Figure 5

Active cofilin 1 prevents Syn-driven defects in axon elongation and turning.

(a) Immunoblots showing the proteins indicated on the right in homogenates from neurons electroporated with RFP-wt cofilin, or RFP-S3A cofilin, or RFP-S3E cofilin, or RFP as a control. (b) Quantification of the velocity of actin waves in neurons electroporated with constructs as in (a). (c) Quantification of the velocity of actin waves in neurons electroporated with RFP or RFP-S3A cofilin and incubated in the absence or presence of wt or A30P Syn for 2 days. (d) Quantification of axon elongation during 30 min in neurons electroporated with RFP or RFP-S3A cofilin and treated with or without wt or A30P Syn. (e) Quantification of the percentage of axons turning toward the attraction gradient in neurons electroporated and treated as in (d). Data from neurons of each experiment were pooled and statistical analysis was performed comparing the data from independent experiments. In (b–e) data are expressed as mean values ± SEM. Statistical significance was determined by two tailed t-test. In (b), RFP/S3A, P = 0.0176, alpha value: 0.050:0.747; RFP/S3E, P = 0.0381, alpha value: 0.050:0.273; RFP, n = 41; wt cofilin, n = 13; S3A, n = 43; S3E, n = 11, from 3 independent cultures. In c, RFP/wt Syn, P = 0.0226, alpha value: 0.050:0.547; RFP/A30P Syn P = 0.0191, alpha value: 0.050:0.181; wt Syn/S3A + wt Syn P = 0.0291, alpha value: 0.050:0.604; A30P Syn/S3A + A30P Syn, P = 0.0135, alpha value: 0.050:0.421; RFP, n = 43; wt Syn, n = 17; A30P Syn, n = 20; S3A + wt Syn, n = 14; S3A + A30P Syn, n = 27, from 3 independent cultures. In d, RFP/wt Syn P = 0.0231, alpha value: 0.050:0.634; RFP/A30P Syn P = 0.0282, alpha value: 0.050:0.602; wt Syn/S3A + wt Syn, P = 0.0035, alpha value: 0.050:0.884; A30P Syn/S3A + A30P Syn, P = 0.0426, alpha value: 0.050:0.540; RFP, n = 33; wt Syn, n = 13; A30P Syn, n = 13; S3A + wt Syn, n = 9; S3A + A30P Syn, n = 10, from 3 independent cultures. In e, statistical significance was determined by one-way ANOVA followed by Dunnett’s test for multiple comparison, ***P < 0.001, (RFP/wt Syn, RFP/A30P Syn, P = 0.0001, alpha value: 0.050:1.000) and by two tailed t-test: wt Syn/S3A + wt Syn P = 0.0012, alpha value: 0.050:0.874; A30P Syn/S3A + A30P Syn, P = 0.0044, alpha value: 0.050:0.688; RFP, n = 43; wt Syn, n = 17; A30P Syn, n = 20; S3A + wt Syn, n = 14; S3A + A30P Syn, n = 27, from 3 independent cultures.