F-actin levels and cofilin activity are impacted by loss of Coro1B and Coro1C. (A) Immunofluorescent staining of parental and null populations for F-actin; Scale bar, 100 μm. (B) Integrated pixel density of phalloidin staining in fixed parental (n = 1,271) and null (n = 1,154) cells from A (top). Blots of total actin from matched whole cell lysates below. Ratios of actin levels relative to the HSC70 loading control are indicated below the blot. (C) Representative still frames from live cell imaging of parental and null cells expressing cofilin-mScarlet. Scale bar,10 μm. (D) Immunofluorescent staining for endogenous cofilin in parental and null cells. Scale bar, 10 μm. (E) Width of cofilin at the edge of parental (n = 46) and null (n = 48) cells. (F) Fold change in polymerization rate of parental and null cells after treatment with 100 nM jasplakinolide. Data is displayed using a logarithmic transformation to the base 2 and color-coded by experimental replicate. For bar graph, an unpaired Student’s t test with Welch’s correction was performed and error bars represent standard deviation. For beeswarm superplots, the mean of experimental replicates are color-coded and overlayed on violin plots representing cumulative cell level data. Error bars represent SEM. For all graphs, Student’s t tests were performed, unless otherwise stated. *P value = 0.04, **P value = 0.0032, ****P value <0.0001. Source data are available for this figure: SourceData F4.