Mucin 2

This gene encodes a member of the gel-forming mucin protein family. The protein encoded by this gene, also called mucin 2, is secreted onto mucosal surfaces^[5].

Mucin 2 is particularly prominent in the gut where it is secreted from goblet cells in the epithelial lining. There, mucin 2, along with small amounts of related-mucin proteins, polymerizes into a gel of which 80% by weight is oligosaccharide side-chains that are added as post-translational modifications to the mucin proteins. This gel serves as a physico-chemical barrier to protect the intestinal epithelium from for example shear stress, pathogens, and external particles.

Various intestinal diseases, like intestinal bowel disease (IBD) are associated with MUC2 dysregulation^[7].

The mucin 2 protein features a central domain containing tandem repeats rich in threonine and proline that varies between 50 and 115 copies in different individuals. Alternatively spliced transcript variants of this gene have been described, but their full-length nature is not known.^[8]

Newly synthesized MUC2 proteins are densly packed in mucus granules and transported to the plasma membranes within goblet cells. Those mucus ganules fuse with the plasma membrane and MUC2 is being released into the gut lumen. Due to its physical properties, MUC2 expands and disperses upon release, becoming a part of the existing mucus barrier.^[7]