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.
Reg1A, also known as PTP, PSP, and lithostathine, is a member of the Reg family of secreted proteins with a C-type lectin domain. Due to variable glycosylation, pancreatic Reg1A exists as multiple species of 16 - 18 kDa. Reg1A promotes the maintenance and growth of pancreatic islet β-cells and intestinal villi. It is upregulated in pancreatitis and some carcinomas. Reg1A is an antigenic target in autoimmune diabetes. Human Reg1A shares 65% - 68% aa sequence identity with mouse and rat Reg1A.