May be considered as a candidate tumor suppressor gene for brain, lung, esophageal, gastric, and colorectal cancers. May play roles in mucosal defense system, cellular immune defense and epithelial differentiation. May play a role as an opsonin receptor for SFTPD and SPAR in macrophage tissues throughout the body, including epithelial cells lining the gastrointestinal tract. May play a role in liver regeneration. May be an important factor in fate decision and differentiation of transit-amplifying ductular (oval) cells within the hepatic lineage. Required for terminal differentiation of columnar epithelial cells during early embryogenesis. May function as a binding protein in saliva for the regulation of taste sensation. Binds to HIV-1 envelope protein and has been shown to both inhibit and facilitate viral transmission. Displays a broad calcium-dependent binding spectrum against both Gram-positive and Gram-negative bacteria, suggesting a role in defense against bacterial pathogens. Binds to a range of poly-sulfated and poly-phosphorylated ligands which may explain its broad bacterial-binding specificity. Inhibits cytoinvasion of S.enterica. Associates with the actin cytoskeleton and is involved in its remodeling during regulated exocytosis. Interacts with pancreatic zymogens in a pH-dependent manner and may act as a Golgi cargo receptor in the regulated secretory pathway of the pancreatic acinar cell.
Subcellular locations: Secreted
Some isoforms may be membrane-bound. Localized to the lumenal aspect of crypt cells in the small intestine. In the colon, seen in the lumenal aspect of surface epithelial cells. Formed in the ducts of von Ebner gland, and released into the fluid bathing the taste buds contained in the taste papillae (By similarity).
Highly expressed in alveolar and macrophage tissues. In some macrophages, expression is seen on the membrane, and in other macrophages, strongly expressed in the phagosome/phagolysosome compartments. Expressed in lung, trachea, salivary gland, small intestine and stomach. In pancreas, expressed in certain cells of the islets of Langerhans. In digestive tract, confined to tissues with large epithelial surfaces. In intestinal tissue, moderately expressed in epithelial cells of the midcrypts and the crypt base. Expression is significantly elevated in intestinal tissue from patients with inflammatory bowel disease (IBD), particularly in surface epithelial and Paneth cells, but not in IBD patients with mutant NOD2. Present in crypt bases of the duodenum, in crypt tops of the colon, and in collecting ducts of the cortical kidney. Expressed in stratified squamous epithelium of vagina and in outer luminar surface and basilar region of columnar epithelial cells in cervix (at protein level). Isoform 1 is secreted to the lumen of the respiratory tract.