Predict the consequences of a temperature-sensitive mutation in which phosphorylation of the β-catenin protein is blocked.Above the permissive temperature:
A)β-catenin levels will increase and β-catenin will be constitutively active.
B)β-catenin levels will increase and β-catenin will be inactive.
C)β-catenin levels will decrease.
D)β-catenin will remain constant but cells will be unresponsive to Wnt signaling.

Question

Quizplus · Accepted Answer

Phosphorylation of β-catenin targets it for degradation. If phosphorylation is blocked, β-catenin will not be degraded, leading to increased levels and constitutive activity, as it can then enter the nucleus and activate transcription of target genes.

Predict the Consequences of a Temperature-Sensitive Mutation in Which Phosphorylation