A β-Catenin Truncation Mutant Lacking Its TCF Transactivation Domain Sustains Pluripotency
(A) Schematic of full-length β-catenin (β-catS33A; aa 1–781) and the C-terminal deletion mutant (β-catS33AΔC; aa 1–694) used in this study.
(B) Relative protein levels of myc-tagged β-catS33A and β-catS33AΔC transgenes in mESC lines.
(C and D) TCF reporter assays (C) and qRT-PCR analysis of the β-catenin/TCF targets Axin2, Brachyury, and Cdx1 (D) demonstrate that β-catS33AΔC activates β-catenin/TCF signaling ~10-fold less than full-length β-catS33A in mESC lines.
(E) Morphology of WT-Control, β-catS33A, and β-catS33AΔC mESCs grown on gelatin-coated dishes.
(F) Expression of β-catS33AΔC in WT mESCs sustains the retention of pluripotency markers under conditions promoting differentiation (72 hr incubation).
(G) Immunofluorescent staining reveals that stable expression of β-catS33AΔC in WT mESCs inhibits the expression of the neural marker β-III-tubulin and promotes the retention of Oct-4 and Nanog in day 10 EBs.
(H) qRT-PCR analyses of several neural markers in day 10 EBs derived from the indicated control and β-catS33A overexpression mESCs demonstrates that β-catS33AΔC overexpression inhibits the expression of neural-specific genes.