Journal: bioRxiv
Article Title: Differentiation of Toxoplasma into latent forms is linked to central carbon metabolism and requires a GID/CTLH-type E3 ubiquitin ligase
doi: 10.1101/2025.07.27.667068
Figure Lengend Snippet: (A) Localisation of TgGID7-HA and TgGID8-HA by immunofluorescence together with GAP45 (parasite periphery) and DAPI (Bi) Quantitative αHA Immunoprecipitation of TgGID7-HA and TgGID8-HA as compared with parental control. Statistically significant hit marked in red and other TgGID components in blue. (ii) Venn diagram comparing results across all four experiments highlighting the identification of 5 common proteins. (iii) a model of TgGID complex based on previous structural data , , . (C) Analysis of differentiation in individual CRISPR mutant lines generated in ME49:Cas9 reporter strain as determined by BAG1 promoter -mNG by FACS. Normalized to parental strain. n=3 biological replicates, One way ANOVA, where ****p<0.0001. (D) Representative images of IFA analysis of differentiation after 48hrs of alkaline stress of parent, DTgGID7 and DTgGID8 strains, where DBA(Fire tone) marks cysts wall, GAP45 marks parasite periphery and DAPI-host cell nuclei. (E) Analysis of differentiation of mutants after 48hrs of alkaline stress (i) Percentage differentiation of WT (parent) versus ΔTgGID7 and ΔBFD1 as determined by DBA cyst wall staining. n=3 biological replicates, mean +/− SD, One way ANOVA, where ****p<0.0001, ns=not significant. (ii) Percentage differentiation of WT (parent) versus ΔTgGID8 and ΔBFD1 as determined by DBA cyst wall staining. n=3 biological replicates, mean +/− SD, One way ANOVA, where ****p<0.0001. (iii) Cyst wall intensity measurements across WT, ΔBFD1, ΔTgGID7 and ΔTgGID8 as determined by mean peripheral DBA staining intensity (0.1μm outside GAP45 staining) divided by the local mean background intensity of individual parasites. Single representative experiment, where each datapoint represents a single vacuole and bar represents median value. One way ANOVA, where ****p<0.0001 and ns=not significant. (F) Analysis of differentiation of parent and ΔTgGID7 in KD3 myotubes as quantitated by DBA staining. n=3 biological replicates, mean+/− SD, Unpaired, two-tailed t-test, where ***p<0.001. (G) Log-Log plot of quantitative global proteomic analysis of WT vs ΔBFD1 vs ΔTgGID7 upon 48hrs of alkaline stress. Blue datapoint represent proteins, where their gene promoter has been shown to bind to BFD1 . Yellow datapoints represent known tachyzoite-specific proteins. Annotated proteins represent known bradyzoite and tachyzoite-specific proteins. Dotted lines represent Log 2 FC=1in both dimensions. (H) BFD1 protein levels as determined by quantitative proteomics in WT parent and ΔTgGID7 strains in both complete media (standard tachyzoite growth conditions) and alkaline stress. n=5 biological repeats, mean +/−SD. One way ANOVA, where ****p<0.0001 and ns=not significant.
Article Snippet: For each replicate, eight 60 ug aliquots of whole genome CRISPR library plasmid DNA (Addgene #80636) were linearized by AseI (NEB) digestion, ethanol precipitated, air dried and resuspended in 131 ml of cytomix (10 mM KPO4; 20 mM KCl, 5 mM MgCl 2 , 25 mM HEPES, 2 mM EGTA, pH 7.6 with KOH).
Techniques: Immunofluorescence, Immunoprecipitation, Control, CRISPR, Mutagenesis, Generated, Staining, Two Tailed Test, Quantitative Proteomics