Effect of mutations at S/T₀P₊₁ residues. (A) Representative results of mutations at S227 residue on the expression profile of GFP-M2-2 fusion proteins. Black and gray histograms represent the DNA content of GFP⁺⁺ (channel > 10³) and total cells in the same dishes, respectively. (B-C) S phase–specific expression of GFP-M2-2 fusion proteins was represented as the shift of X geometric mean channel (DNA content) of GFP⁺⁺ cells, from that of total cells in the experiments with (C) or without (B) nocodazole treatment. A value of 1.00 means that the DNA content of GFP⁺⁺ cells is equal to that of total cells. (D) Fluorescence intensity (Y geometric mean channel) of cells expressing GFP-M2-2 fusion protein (channel > 10¹) or mutants in 4N population after nocodazole treatment. (E) Effect of the mutation at S227 residue in GFP-GATA2 fusion protein on the DNA content (X geometric mean) of GFP⁺⁺ cells. (F-G) Effect of S/T to A mutations on the expression of GFP-CT fusion proteins. Representative results are shown in panel F. Left panel in G shows the change of X geometric mean channel (DNA content) of GFP⁺ cells (channel > 10²). Right panel shows the fluorescent intensity (Y geometric mean channel) of GFP⁺ cells (channel > 10¹). (B-E,G) Mean ± standard error of the mean; *P < .05, compared with wild-type results. For panels A and F, numbers indicate the percentage of cells in each rectangle region.