Nectin-3

Nectin-3 is a transmembrane protein belonging to the nectin family, which are immunoglobulin-like cell adhesion molecules (CAMs). Nectins play crucial roles in the formation and maintenance of cell junctions, particularly adherens junctions, in various tissues and cell types. Nectin-3 is involved in cell-cell adhesion, polarity, and signaling, contributing to tissue organization and function.

Nectin-3 interacts homophilically (with another Nectin-3 molecule) and heterophilically (with other nectin family members) on adjacent cells, initiating and strengthening cell-cell contacts. These interactions are calcium-independent, setting them apart from cadherins, another major class of CAMs. Following nectin engagement, recruitment of afadin, an F-actin binding protein, to the cytoplasmic tail of nectin initiates the formation of mature adherens junctions. This connection to the actin cytoskeleton is essential for junction stability and downstream signaling.

Nectin-3 is widely expressed in various tissues, including epithelial, endothelial, and neuronal cells. In the nervous system, Nectin-3 is particularly important for synapse formation and function. It plays a role in the clustering of synaptic vesicles and the organization of presynaptic terminals. Disruptions in Nectin-3 expression or function have been implicated in neurological disorders.

The gene encoding Nectin-3 is designated Nectin3. Alternative splicing of the Nectin3 gene can generate different isoforms of the protein, potentially with varying functions.

The precise functions of Nectin-3 can vary depending on the cell type and tissue context. Further research is ongoing to fully elucidate its roles in development, tissue homeostasis, and disease.