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Background: Bovine Mx2 gene sequences were already reported, but further information about the gene properties is not yet available. The objective of the current study was to elucidate the structural properties of the bovine Mx2 gene mainly the promoter region and its possible functional role. If available, such information would help in assessing the functional properties of the gene, which was reported to confer antiviral action against recombinant VSV. Results: Examinations on the bovine genomic BAC clone-confirmed to contain the Mx2 gene-revealed 883-bp sequences. A computer scan unequivocally identified a 788-bp promoter region containing a typical TATA box, three ISREs and other promoter-specific motifs. Comparative analysis of nine bovine genomic DNA samples showed 19 nucleotide substitutions suggesting the existence of five different genotypes in the promoter region. The water buffalo Mx2 promoter region was determined by using primers based on the bovine Mx2 promoter region disclosing 893-bp, with 56 substitutions, two insertions, 9 and 1 nt at two different sites. A functional analysis of the putative ISRE indicated that ISRE played a synergetic role in the activation of bovine Mx2 gene transcription. Conclusion: Bovine and water buffalo Mx2 promoter region was identified disclosing, the conserved ISRE, located in the proximal end of the promoter region like other members of the antiviral family, suggesting functional activity under interferon stimulation. [ABSTRACT FROM AUTHOR]

We have applied hard x-ray photoelectron spectroscopy to LiRh2O4 to study its bulk electronic structures. LiRh2O4 shows the metal-insulator transition (MIT) at 170 K when the temperature is decreased via an intermediate phase, which appears below 230 K and is ascribed to the band Jahn-Teller instability. Clear spectral changes are observed across the MIT for both the valence band near the Fermi level (EF) and the Rh 3d core state. Their slight spectral changes are also observed across 230 K, induced by the orbital ordering and the slight change of the screening by conduction electrons. The linear polarization dependence of the spectra was measured for the O 2s and valence-band states. The contribution of the Rh 5s state hybridized with the O 2p states in the valence band is semiquantitatively evaluated. [ABSTRACT FROM AUTHOR]

Hard and soft x-ray photoelectron spectroscopy was performed for core and valence electrons in solid compounds containing V and O atoms. The single-nucleus recoil effects on photoelectron emission were observed in the form of recoil shifts for all core levels and the valence band in a heavy Fermion material LiV2O4, whereas such shifts were negligible in VO2 even in the high temperature metal phase. The valence band recoil shifts of V5O9 and V2O3 metal are found to be in between. These differences in the valence band are ascribable to the difference in the relative spectral weight of the O 2p component near the Fermi level. [ABSTRACT FROM AUTHOR]

O6-Methylguanine produced in DNA induces mutation due to its ambiguous base-pairing properties during DNA replication. To suppress such an outcome, organisms possess a mechanism to eliminate cells carrying O6-methylguanine by inducing apoptosis that requires the function of mismatch repair proteins. To identify other factors involved in this apoptotic process, we performed retrovirus-mediated gene-trap mutagenesis and isolated a mutant that acquired resistance to a simple alkylating agent, N-methyl-N-nitrosourea (MNU). However, it was still sensitive to methyl methanesulfonate, 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea, etoposide and ultraviolet irradiation. Moreover, the mutant exhibited an increased mutant frequency after exposure to MNU. The gene responsible was identified and designated Mapo1 (O6-methylguanine-induced apoptosis 1). When the expression of the gene was inhibited by small interfering RNA, MNU-induced apoptosis was significantly suppressed. In the Mapo1-defective mutant cells treated with MNU, the mitochondrial membrane depolarization and caspase-3 activation were severely suppressed, although phosphorylation of p53, CHK1 and histone H2AX was observed. The orthologs of the Mapo1 gene are present in various organisms from nematode to humans. Both mouse and human MAPO1 proteins expressed in cells localize in the cytoplasm. We therefore propose that MAPO1 may play a role in the signal-transduction pathway of apoptosis induced by O6-methylguanine-mispaired lesions.Oncogene (2009) 28, 1142–1150; doi:10.1038/onc.2008.462; published online 12 January 2009 [ABSTRACT FROM AUTHOR]

We have succeeded in developing a method for photoemission electron microscopy (PEEM) on fully magnetized ferromagnetic bulk samples and have applied this technique to Dy-doped Nd-Fe-B permanent magnets. Remanence magnetization of the sample was approximately 1.2 T, and its dimension was 3 × 3 × 3 mm3. By utilizing a yoke as an absorber of the stray magnetic field from the sample, we can obtain well-focused PEEM images of magnetized samples. We have observed not only chemical distributions to visualize Dy-rich and Dy-poor areas but also magnetic domains by x-ray magnetic circular dichroism. The formation of reversed magnetic domains is strongly suppressed at room temperature by Dy-doping. As the temperature of the Dy-doped sample is raised, starting from room temperature, the reversed magnetic domains first grow along the magnetization easy axis. Next, above approximately 80°C, the shapes of reversed domains start to expand in the direction perpendicular to the easy axis. Above approximately 85°C, the reversed domains cover more than half of the field of view of 30 μm. More importantly, the reversed magnetic domains tend to nucleate or extend in Dy-poor regions. We discuss the relationship between the chemical distribution and the magnetic domain structure. [ABSTRACT FROM AUTHOR]