Table 3.
The effect of the Mpc54p mutant proteins on vesicle docking at the MOP
| Genotype | Vesicles |
PsMs at MOPs | |||
|---|---|---|---|---|---|
| Docked, 0–35 nm | Tethered, 36–60 nm | Accumulated, 61–300 nm | Total, 0–300 nm | ||
| sso1Δ | 6.4 ± 1.8 | 1.1 ± 1.2 | 13.8 ± 5.8 | 21.3 ± 6.7 | N |
| MPC54 | 3.3 ± 0.6 | 2.3 ± 1.5 | 8.0 ± 2.7 | 13.7 ± 1.2 | Y |
| mpc54Δ | 0.9 ± 1.2 | 0.8 ± 0.6 | 5.2 ± 1.4 | 6.9 ± 2.0 | N |
| mpc54-40-RFP | 0.8 ± 1.1 | 1.6 ± 1.6 | 8.9 ± 2.9 | 11.2 ± 2.8 | N |
| mpc54-47-RFP | 0.1 ± 0.4 | 1.9 ± 1.4 | 5.6 ± 3.1 | 7.6 ± 3.8 | N |
| mpc54-118-RFP | 0.2 ± 0.4 | 2.8 ± 1.7 | 7.5 ± 5.2 | 10.5 ± 5.6 | Y |
| mpc54-119-RFP | 0.3 ± 0.5 | 3.8 ± 1.8 | 7.4 ± 4.3 | 11.4 ± 4.9 | Y |
| mpc54-145-RFP | 0.5 ± 1.0 | 3.1 ± 1.4 | 7.4 ± 4.0 | 10.9 ± 4.8 | Y |
For all samples, except mpc54Δ, the distance between the surface of the MOP and the center of the vesicles was measured. For mpc54Δ, the distance between the surface of the central plaque and the center of the vesicles was measured and then corrected based on the average distance between the surface of the central plaque and the surface of the MOP in wild-type cells. Each vesicle was categorized according to its distance from the MOP surface (Supplementary Figure 1). The numbers displayed were derived from averaging the number of vesicles in each category for each MOP analyzed. Only MOPs that displayed proper electron-dense layering but lacked prospore membranes were analyzed. The number of spindle pole bodies examined for each strain was (from top to bottom) as follows: 16, 11, 3, 9, 21, 15, 12, and 11. The number of docked vesicles in the mpc54 mutants was significantly different from both the sso1Δ strain (p < 0.0001 for all mutants) and the MPC54-RFP strain (p < 0.0001 for all mutants except mpc54-47-RFP where p < 0.003).