Western blot of human embryonic kidney (HEK) 293 cell lysate showing specific immunolabeling of the ~83k CTNNB1 phosphorylated at Ser33 and Ser37 . Control (lane 1) is a standard HEK293 cell lysate. GSK3 (lane 2) is a HEK cell lysate with glycogen synthase kinase 3 beta knocked down by SiRNA.
Beta-catenin is an adherens junction protein. Adherens junctions (AJs; also called the zonula adherens) are critical for the establishment and maintenance of epithelial layers, such as those lining organ surfaces. AJs mediate adhesion between cells, communicate a signal that neighboring cells are present, and anchor the actin cytoskeleton. In serving these roles, AJs regulate normal cell growth and behavior. At several stages of embryogenesis, wound healing, and tumor cell metastasis, cells form and leave epithelia. This process, which involves the disruption and reestablishment of epithelial cell-cell contacts, may be regulated by the disassembly and assembly of AJs. AJs may also function in the transmission of the 'contact inhibition' signal, which instructs cells to stop dividing once an epithelial sheet is complete.[supplied by OMIM