CTNNB1 Gene

The CTNNB1 gene provides instructions for making a protein called beta-catenin. This protein is present in many types of cells and tissues, where it is primarily found at junctions that connect neighboring cells (adherens junctions). Beta-catenin plays an important role in sticking cells together (cell adhesion) and in communication between cells.

The beta-catenin protein is also involved in cell signaling as an essential part of the Wnt signaling pathway. Certain proteins in this pathway attach (bind) to beta-catenin, which triggers a multistep process that allows the protein to move into the cell nucleus. Once in the nucleus, beta-catenin interacts with other proteins to control the activity (expression) of particular genes. The Wnt signaling pathway promotes the growth and division (proliferation) of cells and helps determine the specialized functions a cell will have (differentiation). Wnt signaling is known to be involved in many aspects of development before birth. In adult tissues, this pathway plays a role in the maintenance and renewal of stem cells, which are cells that help repair tissue damage and can give rise to other types of cells.

Among its many activities, beta-catenin appears to play an important role in the normal function of hair follicles, which are specialized structures in the skin where hair growth occurs. This protein is active in cells that make up a part of the hair follicle known as the matrix. These cells divide and mature to form the different components of the hair follicle and the hair shaft. As matrix cells divide, the hair shaft is pushed upward and extends beyond the skin.