The Reg family constitutes a subset of the calcium-dependent C-type lectin superfamily. These small, secreted proteins have been implicated in a range of physiological processes including acting as acute phase reactants, lectins, survival/growth factors for insulin-producing pancreatic beta-cells, neural cells, and epithelial cells of the digestive system. Studies also indicate a role for Reg family members in tumor formation and indicate their potential for use as biomarkers of carcinogenesis.
Reg3B (regenerating islet-derived protein III beta; also PAP-I and HIP) is a secreted 17 kDa member of the Reg gene family, C-type lectin gene superfamily. It is found in pancreatic acinar cells, intestinal enterocytes, and developing spinal motoneurons. Reg3B may play a role in intestinal epithelial cell renewal. Mouse Reg3B contains one C-type lectin domain (aa 38 - 173). Mature mouse Reg3B is 59%, 71% and 51% aa identical to the products of three other Reg3 named genes termed Reg III alpha, gamma and delta, respectively. Mature mouse Reg3B is also 91% and 67% aa identical to rat and human Reg3B, respectively.