Dissection of Ire1 functions required for the ER stress response in <i>C. glabrata</i>.

<p>(A) Both the kinase and nuclease activity of Ire1 are required for cell growth in the presence of ER stress. The <i>C. glabrata</i> Δ<i>ire1</i> mutant was transformed with an empty vector or a plasmid containing wild-type <i>IRE1</i>, kinase-dead <i>IRE1</i> (<i>IRE1</i>-KD), or nuclease-dead <i>IRE1</i> (<i>IRE1</i>-ND). Logarithmic-phase cells were adjusted to 2×10⁷ cells/ml, and then 5 µl of serial 10-fold dilutions were spotted onto synthetic complete medium without tryptophan (SC-trp) plates in the presence and absence of tunicamycin (TM) and dithiothreitol (DTT) at the indicated concentrations. Plates were incubated at 30°C for 48 h. <i>C. glabrata</i> strains: WT+vector, TG11; Δ<i>ire1</i>+vector, TG122; Δ<i>ire1</i>+<i>IRE1</i>, TG123; Δ<i>ire1</i>+<i>IRE1</i>-ND, TG125; and Δ<i>ire1</i>+<i>IRE1</i>-KD, TG124.