Rescue of mutant gonadotropin-releasing hormone receptor function independent of cognate receptor activity

Sci Rep. 2020 Jun 29;10(1):10579. doi: 10.1038/s41598-020-67473-w.

Abstract

Molecules that correct the folding of protein mutants, restoring their functional trafficking, are called pharmacoperones. Most are clinically irrelevant and possess intrinsic antagonist or agonist activity. Here, we identify compounds capable of rescuing the activity of mutant gonadotropin-releasing hormone receptor or GnRHR which, is sequestered within the cell and if dysfunctional leads to Hypogonadotropic Hypogonadism. To do this we screened the E90K GnRHR mutant vs. a library of 645,000 compounds using a cell-based calcium detection system. Ultimately, we identified 399 compounds with EC50 ≤ 5 µM with no effect in counterscreen assays. Medicinal chemistry efforts confirmed activity of 70 pure samples and mode of action studies, including radioligand binding, inositol phosphate, and toxicity assays, proved that we have a series of tractable compounds that can be categorized into structural clusters. These early lead molecules rescue mutant GnRHR function and are neither agonist nor antagonists of the GnRHR cognate receptor, a feature required for potential clinical utility.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Calcium / metabolism
  • Drug Evaluation, Preclinical
  • Gonadotropin-Releasing Hormone / agonists
  • Gonadotropin-Releasing Hormone / metabolism
  • HeLa Cells
  • High-Throughput Screening Assays
  • Humans
  • Inositol Phosphates / metabolism
  • Mutation
  • Protein Folding
  • Protein Transport
  • Receptors, LHRH / agonists*
  • Receptors, LHRH / genetics
  • Receptors, LHRH / metabolism*
  • Small Molecule Libraries / pharmacology*

Substances

  • GNRHR protein, human
  • Inositol Phosphates
  • Receptors, LHRH
  • Small Molecule Libraries
  • Gonadotropin-Releasing Hormone
  • Calcium