Figure 2.

Partial knockout of TRMT6/61A sensitizes cells to heat shock and arsenite stress. (A) TRMT61A amount determined by western blotting. GAPDH was used as loading control. WT, wild-type HeLa cells; pKOi, partial knockout with intermediate level of TRMT61A; pKO, partial knockout with strong reduction of TRMT61A level. **P < 0.01, ***P < 0.001, two-tailed t-test; N = 3 independent experiments (mean + SD). (B) High-pressure liquid chromatography (HPLC) analysis of N1-methylated adenosine (m¹A) from cellular tRNAs in wild-type HeLa cells (WT) and TRMT61A partial knockout cells (pKO). One representative out of three independent experiments is shown. (C) Reduced amounts of the methyltransferase correlate with the increased sensitivity to heat shock. WT, wild-type cells with normal amount of TRMT61A; pKO and pKOi, partial knockout cells with strongly reduced and intermediate amounts of TRMT61A, respectively. *P < 0.05, two-tailed t-test; N = 3 independent experiments (mean + SD). (D) Viability of TRMT61A knockout cells after arsenite treatment for 1 h in comparison (%) to wild-type cells at the same concentrations of arsenite. *P < 0.05, **P < 0.01, two-tailed t-test; #, not significant difference. N = 3 independent experiments (mean + SD).