Loss of coronin 1C increases stability of Arp3B, but not Arp3 actin networks. (A) The immunoblot shows the expression level of RNAi-resistant GFP-tagged Arp3 (blue) and Arp3B (red) in HeLa cells treated with Arp3/Arp3B and coronin 1C siRNA. The immunofluorescent images show representative actin tails (magenta) in the siRNA-treated HeLa cells stably expressing GFP-tagged Arp3 and Arp3B (green). Scale bar = 5 µm. (B) Quantification of actin tail lengths in cells stably expressing RNAi-resistant GFP-tagged Arp3 or Arp3B and treated with Arp3/Arp3B and coronin 1C siRNA. The error bars represent SEM from n = 3 independent experiments in which the length of 100 tails was analyzed per condition. (C) Quantification of the half-life of photoactivated GFP^PA-tagged Arp3 or Arp3B in actin tails in cells treated with coronin 1C and/or MICAL2 siRNA. (D) Quantification of the half-life of photoactivated Cherry-GFP^PA-β-actin in actin tails in cells treated with different combinations of Arp3B, coronin 1C, and MICAL2 siRNA. The graphs in C and D show the mean half-life and SEM from n = 3 independent experiments. Tukey’s multiple comparisons test was used to determine statistical significance; ***, P < 0.001; **, P < 0.01; *, P < 0.05.