TABLE 1.

Complementation of the trehalose synthesis defect of S. cerevisiae and S. pombe Δtps1 mutants by H. polymorpha TPS1^a

Strain	Relevant genotype	Mean amt of trehalose ± SE (g/g of protein)
		After heat shock	In stationary phase
S. cerevisiae
YSH 6.106.-3A	TPS1	0.150 ± 0.012	0.008 ± 0.001
YSH 6.106.-1A	Δtps1::TRP1	<0.001	<0.001
YSH 6.106.-1A/  YEp-HpTPS1	Δtps1::TRP1/TPS1	0.015 ± 0.006	0.009 ± 0.004
S. pombe
PB003	tps1+	0.255 ± 0.015	0.225 ± 0.018
PBL-17	tps1::LEU2	<0.001	<0.001
PBL-17/pUR-HpTPS1	tps1::LEU2/TPS1	0.187 ± 0.018	0.050 ± 0.010

^aCells were grown at 27°C to exponential phase (for heat shock experiments) or stationary phase (4 days) on synthetic defined media containing either 2% galactose (YSH 6.106.-1A [MATα leu2 ura3 trp1 his3 ade2 Δtps1::TRP1] and its isogenic wild type YSH 6.106.-3A [MATα leu2 ura3 trp1 his3 ade2]) (15) or 2% glucose (PBL-17 [h⁺ ade6-M216 leu1-32 ura4-D18 tps1::LEU2] and its isogenic wild type PB003 [h⁺ ade6-M216 leu1-32 ura4-D18]) (16) as the carbon source. For heat shock experiments, cells growing exponentially at 27°C were shifted to 40°C for 2 h. Results are the means ± standard errors from three independent experiments. The detection limit for trehalose levels was 0.001 g/g of protein.