[Corticotrope]

Abstract

Gene structure, transcription and processing of pro-opiomelanocortin (POMC) are described. Some of the regulatory factors for POMC gene transcription are also discussed. POMC gene consists of three exons and two relatively large introns. The exon-1 encodes 5' untranslated region and exon-2 encodes mostly signal peptide and N-terminal peptide of POMC. Exon 3 encodes all of the biologically active peptides contained in POMC. The translation product from mRNA is glycosylated and processed by peptidases to generate ACTH, beta-LPH, gamma-LPH and beta-endorphin in the anterior pituitary. However, in the neurointermediate lobe of the pituitary, ACTH is further processed to alpha-MSH and corticotropin-like intermediate peptide and beta-endorphin is processed to acetyl-beta-endorphin.