Rabbit Anti-Human CRB2 (a.a. 102-282) Polyclonal antibody

Histone lysine methylation is an important chromatin modification that can be catalyzed to a mono-, di-, or tri-methyl state. An ongoing challenge is to decipher how these different methyllysine histone marks can mediate distinct aspects of chromatin function. The fission yeast checkpoint protein Crb2 is rapidly targeted to sites of DNA damage after genomic insult, and this recruitment requires methylation of histone H4 lysine 20 (H4K20). Here we show that the tandem tudor domains of Crb2 preferentially bind the di- methylated H4K20 residue. Loss of this interaction by disrupting either the tudor-binding motif or the H4K20 methylating enzyme Set9/Kmt5 ablates Crb2 localization to double-strand breaks and impairs checkpoint function. Further we show that dimethylation, but not tri-methylation, of H4K20 is required for Crb2 localization, checkpoint function, and cell survival after DNA damage. These results argue that the di- methyl H4K20 modification serves as a binding target that directs Crb2 to sites of genomic lesions and defines an important genome integrity pathway mediated by a specific methyl-lysine histone mark.

M-B-(N) (M = Mo, Cr, Ti) coatings were obtained by the magnetron sputtering of MoB, CrB2, TiB, and TiB2 targets in argon and in gaseous mixtures of argon with nitrogen. The structure and composition of the coatings have been investigated using scanning electron microscopy, glow-discharge optical emission spectroscopy, and X-ray diffraction. The mechanical and tribological properties of the coatings have been determined by nanoindentation, scratch-testing, and ball-on-disk tribological tests. The experiments on estimating the oxidation resistance of coatings were carried out in a temperature range of 600-1000 degrees C. A distinctive feature of TiB2 coatings was their high hardness (61 GPa). The Cr-B-(N) coatings had high maximum oxidation resistance (900 degrees. (CrB2) and 1000 degrees C(Cr-B-N)) and possessed high resistance to the diffusion of elements from the metallic substrate up to a temperature of 1000 degrees CThe Mo-B-N coatings were significantly inferior to the Ti-B-(N) and Cr-B-(N) coatings in their mechanical properties and oxidation resistance, as well as had. tendency to oxidize in air atmosphere after long exposure at room temperature. All of the coatings with nitrogen possessed a low coefficient of friction (in a range of 0.3-0.5) and low relative wear ((0.8-1.2) x 10(-6) mm(3) N-1 m(-1).