Figure S2.

The Zn²⁺ Ion in the CM2 Dimer Is Required for CM2 Dimerization In Vitro and Efficient Cnn-Scaffold Assembly In Vivo, Related to Figures 2 and 4

(A) SEC-MALS analysis of WT-CM2 in buffer without (black) or with (brown) EDTA, or a mutant form of CM2 in which the Zn²⁺ coordinating His and Cys residues have been mutated to Ala (CM2-HCAA). Removing the Zn²⁺ or mutating the Zn²⁺ binding residues causes the purified CM2 to behave as a monomer.

(B) Micrographs illustrate and graphs quantify the centrosomal localization of WT-GFP-Cnn, GFP-Cnn-ΔCM2 and GFP-Cnn-HCAA; Spd-2-RFP is shown as a centrosomal marker. Error bars represent the SD of the mean from at least 5 embryos. Statistical significance (compared to WT [above each bar] or Cnn-ΔCM2 [line at the top of the graph]) was assessed using an unpaired t test in GraphPad Prism (^∗∗∗∗p < 0.0001). Scale bar = 2 μm.