Targeting the FKBP51/GR/Hsp90 Complex to Identify Functionally Relevant Treatments for Depression and PTSD

ACS Chem Biol. 2018 Aug 17;13(8):2288-2299. doi: 10.1021/acschembio.8b00454. Epub 2018 Jun 19.


Genetic and epigenetic alterations in FK506-binding protein 5 ( FKBP5) have been associated with increased risk for psychiatric disorders, including post-traumatic stress disorder (PTSD). Some of these common variants can increase the expression of FKBP5, the gene that encodes FKBP51. Excess FKBP51 promotes hypothalamic-pituitary-adrenal (HPA) axis dysregulation through altered glucocorticoid receptor (GR) signaling. Thus, we hypothesized that GR activity could be restored by perturbing FKBP51. Here, we screened 1280 pharmacologically active compounds and identified three compounds that rescued FKBP51-mediated suppression of GR activity without directly activating GR. One of the three compounds, benztropine mesylate, disrupted the association of FKBP51 with the GR/Hsp90 complex in vitro. Moreover, we show that removal of FKBP51 from this complex by benztropine restored GR localization in ex vivo brain slices and primary neurons from mice. In conclusion, we have identified a novel disruptor of the FKBP51/GR/Hsp90 complex. Targeting this complex may be a viable approach to developing treatments for disorders related to aberrant FKBP51 expression.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benztropine / chemistry
  • Benztropine / pharmacology*
  • Brain / drug effects
  • Brain / metabolism
  • Cells, Cultured
  • Depression / drug therapy*
  • Depression / metabolism
  • Drug Discovery
  • HSP90 Heat-Shock Proteins / metabolism*
  • Humans
  • Mice
  • Molecular Targeted Therapy
  • Protein Binding / drug effects
  • Receptors, Glucocorticoid / metabolism*
  • Stress Disorders, Post-Traumatic / drug therapy*
  • Stress Disorders, Post-Traumatic / metabolism
  • Tacrolimus Binding Proteins / antagonists & inhibitors
  • Tacrolimus Binding Proteins / metabolism*


  • HSP90 Heat-Shock Proteins
  • Receptors, Glucocorticoid
  • Benztropine
  • Tacrolimus Binding Proteins
  • tacrolimus binding protein 5