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A Guide to Production, Crystallization, and Structure Determination of Human IKK1/α
Published on: November 2, 2018
Structure-Based Development of Isoform-Selective Inhibitors of Casein Kinase 1ε vs Casein Kinase 1δ
Jun Yong Choi1,2,3, Yoshihiko Noguchi1, James M Alburger1
1Department of Chemistry, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458, United States.
Researchers developed a novel inhibitor, SR-4133, that selectively targets Casein Kinase 1 epsilon (CK1ε). This breakthrough offers potential for treating bladder cancer by inhibiting CK1ε activity and downstream signaling pathways.
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- Targeting specific kinase isoforms is difficult due to conserved ATP-binding sites.
- Casein Kinase 1 delta (CK1δ) and epsilon (CK1ε) share 97% sequence identity in catalytic domains.
Purpose of the Study:
- To develop a potent and highly CK1ε-isoform-selective inhibitor.
- To understand the structural basis for CK1ε selectivity.
Main Methods:
- X-ray crystallography of CK1δ and CK1ε.
- Structure-based drug design of SR-4133.
- Cell-based assays for growth inhibition and target engagement.
Main Results:
- SR-4133 selectively inhibits CK1ε over CK1δ.
- Structural analysis revealed mismatched electrostatic and stabilized hydrophobic interactions driving selectivity.
- SR-4133 demonstrated nanomolar growth inhibition of bladder cancer cells (T24).
- Inhibition of 4E-4-BP1 phosphorylation, a downstream CK1ε effector, was observed.
Conclusions:
- SR-4133 is a potent and selective CK1ε inhibitor.
- Structural insights explain the mechanism of isoform selectivity.
- CK1ε inhibition shows promise for bladder cancer therapy.
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