title: Peptide and immunochemical mapping of the ectodomain of the porcine LH receptor.
abstract: The LH/hCG receptor is a G protein-coupled receptor with an N-terminal extracellular domain involved in hormone-receptor interaction. The recombinant porcine receptor, stably expressed in Chinese hamster ovary (CHO) cells, has the same characteristics (Kd and cAMP production) as in Leydig cells. Six synthetic peptides derived from the receptor ectodomain and two polyclonal anti-peptide sera were tested in the homologous system porcine LH and porcine LH receptor. Their ability to inhibit hormone binding and signal transduction on CHO cells expressing the recombinant receptor was evaluated. Peptides 25-40 and 107-121 exhibited a high transduction inhibition as compared with hormone binding, peptides 21-36, 102-111, and 102-121 inhibited hormone binding more efficiently than signal transduction, and peptide 7-24 exhibited inhibition of both hormone binding and hormone-induced cAMP production. Immunoglobulins against peptides 21-36 and 102-111 inhibited both hormone binding and receptor activation suggesting that these sequences are located on the receptor surface. The data suggest that multiple, discontinuous regions of the extracellular domain of porcine LH receptor are involved in hormone binding and signal transduction. Two minimum critical sequences, 21-24 and 102-107, are involved in hormone binding and vicinal segments may be implicated in signal transduction.
authors.affiliation: Unité Récepteurs et Communication Cellulaire, INRA-Biotechnologies, Jouy-en-Josas, France.
authors.forename: L
authors.initials: L
authors.lastname: Couture
authors.forename: H
authors.initials: H
authors.lastname: Naharisoa
authors.forename: D
authors.initials: D
authors.lastname: Grebert
authors.forename: J J
authors.initials: JJ
authors.lastname: Remy
authors.forename: E
authors.initials: E
authors.lastname: Pajot-Augy
authors.forename: V
authors.initials: V
authors.lastname: Bozon
authors.forename: T
authors.initials: T
authors.lastname: Haertle
authors.forename: R
authors.initials: R
authors.lastname: Salesse
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D016466:CHO Cells; D016384:Consensus Sequence; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005091:Exons; D007700:Kinetics; D007986:Luteinizing Hormone / Q000378:metabolism* / Q000494:pharmacology; D008961:Models, Structural; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology / Q000494:pharmacology; D017433:Protein Structure, Secondary; D051381:Rats; D011974:Receptors, LH / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000187:drug effects; D013552:Swine; D014162:Transfection
chemical_list: D000906:Antibodies; D010446:Peptide Fragments; D011974:Receptors, LH; D011994:Recombinant Proteins; D007986:Luteinizing Hormone; D000242:Cyclic AMP