Research Paper Volume 10, Issue 3 pp 402—424

Preferential Ty1 retromobility in mother cells and nonquiescent stationary phase cells is associated with increased concentrations of total Gag or processed Gag and is inhibited by exposure to a high concentration of calcium

Figure 8. Ty1 retromobility and the proportion of mature p45-Gag decrease as cells transition to stationary phase. (A) His+ rates per cell generation for cells grown to mid-exponential (Exp, two days) or early stationary phase (Stat, four days). Data are for five trials. (B) Western blot probed with Gag antibody (upper panel) or reprobed with beta-actin antibody as a loading control (lower panel) for protein extracts prepared from cells grown for two days to exponential phase (d2), four days to early stationary phase (d4), or seven days to stationary phase (d7). Arrows indicate the migration of the different forms of Gag. (C) Quantification of Gag levels normalized to beta-actin in cells grown for the indicated number of days. Data are for three trials. (D) Quantification of the proportion of the total Gag signal that was comprised of p45 for cells grown for the indicated number of days for three trials. Data are from three trials. Horizontal bars indicate comparisons between days two and four or days four and seven. (E-F) Western blots for Gag and beta-actin as described for panel B for cell extracts prepared from exponential phase cells (d2, spt3∆), stationary phase cells (d7), or fractionated NQ and Q cells grown in YPD without (panel E and panel F Mock) or with (CaCl2) 100 mM calcium chloride. Graphs show mean values with standard deviation. Asterisks indicate significant differences as for Fig. 2.