Suppressive effect on food intake of a potato extract (Potein®) involving cholecystokinin release in rats

We have recently reported that oral gavage of a potato extract (Potein?) suppressed the food intake in rats. The satiating effect of the potato extract was compared in the present study to other protein sources, and the involvement of endogenous cholecystokinin (CCK) secretion was examined. Food consumption was measured in 18-h fasted rats after oral gavage of the potato extract or other protein sources. The CCK-releasing activity of the potato extract was then examined in anesthetized rats with a portal cannula. Oral gavage of the potato extract reduced the food intake in the rats, the effect being greater than with casein and a soybean β-conglycinin hydrolysate. The suppressive effect on appetite of the potato extract was attenuated by treating with a CCK-receptor antagonist (devazepide). The portal CCK concentration was increased after a duodenal administration of the potato extract to anesthetized rats. These results indicate that the potato extract suppressed the food intake in rats through CCK secretion.     

A comparative analysis of the molecular characteristics of the Arabidopsis CoA pyrophosphohydrolases AtNUDX11, 15, and 15a

Coenzyme A (CoA) is an essential, ubiquitous cofactor in all biological systems, where it acts as the major acyl group carrier in various central metabolic reactions. Although much is known about CoA biosynthesis, it is unclear how the CoA pool is regulated the various cellular compartments. It has been found that the nucleoside diphosphates linked to some moiety X (Nudix) hydrolases, AtNUDX11 and 15, have pyrophosphohydrolase activity toward CoA and its derivatives. In this study we identified two alternatively spliced variants, AtNUDX15 and 15a, produced from the AtNUDX15 gene, and carried out comparative studies of the gene regulation, the kinetic parameters, and the intracellular localization of AtNUDX11, 15, and 15a. The present findings indicate that AtNUDX11 and AtNUDX15(a) function in the hydrolysis of malonyl-CoA in cytosol and succinyl-CoA in the mitochondria, respectively, suggesting their impact not only on CoA biosynthesis but also on various CoA-related pathways such as the TCA cycle.     

Isolation of uracil auxotrophs of the fungus Acremonium cellulolyticus and the development of a transformation system with the pyrF gene

Acremonium cellulolyticus CF-2612 is a cellulase hyper-producing mutant that originated from A. cellulolyticus Y-94. In this study, we isolated a uracil auxotroph (strain CFP3) derived from CF-2612, and cloned a wild-type pyrF gene encoding orotate phosphoribosyl transferase (OPRTase) from Y-94. OPRTase activity was not detected in strain CFP3, which had one nucleotide substitution in its pyrF gene. The wild-type pyrF gene restored the defective growth of CFP3 on uracil-free medium, and PCR and Southern analyses revealed that wild-type pyrF was integrated into the genome. These results indicate that our transformation system for A. cellulolyticus with the pyrFgene as a selection marker was successful.     

Abiotic stress-inducible receptor-like kinases negatively control ABA signaling in Arabidopsis

Membrane-anchored receptor-like protein kinases (RLKs) recognize extracellular signals at the cell surface and activate the downstream signaling pathway by phosphorylating specific target proteins. We analyzed a receptor-like cytosolic kinase (RLCK) gene, ARCK1, whose expression was induced by abiotic stress. ARCK1 belongs to the cysteine-rich repeat (CRR) RLK sub-family and encodes a cytosolic protein kinase. The arck1 mutant showed higher sensitivity than the wild-type to ABA and osmotic stress during the post-germinative growth phase. CRK36, an abiotic stress-inducible RLK belonging to the CRR RLK sub-family, was screened as a potential interacting factor with ARCK1 by co-expression analyses and a yeast two-hybrid system. CRK36 physically interacted with ARCK1 in plant cells, and the kinase domain of CRK36 phosphorylated ARCK1 in vitro. We generated CRK36 RNAi transgenic plants, and found that transgenic plants with suppressed CRK36 expression showed higher sensitivity than arck1-2 to ABA and osmotic stress during the post-germinative growth phase. Microarray analysis using CRK36 RNAi plants revealed that suppression of CRK36 up-regulates several ABA-responsive genes, such as LEA genes, oleosin, ABI4 and ABI5. These results suggest that CRK36 and ARCK1 form a complex and negatively control ABA and osmotic stress signal transduction.     

Studies on the formation mechanism and the structure of the anisotropic collagen gel prepared by dialysis-induced anisotropic gelation

We have found that dialysis of 5 mg/mL collagen solution into the phosphate solution with a pH of 7.1 and an ionic strength of 151 mM [corrected] at 25 °C results in a collagen gel with a birefringence and tubular pores aligned parallel to the growth direction of the gel. The time course of averaged diameter of tubular pores during the anisotropic gelation was expressed by a power law with an exponent of 1/3, suggesting that the formation of tubular pores is attributed to a spinodal decomposition-like phase separation. Small angle light scattering patterns and high resolution confocal laser scanning microscope images of the anisotropic collagen gel suggested that the collagen fibrils are aligned perpendicular to the growth direction of the gel. The positional dependence of the order parameter of the collagen fibrils showed that the anisotropic collagen gel has an orientation gradient.     

A new species of parasitic copepod, Sarcotretes umitakae sp. n. (Siphonostomatoida,Pennellidae), on the rattail (Actinopterygii,Macrouridae) from?the?East?China Sea,Japan

A new species of copepod, Sarcotretes umitakae sp. n., of the siphonostomatoid family Pennellidae is described based on female specimens from the rattail Coelorinchus jordani Smith and Pope (Actinopterygii: Gadiformes: Macrouridae) caught in the East China Sea. This species is characterized by exhibiting the following characters: the large proboscis projects strongly; the head bears paired lateral processes which are bulbous and taper into a slender horn; the twisting neck is significantly longer than the trunk; and the trunk bears an anterior constriction with a reduced abdomen.     

The Ubiquitin Ligase PUB22 Targets a Subunit of the Exocyst Complex Required for PAMP-Triggered Responses in Arabidopsis

Plant pathogens are perceived by pattern recognition receptors, which are activated upon binding to pathogen-associated molecular patterns (PAMPs). Ubiquitination and vesicle trafficking have been linked to the regulation of immune signaling. However, little information exists about components of vesicle trafficking involved in immune signaling and the mechanisms that regulate them. In this study, we identified Arabidopsis thaliana Exo70B2, a subunit of the exocyst complex that mediates vesicle tethering during exocytosis, as a target of the plant U-box–type ubiquitin ligase 22 (PUB22), which acts in concert with PUB23 and PUB24 as a negative regulator of PAMP-triggered responses. We show that Exo70B2 is required for both immediate and later responses triggered by all tested PAMPs, suggestive of a role in signaling. Exo70B2 is also necessary for the immune response against different pathogens. Our data demonstrate that PUB22 mediates the ubiquitination and degradation of Exo70B2 via the 26S Proteasome. Furthermore, degradation is regulated by the autocatalytic turnover of PUB22, which is stabilized upon PAMP perception. We therefore propose a mechanism by which PUB22-mediated degradation of Exo70B2 contributes to the attenuation of PAMP-induced signaling.