Table 4.

Btn2p and Cur1p overproduction (under the CUP1-promoter) curing of [URE3] in mutants and wild-type

	Overproduction
Host	Btn2p		Cur1p
	#	% Curing	#	% Curing
WT	732	60	209	90
hsp42Δ	614	0.5*	112	12*
ubr2Δ	708	1.6*	112	9*
ubr2Δ rpn4Δ	354	59††	110	21
rpl21bΔ	1152	1.1*	122	8*
rpl4aΔ	1063	0.7*	150	46*
WT	—	—	99	29
ubr2Δ	—	—	85	3*
ubr2Δ rpn4Δ	—	—	84	31**
WT	361	94	290	76
rpl21bΔ	251	7*	272	6*
rpn4Δ#1	580	57	393	54
rpn4Δ#2	207	70	423	65
rpl21bΔ rpn4Δ	246	67†	162	55†

Cells were grown with inducing concentrations of copper for 12 generations before plating. The stability of [URE3] in the wild-type and mutant strains was tested before introduction of the CUR1/BTN2 overexpression plasmids as well as a 0 mM copper control for the WT (using “copper-free” YNB). Loss of [URE3] was <1% in all of those cases.

^*= differs from w.t. with p < 2 × 10⁻⁴,

^**= differs from ubr2Δ with p < 2 × 10⁻³,

^†= differs from rpl21bΔ with p < 10⁻⁴,

^††= differs from ubr2Δ with p < 10⁻⁴.