No abstract

Gene expression is controlled by alterations in the epigenome, including DNA methylation and histone modification. Recently, it was reported that 5-methylcytosine (5mC) is converted to 5-hydroxymethylcytosine (5hmC) by proteins in the ten-eleven translocation (TET) family. This conversion is believed to be part of the mechanism by which methylated DNA is demethylated. Moreover, histones undergo modifications such as phosphorylation and acetylation. In addition, modification with O-linked-N-acetylglucosamine (O-GlcNAc) by O-GlcNAc transferase (OGT) was recently identified as a novel histone modification. Herein, we focused on TET3, the regulation of which is still unclear. We attempted to elucidate the mechanism of its regulation by biochemical approaches. First, we conducted mass spectrometric analysis in combination with affinity purification of FLAG-TET3, which identified OGT as an important partner of TET3. Co-immunoprecipitation assays using a series of deletion mutants showed that the C-terminal H domain of TET3 was required for its interaction with OGT. Furthermore, we showed that TET3 is GlcNAcylated by OGT, although the GlcNAcylation did not affect the global hydroxylation of methylcytosine by TET3. Moreover, we showed that TET3 enhanced its localization to chromatin through the stabilization of OGT protein. Taken together, we showed a novel function of TET3 that likely supports the function of OGT.

ABSTRACT:Polyethylene gels were prepared by gelation/crystallization from dilute decalin solutions using five kinds of polyethylenes with different molecular weights and degrees of branching. The decalin was allowed to evaporate from the gels under ambient condition in order to prepare dry gels. The dry gel of ultra-high molecular weight polyethylene (UHMWP) of M w = 6 x 10 6 forms a film but the other low molecular weight polyethylenes (LMWP) with molecular weight lower than 3 x I 0 5 do not form a film. In order to investigate such a difference, the morphological properties of five kinds of dry gels were investigated by scanning electron microscopy, polarized microscopy, small angle light scattering, and small angle X-ray scattering. Within LMWP dry gels, observation reveals spherulitic textures whose crystal lamellae are rotated around a radial direction. In contrast, within the dry gels of UHMWP, there exists rodlike textures as assemblies of large lamellar crystals which are highly oriented with their fiat faces parallel to the film surface. To assure ultradrawing up to consistently high draw ratio, a suitable number of entanglements should be formed by tie molecules which connect the crystal lamellae.

No abstract

A novel nano-scale triarylsilanol bearing a bowl-shaped framework was synthesized, the structure of which was established by X-ray crystallographic analysis. The silanol was found to be extremely resistant to self-condensation whereas it reacted easily with appropriate molecules to give the corresponding derivatives.