Control of mucin transcription by diverse injury-induced signaling pathways

Mucin production is an evolutionarily ancient defense mechanism that is ret ained in mammals and operates at all mucosal surfaces to protect the host a gainst pathogens and irritants. As in lower organisms, the mammalian mucosa (epithelium) produces mucin in response to diverse insults. Our studies ai m to understand the intracellular signaling and gene regulation mechanisms mediating mucin production in response to clinically important insults. To date, we find that the signaling pathway triggered by each type of insult i s distinct. Relatively common, however, is the involvement of the protein t yrosine kinase c-Src, the MAP kinase kinase MEK 1/2, and the transcription factor NF-kappa B.