Dissecting the structural and functional features of the Luteinizing hormone receptor using receptor specific single chain fragment variables

Mol Cell Endocrinol. 2016 May 15:427:1-12. doi: 10.1016/j.mce.2016.02.022. Epub 2016 Mar 3.

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.

Keywords: Agonistic antibodies; Conformational change; Glycoprotein hormones; Hinge region; Luteinizing hormone receptor; Phage display.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CHO Cells
  • Chorionic Gonadotropin / chemistry
  • Chorionic Gonadotropin / metabolism
  • Cricetulus
  • Epitope Mapping
  • HEK293 Cells
  • Humans
  • Models, Molecular
  • Protein Domains
  • Receptors, LH / chemistry
  • Receptors, LH / metabolism
  • Receptors, LH / physiology*
  • Single-Chain Antibodies* / chemistry

Substances

  • Chorionic Gonadotropin
  • Receptors, LH
  • Single-Chain Antibodies