Intracellular proteolytic processing of proopiomelanocortin in heterologous COS-1 cells by the yeast KEX2 endoprotease.
We have transiently expressed the yeast KEX2 gene together with the proopiomelanocortin (POMC) cDNA in COS-1 cells. Characterization of the POMC-related immunoreactive peptides by gel permeation and reversed-phase high pressure liquid chromatography showed that the KEX2 enzyme was active and capable of carrying out cleavage of POMC to release the authentic maturation product beta-endorphin(1-31). Peptides resembling beta-lipotropin, the amino terminal glycopeptide, and ACTH(1-39) were also detected as major products in the cell extracts. Our results indicate that the KEX2 enzyme can proteolytically release from POMC a set of peptides similar to that normally found in interior pituitary.
Zollinger
L
L
Département de Biochimie, Faculté de Médecine, Université de Montréal, Québec, Canada.
Racine
C
C
Crine
P
P
Boileau
G
G
Germain
D
D
Thomas
D Y
DY
Gossard
F
F
D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis; D010957:Plasmids / Q000235:genetics; D011333:Pro-Opiomelanocortin / Q000378:metabolism*; D043484:Proprotein Convertases; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D012697:Serine Endopeptidases / Q000378:metabolism*; D013381:Subtilisins; D013552:Swine; D014162:Transfection / Q000235:genetics; D001615:beta-Endorphin / Q000378:metabolism; D008083:beta-Lipotropin / Q000378:metabolism
D010455:Peptides; D029701:Saccharomyces cerevisiae Proteins; D001615:beta-Endorphin; D011333:Pro-Opiomelanocortin; D000324:Adrenocorticotropic Hormone; D008083:beta-Lipotropin; D043484:Proprotein Convertases; D012697:Serine Endopeptidases; D013381:Subtilisins; C058751:KEX2 protein, S cerevisiae