Discovery of a Potent, Cell Penetrant, and Selective p300/CBP-Associated Factor (PCAF)/General Control Nonderepressible 5 (GCN5) Bromodomain Chemical Probe

J Med Chem. 2017 Jan 26;60(2):695-709. doi: 10.1021/acs.jmedchem.6b01566. Epub 2017 Jan 9.

Abstract

p300/CREB binding protein associated factor (PCAF/KAT2B) and general control nonderepressible 5 (GCN5/KAT2A) are multidomain proteins that have been implicated in retroviral infection, inflammation pathways, and cancer development. However, outside of viral replication, little is known about the dependence of these effects on the C-terminal bromodomain. Herein, we report GSK4027 as a chemical probe for the PCAF/GCN5 bromodomain, together with GSK4028 as an enantiomeric negative control. The probe was optimized from a weakly potent, nonselective pyridazinone hit to deliver high potency for the PCAF/GCN5 bromodomain, high solubility, cellular target engagement, and ≥18000-fold selectivity over the BET family, together with ≥70-fold selectivity over the wider bromodomain families.

MeSH terms

  • Animals
  • Cell Membrane Permeability
  • Histone Acetyltransferases / chemistry*
  • Humans
  • Membranes, Artificial
  • Mice
  • Molecular Probes / chemical synthesis
  • Molecular Probes / chemistry*
  • Piperidines / chemical synthesis
  • Piperidines / chemistry*
  • Protein Domains
  • Pyridazines / chemical synthesis
  • Pyridazines / chemistry*
  • Stereoisomerism
  • Structure-Activity Relationship
  • p300-CBP Transcription Factors / chemistry*

Substances

  • GSK4027
  • Membranes, Artificial
  • Molecular Probes
  • Piperidines
  • Pyridazines
  • Histone Acetyltransferases
  • KAT2A protein, human
  • p300-CBP Transcription Factors
  • p300-CBP-associated factor