FIGURE 4.

Targeting of the N-ter mutants in onion and Arabidopsis cells and the relationship with the properties of the N-ter. Representative images of transiently expressed N-ter mutant TP-YFP fusion proteins in onion (A–D) and Arabidopsis (E–H) cells. Left and right labels indicate the N-ter peptides used to generate the mutants. Top labels indicate the original constructs. N10R and N10S denote the reversed and scrambled mutants. The bars in D and H show the scales for A–D and E–H, respectively. Bars, 10 μm; n/a, not applicable. A and E, mutants containing Hsp70-inteacting peptides. For clarity of dual localization, two images taken from the same cell with different exposure time of V10-SSF are shown in A and E, and the two images of the same cells of A6R-SSF are shown in E. B and F, mutants containing noninteracting peptides. C and G, control constructs from previously published results (21). D and H, reversed (N10R) and scrambled (N10S) mutants. I and J, ratios of plastid/cytosolic YFP were measured from onion assays similar to those shown in A–D. Means ± S.E. are shown. 20 ≤ n ≤ 30. In addition, FDF, FDR, SSF10, SSR10, FDF10, and FDR10 from a previous study (21) are included. These constructs with suffix 10 contain the N-ter 10 aa of the opposite TP at their N-ter. I, ratios from the N-ter peptide constructs. J, ratios from the reversed (N10R) and scrambled (N10S) N-ter constructs. K, plastid targeting efficiency ratios were plotted against the %UA calculated from the N-ter 15 aa of the precursors. The correlation line was determined without the dual-localized mutants, pp9 and pp38 mutants. L, plastid targeting efficiency ratios were plotted against the relative mCSS1 affinity. The correlation line was determined without the dual-localized mutants, pp9 and pp38 mutants.