Figure 2
From: Signaling by epithelial members of the CEACAM family – mucosal docking sites for pathogenic bacteria
Signaling initiated by epithelial CEACAMs. Schematic summary of recent findings with regard to CEACAM-initiated signaling events in epithelial cells. Upon ligand binding, CEACAM1 forms oligomers supported by cis-interactions between the extracellular and the transmembrane domains (1) and is recruited to membrane microdomains (2). GPI-anchored epithelial CEACAMs, such as CEA or CEACAM6, constitutively localize to membrane microdomains (3). In membrane microdomains, epithelial CEACAMs connect to putative co-receptor(s) (black) via extracellular IgC2-like domains (4). Intracellular signaling triggered by epithelial CEACAMs either directly or indirectly via co-receptor(s) leads to phosphatidylinositol-3’-kinase dependent signaling processes connected to receptor-mediated endocytosis (5). Furthermore, stimulation of epithelial CEACAMs triggers novel gene expression events, e.g. de novo expression of CD105, which extracts zyxin from basal integrin-rich focal adhesion sites (6), resulting in increased integrin activity and enhanced binding to the basal extracellular matrix (ECM) (7).