title: Insect cells infected with a recombinant baculovirus express both O- and N-glycosylated forms of the rat glycoprotein hormone alpha-subunit.
abstract: Glycoprotein hormones LH, FSH, TSH and chorionic gonadotrophin are heterodimers composed of two non-covalently associated subunits, a common alpha- and a specific beta-subunit. A recombinant baculovirus containing a cDNA encoding the alpha-subunit of rat glycoprotein hormones was constructed. Viral-infected cells expressed, 48 h post infection, 7-10 mg immunoreactive alpha-glycopolypeptide/6 x 10(8) cells, of which 65-6% was able to associate with native LH beta and formed a biologically active heterodimeric hormone that bound to testicular receptors. The treatment with specific glycanases showed that the recombinant alpha-subunit was produced as two differently glycosylated forms; an M(r) 23 000 form which contained exclusively N-linked carbohydrate units and another of M(r) 25 000 which appeared to contain additional 0-linked carbohydrate. Data demonstrated that the alpha-subunit was expressed by insect cells in a manner similar to that by mammalian pituitary gonadotropes producing both the N- and O-glycosylated forms although only the N-glycosylated alpha-subunit is known to be capable of associating with the beta-subunit.
authors.affiliation: Endocrinologie Cellulaire et Moleculaire de la Reproduction, Universite Pierre et Marie Curie, Paris, France.
authors.forename: R
authors.initials: R
authors.lastname: Delahaye
authors.forename: P
authors.initials: P
authors.lastname: Berreur
authors.forename: R
authors.initials: R
authors.lastname: Salesse
authors.forename: R
authors.initials: R
authors.lastname: Counis
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics*; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D015292:Glycoprotein Hormones, alpha Subunit / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006031:Glycosylation; D066298:In Vitro Techniques; D007986:Luteinizing Hormone / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015394:Molecular Structure; D008970:Molecular Weight; D011487:Protein Conformation; D051381:Rats; D011974:Receptors, LH / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018411:Spodoptera; D013552:Swine
chemical_list: D018076:DNA, Complementary; D015292:Glycoprotein Hormones, alpha Subunit; D011974:Receptors, LH; D011994:Recombinant Proteins; D007986:Luteinizing Hormone