Figure 4.

Heatmap showing the ZMPSTE24 cleavage efficiency of prelamin A for every individual amino acid substitution in residues P4–P4’. The P4–P4’ region surrounding the prelamin A cleavage site was comprehensively interrogated by positional scanning mutagenesis, as shown in Figures 2 and 3. The effects of individual amino acid substitutions at each site were scored relative to WT at 100% cleavage efficiency and assigned into ten bins. Residues are shaded in accordance with cleavage efficiency, ranging from WT level of cleavage (white) to poor or no cleavage (black).