title: Molecular cloning and sequencing of salmon gonadotropin beta subunit.
abstract: Gonadotropin (GTH) was purified from the pituitaries of the Pacific chinook salmon using a combination of stepwise ethanol precipitation and concanavalin-A affinity chromatography. The alpha and beta subunits were dissociated and fractionated by C-18 reverse-phase high-performance liquid chromatography with a 0.1% trifluoroacetic acid/acetonitrile gradient. An enriched cDNA library was screened for the beta-GTH gene(s) using two synthetic oligonucleotides based on partial protein data. A positive, full-size clone (E3) was identified and sequenced. It contains 657 base pairs and codes for a 142-amino-acid precursor protein. The mature salmon beta-GTH (119 amino acids) is structurally homologous to human luteinizing hormone and chorionic gonadotropin. The effect of testosterone implantation on pituitary GTH and beta-GTH mRNA was examined with radioimmunoassay and Northern blot analysis. There was a corresponding increase in both the pituitary GTH and mRNA levels.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004247:DNA; D006062:Gonadotropins / Q000302:isolation & purification; D010446:Peptide Fragments / Q000302:isolation & purification; D010902:Pituitary Gland / Q000032:analysis; D011061:Poly A; D014176:Protein Biosynthesis; D011487:Protein Conformation; D012313:RNA; D012333:RNA, Messenger; D012474:Salmon; D013739:Testosterone / Q000494:pharmacology; D014337:Trout
chemical_list: D006062:Gonadotropins; D010446:Peptide Fragments; D012333:RNA, Messenger; C016844:salmon gonadotropin; D011061:Poly A; D013739:Testosterone; D012313:RNA; D004247:DNA