title: 60 YEARS OF POMC: From the prohormone theory to pro-opiomelanocortin and to proprotein convertases (PCSK1 to PCSK9).
abstract: Pro-opiomelanocortin (POMC), is a polyprotein expressed in the pituitary and the brain where it is proteolytically processed into peptide hormones and neuropeptides with distinct biological activities. It is the prototype of multipotent prohormones. The prohormone theory was first suggested in 1967 when Chrétien and Li discovered γ-lipotropin and observed that (i) it was part of β-lipotropin (β-LPH), a larger polypeptide characterized 2 years earlier and (ii) its C-terminus was β-melanocyte-stimulating hormone (β-MSH). This discovery led them to propose that the lipotropins might be related biosynthetically to the biologically active β-MSH in a precursor to end product relationship. The theory was widely confirmed in subsequent years. As we celebrate the 50th anniversary of the sequencing of β-LPH, we reflect over the lessons learned from the sequencing of those proteins; we explain their extension to the larger POMC precursor; we examine how the theory of precursor endoproteolysis they inspired became relevant for vast fields in biology; and how it led, after a long and arduous search, to the novel proteolytic enzymes called proprotein convertases. This family of nine enzymes plays multifaceted functions in growth, development, metabolism, endocrine, and brain functions. Their genetics has provided many insights into health and disease. Their therapeutic targeting is foreseeable in the near future. Thus, what started five decades ago as a theory based on POMC fragments, has opened up novel and productive avenues of biological and medical research, including, for our own current interest, a highly intriguing hypocholesterolemic Gln152His PCSK9 mutation in French-Canadian families.
authors.affiliation: Laboratory of Functional EndoproteolysisClinical Research Institute of Montreal, Montreal, Quebec, Canada michel.chretien@ircm.qc.ca.
authors.forename: Michel
authors.initials: M
authors.lastname: Chrétien
authors.affiliation: Laboratory of Functional EndoproteolysisClinical Research Institute of Montreal, Montreal, Quebec, Canada.
authors.forename: Majambu
authors.initials: M
authors.lastname: Mbikay
mesh_terms: D000818:Animals; D004704:Endocrinology / Q000266:history; D004792:Enzyme Precursors; D005786:Gene Expression Regulation; D049673:History, 20th Century; D006801:Humans; D007527:Isoenzymes; D036361:Peptide Hormones / Q000737:chemistry / Q000378:metabolism*; D011333:Pro-Opiomelanocortin / Q000737:chemistry / Q000235:genetics / Q000266:history / Q000378:metabolism*; D045664:Proprotein Convertase 1 / Q000378:metabolism; D000071449:Proprotein Convertase 9 / Q000378:metabolism; D043484:Proprotein Convertases / Q000378:metabolism*; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D059748:Proteolysis
chemical_list: D004792:Enzyme Precursors; D007527:Isoenzymes; D036361:Peptide Hormones; D011498:Protein Precursors; D011333:Pro-Opiomelanocortin; D000071449:Proprotein Convertase 9; D043484:Proprotein Convertases; D045664:Proprotein Convertase 1
keywords: POMC; endoproteolysis; prohormone; proprotein convertases