Transcriptional regulation by Asf1: new mechanistic insights from studies of the DNA damage response to replication stress.

Asf1 is a conserved histone H3/H4 chaperone. We find that Asf1 in budding yeast promotes an essential cellular response to replication stress caused by the ribonucleotide reductase inhibitor hydroxyurea. That is, Asf1 stimulates derepression of DNA damage response (DDR) genes during the S phase.