-tetrazolylacetate methylester and 7-aminodesacetoxycephalosporanic acid.     

Diurnal changes in needle gas exchange in alpine Pinus pumila during snow-melting and summer seasons

Pinus pumila (Pallas) Regel. is a dominant dwarf tree in alpine regions of Japan. The possible factors limiting the net photosynthetic rate (P_n) of the needles of P. pumila were examined in the snow-melting (May) and the summer (August) seasons. In August, in situ maximum P_n was 20 mol kg^–1 needle s^–1 in the current-year needles and 25 mol kg^–1 needle s^–1 in the 1-year-old needles. Diurnal trends of P_n in August were positively related to fluctuations in photosynthetic photon flux density (PPFD) and no midday depression of P_n was found, indicating that a decrease in PPFD rather than an increase in needle-to-air vapor pressure deficit (W) might cause the reduction of P_n. Both stomatal conductance (g_s) and P_n were lower in May than in August. In May, P_n and g_s were almost zero in the morning, but gradually increased with decreasing W, reaching maximum P_n values (4 mol kg^–1 needle s^–1) and g_s (60 mmol kg^–1 needle s^–1) at 16.00 hours. The daytime P_n in May was positively related to g_s. Relative water content in the exposed needles above the snow in May was 83%, which was far above the lethal level. This indicates that the water flow from stems or soils to needles was enough to compensate for a small amount of water loss due to the low g_s in May, although the water supplied to needles would be impeded by the low temperatures. Thus, the reduced g_s in May would be important for avoiding needle desiccation, and would result in a reduced P_n.