Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1)

Isoform 1: Cell adhesion protein which mediates homophilic cell adhesion in a calcium-independent manner (By similarity). Plays a role as coinhibitory receptor in immune response, insulin activity and functions also as an activator during angiogenesis (PubMed:18424730, PubMed:23696226, PubMed:25363763).

Its coinhibitory receptor function is phosphorylation- and PTPN6 -dependent, which in turn, suppress signal transduction of related receptors by dephosphorylation of the downstream effectors. Upon TCR/CD3 complex stimulation, inhibits TCR-mediated cytotoxicity by blocking granule exocytosis by mediating homophilic binding to adjacent cells, allowing interaction with and phosphorylation by LCK and interaction with the TCR/CD3 complex which recruits PTPN6 resulting in dephosphorylation of CD247 and ZAP70 (PubMed:18424730).