Open AccessRecombinant type 1 transforming growth factor beta precursor produced in Chinese hamster ovary cells is glycosylated and phosphorylated.
Author(s) -
Amy M. Brunner,
L E Gentry,
J A Cooper,
Anthony F. Purchio
Publication year - 1988
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.8.5.2229
Subject(s) - biology , chinese hamster ovary cell , glycosylation , sialic acid , microbiology and biotechnology , biochemistry , transforming growth factor beta , endoglycosidase , glycoprotein , recombinant dna , phosphorylation , tgf beta receptor 2 , endoglycosidase h , growth factor , tgf alpha , gene , signal transduction , cell , receptor , golgi apparatus
Analyses of cDNA clones coding for simian type 1 transforming growth factor beta (TGF-beta 1) suggest that there are three potential sites for N-linked glycosylation located in the amino terminus of the precursor region. Analysis of [3H]glucosamine-labeled serum-free supernatants from a line of Chinese hamster ovary cells which secrete high levels of recombinant TGF-beta 1 indicate that the TGF-beta 1 precursor, but not the mature form, is glycosylated. Digestion with neuraminidase resulted in a shift in migration of the two TGF-beta 1 precursor bands, which suggests that they contain sialic acid residues. Endoglycosidase H had no noticeable effect. Treatment with N-glycanase produced two faster-migrating sharp bands, the largest of which had a molecular weight of 39 kilodaltons. TGF-beta 1-specific transcripts produced by SP6 polymerase programmed the synthesis of a 42-kilodalton polypeptide which, we suggest, is the unmodified protein backbone of the precursor. Labeling with 32Pi showed that the TGF-beta 1 precursor was phosphorylated in the amino portion of the molecule.