Skip to main content
. 2014 Sep;82(9):3740–3752. doi: 10.1128/IAI.01729-14

FIG 4.

FIG 4

Three C. burnetii effectors affect the CWI MAP kinase pathway in yeast. (A) Diagram of the yeast Rho1-activated Pkc1 CWI MAP kinase pathway. The function of each protein is indicated on the left. T.F., transcription factor. (B) Yeast deletion mutants in the CWI MAP kinase pathway are sensitive to caffeine. The deletion mutant strains indicated on the right were examined on plates containing glucose (Glu), galactose (Gal), or galactose and caffeine (Gal+Caff). (C) Examination of the inhibition of yeast growth mediated by the three C. burnetii effectors CBU1676, CBU0885, and CBU0388 in deletion mutants of the CWI MAP kinase pathway. The C. burnetii effectors (indicated above) were overexpressed in the wild-type S. cerevisiae BY4741 (Wild-type) and in the bck1, mkk1, mkk2, and mpk1 deletion mutants (bck1Δ, mkk1Δ, mkk2Δ, and mpk1Δ, respectively). pGREG523 (Vector) was used as a control. (D) The yeast growth inhibition of the C. burnetii effectors CBU1676, CBU0885, and CBU0388 was also examined in two other yeast MAP kinase deletion mutants, the hog1 and kdx1 strains (hog1Δ and kdx1Δ, respectively). The glucose control plates for panels C and D are presented in Fig. S1 in the supplemental material. (E) Three C. burnetii effectors modulate the activity of the Rlm1 transcription factor. The activity of the Rlm1-regulated lacZ reporter was examined following incubation of S. cerevisiae BY4741 containing a vector or expressing the C. burnetii effector CBU1676, CBU0885, or CBU0388 under normal conditions (white bars) and after heat shock (gray bars). β-Galactosidase activity was measured as described in Materials and Methods. Data are the means ± standard deviations (error bars) of three independent transformations. The assay was repeated three times, and similar results were obtained. The levels of expression of the Rlm1 reporter after heat shock of yeast containing each of the effectors were found to be significantly different (*, P < 0.05; **, P < 0.001, paired Student's t test) in comparison to the vector control.