Fig. 3

Fig. 3

Fig. 3. Disruption of zfIMPDHs cytoophidium-forming properties with point mutations. (A) Sequence comparison of human and zebrafish IMPDH isoforms at regions around Lys12 and Arg224. (B) Immunoblotting of HeLa cells expressing WT or Y12A mutant zfIMPDH isoforms under conditions with or without MPA treatments shows similar expression levels of WT and Y12A mutant zfIMPDHs. (C–F) Immunofluorescence of HEp-2 ​cells expressing Y12A or R224P mutant zfIMPDH1b and zfIMPDH2. Cells were treated with MPA or DON for 2 ​h before fixation. Asterisks in panels C and E indicates the cells with endogenous cytoophidia, but not the zf-IMPDH cytoophidium. Arrows and arrowheads in panels D and F indicate zfIMPDH cytoophidia and clumps, respectively. Scale bars ​= ​10 ​μm. (G) Quantification of the proportion of HEp-2 ​cells with zfIMPDH cytoophidia or clumps under the conditions shown in (C–F). Only transfected cells were counted and the number of cells counted (n) is shown for each group. Error bars ​= ​S.E.M. With MPA and DON treatments, non-transfected cells also present endogenous cytoophidia, which are labeled by the α-IMPDH antibody.