Table 1.
Quantification of filopodia formation by DdMyo7 mutants in myo7 − cells
| Region | Name | % Cells with filopodia | Filopodia per cell ± SEM | Cortex/cell intensity ratio ± SEM | Filopod length ± SEM, μm | Tip/cell intensity ratio ± SEM | Tip accumulation | n (cells) | N (experiments) | Autoinhibition dysregulated | Activity in filopodia formation |
| DdMyo7 | 58 | 2.26 ± 0.32 | 1.17 ± 0.03 | 3.05 ± 0.12 | 1.86 ± 0.16 | No | 84 | 4 | No | WT | |
| KKAA | 79 | 5.32 ± 0.37 | 1.76 ± 0.08 | 2.69 ± 0.08 | 3.05 ± 0.12 | No | 130 | 3 | Yes | More than WT, due to increase in active form | |
| Motor-Pro | 6 | N/A | 1.02 ± 0.01 | N/A | N/A | N/A | 206 | 4 | Yes | None (lacks required domains) | |
| Motor-Pro-CC | 11 | 1.32 ± 0.14 | 1.38 ± 0.02 | 2.14 ± 0.27 | 1.23 ± 0.18 | No | 181 | 7 | Yes | More targeted, but less active; forms shorter filopodia than WT | |
| Proximal tail | ΔcDD | 59 | 2.52 ± 0.27 | 1.49 ± 0.07 | 3.0 ± 0.16 | 3.15 ± 0.19 | No | 94 | 2 | Yes | More in active form, but not efficient to lack of proximal dimerization |
| ΔPro1 | 51 | 2.49 ± 0.25 | 1.23 ± 0.06 | 2.8 ± 0.18 | 1.5 ± 0.17 | — | 68 | 5 | No | WT | |
| ΔSAH-PLA | 40 | 2.29 ± 0.32 | 2.16 ± 0.17 | 3.1 ± 0.24 | 5.08 ± 0.58 | Yes | 78 | 3 | Yes | Active, less efficient (LA and distal oligomerization sufficient for activity) | |
| MF deletions | ΔMF1-SH3 | 58 | 3.20 ± 0.27 | 1.33 ± 0.04 | 2.38 ± 0.11 | 2.03 ± 0.13 | No | 203 | 5 | Yes | Less active due to less targeting |
| ΔSAH-SH3 | 25 | 1.60 ± 0.13 | 1.26 ± 0.05 | 3.1 ± 0.17 | 2.49 ± 0.19 | Yes | 219 | 4 | Yes | Less efficient in filopodia formation (poor targeting + no proximal dimerization) | |
| ΔPro2-MF2 | 35 | 3.18 ± 0.40 | 1.38 ± 0.08 | 2.7 ± 0.23 | 2.99 ± 0.35 | No | 82 | 5 | Yes | Less active due to less targeting | |
| ΔcDD/MF2 | 3 | N/A | 0.98 ± 0.02 | N/A | N/A | N/A | 84 | 4 | Yes | None (need proximal dimerization when targeting/distal oligomerization is less efficient) | |
| ΔSAH-PLA/MF2 | 1 | N/A | 1.08 ± 0.02 | N/A | N/A | N/A | 165 | 6 | Yes | None (need proximal dimerization when targeting/distal oligomerization is less efficient) | |
| Lever arm | Δ2IQ | 68 | 3.18 ± 0.40 | 1.43 ± 0.06 | 3.8 ± 0.18 | 3.31 ± 0.18 | No | 95 | 4 | Yes | More in active form, less efficient due to shorter lever arm |
| Δ3IQ-PLA | 14 | 1.17 ± 0.17 | 1.70 ± 0.14 | N/A | N/A | N/A | 46 | 3 | Yes | More in active form, less efficient due to short LA and proximal dimerization | |
| Δ2IQ/SAH-PLA | 0 | N/A | 1.51 ± 0.03 | N/A | 4.32 ± 0.26* | No* | 179 | 2 | Υes | None (short lever arm and no proximal dimerization) |
WT, wild type.
*
WT background.