Fig. 5. Deletion of DegP2 alters porphyrin concentrations and DHA susceptibility.

a ∆DegP2 and ∆DegP2/DegP2-HA parasites formed smaller plaques than their parental strains, indicating a growth defect. b Endogenously Ty-tagged DegP2 (DegP2-Ty) parasites and a derived line bearing a mutation in the protease domain (DegP2^S569A-Ty) formed plaques normally. c Total porphyrin concentrations (pmol/mg protein) showing reduced porphyrin concentrations for both ∆DegP2 and DegP2^S569A-Ty parasites. Results are mean ± SD for n = 3–4 independent experiments; p-values are from one-way ANOVA with Sidak’s multiple comparison test. d DHA Mean EC₅₀ values ± SD were calculated by curve-fitting 4–7 independent experiments together. e Porphyrin levels show a negative correlation with DHA EC₅₀ (r² = 0.75) in the strains and conditions tested. f DegP2 cKD parasites formed plaques similarly to DiCre, both in the presence or absence of rapamycin. g Total porphyrin concentrations for DiCre and DegP2 cKD in the presence or absence of rapamycin. Results are mean ± SEM for n = 4 independent experiments; p-values are from a two-way ANOVA. h DegP2 cKD parasites outcompeted DiCre parasites in the presence of DHA. The fraction of the population composed of mutant parasites was calculated at each time point by flow cytometry. Results are mean ± SEM for n = 3 independent experiments.