Coronin displays reduced binding, yet overexpression rescues the PbS4Oc phenotype.

<p>(A) Overexpression of actin binding proteins specifically in the sporozoite stage of the life cycle. (B) Coronin localises at the back of motile wild-type but along the cell periphery in PbS4Oc sporozoites or sporozoites treated with CD, suggesting reduced efficiency of coronin binding. Red arrowheads indicate the front of the sporozoites, scale bar: 5 μm. (C–E) Profilin and ADF2 overexpression were unable to restore organ penetration (c), motility (d), and reduce pausing (e), while coronin overexpression was able to partially rescue the phenotype observed in the PbS4Oc line. In (C) data represented by mean ± standard error. In (D) black, grey, and white bars: efficiently, partially, and non-motile but attached sporozoites, respectively. Fisher’s exact test comparing moving groups in [D] and 0 pause groups in [E]; <i>n</i> is the total numbers of parasites counted per group. A coronin actin binding mutant (K349E,R350E) and a coronin construct lacking the C-terminal region (yet having the intact actin binding domain, ΔC) were unable to rescue the phenotype, suggesting an interplay between N- and C-terminal regions to mediate rescue. Please note that the wild-type and PbS4Oc data are the same as from <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.2005345#pbio.2005345.g002" target="_blank">Fig 2C, 2F and 2H</a>. Underlying data can be found in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.2005345#pbio.2005345.s016" target="_blank">S1 Data</a>. ADF2, actin depolymerising factor 2; CD, cytochalasin D; ΔC, coronin construct lacking C-terminal region; K349E,R350E, full length coronin actin binding mutant; mCh, mCherry.