CRB2 blocking peptide

Superhard CrB2 coatings with hardness around 45.7 +/- 1.6 GPa were deposited on cemented carbide sub-strates via a direct current magnetron sputtering at the deposition temperature of 300 degrees C. The composition, microstructure and corrosion resistance of the deposited coatings were investigated. The results revealed that the deposited CrB2 coating had a preferred (0 01) orientation and dense nanocolumnar structure. The great improvement in corrosion resistance of CrB2 coated substrate was obviously observed from potentiodynamic polarization and electrochemical impedance spectroscopy. The formation of Cr2O3 was supposed to be the key factor for the obvious passivation phenomenon. Consequently, the corrosion current density was reduced by 100-fold in combination with a higher polarization resistance compared with the pristine substrate. (C) 2019 Elsevier B.V. All rights reserved.

Bromodomain proteins bind acetylated histones to regulate transcription. Emerging evidence suggests that histone acetylation plays an important role in DNA replication and repair, although its precise mechanisms are not well understood. Here we report studies of two double bromodomain-containing proteins, Bdf1 and Bdf2, in fission yeast. Loss of Bdf1 or Bdf2 led to a reduction in the level of histone H4 acetylation. Both bdf1 Delta and bdf2 Delta cells showed sensitivity to DNA damaging agents, including camptothecin, that cause replication fork breakage. Consistently, Bdf1 and Bdf2 were important for recovery of broken replication forks and suppression of DNA damage. Surprisingly, deletion of bdf1 or bdf2 partially suppressed sensitivity of various checkpoint mutants including swi1 Delta, mrc1 Delta, cds1 Delta, crb2 Delta, chk1 Delta, and rad3 Delta, to hydroxyurea, a compound that stalls replication forks and activates the Cds1-dependent S-phase checkpoint. This suppression was not due to reactivation of Cds1. Instead, we found that bdf2 deletion alleviates DNA damage accumulation caused by defects in the DNA replication checkpoint. We also show that hydroxyurea sensitivity of mrc1 Delta and swi1 Delta was suppressed by mutations in histone H4 acetyltransferase subunits or histone H4. These results suggest that the double bromodomain-containing proteins modulate chromatin structure to coordinate DNA replication and S-phase stress response.