The halo and mating assays reveal measurable differences in activity of ZMPSTE24 mutants. Results of the qualitative halo assay (A) and the plate mating assay (B) are shown. Results of a quantitative filter mating assay are graphically represented below (C). The details of how these tests were performed are discussed in the text. The mating percentages graphed in (C) are normalized to WT (100%). The values for each mutant tested were: H335A (1%), W340R (47%), P248L (25%), N265S (11%), L438F (6%), L94P (2%), W450X (1%), L362F(fsX18) (1%) and T159_L209del (1%).