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Expression of murine and human granulocyte‐macrophage colony‐stimulating factors in S. cerevisiae: mutagenesis of the potential glycosylation sites.
Author(s) -
Miyajima A.,
Otsu K.,
Schreurs J.,
Bond M.W.,
Abrams J.S.,
Arai K.
Publication year - 1986
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1986.tb04346.x
Subject(s) - biology , microbiology and biotechnology , monoclonal antibody , glycosylation , granulocyte , granulocyte macrophage colony stimulating factor , blot , cell culture , biochemistry , antibody , immunology , gene , in vitro , genetics
Murine (m) and human (h) granulocyte‐‐macrophage colony‐stimulating factors (GM‐CSF) have been expressed in large quantities in Saccharomyces cerevisiae using a secretion vector containing the promoter and leader sequences of the mating pheromone alpha‐factor. Functionally active mGM‐CSF was identified by a proliferation assay with a factor‐dependent cell line and by a granulocyte‐‐macrophage colony formation assay using bone marrow cells. The activity of hGM‐CSF was confirmed by stimulation of granulocyte‐‐macrophage colony formation using human cord blood cells. Murine GM‐CSF with various apparent mol. wts (13, 18, 24, 34 and 40 kd, as well as a smear of higher mol. wts) was detected in yeast culture medium by protein blotting using a rat monoclonal antibody specific for the mGM‐CSF N‐terminal region peptide. Protein blotting using a rat monoclonal antibody specific for the hGM‐CSF N‐terminal region demonstrated that a 15.6‐kd and higher mol. wt heterogeneous species were secreted. Mutations introduced at each of the two potential N‐linked glycosylation sites in mGM‐CSF showed that the 13‐kd protein is not glycosylated and the major 18‐kd protein is mainly glycosylated at the more C‐terminal site, whereas the heterogeneous higher mol. wt species were not affected by the mutations. The N‐terminal amino acid of the 13‐kd protein was shown to be Ser which was four amino acids in the C‐terminal direction from the fusion point.