Wnt Signaling Pathway

Wnt Signaling Pathway

The Wnt signaling pathway is a network of proteins that passes signals from receptors on the surface of the cell to DNA expression in the nucleus. It controls cell-cell communication in the embryo and adult (ie, cell proliferation and differentiation during development and healing).

It was identified first as a gene involved in mouse breast cancers, and separately as a gene involved in creating normal patterns of embryo development. Mutations in the pathway produced bizarrely-shaped fruit fly embryos. Later research found that the two genes were in the same family.

It is also required for adult tissue maintenance, in bone, heart muscle, and elsewhere. Mutations in the pathway in adults promote degenerative disease and cancer.

The Wnt signaling pathway controls beta-catenin, which enters the nucleus, binds to DNA, and turns on the expression of genes. By its control of the phosphatase PPA2, Wnt signaling inhibits phosphorylation of beta-catenin, thereby inhibiting the degradation of beta-catenin. When the pathway is damaged by mutations, it can no longer control beta-catenin, and those genes are over-expressed. The pathway is therefore a target for drugs to control these diseases.