Algal protein kinase, Triacylglycerol Accumulation Regulator 1, modulates cell viability and gametogenesis in carbon/nitrogen imbalanced conditions

Nutrient-deprived microalgae accumulate triacylglycerol (TAG) in lipid droplets. A dual-specificity tyrosine phosphorylation-regulated kinase, TAG accumulation regulator 1 (TAR1) has been shown to be required for acetate-dependent TAG accumulation and the degradation of chlorophyll and photosynthesis-related proteins in photomixotrophic nitrogen (N)-deficient conditions (Kajikawa et al. 2015). However, this previous report only examined particular condition. Here, we report that in photoautotrophic N-deficient conditions, tar1-1 cells, with a mutation in the TAR1 gene, maintained higher levels of cell viability and lower levels of hydrogen peroxide generation and accumulated higher levels of TAG and starch compared with those of wild-type (WT) cells with bubbling of air containing 5% carbon dioxide. Transcriptomic analyses suggested that genes involved in the scavenging of reactive oxygen species are not repressed in tar1-1 cells. In contrast, the mating efficiency and mRNA levels of key regulatory genes for gametogenesis, MID, MTD, and FUS, were suppressed in tar1-1 cells. Among the TAR1-dependent phosphopeptides deduced by phosphoproteomic analysis, protein kinases and enzymes related to N assimilation and carbon (C) metabolism are of particular interest. Characterization of these putative downstream factors may elucidate the molecular pathway whereby TAR1 mediates cellular propagation and C and N metabolism in C/N-imbalanced stress conditions

Surface configuration of the Antarctic ice sheet in the sector 30゜E - 80゜E using SEASAT altimetry data

Using Interim Geophysical Data Record (IGDR) of SEASAT radar altimetry, a configuration map of the Antarctic ice sheet in the area bounded by 30°and 80°E and latitude 72°S is compiled. A total of 7480 footprint data of every second sampling (6.62km apart) along 63 subsatellite groundtracks are obtained in the area. The area was divided into rectangles with side lengths of 0.1°in latitude and 0.4°in longitude, and the average elevation above sea level by SEASAT altimetry data within the rectangle is used for computer-aided contouring. Since the height error for 147 crossover points on the ice sheet was±6.7m in standard deviation, and height errors from slope-induced effect and other sources were 20m, the contour interval of 100m was chosen for an inland area higher than 500m above sea level. The obtained configuration resembles the map published by the Scott Polar Research Institute (1983). A total of 157 ground survey data from triangulation survey, satellite Doppler positioning and previously published topographic map are used to estimate an overall accuracy of the obtained configuration map. The ground survey height is on an average 2.2m lower than the SEASAT-derived elevation with a standard deviation of ±21.5m, which may reflect the limited data quality of IGDR without retracking correction of the return-pulse waveform. Drawing orthogonals to the contours, ice drainage basins are determined and they are slightly different from the previous ones defined by the over-snow traverse surveys

The long-term immunosuppressive effects of disulfide-linked HLA-G dimer in mice with collagen-induced arthritis

HLA-G, a natural immunosuppressant present in the human placenta during pregnancy, prevents fetal destruction by the maternal immune system. The immunosuppressive effect of HLA-G is mediated by the immune cell inhibitory receptors, LILRB1 and LILRB2. HLA-G forms disulfide-linked dimers by natural oxidation, and the dimer associates with LILRB1/B2 much more strongly than the monomer. Furthermore, the dimer formation remarkably enhanced the LILRB-mediated signaling. In this report, we studied the in vivo immunosuppressive effect of the HLA-G dimer, using the collagen-induced arthritis model mouse. Mice were treated with the HLA-G monomer or dimer intracutaneously at the left foot joint, once or for 5 days, and the clinical severity was evaluated daily in a double-blind study. The HLA-G monomer and dimer both produced excellent anti-inflammatory effects with a single, local administration. Notably, as compared to the monomer, the dimer exhibited significant immunosuppressive effects at lower concentrations, which persisted for about two months. In accordance with this result, a binding study revealed that the HLA-G dimer binds PIR-B, the mouse homolog of the LILRBs, with higher affinity and avidity than the monomer. The HLA-G dimer is expected to be quite useful as an anti-rheumatoid arthritis agent, in small amounts with minimal side effects. (C) 2012 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved

Difference in cesium accumulation among rice cultivars grown in the paddy field in Fukushima Prefecture in 2011 and 2012

After the accident of the Fukushima 1 Nuclear Power Plant in March 2011, radioactive cesium was released and paddy fields in a wide area including Fukushima Prefecture were contaminated. To estimate the levels of radioactive Cs accumulation in rice produced in Fukushima, it is crucial to obtain the actual data of Cs accumulation levels in rice plants grown in the actual paddy field in Fukushima City. We herein conducted a two-year survey in 2011 and 2012 of radioactive and non-radioactive Cs accumulation in rice using a number of rice cultivars grown in the paddy field in Fukushima City. Our study demonstrated a substantial variation in Cs accumulation levels among the cultivars of rice