DYNAMIC CONTROL OF CELL-CELL ADHESION FOR MULTICELLULAR ORGANIZATION

Cadherin cell-cell adhesion molecules are associated with cytoskeletal proteins, including alpha and beta catenin, and plakoglobin. This cad herin-catenin complex plays an indispensable role in construction of o rdered multicellular structures such as polarized epithelium. Alpha-ca tenin is crucial for the cell binding function of cadherins; without i t, cells cannot use the cadherin adhesion system for their adhesion. B eta-catenin and plakoglobin possibly play more regulatory roles, as it was shown that their tyrosine phosphorylation correlated with modifie d cadherin activities. The expression of some cadherin-associated prot eins is controlled by the wingless/Wnt-1 signal in embryos. These regu latory mechanisms of cadherin function and expression may be involved in dynamic control of cell-cell contacts during morphogenesis, and eve n in certain processes of cell growth and differentiation.