Table 1. Dynamic parameters of MTs measured at the cell cortex of LLCPK-1α cells stably expressing GFP-α-tubulin upon ectopic expression of WT or mutant (EBmut) mCherry-NAV1.
| Dynamic parameters | mCherry | mCh-NAV1-WT | mCh-NAV1-EBmut |
|---|---|---|---|
| Growth | |||
| Duration (s) | 9.37 ± 6.47 | 8.78 ± 5.40 | 8.35 ± 4.92 |
| Rate (μm/min) | 9.32 ± 3.65 | 8.69 ± 4.19 | 9.48 ± 3.96 |
| Shrinkage | |||
| Duration (s) | 2.46 ± 1.93 | 2.02 ± 1.60a | 2.38 ± 1.82b |
| Rate (μm/min) | 42.33 ± 19.09 | 44.59 ± 26.69 | 41.92 ± 24.47 |
| Pause duration (s/min) | 30.50 ± 11.26 | 37.23 ± 13.19c | 36.13 ± 11.85c |
| Transition frequencies | |||
| Growth-shrinkage (min−1) | 3.05 ± 2.11 | 3.50 ± 2.51 | 2.58 ± 2.24 |
| Growth-pause (min−1) | 3.76 ± 2.58 | 4.19 ± 4.04 | 4.92 ± 2.89 |
| Shrinkage-growth (min−1) | 19.02 ± 10.48 | 18.78 ± 12.98 | 20.88 ± 12.34 |
| Shrinkage-pause (min−1) | 6.87 ± 8.12 | 13.29 ± 12.51a | 6.10 ± 9.32b |
| Pause-growth (min−1) | 1.54 ± 1.32 | 1.49 ± 1.28 | 1.29 ± 1.28 |
| Pause-shrinkage (min−1) | 2.27 ± 1.34 | 1.48 ± 1.29a | 2.01 ± 1.72b |
| Number of MTs analyzed | 69 | 65 | 69 |
| Number of cells analyzed | 30 | 27 | 29 |
The average growth and shrinkage durations and rates are the average of all instantaneous durations and rates for the population of MTs. The average pause duration and transition frequencies are the average pause duration and transition frequencies for each MT. Values are means ± SD. Analyzed by two-tailed Student's t test.
a
Significant compared with mCherry-expressing cells (P < 0.001).
b
Nonsignificant compared with mCherry-expressing cells (P > 0.05) and significant compared with mCherry-NAV1-WT–expressing cells (P < 0.05).
c
Significant compared with mCherry-expressing cells (P < 0.01).