Animal cells have the intrinsic ability to adhere to each other and to form multicellular structures. Classic studies suggested that cells have divalent cation-dependent mechanisms for holding themselves together. Cadherins were identified as Ca²⁺-sensitive cell surface molecules; and extensive studies revealed that this family of molecules plays critical roles in cell-to-cell adhesion and tissue organization, and even in synapse formation. Further studies showed that molecules belonging to the cadherin superfamily have more diverse functions, such as those to regulate planar cell polarity. Thus, we have been able to disclose parts of the molecular mechanisms of how animal cells can assemble and organize themselves into complex multicellular structures.


(Contributed by Masatoshi TAKEICHI, M.J.A.)