PUBLICATION

Discovery of small molecules that target the P-Rex1 PIP3-binding site and inhibit P-Rex1-dependent functions in neutrophils

Authors
Cash, J.N., Chandan, N.R., Hsu, A.Y., Sharma, P.V., Deng, Q., Smrcka, A.V., Tesmer, J.J.G.
ID
ZDB-PUB-200105-2
Date
2020
Source
Molecular pharmacology   97(3): 226-236 (Journal)
Registered Authors
Deng, Qing, Hsu, Alan
Keywords
Guanine nucleotide exchange factors (GEFs), Neutrophils, Phosphatidylinositol, Signal transduction inhibitors
MeSH Terms
  • Animals
  • Binding Sites/drug effects
  • Binding Sites/physiology
  • Cells, Cultured
  • Crystallography, X-Ray/methods
  • Dose-Response Relationship, Drug
  • Drug Delivery Systems/methods
  • Drug Discovery/methods*
  • Guanine Nucleotide Exchange Factors/antagonists & inhibitors*
  • Guanine Nucleotide Exchange Factors/chemistry
  • Guanine Nucleotide Exchange Factors/metabolism*
  • Humans
  • Neutrophils/drug effects
  • Neutrophils/metabolism*
  • Phosphatidylinositol Phosphates/chemistry
  • Phosphatidylinositol Phosphates/metabolism*
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Zebrafish
PubMed
31900312 Full text @ Mol. Pharmacol.
Abstract
Phosphatidylinositol (3,4,5) trisphosphate (PIP3)-dependent Rac exchanger 1 (P-Rex1) is a Rho guanine-nucleotide exchange factor that was originally discovered in neutrophils and is regulated by G protein β γ subunits (Gβγ) and the lipid PIP3 in response to chemoattractants. P-Rex1 has also become increasingly recognized for its role in promoting metastasis of breast cancer, prostate cancer, and melanoma. Recent structural, biochemical, and biological work has shown that binding of PIP3 to the pleckstrin homology (PH) domain of P-Rex1 is required for its activation in cells. Here, differential scanning fluorimetry was used in a medium-throughput screen to identify six small molecules that interact with the P-Rex1 PH domain and block binding of and activation by PIP3. Three of these compounds inhibit fMLP-induced spreading of human neutrophils as well as activation of the GTPase Rac2, both downstream effects of P-Rex1 activity. Furthermore, one of these compounds reduces neutrophil velocity and inhibits neutrophil recruitment in response to inflammation in a zebrafish model. These results suggest that the PH domain of P-Rex1 is a tractable drug target and that these compounds might be useful for inhibiting P-Rex1 in other experimental contexts. SIGNIFICANCE STATEMENT: A set of small molecules identified in a thermal shift screen directed against the P-Rex1 PH domain have effects consistent with P-Rex1 inhibition in neutrophils.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping