TABLE 3.

Heat stress and phytosphingosine causes calcineurin-dependent 4× CDRE::lacZ expression^a

Stress condition	β-Galactosidase activity (U/μg protein) in:
	Absence of FK506	Presence of FK506
Control (30°C)	0.29 ± 0.05	0.29 ± 0.04
Heat stress (25-37°C)	1.37 ± 0.145	0.11 ± 0.06
Phytosphingosine (25°C)	3.93 ± 0.178	0.38 ± 0.12
Phytosphingosine (30°C)	7.51 ± 0.51	0.29 ± 0.11

^aStrain LBY66 containing the lacZ reporter gene under the control of four copies of the 24-bp calcineurin downstream response element in its genome was grown in YPD under different conditions in the absence or presence of FK506 (2 μg/ml). After reaching log phase, cells either were not triggered (no stress; control) or were triggered with a heat stress for 3 h or with 20 μM phytosphingosine for 3 h at the indicated temperatures; then, β-galactosidase activity was assayed in cell lysates. Values represent the mean specific β-galactosidase activity obtained from two independent experiments each performed in triplicate.