Fig. 2

CORO1B specifically senses cortical branched actin. a RNAi screen for the proteins that control cell cycle progression among the known proteins that recognise the Arp2/3 complex at the actin branch. CTTN encodes Cortactin, GMFB and GMFG encode the two Glial Maturation Factors β and γ, and CORO1A, CORO1B and CORO1C encode the three type I coronins. Western blot targeting Cortactin and CORO1B validate their depletion. b Confocal images of MCF10A expressing GFP-CORO1B stained with antibodies targeting the WAVE2 NPF and the branched actin marker, Cortactin. Sum of radial line scans registered with respect to the cell edge of one lamellipodium (representative of 10 from different cells). c Cortical enrichment of CORO1B depends on Arp2/3 activity. Confocal images of MCF10A expressing GFP-CORO1B. Cells were treated with the Arp2/3 inhibitor CK-666 or depleted of ARPIN, as indicated. Data are mean ± s.e.m of five technical repeats (a, c); two biological repeats with similar results; two-way ANOVA followed by Sidak’s test for c. Scale bar: 10 µm