TABLE 1.

Comparison of focus formation in RK3E cells by replication-defective retroviruses expressing wild-type or mutated forms of β-cat with the ability of the proteins to activate Tcf transcription

Proteina	Fold Tcf activationb	No. of foci formedc in:
		Expt 1	Expt 2	Expt 3	Expt 4
WT	2.8 ± 0.15	1	4	6	5
S33Y	12.3 ± 3.1	408	296	440	276
ΔN47	5.6 ± 0.12	192	168	160	104
ΔN89	3.55 ± 0.17	180	144	240	160
ΔN132	2.3 ± 0.35	96	68	48	60
ΔN217	0.7 ± 0.05	7	3	6	3
S33Y/Δ48-217	4.32 ± 0.10	102	74	88	NDd
S33Y/Δ218-467	0.75 ± 0.07	9	6	1	4
S33Y/ΔC468	0.92 ± 0.4	11	8	5	3
S33Y/ΔC695	2.05 ± 0.1	24	27	21	32
S33Y/ΔC723	3.07 ± 0.15	76	86	88	72
S33Y/ΔC751	5.2 ± 0.1	164	128	124	132

^aβ-cat proteins encoded by the retroviral constructs are illustrated in Fig. 1A. 

^bMean Tcf transcriptional activation ± standard deviation was measured in triplicate transient-transfection assays with pcDNA3 expression vectors and RK3E cells. The data are displayed graphically in Fig. 1B. The empty-vector control was assigned a value of 1.0. 

^cNumber of macroscopic foci at 4 weeks after infection of RK3E cells in 100-mm dishes at 70 to 80% confluency with retroviral supernatants. Results of four independent experiments are shown. 

^dND, not determined.