Carboxypeptidase E is a regulated secretory pathway sorting receptor: genetic obliteration leads to endocrine disorders in Cpe(fat) mice

Cell. 1997 Jan 10;88(1):73-83. doi: 10.1016/s0092-8674(00)81860-7.


A proposed mechanism for sorting secretory proteins into granules for release via the regulated secretory pathway in endocrine-neuroendocrine cells involves binding the proteins to a sorting receptor at the trans-Golgi network, followed by budding and granule formation. We have identified such a sorting receptor as membrane-associated carboxypeptidase E (CPE) in pituitary Golgi-enriched and secretory granule membranes. CPE specifically bound regulated secretory pathway proteins, including prohormones, but not constitutively secreted proteins. We show that in the Cpe(fat) mutant mouse lacking CPE, the pituitary prohormone, pro-opiomelanocortin, was missorted to the constitutive pathway and secreted in an unregulated manner. Thus, obliteration of CPE, the sorting receptor, leads to multiple endocrine disorders in these genetically defective mice, including hyperproinsulinemia and infertility.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Biological Transport
  • Carboxypeptidase H
  • Carboxypeptidases / metabolism
  • Carboxypeptidases / physiology*
  • Cattle
  • Cell Line
  • Chromogranin A
  • Chromogranins / metabolism
  • Cytoplasmic Granules / enzymology*
  • Dopamine / pharmacology
  • Endocrine System Diseases / enzymology*
  • Female
  • Golgi Apparatus / enzymology
  • Hydrogen-Ion Concentration
  • Intracellular Membranes / enzymology*
  • Intracellular Membranes / metabolism
  • Mice
  • Mice, Mutant Strains
  • Molecular Sequence Data
  • Neurosecretory Systems / cytology
  • Pituitary Gland / metabolism
  • Pro-Opiomelanocortin / metabolism
  • Protein Precursors / metabolism
  • Protein Sorting Signals
  • Proteins / metabolism*
  • RNA, Antisense


  • Chromogranin A
  • Chromogranins
  • Protein Precursors
  • Protein Sorting Signals
  • Proteins
  • RNA, Antisense
  • Pro-Opiomelanocortin
  • Carboxypeptidases
  • Carboxypeptidase H
  • Dopamine

Associated data

  • GENBANK/X61231