Discovery of a σ1 receptor antagonist by combination of unbiased cell painting and thermal proteome profiling

Cell Chem Biol. 2021 Jun 17;28(6):848-854.e5. doi: 10.1016/j.chembiol.2021.01.009. Epub 2021 Feb 9.


Phenotypic screening for bioactive small molecules is typically combined with affinity-based chemical proteomics to uncover the respective molecular targets. However, such assays and the explored bioactivity are biased toward the monitored phenotype, and target identification often requires chemical derivatization of the hit compound. In contrast, unbiased cellular profiling approaches record hundreds of parameters upon compound perturbation to map bioactivity in a broader biological context and may link a profile to the molecular target or mode of action. Herein we report the discovery of the diaminopyrimidine DP68 as a Sigma 1 (σ1) receptor antagonist by combining morphological profiling using the Cell Painting assay and thermal proteome profiling. Our results highlight that integration of complementary profiling approaches may enable both detection of bioactivity and target identification for small molecules.

Keywords: antagonist; cellular thermal shift assay; lysosomotropism; morphological profiling; small molecule; target identification; thermal proteome profiling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aniline Compounds / chemistry
  • Aniline Compounds / pharmacology*
  • Animals
  • Drug Discovery*
  • Female
  • Gene Expression Profiling
  • Heterocyclic Compounds, 2-Ring / chemistry
  • Heterocyclic Compounds, 2-Ring / pharmacology*
  • Humans
  • Mice
  • Molecular Structure
  • Proteome / genetics*
  • Receptors, sigma / antagonists & inhibitors*
  • Small Molecule Libraries / chemistry
  • Small Molecule Libraries / pharmacology*
  • Temperature*
  • Tumor Cells, Cultured


  • Aniline Compounds
  • Heterocyclic Compounds, 2-Ring
  • N,N-bis(2-(8-carbamoyl-4-oxo-3H,4H-imidazotetrazin-3-yl)ethyl)-4-methylaniline
  • Proteome
  • Receptors, sigma
  • Small Molecule Libraries
  • sigma-1 receptor