APOBEC3G and infection: Consistent with the onset of Vif expression, YFP-A3G levels began to decline ~1.5 h after productive infection (defined as the onset of CFP expression) with a half-time (T1/2) of decay of 4.58 ± 1.27 h (n = 30), consistent with previous estimates of Vif-mediated A3G degradation kinetics (68, –, 72) (Fig. 1C with quantification in Fig. 1D).