Figure 7. Viscoadaptation occurs in cells with low ATP.

(A) FRAP measurements on WT cells untreated (UT) or treated with sodium azide, sodium arsenite, or a combination of oligomycin (O), antimycin A (A), and FCCP (F) +/− 50 mM LiCl (n>3 experiments, >10 cells/experiment)(unpaired t-test, UT vs Azide p=.0002, UT vs Arsenite p=.001, UT vs AOF p<.0001; Azide vs Azide +Li p=.054, Arsenite vs Arsenite +Li p=.025, AOF vs AOF +Li p=.016) Error bars are s.e.m. (B) WT cells expressing a FRET-based ATP nanosensor were switched from 2% to 0.1% glucose for 30–60 minutes. Each point is one cell. ATP levels for single cells were determined by the ratio of 528:488 fluorescence (see Figure S7A). Mobility was assessed by performing FRAP of the fluorescent sensor on the same cells. Orange dots represent cells treated with 50 mM LiCl during starvation (without LiCl R= −0.597 p<.0001; with LiCl R= −0.361 p=0.0063) (C) WT cells in 0% glucose SD media. Measurements occur between 30–60 minutes after starvation onset (R= −0.047, p=.38) (D) t-half values and ATP levels for unstressed WT cells in 2% glucose SD media. Cells were sampled to capture a range of ATP levels. (R= −0.555 p<.0001) (E) Cells expressing the ATP FRET sensor were heated over the course of an hour from 22°C to 42°C. ATP level and t-half was recorded for each cell. X-axis is time in minutes. Data is plotted as a rolling average of every 3 values and normalized on a scale of 0 to 1 to facilitate comparison. Dotted lines represent s.e.m. See also Figure S7.