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Updated: Jun 16, 2026
07:15
Amide Hydrogen/Deuterium Exchange & MALDI-TOF Mass Spectrometry Analysis of Pak2 Activation
Published on: November 26, 2011
p21-Activated Kinase (PAK) Group I-Targeting Inhibitors Promote the Dimeric Conformation in Live Cells
Theresa A L Ehret1,2, Benedict-Tilman Berger1,2, Nicolai Raig1,2
1Institut für Pharmazeutische Chemie, Goethe-University Frankfurt, Biozentrum, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany.
ACS Chemical Biology
|June 13, 2026
Summary
New live-cell assays quantify p21-activated kinase (PAK) inhibitor engagement and dimerization. Inhibitors may promote group I PAK dimer formation, revealing a novel drug mechanism for future PAK inhibitor design.
Area of Science:
- Biochemistry
- Cell Biology
- Pharmacology
Background:
- p21-activated kinases (PAKs) are crucial in cellular functions and represent significant drug targets.
- The human PAK family comprises six isoforms (PAK1-6), split into Group I (PAK1-3) and Group II (PAK4-6), with distinct regulatory pathways.
- Existing assays lack the capability to study the on-target activity of all PAK isoforms within living cells.
Purpose of the Study:
- To develop novel bioluminescence resonance energy transfer (BRET) assays for studying PAK isoforms in living cells.
- To enable quantification of inhibitor target engagement and dimerization for all human PAK isoforms.
- To investigate the impact of PAK inhibitors on PAK dimerization in real-time.
Main Methods:
- Development of NanoLuc- and HaloTag-based BRET assays.
- Application of assays to monitor PAK isoform activity and dimerization in live cells.
- Analysis of inhibitor effects on PAK target engagement and dimer formation.
Main Results:
- Successful development of BRET assays for studying all PAK isoforms in living cells.
- Quantification of inhibitor target engagement and dimerization across PAK family members.
- Evidence suggesting that certain inhibitors may induce the formation of Group I PAK dimers.
Conclusions:
- The developed BRET assays provide unprecedented tools for studying PAKs in living cells.
- Inhibitor-induced dimerization of Group I PAKs represents a newly uncovered mechanism of action.
- These findings offer valuable insights for the future design and optimization of PAK inhibitors.
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