Table 1.

Relative ALR1 mRNA levels in yeast upf1Δ UPF2 or upf1Δ upf2Δ cells harboring different UPF1 alleles^a

UPF1 allele	Relative ALR1 mRNA level
	upf1Δ UPF2 cells	upf1Δ upf2Δ cells
None	1.00	1.00
UPF1	0.47	1.00
C84S	0.60	1.00
C62Y	0.94	1.12
K436E	1.02	1.10
DE572AA	1.16	1.10
RR793AA	0.83	1.10

^aData were taken from the Northern blots shown in Fig. 5A. ALR1 mRNA signals in each of these strains were first adjusted based on the SCR1 signals. The adjusted ALR1 mRNA signals in upf1Δ UPF2 or upf1Δ upf2Δ cells harboring different UPF1 alleles were then compared to those of the corresponding cells harboring the empty vector.