Kinetic parameters of IC-1B and IC-2C dynein movement in hippocampal neurons
. | 1B dynein . | 2C dynein . |
|---|---|---|
| Number of dynein puncta | 152 | 98 |
| Retrograde | ||
| Mean interval velocity μm/s [n] | 0.7 ± 0.02 [692] | 0.7 ± 0.02 [592] |
| Excursions | ||
| Number | 94 | 49 |
| Mean velocity (μm/s) | 0.6 ± 0.04 | 0.7 ± 0.05 |
| Mean distance (μm) | 2.7 ± 0.24 | 2.3 ± 0.25 |
| Mean time (s)a | 4.8 ± 0.33 | 3.4 ± 0.2 |
| Pauses | ||
| Number | 42 | 55 |
| Average time (s)b | 4.6 ± 0.49 | 3.3 ± 0.24 |
| Anterograde | ||
| Average interval velocity μm/s [n] | 0.7 ± 0.02 [1,061] | 0.7 ± 0.02 [590] |
| Excursions | ||
| Number | 128 | 47 |
| Mean velocity (μm/s)c | 0.6 ± 0.03 | 0.7 ± 0.05 |
| Mean distance (μm) | 2.6 ± 0.18 | 3.0 ± 0.51 |
| Average time (s) | 4.8 ± 0.29 | 3.7 ± 0.34 |
| Pauses | ||
| Number | 56 | 59 |
| Mean time (s) | 4.0 ± 0.27 | 4.5 ± 0.43 |
. | 1B dynein . | 2C dynein . |
|---|---|---|
| Number of dynein puncta | 152 | 98 |
| Retrograde | ||
| Mean interval velocity μm/s [n] | 0.7 ± 0.02 [692] | 0.7 ± 0.02 [592] |
| Excursions | ||
| Number | 94 | 49 |
| Mean velocity (μm/s) | 0.6 ± 0.04 | 0.7 ± 0.05 |
| Mean distance (μm) | 2.7 ± 0.24 | 2.3 ± 0.25 |
| Mean time (s)a | 4.8 ± 0.33 | 3.4 ± 0.2 |
| Pauses | ||
| Number | 42 | 55 |
| Average time (s)b | 4.6 ± 0.49 | 3.3 ± 0.24 |
| Anterograde | ||
| Average interval velocity μm/s [n] | 0.7 ± 0.02 [1,061] | 0.7 ± 0.02 [590] |
| Excursions | ||
| Number | 128 | 47 |
| Mean velocity (μm/s)c | 0.6 ± 0.03 | 0.7 ± 0.05 |
| Mean distance (μm) | 2.6 ± 0.18 | 3.0 ± 0.51 |
| Average time (s) | 4.8 ± 0.29 | 3.7 ± 0.34 |
| Pauses | ||
| Number | 56 | 59 |
| Mean time (s) | 4.0 ± 0.27 | 4.5 ± 0.43 |
Interval velocities for dynein complexes with mRFP–IC-2C or mRFP–IC-1B moving in hippocampal neuronal axons were calculated for every movement between each pair of video frames and averaged. Excursions are puncta movements greater than one pixel for four frames (1 pixel = 137 μm; 1 frame per 0.5 s). Excursion velocity is total distance traveled per total time traveled. Pauses are periods with no dynein movement that separate two excursions.
Retrograde IC-1B dynein has excursions with longer mean durations than dynein with IC-2C (P < 0.0003, Student's t test).
Retrograde IC-1B dynein pauses for longer mean times than dynein with IC-2C (P < 0.01, Student's t test).
The mean velocity of anterograde IC-2C dynein is faster than that of dynein with IC-1B (P < 0.02, Student's t test).