Fig. 1. Coronin 1B induces F-actin cables in Drosophila S2 cells independently of the Arp2/3 complex. (A) S2 cells were transfected with GFP-tagged coronin 1B or coronin 2A expression constructs, plated on ConA-treated coverslips, and stained for F-actin using phalloidin. (B) S2 cells transfected with GFP-tagged coronin 1B expression constructs were immunostained for Arp2, a subunit of the Arp2/3 complex. (C) Endogenous Drosophila p20Arc was depleted by siRNA for 7 days. S2 cells were transfected with coronin 1B expression constructs and stained with phalloidin. Arrowheads show a colocalization of F-actin and coronin 1B in p20Arc depleted S2 cells. (D) Diagram of coronin-1B–coronin-2A chimeras showing cable-formation ability of each construct. Fragments from coronin 1B are in black, and fragments from coronin 2A are in white. Red numbers indicate the start position of each region according to amino acid sequence of coronin 1B. Corresponding coronin 2A regions were chosen by sequence alignment using ClustalX 1.83.