Asf1 and Snf2 have partially overlapping functions in cell cycle and checkpoint control.

<p>A. Rad53 activation is impaired in <i>asf1Δ snf2Δ</i> double mutants. Cells were grown in the presence or absence of 0.2 M HU for two hours. Actin is the loading control. The apparent lower expression of Rad53 in the double mutant was not reproducible – see Figure 7B. B. <i>asf1Δ snf2Δ</i> mutants fail to fully arrest in S phase in response to HU. DNA content of normally cycling cells (time 0) and cells grown in the presence of 0.2 M HU. C. Rad53 activation is delayed in <i>asf1Δ snf2Δ</i> double mutant cells. Cells from the cultures assayed in B were processed for analysis of Rad53 modification state. Actin is the loading control. D. Recovery from replication stress is compromised in <i>asf1Δ snf2Δ</i> mutants. Ten-fold serial dilutions of early log phase cells were grown in YPD or YPD + 0.2 M HU for 24 hours. Aliquots of these cultures were then diluted to 1×10⁶ cells/mL and spotted onto rich solid medium. Cells were grown at 30°C and photographs were taken after 2 and 3 days.