TABLE 2.

Effect of heat shock on half-lives of cps(2)A and ply mRNAsa

Temp (°C)Half-life (min) of mRNA for:
D39ClpP mutant
cps(2)Aplycps(2)Aply
303.8 ± 1.232.75 ± 0.165.0 ± 0.625.8 ± 2.71
422.0 ± 0.45b1.75 ± 0.33b4.1 ± 0.55b,c3.75 ± 0.79d
  • a For measuring mRNA half-lives, rifampin (100 μg/ml) was added, and 1.5-ml aliquots of culture suspension were collected at 10-min intervals. Total RNA was extracted from these aliquots by the hot acid-phenol method. Subsequently, mRNA levels were determined by real-time RT-PCR. The mRNA half-lives were analyzed by nonlinear least-squares fitting to the sum of exponentials functions. All experiments were carried out in quadruplicate, and values are reported as means and standard deviations.

  • b Significantly different (P < 0.05) from the half-life at 30°C.

  • c Significantly different (P < 0.001) from the half-life of D39 cps(2)A mRNA at 42°C.

  • d Significantly different (P < 0.05) from the half-life of D39 ply mRNA at 42°C.