A. CHX assay with S309A. N2a cells transfected with either S309A or S309A+4D were treated with CHX for 0, 4 or 8 hrs before harvest. Lysates were subjected to immunoblotting with anti-Atoh1 or β-actin. Quantification of relative levels of ATOH1 to the β-ACTIN (right panel). Error bars are representing as Mean ± SEM from three trials of each condition. 