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Transcription factor IRF-3 is post-translationally activated by Toll-like receptor (TLR) signaling and has critical roles in the regulation of innate immunity. Here we present the X-ray crystal structure of the C-terminal regulatory domain of IRF-3(175-427) (IRF-3 175C) at a resolution of 2.3 Å. IRF-3 175C is structurally similar to the Mad homology domain 2 of the Smad family. Structural and functional analyses reveal phosphorylation-induced IRF-3 dimerization, which generates an extensive acidic pocket responsible for binding with p300/CBP. Although TLR and Smad signaling are evolutionarily independent, our results suggest that IRF-3 originates from Smad and acquires its function downstream of TLR. [ABSTRACT FROM AUTHOR]

Fushi tarazu transcription factor-1 (FTZ-F1) was originally found as a regulator of fushi tarazu gene expression in Drosophila. The frog homologue (FTZ-F1α) and the 3.5 kb 5'-flanking region of the FTZ-F1α gene have been cloned, and it has been shown by reverse transcription-polymerase chain reaction that FTZ-F1α expression begins in embryos at stage 11 and becomes stronger after that. By in situ hybridization analysis, the FTZ-F1α mRNA was also found in immature frog oocytes. In this study, immunohistology revealed that the product of FTZ-F1α was localized in the cytoplasm of the immature oocyte. To analyze the promoter activity of the Rana rugosa FTZ-F1α gene, transgenic Xenopus were produced carrying the fusion construct, consisting of truncated 5'-flanking regions (3.0, 1.8 and 0.3 kb) of the FTZ-F1α gene and the green fluorescent protein (GFP) open reading frame. The 0.3 kb 5'-flanking region could drive GFPexpression in Xenopus embryos at stage 20 and in immature oocytes in the ovary 2 months after metamorphosis. Gel mobility shift assay was used to test whether proteins in extracts from Xenopus embryos and ovaries bound to the 0.3 kb DNA. The extract from embryos at stage 11 formed one retarded band. The extract from ovaries formed a different retarded band. The results, taken together, indicate that production of transgenic Xenopus is very useful for the analysis of the promoter activity of genes in amphibians. The results also suggest that at least two proteins (one in the embryo and the other in the ovary of 2-month-old postmetamorphosing Xenopus) bind the 0.3 kb 5'-flanking region of the FTZ-F1α gene. These proteins may be involved in the regulation of FTZ-F1α gene expression in amphibians. [ABSTRACT FROM AUTHOR]

Abstract: Certain foodstuffs exhibit matrix interference effects on the vitamin B1 analysis prescribed in the official methods of the European Union, AOAC International, and Japan. In this study, we demonstrated that one of the problematic polyphenols in green tea or cocoa was tannin. For these matrices, thiamine was found to interact with tannin in the extraction step and was thus removed by filtration as a residue. To resolve the matrix interference, we proposed lowering the pH of the extraction solution by adding hydrochloric acid after the enzyme reaction. High precision (2–3% RSDr) and good recovery (98.3–103%) were obtained with reference materials using the proposed method. We also confirmed the equivalence of the obtained data from the proposed method and the Japanese official method for nutritional labeling. From these results, the method was found to be effective for vitamin B1 analysis regardless of the presence of interference matrices. [Copyright &y& Elsevier]