title: Expression and processing of the activin-A/erythroid differentiation factor precursor: a member of the transforming growth factor-beta superfamily.
abstract: The biosynthesis and intracellular processing of the polypeptide precursor of the beta A-chain of the fertility hormone inhibin were assessed by infecting a wide spectrum of cell types with a recombinant vaccinia virus. Most cell lines, including follicular granulosa cells, secrete both prohormone and mature hormone as homodimers (activin) composed of disulfide-linked subunits of 54 kDa (proactivin-A) and 14 kDa (activin-A), respectively, and a small amount of prohormone-mature hormone heterodimers. Mature activin is secreted from mouse pituitary cells (AtT-20), while pig kidney cells [PK(15)] secrete mostly proactivin. More prohormone is secreted in the presence of NH4Cl, suggesting that prohormone processing is facilitated by low pH. Proactivin-A is not a ligand for the mannose-6-phosphate/insulin growth factor-II receptor. The recombinant activin stimulates FSH release from pituitary cells and differentiates erythroleukemia cell lines in vitro.
authors.affiliation: Innogenetics S.A. Industriepark Zwijnaarde, Ghent, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Huylebroeck
authors.forename: K
authors.initials: K
authors.lastname: Van Nimmen
authors.forename: A
authors.initials: A
authors.lastname: Waheed
authors.forename: K
authors.initials: K
authors.lastname: von Figura
authors.forename: A
authors.initials: A
authors.lastname: Marmenout
authors.forename: L
authors.initials: L
authors.lastname: Fransen
authors.forename: P
authors.initials: P
authors.lastname: De Waele
authors.forename: J M
authors.initials: JM
authors.lastname: Jaspar
authors.forename: P
authors.initials: P
authors.lastname: Franchimont
authors.forename: H
authors.initials: H
authors.lastname: Stunnenberg
mesh_terms: D000118:Acetylglucosaminidase / Q000378:metabolism; D028341:Activins; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D006224:Cricetinae; D004912:Erythrocytes / Q000166:cytology; D005089:Exocytosis; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007265:Inhibins / Q000096:biosynthesis* / Q000378:metabolism / Q000494:pharmacology; D046911:Macromolecular Substances; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D014176:Protein Biosynthesis; D011498:Protein Precursors / Q000096:biosynthesis* / Q000378:metabolism; D017527:Receptor, IGF Type 2; D011956:Receptors, Cell Surface / Q000378:metabolism; D017451:Receptors, Somatomedin; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D013552:Swine; D014162:Transfection; D014616:Vaccinia virus / Q000235:genetics
chemical_list: D046911:Macromolecular Substances; D011498:Protein Precursors; D017527:Receptor, IGF Type 2; D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D011994:Recombinant Proteins; D028341:Activins; D007265:Inhibins; D000118:Acetylglucosaminidase; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase