Plant acetyl-CoA carboxylase: structure, biosynthesis, regulation, and gene manipulation for plant breeding

Acetyl-CoA carboxylase (ACCase) catalyzes the first committed step of fatty acid synthesis, the carboxylation of acetyl-CoA to malonyl-CoA. Two physically distinct types of enzymes are found in nature. Heteromeric ACCase composed of four subunits is usually found in prokaryotes, and homomeric ACCase composed of a single large polypeptide is found in eukaryotes. Most plants have both forms, the heteromeric form in plastids, in which de novo fatty acids are synthesized, and the homomeric form in cytosol. This review focuses on the structure and regulation of plant heteromeric ACCase and its manipulation for plant breeding.     

Crystallization and preliminary X-ray crystallographic analysis of Plasmodium falciparum S-adenosyl-L-homocysteine hydrolase

S-adenosyl-l-homocysteine hydrolase from a malaria parasite Plasmodium falciparum (PfSAHH) has been crystallized by the vapor diffusion method. The crystals belong to an orthorhombic space group P212121 with the cell dimensions of a = 76.66 A, b = 86.31 A, and c = 335.6 A. There are four subunits (one tetramer) per asymmetric unit. X-ray diffraction data have been collected up to 2.8 A resolution. Self-rotation function studies suggest that the tetrameric PfSAHH molecule has the 222 point group symmetry.     

Crystallization and MAD data collection of high-molecular weight cytochrome c from Desulfovibrio vulgaris Miyazaki F

Hexadecaheme high molecular weight cytochrome c from a sulfate-reducing bacterium, Desulfovibrio vulgaris Miyazaki F has been successfully purified and crystallized. X-ray diffraction data have been collected by the multiple wavelength anomalous dispersion method. The crystal belongs to the space group P2(1)2(1)2(1) with unit-cell parameters a=60.42, b=84.29 and c=144.16 A and contains one molecule per asymmetric unit.     

Genetic variations at urotensin II and urotensin II receptor genes and risk of type 2 diabetes mellitus in Japanese

Urotensin II is among the most potent vasoactive hormones known and the urotensin II (UTS2) gene is localized to 1p36-p32, one of the regions reported to show possible linkage with type 2 diabetes in Japanese. When we surveyed genetic polymorphisms in the UTS2 and urotensin II receptor (GPR14) gene, we identified two SNPs with amino acid substitutions (designated T21M and S89N and an SNP in the promotor region (-605G>A) of the UTS2 gene, and two SNPs in the non-coding region of the GPR14 gene. We then studied these three SNPs in the UTS2 gene and two SNPs in the GPR14 gene in 152 Japanese subjects with type 2 diabetes mellitus and two control Japanese populations. The allele frequency of 89N was significantly higher in type 2 diabetic patients than in both elderly normal subjects (P = 0.0018) and subjects with normal glucose tolerance (P = 0.0011), whereas the allele frequency of T21M and -605G>A in the UTS2 gene and those of two SNPs in the GPR14 gene were essentially identical in these three groups. Furthermore, in the subjects with normal glucose tolerance, 89N was associated with significantly higher insulin levels on oral glucose tolerance test, suggesting reduced insulin sensitivity in subjects with 89N. These results strongly suggest that subjects with S89N in the UTS2 gene are more insulin-resistant and thus more susceptible to type 2 diabetes mellitus development.     

Bambusicolous fungi in Japan (2): <Emphasis Type="Italic">Phialosporostilbe gregariclava</Emphasis>, a new anamorphic fungus from <Emphasis Type="Italic">Sasa</Emphasis>

One new hyphomycete, Phialosporostilbe gregariclava, is described and illustrated based on specimens collected on dead culms of two Sasa species in Hokkaido and Iwate, Japan. This fungus is compared with previously described species of Phialosporostilbe and Nawawia, and its morphological and cultural characteristics are reported.     

<Emphasis Type="Italic">Puccinia calystegiae-soldanellae</Emphasis>, a new rust species on <Emphasis Type="Italic">Calystegia soldanella</Emphasis> from Japan

A rust species on Calystegia soldanella in Japan has been treated as Puccinia convolvuli to date. However, morphological characteristics of specimens on C. soldanella collected from Japan are significantly different from those of specimens on other Calystegia and Convolvulus species from different areas of the world. It is proved by inoculation experiment that the rust on C. soldanella is specific to C. soldanella. Based on these results, Puccinia rust on C. soldanella from Japan is described as a new species, Puccinia calystegiae-soldanellae.     

Bambusicolous fungi in Japan (1): four <Emphasis Type="Italic">Phaeosphaeria</Emphasis> species

Four Phaeosphaeria species on bamboos are reported. Leptosphaeria lelebae on culms of Bambusa multiplex is synonymized with P. oryzae. A Phaeosphaeria sp. on leaves of Sasa kurilensis is noted to have some similarities to Leptosphaeria sasae. Cultural characteristics of P. brevispora collected from culms of Sasa sp. are first recorded. Phaeosphaeria bambusae on leaves of Pleioblastus simoni is redescribed. In addition, the history of taxonomic studies on bambusicolous fungi in Japan is briefly reviewed.     

Thresholds of color attribute differences in detecting camouflaged textures

We examined the threshold at which a camouflaged color texture pattern (target) embedded in a surrounding colored texture pattern (background) was discriminated by making the difference between their color distributions serve as a cue. The texture consisted of 900 colored disks. The color applied to the disk was chosen from a normal distribution with the mean and the standard deviation set beforehand. The mean of the background's distribution was a standard achromatic color set at L*=40, u*=0, and v*=0 of CIELUV. In experiment 1, the mean of the target's color distribution was shifted from the background's one. The threshold for the mean of the target's color distribution depended on the standard deviation and increased as the standard deviation became bigger. In experiment 2, the standard deviation of the target's color distribution was shifted. There was the slight dependence of threshold of the standard deviation of the target's distribution on that of the background's distribution. In experiment 3, both of the mean and the standard deviation of the target's color distribution were shifted at the same time. The threshold was not determined by each of the mean and the standard deviation independently. There seemed to be some compensating contribution between them to each other. The threshold could be characterized by Doyle metric or modified Doyle metric.