Correlation between Chemoattractant-induced F Actin Assembly, Phagocytosis, and Growth on Bacteria
Strain . | . | Doubling in medium . | . | Cytokinesis (nuclei/cell) . | . | Plaque growth . | . | Doubling in shaken E. coli . | . | Phagocytosis rate (% of WT) . | . | F actin formation (% of WT) . |
---|---|---|---|---|---|---|---|---|---|---|---|---|
(h) | (μm/h) | (h) | ||||||||||
AX2 | 8 | 1.18 ± 0.02 | 0.60 | 3 | 100 | 100 | ||||||
LW6 | 8 | 1.32 ± 0.13 | 0.09 | 10 | 21 | <10 | ||||||
LW14 | 8 | NT | 0.11 | 10 | 29 | <10 | ||||||
LW18 | 8 | 1.22 ± 0.08 | 0.45 | 3 | 70 | 90 | ||||||
LW20 | 8 | 1.21 ±0.03 | 0.40 | 4 | 70 | 85 | ||||||
S1 | 8 | NT | 0.39 | 6 | 67 | 59 | ||||||
I1 | 8 | NT | 0.09 | 10 | 25 | 17 | ||||||
I2 | 8 | NT | 0.10 | 10 | 33 | 14 | ||||||
S2 | 8 | NT | 0.25 | 6 | 40 | 48 | ||||||
S3 | 8 | NT | 0.47 | 4.5 | 70 | 43 |
Strain . | . | Doubling in medium . | . | Cytokinesis (nuclei/cell) . | . | Plaque growth . | . | Doubling in shaken E. coli . | . | Phagocytosis rate (% of WT) . | . | F actin formation (% of WT) . |
---|---|---|---|---|---|---|---|---|---|---|---|---|
(h) | (μm/h) | (h) | ||||||||||
AX2 | 8 | 1.18 ± 0.02 | 0.60 | 3 | 100 | 100 | ||||||
LW6 | 8 | 1.32 ± 0.13 | 0.09 | 10 | 21 | <10 | ||||||
LW14 | 8 | NT | 0.11 | 10 | 29 | <10 | ||||||
LW18 | 8 | 1.22 ± 0.08 | 0.45 | 3 | 70 | 90 | ||||||
LW20 | 8 | 1.21 ±0.03 | 0.40 | 4 | 70 | 85 | ||||||
S1 | 8 | NT | 0.39 | 6 | 67 | 59 | ||||||
I1 | 8 | NT | 0.09 | 10 | 25 | 17 | ||||||
I2 | 8 | NT | 0.10 | 10 | 33 | 14 | ||||||
S2 | 8 | NT | 0.25 | 6 | 40 | 48 | ||||||
S3 | 8 | NT | 0.47 | 4.5 | 70 | 43 |
WT (AX2), gβ− (LW6 and LW14), “rescue” (LW18 and LW20) and β-subunit point mutants (S1 to S3) were tested for growth (column 2) and cytokinesis (column 3) in axenic medium, growth on a lawn of E. coli B/2 (column 4) or in shaken cultures of E. coli B/r (column 5). Percentage inhibition of phagocytosis rate after 10 min incubation with FITC-E. coli B/r is shown in column 6. Percentage actin polymerization in response to chemoattractants present in bacterial supernatants was measured per each strain as described in Fig. 2, and shown in column 7. NT, not tested. The values shown are mean values of: two experiments (column 2), 100–150 cells per clone (column 3), three experiments for a total of six plaques per clone (column 4), two experiments for a total of four cultures (column 5), six (AX2 to LW20) and two (S1 to S3) duplicate determinations (column 6), two experiments in triplicates. For details refer to Materials and Methods.