sentences:  However, a protein complex including a cadherin, actin, beta-catenin and alpha-catenin has not been isolated.It has been suggested that alpha-catenin does not bind with high affinity to both actin filaments and the E-cadherin-beta-catenin complex at the same time.It has been observed that when alpha-catenin is not in a molecular complex with beta-catenin, it dimerizes and functions to regulate actin filament assembly, possibly by competing with Arp2/3 protein.