Overview of Clp1-mediated modulation of UPR core genes.

(A) Overview of log2 transformed fold changes comparing UPR core gene expression after TM treatment in the clp1 expressing P_crg:clp1 strain vs. WT. Red color indicates increased expression, blue color indicates reduced expression in the P_crg:clp1 strain, respectively (log2FC>1). Light colors indicate tendencies for higher/lower expression. Asterisks (*) indicate genes that were further analyzed in (B). (B) qRT-PCR analysis of UPR core genes in strains JB1 (WT) and derivatives harboring clp1 under the control of the arabinose inducible crg1 promoter (P_crg:clp1) or in the cib1 deletion strain (Δcib1). Strains were cultured in YNBG to an OD₆₀₀ of 0.25 and shifted to YNBA medium to induce clp1 expression in strains containing P_crg:clp1. TM was added to a final concentration of 5 μg/mL, and strains were further incubated for 4 hours. The Δcib1 strain served as negative control to test for unspecific effects of TM treatment on gene expression. Expression is shown relative to highest expression value. Expression values represent the mean of three biological replicates with two technical duplicates each. eIF2b (UMAG_04869) was used for normalization. Error bars represent the SD. Statistical significance was calculated using Student’s t test. *P value ≤ 0.05, **P value ≤ 0.01 and ***P value ≤ 0.001.