Characterization of the human islet amyloid polypeptide/amylin gene transcripts: identification of a new polyadenylation site.

Islet amyloid polypeptide (IAPP) or Amylin is synthesized by the pancreatic beta-cells. IAPP is the major component of islet amyloid in the pancreas of patients with non-insulin-dependent diabetes mellitus. We report the composition and complete nucleotide sequence of the two human IAPP mRNAs of 1.6 and 2.1 kb. A new polyadenylation site was identified and shown to be used in generation of the 2.1 kb RNA. A previously identified polyadenylation signal is assigned to the 1.6 kb RNA. We exactly determined the major transcription start site, which is used in generation of these mRNAs. Lower abundance RNAs containing sequences located further upstream in the IAPP gene were also detected.