Clustering properties of the Cdr2-Cter domain. (A, top) Medial plane epifluorescence images of GFP–Cdr2-Cter (residues 591–747) and GFP–Kcc4-Cter (residues 893–1,037). Bar, 5 µm. (bottom) 1.75× magnification of boxed regions. Bar, 1 µm. (B) Fluorescence intensity along the cortex in regions boxed in A, representative of the cell population. (C) Pull-down assay between differentially tagged Cdr2-Cter or Kcc4-Cter. Overexpressed GST–Cdr2-Cter or GST–Kcc4-Cter was coupled to glutathione beads and mixed with extracts of cells expressing Cdr2-Cter–myc₁₂ or Kcc4-Cter–myc₁₂, respectively. Cdr2-Cter and Kcc4-Cter were revealed in input and pull-down fractions with anti-GST or antimyc antibodies. (right) Normalized Cter-myc signals in GST pull-down measured in two independent experiments. Molecular masses are indicated. (D) Cdr2 KA-1 model highlighting the two hydrophobic residues of the β4–β5 loop (F704 and F705) and the Kcc4 KA-1 structure 3OST (Moravcevic et al., 2010), in which the equivalent loop contains a charged residue (D1001) surrounded by two neutral residues (G1000 and G1002; not depicted). A.U., arbitrary unit; WB, Western blot.