Figure 3.

CXCR (CXC receptor) and LINGO (leucine-rich repeat and immunoglobulin-like domain–containing NoGo) family members as TFF receptors. (A) TFF2 requires CXCR4 for calcium mobilization, ERK1/2 activation, and AKT activation. Antagonism of CXCR4–CXCR7 dimer prevents TFF3-mediated cell migration but does not prevent cell proliferation or MAPK activity. Direct binding has not been demonstrated, indicated by the circled question mark. (B) TFF3 interacts with LINGO2 to competitively reverse LINGO2–EGFR binding, enhancing cell proliferation and protection against helminths. LINGO3 is required for TFF2-mediated repair of nasal epithelial cultures. ERK1/2 = extracellular regulated kinase 1/2; KO = knockout; PLC = primary liver cancer; Src = scrambled; WT = wild-type.