Sucrose nonfermenting-1 (SNF1)-related protein kinases (SnRKs) form a major family of signalling proteins in plants and have been associated with metabolic regulation and stress responses. They comprise three subfamilies: SnRK1, SnRK2, and SnRK3. SnRK1 plays a major role in the regulation of carbon metabolism and energy status, while SnRKs 2 and 3 have been implicated in stress and abscisic acid (ABA)-mediated signalling pathways. The burgeoning and divergence of this family of protein kinases in plants may have occurred to enable cross-talk between metabolic and stress signalling, and ABA-response-element-binding proteins (AREBPs), a family of transcription factors, have been shown to be substrates for members of all three subfamilies. In this study, levels of SnRK1 protein were shown to decline dramatically in wheat roots in response to ABA treatment, although the amount of phosphorylated (active) SnRK1 remained constant. Multiple SnRK2-type protein kinases were detectable in the root extracts and showed differential responses to ABA treatment. They included a 42 kDa protein that appeared to reduce in response to 3 h of ABA treatment but to recover after longer treatment. There was a clear increase in phosphorylation of this SnRK2 in response to the ABA treatment. Fractions containing this 42 kDa SnRK2 were shown to phosphorylate synthetic peptides with amino acid sequences based on those of conserved phosphorylation sites in AREBPs. The activity increased 8-fold with the addition of calcium chloride, indicating that it is calcium-dependent. The activity assigned to the 42 kDa SnRK2 also phosphorylated a heterologously expressed wheat AREBP.

RIG-I-like receptor (RLR) plays a pivotal role in the detection of invading pathogens to initiate type I interferon (IFN) gene transcription. Since aberrant IFN production is harmful, RLR signaling is strictly regulated. However, the regulatory mechanisms are not fully understood. By expression cloning, we identified Pumilio proteins, PUM1 and PUM2, as candidate positive regulators of RIG-I signaling. Overexpression of Pumilio proteins and their knockdown augmented and diminished IFN-β promoter activity induced by Newcastle disease virus (NDV), respectively. Both proteins showed a specific association with LGP2, but not with RIG-I or MDA5. Furthermore, all of these components were recruited to NDV-induced antiviral stress granules. Interestingly, biochemical analyses revealed that Pumilio increased double-stranded (ds) RNA binding affinity of LGP2; however, Pumilio was absent in the dsRNA-LGP2 complex, suggesting that Pumilio facilitates viral RNA recognition by LGP2 through its chaperon-like function. Collectively, our results demonstrate an unknown function of Pumilio in viral recognition by LGP2.

We suggest that the PPARgammaPro12Ala polymorphism may represent a genetic susceptibility factor for the clinical measurements of periodontitis in a limited number of pregnant Japanese women, but it probably cannot influence the relationship between periodontitis and preterm birth.

The purpose of this study was to find whether the concentration of N-acetylglutamate and ornithine transport into mitochondria would regulate urea synthesis when the dietary protein quality was manipulated. Experiments were done on three groups of rats given diets containing 10 g of gluten, 10 g of casein, or 10 g of whole egg protein/100 g for 10 days. The plasma concentration and urinary excretion of urea, the liver concentration and synthesis of N-acetylglutamate, the liver concentrations of glutamate and lysine, and the liver ornithine transport into mitochondria increased with the decrease in quality of dietary protein. A reverse correlation was observed between the activities of urea cycle enzymes, the plasma concentration of arginine, and urinary excretion of urea under these conditions. N-Acetylglutamate concentration and ornithine transport into mitochondria in the liver were closely correlated with the excretion of urea. These results suggest that greater N-acetylglutamate concentration and ornithine transport into isolated mitochondria in the liver of rats, given the lower quality of protein, stimulate urea synthesis and that the concentrations of glutamate and lysine in the liver are at least partly related to the hepatic N-acetylglutamate synthesis and ornithine transport, respectively.