Quantification of MT plus end dynamics
| Parameter | Cell interior | Cell periphery | ||
| Control siRNA | SEPT2 siRNA | Control siRNA | SEPT2 siRNA | |
| Growth rate (µm/min) | 8.92 ± 0.4030 | 9.42 ± 0.6647 | 5.32 ± 0.23 | 4.18 ± 0.17b |
| Shortening rate (µm/min) | 11.8 ± 1.7474 | 14.9 ± 1.8596 | 7.09 ± 0.44 | 6.65 ± 0.41 |
| Catastrophe rate (µm/min) | 19.4 ± 3.8667 | 18.1 ± 2.3859 | 10.1 ± 0.99 | 9.18 ± 0.74 |
| Attenuation duration (s) | 9.45 ± 0.9234 | 11.3 ± 1.0191 | 12.5 ± 0.83 | 11.1 ± 0.64 |
| Transition frequency (s−1) | ||||
| Shortening to growth | 0.018 ± 0.003 | 0.017 ± 0.003 | 0.024 ± 0.002 | 0.025 ± 0.002 |
| Growth to shortening | 0.019 ± 0.003 | 0.018 ± 0.003 | 0.025 ± 0.002 | 0.028 ± 0.003 |
| Growth to catastrophe | 0.004 ± 0.002 | 0.013 ± 0.002a | 0.006 ± 0.001 | 0.009 ± 0.001a |
| Percent time | ||||
| Growth | 84.1 ± 3.0123 | 80.4 ± 3.3093 | 58.3 ± 2.74 | 49.4 ± 2.62a |
| Shortening | 8.87 ± 1.6971 | 11.9 ± 2.5739 | 22.9 ± 2.11 | 30.1 ± 2.30a |
| Catastrophe | 3.56 ± 1.1483 | 9.64 ± 2.5314a | 9.85 ± 1.92 | 16.1 ± 2.29a |
| Attenuation | 35.1 ± 2.2910 | 34.9 ± 1.4142 | 18.8 ± 2.36 | 20.5 ± 2.41 |
| Parameter | Cell interior | Cell periphery | ||
| Control siRNA | SEPT2 siRNA | Control siRNA | SEPT2 siRNA | |
| Growth rate (µm/min) | 8.92 ± 0.4030 | 9.42 ± 0.6647 | 5.32 ± 0.23 | 4.18 ± 0.17b |
| Shortening rate (µm/min) | 11.8 ± 1.7474 | 14.9 ± 1.8596 | 7.09 ± 0.44 | 6.65 ± 0.41 |
| Catastrophe rate (µm/min) | 19.4 ± 3.8667 | 18.1 ± 2.3859 | 10.1 ± 0.99 | 9.18 ± 0.74 |
| Attenuation duration (s) | 9.45 ± 0.9234 | 11.3 ± 1.0191 | 12.5 ± 0.83 | 11.1 ± 0.64 |
| Transition frequency (s−1) | ||||
| Shortening to growth | 0.018 ± 0.003 | 0.017 ± 0.003 | 0.024 ± 0.002 | 0.025 ± 0.002 |
| Growth to shortening | 0.019 ± 0.003 | 0.018 ± 0.003 | 0.025 ± 0.002 | 0.028 ± 0.003 |
| Growth to catastrophe | 0.004 ± 0.002 | 0.013 ± 0.002a | 0.006 ± 0.001 | 0.009 ± 0.001a |
| Percent time | ||||
| Growth | 84.1 ± 3.0123 | 80.4 ± 3.3093 | 58.3 ± 2.74 | 49.4 ± 2.62a |
| Shortening | 8.87 ± 1.6971 | 11.9 ± 2.5739 | 22.9 ± 2.11 | 30.1 ± 2.30a |
| Catastrophe | 3.56 ± 1.1483 | 9.64 ± 2.5314a | 9.85 ± 1.92 | 16.1 ± 2.29a |
| Attenuation | 35.1 ± 2.2910 | 34.9 ± 1.4142 | 18.8 ± 2.36 | 20.5 ± 2.41 |
MDCK-EB1-dsRed cells were simultaneously transfected with α-tubulin–GFP and control or SEPT2 siRNAs. EB1-dsRed displacements were quantified as described in Materials and methods. All values are means ± SEM. Values with statistically significant differences between control and SEPT2 siRNAs are highlighted in italics. Cell interior control siRNA: n = 50; 13 cells. Cell interior SEPT2 siRNA: n = 50; 16 cells. Cell periphery control siRNA: n = 117; nine cells. Cell periphery SEPT2 siRNA: n = 104; seven cells.
P < 0.05.
P < 0.001.