Conserved region found in both cAMP-regulated phosphoprotein 19 (ARPP-19) and Alpha/Beta endosulfine. No function has yet been assigned to ARPP-19. Endosulfine is the endogenous ligand for the ATP-dependent potassium (K ATP) channels which occupy a key position in the control of insulin release from the pancreatic beta cell by coupling cell polarity to metabolism. In both cases the region occupies the majority of the protein [1,2].

1: ARPP-16/ARPP-19: a highly conserved family of cAMP-regulated phosphoproteins. Dulubova I, Horiuchi A, Snyder GL, Girault JA, Czernik AJ, Shao L, Ramabhadran R, Greengard P, Nairn AC; J Neurochem 2001;77:229-238. PMID:11279279

2: alpha-Endosulfine, a new entity in the control of insulin secretion. Bataille D, Heron L, Virsolvy A, Peyrollier K, LeCam A, Gros L, Blache P; Cell Mol Life Sci 1999;56:78-84. PMID:11213264