Yeast KEX2 endopeptidase correctly cleaves a neuroendocrine prohormone in mammalian cells.
Mammalian cell lines (BSC-40, NG108-15, and GH4C1) that cannot process the murine neuroendocrine peptide precursor prepro-opiomelanocortin (mPOMC) when its synthesis is directed by a vaccinia virus vector were coinfected with a second recombinant vaccinia virus carrying the yeast KEX2 gene, which encodes an endopeptidase that cleaves at pairs of basic amino acid residues. mPOMC was cleaved intracellularly to a set of product peptides normally found in vivo, including mature gamma-lipotropin and beta-endorphin1-31. In GH4C1 cells (a rat pituitary line), product peptides were incorporated into stored secretory granules. These results suggest that the inability of any particular cell line to process a prohormone precursor is due to the absence of a suitable endogenous processing enzyme.
Thomas
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G
Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201.
Thorne
B A
BA
Thomas
L
L
Allen
R G
RG
Hruby
D E
DE
Fuller
R
R
Thorner
J
J
D002460:Cell Line; D003001:Cloning, Molecular; D004274:DNA, Recombinant; D010450:Endopeptidases / Q000378:metabolism*; D066298:In Vitro Techniques; D011333:Pro-Opiomelanocortin / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D012441:Saccharomyces cerevisiae / Q000201:enzymology
D004274:DNA, Recombinant; D011498:Protein Precursors; D011333:Pro-Opiomelanocortin; D010450:Endopeptidases