The catenins, α, β and γ, are proteins which bind to the highly conserved,
intracellular cytoplasmic tail of E-cadherin. Together, the catenin/cadherin
complexes play an important role mediating cellular adhesion. α-catenin
was initially described as an E-cadherin associated protein, and since has
been shown to associate with other members of the cadherin family, such
as N-cadherin and P-cadherin. β-catenin associates with the cytoplasmic
portion of E-cadherin, which is necessary for the function of E-cadherin as
an adhesion molecule. β-catenin has also been found in complexes with the
tumor suppressor protein APC. γ-catenin, also known as plakoglobin, binds
with α-catenin and N-cadherin. It has been shown that the transmembrane
phosphatase PTPμ associates with catenin/cadherin complexes and may
regulate complex signaling.