title: Dissecting the structural and functional features of the Luteinizing hormone receptor using receptor specific single chain fragment variables.
abstract: The Luteinizing hormone receptor (LHR) has a large extracellular domain (amino acid residues, a.a.1-355) and a transmembrane domain (TMD; a.a. 356-699), essential for hormone binding and signaling, respectively. The LHR hinge region (a.a. 256-355) connects the two domains and acts as an activating switch for the receptor by an unknown mechanism. LHR hinge-specific Single chain fragment variables (ScFv) stimulated cAMP production by the stable and transiently transfected cell lines expressing LHR in a hormone-independent manner and the C-terminal region of LHR hinge (a.a. 313-349) was identified as the probable epitope for one agonistic ScFv. This epitope attained a helical conformation upon agonistic ScFv binding and the activity of the ScFv was dependent on Y331 sulfation. ScFv was also able to activate TMD mutants, D578Y and A593P, reemphasizing the role of TM helix VI in LHR activation.
authors.affiliation: Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, Karnataka 560012, India.
authors.forename: Neha
authors.initials: N
authors.lastname: Dhar
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka 560012, India.
authors.forename: Abhilash
authors.initials: A
authors.lastname: Mohan
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka 560012, India.
authors.forename: Chandrani
authors.initials: C
authors.lastname: Thakur
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka 560012, India.
authors.forename: Nagasuma R
authors.initials: NR
authors.lastname: Chandra
authors.affiliation: Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, Karnataka 560012, India. Electronic address: rdighe@mrdg.iisc.ernet.in.
authors.forename: Rajan R
authors.initials: RR
authors.lastname: Dighe
mesh_terms: D000818:Animals; D016466:CHO Cells; D006063:Chorionic Gonadotropin / Q000737:chemistry / Q000378:metabolism; D003412:Cricetulus; D018604:Epitope Mapping; D057809:HEK293 Cells; D006801:Humans; D008958:Models, Molecular; D000072417:Protein Domains; D011974:Receptors, LH / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D057127:Single-Chain Antibodies / Q000737:chemistry
chemical_list: D006063:Chorionic Gonadotropin; D011974:Receptors, LH; D057127:Single-Chain Antibodies
keywords: Agonistic antibodies; Conformational change; Glycoprotein hormones; Hinge region; Luteinizing hormone receptor; Phage display