Figure 1.

Sas-4-Thr200 Is Required to Localize Asl to New Centrioles

(A) Schematic and example images illustrate the RNA injection assay used for screening the role of various mutant Sas-4-GFP proteins (green) in the recruitment of Asl-mCherry (red) to new centrioles. Arrows in micrographs highlight a positive hit, where Asl-mCherry has not detectably incorporated into the new centriole that has just separated from its older mother. Scale bars, 2 μm.

(B) Asl-mCherry (red) localization at newly separated centrioles in living embryos expressing various Sas-4-GFP fusions from injected mRNA (green, as indicated). Note that Asl-mCherry localizes normally at new centrioles in embryos expressing WT Sas-4-GFP or Sas-4-9A-GFP, in which nine conserved Ser/Thr residues in the vicinity of Thr200 were substituted to Ala (see Figure S2B). The localization of Asl-mCherry is disrupted in embryos expressing Sas-4-[ΔI]-GFP or embryos expressing full-length Sas-4-GFP carrying either T200A, P201G, or S199G point mutations. Arrows indicate new centrioles that have not incorporated Asl-mCherry. Scale bar, 5 μm.

See also Figures S1 and S2.