Which of the Following Represents the Active Form of β-Catenin

Question

Which of the following represents the active form of β-catenin in cells stimulated with Wnt?
A) Phosphorylated by GSK3 and CK1
B) Bound to APC
C) Bound to Groucho
D) Bound to LRP
E) None of the above

Accepted Answer

Wnt binding to Frizzled and LRP results in the disassembly of the β-catenin degradation complex (containing APC, axin, CK1, and GSK3), which allows β-catenin to accumulate and enter the nucleus, where it binds to LEF1/TCF, displacing the co-repressor Groucho.