The NECTIN Protein is a family of cell-adhesion molecules that, so far, includes four members. They contribute to a wide range of tissue adhesive roles, particularly with the chemical synapse of neurological tissue and the adherents junction of epithelia.
The family of molecules will primarily regulate adhesion between two cells, although Nectin-like molecules - known as Necl - will perform other tasks at a cellular level.
Some mutations of the gene have been found responsible for a cleft lip or cleft palate, as the gene is required (although not essential) for fusing palatal shelves. Other variants of the gene have been identified, but the nature is yet to be fully uncovered.
One of the most important interactions that Nectin proteins engage in is with the platelet-derived growth factor receptor (PDGF), as this encourages tissue development and regeneration. It can also interact with other members of the family.
Nectin proteins have been identified as providing a wide range of functions within the cell. These include cell movement and proliferation. There is also evidence of differentiation, polarization, and cellular survival. Finally, nectin proteins perform cell-to-cell adhesion.
Each of the four discovered nectins boast the same fundamental structure which is highlighted by three extracellular immunoglobulin domains. Besides these domains, there is also one transmembrane helix and an intracellular domain. The intracellular domain enables the protein to bind a scaffold protein known as adafin.
All nectins are capable of forming homo-cis dimers so that two similar molecules exist on the same membrane. After homo-dimer formation, they can interact in a heterophilic or homophilic manner. In recent reports, there is evidence that heterophilic interactions are more successful than homophilic counterparts.